Skip to contentSkip to conversation

use r14 for a per-cpu kernel register

RFC PATCH In review Nicholas Piggin 3 participants 12 messages Dec 20, 2017 – Dec 22, 2017

Subsystems (6)
lore
Share & tools
lore

Nicholas Piggin

author reviewer
#0 lore raw

cover use r14 for a per-cpu kernel register

This makes r14 a fixed register and used to store per-cpu stuff in the kernel, including read-write fields that are retained over interrupts. It ends up being most useful for speeding up per-cpu pointer dereferencing and soft-irq masking and testing. But it can also reduce the number of loads and stores in the interrupt entry paths by moving several bits of interest into r14 (another bit I'm looking at is adding a bit for HSTATE_IN_GUEST to speed up kvmtest).

The series goes on top of Maddy's softi-irq patches, it works on 64s, but KVM and 64e are probably broken at the moment. So it's not intended to merge yet, but if people like the result then maybe the first patch can be merged to stop using r14 in preparation.

Nicholas Piggin (8):
powerpc/64s: stop using r14 register
powerpc/64s: poison r14 register while in kernel powerpc/64s: put the per-cpu data_offset in r14 powerpc/64s: put io_sync bit into r14
powerpc/64s: put work_pending bit into r14 powerpc/64s: put irq_soft_mask bits into r14 powerpc/64s: put irq_soft_mask and irq_happened bits into r14 powerpc/64s: inline local_irq_enable/restore

 arch/powerpc/Makefile                          |   1 +
 arch/powerpc/crypto/md5-asm.S                  |  40 +++----
 arch/powerpc/crypto/sha1-powerpc-asm.S         |  10 +-
 arch/powerpc/include/asm/exception-64s.h       | 127 +++++++++++----------
 arch/powerpc/include/asm/hw_irq.h              | 130 ++++++++++-----------
 arch/powerpc/include/asm/io.h                  |  11 +-
 arch/powerpc/include/asm/irqflags.h            |  24 ++--
 arch/powerpc/include/asm/kvm_book3s_asm.h      |   2 +-
 arch/powerpc/include/asm/kvm_ppc.h             |   6 +-
 arch/powerpc/include/asm/paca.h                |  73 +++++++++++-
 arch/powerpc/include/asm/percpu.h              |   2 +-
 arch/powerpc/include/asm/ppc_asm.h             |  21 +++-
 arch/powerpc/include/asm/spinlock.h            |  21 ++--
 arch/powerpc/kernel/asm-offsets.c              |  23 +++-
 arch/powerpc/kernel/entry_32.S                 |   4 +-
 arch/powerpc/kernel/entry_64.S                 |  95 ++++++++++------
 arch/powerpc/kernel/exceptions-64s.S           |  52 ++++-----
 arch/powerpc/kernel/head_64.S                  |  25 ++--
 arch/powerpc/kernel/idle_book3s.S              |  86 +++++++-------
 arch/powerpc/kernel/irq.c                      |  92 ++++++---------
 arch/powerpc/kernel/kgdb.c                     |   8 +-
 arch/powerpc/kernel/optprobes_head.S           |   3 +-
 arch/powerpc/kernel/paca.c                     |   1 -
 arch/powerpc/kernel/process.c                  |   6 +-
 arch/powerpc/kernel/setup_64.c                 |  19 +++-
 arch/powerpc/kernel/time.c                     |  15 +--
 arch/powerpc/kernel/tm.S                       |  40 ++++---
 arch/powerpc/kernel/trace/ftrace_64_mprofile.S |  10 +-
 arch/powerpc/kvm/book3s_hv.c                   |   6 +-
 arch/powerpc/kvm/book3s_hv_interrupts.S        |   5 +-
 arch/powerpc/kvm/book3s_hv_rmhandlers.S        |   3 +-
 arch/powerpc/kvm/book3s_interrupts.S           |  93 +++++++++++----
 arch/powerpc/kvm/book3s_pr.c                   |   6 +
 arch/powerpc/lib/checksum_64.S                 |  66 +++++------
 arch/powerpc/lib/copypage_power7.S             |  32 +++---
 arch/powerpc/lib/copyuser_power7.S             | 152 ++++++++++++-------------
 arch/powerpc/lib/crtsavres.S                   |   3 +
 arch/powerpc/lib/memcpy_power7.S               |  80 ++++++-------
 arch/powerpc/lib/sstep.c                       |   1 +
 arch/powerpc/xmon/xmon.c                       |   7 +-
 40 files changed, 764 insertions(+), 637 deletions(-)
Signature · 1 line
2.15.0
author reviewer
#1 lore raw

RFC PATCH 1/8 powerpc/64s: stop using r14 register

---
 arch/powerpc/Makefile                          |   1 +
 arch/powerpc/crypto/md5-asm.S                  |  40 +++----
 arch/powerpc/crypto/sha1-powerpc-asm.S         |  10 +-
 arch/powerpc/include/asm/kvm_book3s_asm.h      |   2 +-
 arch/powerpc/include/asm/ppc_asm.h             |  21 +++-
 arch/powerpc/kernel/asm-offsets.c              |   4 +-
 arch/powerpc/kernel/entry_32.S                 |   4 +-
 arch/powerpc/kernel/entry_64.S                 |  45 ++++----
 arch/powerpc/kernel/exceptions-64s.S           |   3 +-
 arch/powerpc/kernel/head_64.S                  |   8 +-
 arch/powerpc/kernel/idle_book3s.S              |  79 +++++++------
 arch/powerpc/kernel/kgdb.c                     |   8 +-
 arch/powerpc/kernel/process.c                  |   4 +-
 arch/powerpc/kernel/tm.S                       |  40 ++++---
 arch/powerpc/kernel/trace/ftrace_64_mprofile.S |  10 +-
 arch/powerpc/kvm/book3s_hv_interrupts.S        |   5 +-
 arch/powerpc/kvm/book3s_interrupts.S           |  93 +++++++++++----
 arch/powerpc/kvm/book3s_pr.c                   |   6 +
 arch/powerpc/lib/checksum_64.S                 |  66 +++++------
 arch/powerpc/lib/copypage_power7.S             |  32 +++---
 arch/powerpc/lib/copyuser_power7.S             | 152 ++++++++++++-------------
 arch/powerpc/lib/crtsavres.S                   |   3 +
 arch/powerpc/lib/memcpy_power7.S               |  80 ++++++-------
 23 files changed, 396 insertions(+), 320 deletions(-)
arch/powerpc/Makefile +1 -0
index 1381693a4a51..8dd38facc5f2 100644
@@ -140,6 +140,7 @@ AFLAGS-$(CONFIG_PPC64)	+= $(call cc-option,-mabi=elfv1)
 endif
 CFLAGS-$(CONFIG_PPC64)	+= $(call cc-option,-mcmodel=medium,$(call cc-option,-mminimal-toc))
 CFLAGS-$(CONFIG_PPC64)	+= $(call cc-option,-mno-pointers-to-nested-functions)
+CFLAGS-$(CONFIG_PPC64)	+= -ffixed-r13 -ffixed-r14
 CFLAGS-$(CONFIG_PPC32)	:= -ffixed-r2 $(MULTIPLEWORD)
 
 ifeq ($(CONFIG_PPC_BOOK3S_64),y)
arch/powerpc/crypto/md5-asm.S +20 -20
index 10cdf5bceebb..99e41af88e19 100644
@@ -25,31 +25,31 @@
 #define rW02	r10
 #define rW03	r11
 #define rW04	r12
-#define rW05	r14
-#define rW06	r15
-#define rW07	r16
-#define rW08	r17
-#define rW09	r18
-#define rW10	r19
-#define rW11	r20
-#define rW12	r21
-#define rW13	r22
-#define rW14	r23
-#define rW15	r24
-
-#define rT0	r25
-#define rT1	r26
+#define rW05	r15
+#define rW06	r16
+#define rW07	r17
+#define rW08	r18
+#define rW09	r19
+#define rW10	r20
+#define rW11	r21
+#define rW12	r22
+#define rW13	r23
+#define rW14	r24
+#define rW15	r25
+
+#define rT0	r26
+#define rT1	r27
 
 #define INITIALIZE \
 	PPC_STLU r1,-INT_FRAME_SIZE(r1); \
-	SAVE_8GPRS(14, r1);		/* push registers onto stack	*/ \
-	SAVE_4GPRS(22, r1);						   \
-	SAVE_GPR(26, r1)
+	SAVE_8GPRS(15, r1);		/* push registers onto stack	*/ \
+	SAVE_4GPRS(23, r1);						   \
+	SAVE_GPR(27, r1)
 
 #define FINALIZE \
-	REST_8GPRS(14, r1);		/* pop registers from stack	*/ \
-	REST_4GPRS(22, r1);						   \
-	REST_GPR(26, r1);						   \
+	REST_8GPRS(15, r1);		/* pop registers from stack	*/ \
+	REST_4GPRS(23, r1);						   \
+	REST_GPR(27, r1);						   \
 	addi	r1,r1,INT_FRAME_SIZE;
 
 #ifdef __BIG_ENDIAN__
arch/powerpc/crypto/sha1-powerpc-asm.S +4 -6
index c8951ce0dcc4..6c38de214c11 100644
@@ -42,10 +42,10 @@
 	or	r6,r6,r0;			\
 	add	r0,RE(t),r15;			\
 	add	RT(t),RT(t),r6;		\
-	add	r14,r0,W(t);			\
+	add	r6,r0,W(t);			\
 	LWZ(W((t)+4),((t)+4)*4,r4);	\
 	rotlwi	RB(t),RB(t),30;			\
-	add	RT(t),RT(t),r14
+	add	RT(t),RT(t),r6
 
 #define STEPD0_UPDATE(t)			\
 	and	r6,RB(t),RC(t);		\
@@ -124,8 +124,7 @@
 
 _GLOBAL(powerpc_sha_transform)
 	PPC_STLU r1,-INT_FRAME_SIZE(r1)
-	SAVE_8GPRS(14, r1)
-	SAVE_10GPRS(22, r1)
+	SAVE_NVGPRS(r1)
 
 	/* Load up A - E */
 	lwz	RA(0),0(r3)	/* A */
@@ -183,7 +182,6 @@ _GLOBAL(powerpc_sha_transform)
 	stw	RD(0),12(r3)
 	stw	RE(0),16(r3)
 
-	REST_8GPRS(14, r1)
-	REST_10GPRS(22, r1)
+	REST_NVGPRS(r1)
 	addi	r1,r1,INT_FRAME_SIZE
 	blr
arch/powerpc/include/asm/kvm_book3s_asm.h +1 -1
index ab386af2904f..fbbd2ca18866 100644
@@ -143,7 +143,7 @@ struct kvmppc_host_state {
 
 struct kvmppc_book3s_shadow_vcpu {
 	bool in_use;
-	ulong gpr[14];
+	ulong gpr[15];
 	u32 cr;
 	ulong xer;
 	ulong ctr;
arch/powerpc/include/asm/ppc_asm.h +18 -3
index ae94b3626b6c..109f4dce8a79 100644
@@ -10,6 +10,16 @@
 #include <asm/ppc-opcode.h>
 #include <asm/firmware.h>
 
+#ifdef __powerpc64__
+#ifdef CONFIG_PPC_BOOK3S
+#define FIRST_NVGPR		15
+#else
+#define FIRST_NVGPR		14
+#endif
+#else
+#define FIRST_NVGPR		13
+#endif
+
 #ifdef __ASSEMBLY__
 
 #define SZL			(BITS_PER_LONG/8)
@@ -75,16 +85,21 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR)
 #ifdef __powerpc64__
 #define SAVE_GPR(n, base)	std	n,GPR0+8*(n)(base)
 #define REST_GPR(n, base)	ld	n,GPR0+8*(n)(base)
+#ifdef CONFIG_PPC_BOOK3S
+#define SAVE_NVGPRS(base)	SAVE_GPR(15, base); SAVE_2GPRS(16, base); SAVE_4GPRS(18, base); SAVE_10GPRS(22, base)
+#define REST_NVGPRS(base)	REST_GPR(15, base); REST_2GPRS(16, base); REST_4GPRS(18, base); REST_10GPRS(22, base)
+#else /* CONFIG_PPC_BOOK3S */
 #define SAVE_NVGPRS(base)	SAVE_8GPRS(14, base); SAVE_10GPRS(22, base)
 #define REST_NVGPRS(base)	REST_8GPRS(14, base); REST_10GPRS(22, base)
-#else
+#endif /* CONFIG_PPC_BOOK3S */
+#else /* __powerpc64__ */
 #define SAVE_GPR(n, base)	stw	n,GPR0+4*(n)(base)
 #define REST_GPR(n, base)	lwz	n,GPR0+4*(n)(base)
 #define SAVE_NVGPRS(base)	SAVE_GPR(13, base); SAVE_8GPRS(14, base); \
 				SAVE_10GPRS(22, base)
 #define REST_NVGPRS(base)	REST_GPR(13, base); REST_8GPRS(14, base); \
 				REST_10GPRS(22, base)
-#endif
+#endif /* __powerpc64__ */
 
 #define SAVE_2GPRS(n, base)	SAVE_GPR(n, base); SAVE_GPR(n+1, base)
 #define SAVE_4GPRS(n, base)	SAVE_2GPRS(n, base); SAVE_2GPRS(n+2, base)
@@ -184,7 +199,7 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR)
 #ifdef CONFIG_PPC64
 
 #define STACKFRAMESIZE 256
-#define __STK_REG(i)   (112 + ((i)-14)*8)
+#define __STK_REG(i)   (112 + ((i)-15)*8)
 #define STK_REG(i)     __STK_REG(__REG_##i)
 
 #ifdef PPC64_ELF_ABI_v2
arch/powerpc/kernel/asm-offsets.c +2 -2
index 397681f43eed..db8407483c9e 100644
@@ -283,9 +283,9 @@ int main(void)
 	STACK_PT_REGS_OFFSET(GPR11, gpr[11]);
 	STACK_PT_REGS_OFFSET(GPR12, gpr[12]);
 	STACK_PT_REGS_OFFSET(GPR13, gpr[13]);
-#ifndef CONFIG_PPC64
+#ifndef CONFIG_PPC_BOOK3E_64
 	STACK_PT_REGS_OFFSET(GPR14, gpr[14]);
-#endif /* CONFIG_PPC64 */
+#endif
 	/*
 	 * Note: these symbols include _ because they overlap with special
 	 * register names
arch/powerpc/kernel/entry_32.S +2 -2
index e780e1fbf6c2..4b3cf4dc7d05 100644
@@ -458,8 +458,8 @@ ret_from_fork:
 ret_from_kernel_thread:
 	REST_NVGPRS(r1)
 	bl	schedule_tail
-	mtlr	r14
-	mr	r3,r15
+	mtlr	FIRST_NVGPR
+	mr	r3,FIRST_NVGPR+1
 	PPC440EP_ERR42
 	blrl
 	li	r3,0
arch/powerpc/kernel/entry_64.S +25 -20

100 lines not on this page · raw message

arch/powerpc/kernel/exceptions-64s.S +1 -2
index 60d9c68ef414..189c456450e2 100644
@@ -1656,8 +1656,7 @@ BEGIN_FTR_SECTION
 	ld	r10,EX_CFAR(r3)
 	std	r10,ORIG_GPR3(r1)
 END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
-	SAVE_8GPRS(14,r1)
-	SAVE_10GPRS(22,r1)
+	SAVE_NVGPRS(r1)
 	lhz	r12,PACA_TRAP_SAVE(r13)
 	std	r12,_TRAP(r1)
 	addi	r11,r1,INT_FRAME_SIZE
arch/powerpc/kernel/head_64.S +4 -4
index 56f9e112b98d..87b2c2264118 100644
@@ -802,9 +802,9 @@ __secondary_start:
 	/* Initialize the kernel stack */
 	LOAD_REG_ADDR(r3, current_set)
 	sldi	r28,r24,3		/* get current_set[cpu#]	 */
-	ldx	r14,r3,r28
-	addi	r14,r14,THREAD_SIZE-STACK_FRAME_OVERHEAD
-	std	r14,PACAKSAVE(r13)
+	ldx	r15,r3,r28
+	addi	r15,r15,THREAD_SIZE-STACK_FRAME_OVERHEAD
+	std	r15,PACAKSAVE(r13)
 
 	/* Do early setup for that CPU (SLB and hash table pointer) */
 	bl	early_setup_secondary
@@ -813,7 +813,7 @@ __secondary_start:
 	 * setup the new stack pointer, but *don't* use this until
 	 * translation is on.
 	 */
-	mr	r1, r14
+	mr	r1, r15
 
 	/* Clear backchain so we get nice backtraces */
 	li	r7,0
arch/powerpc/kernel/idle_book3s.S +39 -40

184 lines not on this page · raw message

arch/powerpc/kernel/kgdb.c +4 -4
index 35e240a0a408..d593e381f34d 100644
@@ -230,11 +230,11 @@ void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
 	for (reg = 0; reg < 3; reg++)
 		PACK64(ptr, regs->gpr[reg]);
 
-	/* Regs GPR3-13 are caller saved, not in regs->gpr[] */
-	ptr += 11;
+	/* Regs GPR3-13/14 are caller saved, not in regs->gpr[] */
+	ptr += FIRST_NVGPR - 2;
 
-	/* Regs GPR14-31 */
-	for (reg = 14; reg < 32; reg++)
+	/* Regs GPR14/15-31 */
+	for (reg = FIRST_NVGPR; reg < 32; reg++)
 		PACK64(ptr, regs->gpr[reg]);
 
 #ifdef CONFIG_FSL_BOOKE
arch/powerpc/kernel/process.c +2 -2
index 2a63cc78257d..f56e42f06f24 100644
@@ -1672,12 +1672,12 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 		childregs->gpr[1] = sp + sizeof(struct pt_regs);
 		/* function */
 		if (usp)
-			childregs->gpr[14] = ppc_function_entry((void *)usp);
+			childregs->gpr[FIRST_NVGPR] = ppc_function_entry((void *)usp);
 #ifdef CONFIG_PPC64
 		clear_tsk_thread_flag(p, TIF_32BIT);
 		childregs->softe = IRQ_SOFT_MASK_NONE;
 #endif
-		childregs->gpr[15] = kthread_arg;
+		childregs->gpr[FIRST_NVGPR + 1] = kthread_arg;
 		p->thread.regs = NULL;	/* no user register state */
 		ti->flags |= _TIF_RESTOREALL;
 		f = ret_from_kernel_thread;
arch/powerpc/kernel/tm.S +23 -17
index b92ac8e711db..3f62b8157aea 100644
@@ -106,27 +106,28 @@ _GLOBAL(tm_reclaim)
 	/* We've a struct pt_regs at [r1+STACK_FRAME_OVERHEAD]. */
 
 	std	r3, STK_PARAM(R3)(r1)
+	SAVE_GPR(14, r1)
 	SAVE_NVGPRS(r1)
 
 	/* We need to setup MSR for VSX register save instructions. */
-	mfmsr	r14
-	mr	r15, r14
-	ori	r15, r15, MSR_FP
-	li	r16, 0
-	ori	r16, r16, MSR_EE /* IRQs hard off */
-	andc	r15, r15, r16
-	oris	r15, r15, MSR_VEC@h
+	mfmsr	r15
+	mr	r16, r15
+	ori	r16, r16, MSR_FP
+	li	r17, 0
+	ori	r17, r17, MSR_EE /* IRQs hard off */
+	andc	r16, r16, r17
+	oris	r16, r16, MSR_VEC@h
 #ifdef CONFIG_VSX
 	BEGIN_FTR_SECTION
-	oris	r15,r15, MSR_VSX@h
+	oris	r16,r16, MSR_VSX@h
 	END_FTR_SECTION_IFSET(CPU_FTR_VSX)
 #endif
-	mtmsrd	r15
-	std	r14, TM_FRAME_L0(r1)
+	mtmsrd	r16
+	std	r15, TM_FRAME_L0(r1)
 
 	/* Do sanity check on MSR to make sure we are suspended */
 	li	r7, (MSR_TS_S)@higher
-	srdi	r6, r14, 32
+	srdi	r6, r15, 32
 	and	r6, r6, r7
 1:	tdeqi   r6, 0
 	EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,0
@@ -205,7 +206,8 @@ _GLOBAL(tm_reclaim)
 	std	r6, GPR12(r7)
 	std	r8, GPR13(r7)
 
-	SAVE_NVGPRS(r7)				/* user r14-r31 */
+	SAVE_GPR(14, r7)			/* user r14 */
+	SAVE_NVGPRS(r7)				/* user r15-r31 */
 
 	/* ******************** NIP ******************** */
 	mfspr	r3, SPRN_TFHAR
@@ -278,12 +280,13 @@ _GLOBAL(tm_reclaim)
 	/* AMR is checkpointed too, but is unsupported by Linux. */
 
 	/* Restore original MSR/IRQ state & clear TM mode */
-	ld	r14, TM_FRAME_L0(r1)		/* Orig MSR */
+	ld	r15, TM_FRAME_L0(r1)		/* Orig MSR */
 
-	li	r15, 0
-	rldimi  r14, r15, MSR_TS_LG, (63-MSR_TS_LG)-1
-	mtmsrd  r14
+	li	r16, 0
+	rldimi  r15, r16, MSR_TS_LG, (63-MSR_TS_LG)-1
+	mtmsrd  r15
 
+	REST_GPR(14, r1)
 	REST_NVGPRS(r1)
 
 	addi    r1, r1, TM_FRAME_SIZE
@@ -319,6 +322,7 @@ _GLOBAL(__tm_recheckpoint)
 	/* We've a struct pt_regs at [r1+STACK_FRAME_OVERHEAD].
 	 * This is used for backing up the NVGPRs:
 	 */
+	SAVE_GPR(14, r1)
 	SAVE_NVGPRS(r1)
 
 	/* Load complete register state from ts_ckpt* registers */
@@ -391,8 +395,9 @@ restore_gprs:
 	REST_GPR(4, r7)				/* GPR4 */
 	REST_4GPRS(8, r7)			/* GPR8-11 */
 	REST_2GPRS(12, r7)			/* GPR12-13 */
+	REST_GPR(14, r7)			/* GPR14 */
 
-	REST_NVGPRS(r7)				/* GPR14-31 */
+	REST_NVGPRS(r7)				/* GPR15-31 */
 
 	/* Load up PPR and DSCR here so we don't run with user values for long
 	 */
@@ -471,6 +476,7 @@ restore_gprs:
 	li	r4, MSR_RI
 	mtmsrd	r4, 1
 
+	REST_GPR(14, r1)
 	REST_NVGPRS(r1)
 
 	addi    r1, r1, TM_FRAME_SIZE
arch/powerpc/kernel/trace/ftrace_64_mprofile.S +5 -5
index 3f3e81852422..a0f62ff3442f 100644
@@ -76,7 +76,7 @@ _GLOBAL(ftrace_caller)
 	ld	r5,0(r3)
 
 #ifdef CONFIG_LIVEPATCH
-	mr	r14,r7		/* remember old NIP */
+	mr	r15,r7		/* remember old NIP */
 #endif
 	/* Calculate ip from nip-4 into r3 for call below */
 	subi    r3, r7, MCOUNT_INSN_SIZE
@@ -100,10 +100,10 @@ ftrace_call:
 	nop
 
 	/* Load the possibly modified NIP */
-	ld	r15, _NIP(r1)
+	ld	r16, _NIP(r1)
 
 #ifdef CONFIG_LIVEPATCH
-	cmpd	r14, r15	/* has NIP been altered? */
+	cmpd	r15, r16	/* has NIP been altered? */
 #endif
 
 #if defined(CONFIG_LIVEPATCH) && defined(CONFIG_KPROBES_ON_FTRACE)
@@ -111,7 +111,7 @@ ftrace_call:
 	beq	1f
 
 	/* Check if there is an active jprobe on us */
-	subi	r3, r14, 4
+	subi	r3, r15, 4
 	bl	__is_active_jprobe
 	nop
 
@@ -130,7 +130,7 @@ ftrace_call:
 #endif
 
 	/* Load CTR with the possibly modified NIP */
-	mtctr	r15
+	mtctr	r16
 
 	/* Restore gprs */
 	REST_GPR(0,r1)
arch/powerpc/kvm/book3s_hv_interrupts.S +3 -2
index dc54373c8780..ef1c0c1e57ff 100644
@@ -46,7 +46,7 @@ _GLOBAL(__kvmppc_vcore_entry)
 	/* Save host state to the stack */
 	stdu	r1, -SWITCH_FRAME_SIZE(r1)
 
-	/* Save non-volatile registers (r14 - r31) and CR */
+	/* Save non-volatile registers (r15 - r31) and CR */
 	SAVE_NVGPRS(r1)
 	mfcr	r3
 	std	r3, _CCR(r1)
@@ -149,9 +149,10 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	 * R3       = trap number on this thread
 	 * R12      = exit handler id
 	 * R13      = PACA
+	 * R14      = ? XXX
 	 */
 
-	/* Restore non-volatile host registers (r14 - r31) and CR */
+	/* Restore non-volatile host registers (r15 - r31) and CR */
 	REST_NVGPRS(r1)
 	ld	r4, _CCR(r1)
 	mtcr	r4
arch/powerpc/kvm/book3s_interrupts.S +68 -25

127 lines not on this page · raw message

arch/powerpc/kvm/book3s_pr.c +6 -0
index d0dc8624198f..b149d4fa4a45 100644
@@ -159,6 +159,9 @@ void kvmppc_copy_to_svcpu(struct kvmppc_book3s_shadow_vcpu *svcpu,
 	svcpu->gpr[11] = vcpu->arch.gpr[11];
 	svcpu->gpr[12] = vcpu->arch.gpr[12];
 	svcpu->gpr[13] = vcpu->arch.gpr[13];
+#ifdef CONFIG_PPC_BOOK3S_64
+	svcpu->gpr[14] = vcpu->arch.gpr[14];
+#endif
 	svcpu->cr  = vcpu->arch.cr;
 	svcpu->xer = vcpu->arch.xer;
 	svcpu->ctr = vcpu->arch.ctr;
@@ -209,6 +212,9 @@ void kvmppc_copy_from_svcpu(struct kvm_vcpu *vcpu,
 	vcpu->arch.gpr[11] = svcpu->gpr[11];
 	vcpu->arch.gpr[12] = svcpu->gpr[12];
 	vcpu->arch.gpr[13] = svcpu->gpr[13];
+#ifdef CONFIG_PPC_BOOK3S_64
+	vcpu->arch.gpr[14] = svcpu->gpr[14];
+#endif
 	vcpu->arch.cr  = svcpu->cr;
 	vcpu->arch.xer = svcpu->xer;
 	vcpu->arch.ctr = svcpu->ctr;
arch/powerpc/lib/checksum_64.S +33 -33

175 lines not on this page · raw message

arch/powerpc/lib/copypage_power7.S +16 -16
index ca5fc8fa7efc..c65fc4a412f2 100644
@@ -113,13 +113,13 @@ _GLOBAL(copypage_power7)
 #endif
 
 .Lnonvmx_copy:
-	std	r14,STK_REG(R14)(r1)
 	std	r15,STK_REG(R15)(r1)
 	std	r16,STK_REG(R16)(r1)
 	std	r17,STK_REG(R17)(r1)
 	std	r18,STK_REG(R18)(r1)
 	std	r19,STK_REG(R19)(r1)
 	std	r20,STK_REG(R20)(r1)
+	std	r21,STK_REG(R21)(r1)
 
 1:	ld	r0,0(r4)
 	ld	r5,8(r4)
@@ -130,13 +130,13 @@ _GLOBAL(copypage_power7)
 	ld	r10,48(r4)
 	ld	r11,56(r4)
 	ld	r12,64(r4)
-	ld	r14,72(r4)
-	ld	r15,80(r4)
-	ld	r16,88(r4)
-	ld	r17,96(r4)
-	ld	r18,104(r4)
-	ld	r19,112(r4)
-	ld	r20,120(r4)
+	ld	r15,72(r4)
+	ld	r16,80(r4)
+	ld	r17,88(r4)
+	ld	r18,96(r4)
+	ld	r19,104(r4)
+	ld	r20,112(r4)
+	ld	r21,120(r4)
 	addi	r4,r4,128
 	std	r0,0(r3)
 	std	r5,8(r3)
@@ -147,22 +147,22 @@ _GLOBAL(copypage_power7)
 	std	r10,48(r3)
 	std	r11,56(r3)
 	std	r12,64(r3)
-	std	r14,72(r3)
-	std	r15,80(r3)
-	std	r16,88(r3)
-	std	r17,96(r3)
-	std	r18,104(r3)
-	std	r19,112(r3)
-	std	r20,120(r3)
+	std	r15,72(r3)
+	std	r16,80(r3)
+	std	r17,88(r3)
+	std	r18,96(r3)
+	std	r19,104(r3)
+	std	r20,112(r3)
+	std	r21,120(r3)
 	addi	r3,r3,128
 	bdnz	1b
 
-	ld	r14,STK_REG(R14)(r1)
 	ld	r15,STK_REG(R15)(r1)
 	ld	r16,STK_REG(R16)(r1)
 	ld	r17,STK_REG(R17)(r1)
 	ld	r18,STK_REG(R18)(r1)
 	ld	r19,STK_REG(R19)(r1)
 	ld	r20,STK_REG(R20)(r1)
+	ld	r21,STK_REG(R21)(r1)
 	addi	r1,r1,STACKFRAMESIZE
 	blr
arch/powerpc/lib/copyuser_power7.S +76 -76

235 lines not on this page · raw message

arch/powerpc/lib/crtsavres.S +3 -0
index 7e5e1c28e56a..c46ad2f0a718 100644
@@ -314,9 +314,12 @@ _GLOBAL(_restvr_31)
 
 #else /* CONFIG_PPC64 */
 
+/* 64-bit has -ffixed-r13, Book3S also has -ffixed-r14 */
+#ifdef CONFIG_PPC_BOOK3E
 .globl	_savegpr0_14
 _savegpr0_14:
 	std	r14,-144(r1)
+#endif
 .globl	_savegpr0_15
 _savegpr0_15:
 	std	r15,-136(r1)
arch/powerpc/lib/memcpy_power7.S +40 -40

171 lines not on this page · raw message

Signature · 1 line
2.15.0
author reviewer
#2 lore raw

RFC PATCH 2/8 powerpc/64s: poison r14 register while in kernel

In reply to Nicholas Piggin

Poison r14 register with the PIR SPR, an a magic number. This means it must be treated like r13, saving and restoring the register on kernel entry/exit, but not restoring it when returning back to kernel

However r14 will not be a constant like r13, but may be modified by the kernel, which means it must not be loaded on exception entry if the exception is coming from the kernel.

This requires loading SRR1 earlier, before the exception mask/kvm test. That's okay because SRR1 almost always gets loaded anyway.

---
 arch/powerpc/include/asm/exception-64s.h | 121 ++++++++++++++++---------------
 arch/powerpc/include/asm/paca.h          |   5 +-
 arch/powerpc/kernel/asm-offsets.c        |   3 +-
 arch/powerpc/kernel/entry_64.S           |  23 ++++++
 arch/powerpc/kernel/exceptions-64s.S     |  45 ++++++------
 arch/powerpc/kernel/head_64.S            |   5 ++
 arch/powerpc/kernel/idle_book3s.S        |   4 +
 arch/powerpc/kernel/paca.c               |   1 -
 arch/powerpc/kernel/setup_64.c           |   3 +
 arch/powerpc/lib/sstep.c                 |   1 +
 10 files changed, 128 insertions(+), 83 deletions(-)
arch/powerpc/include/asm/exception-64s.h +63 -58
index 54afd1f140a4..dadaa7471755 100644
@@ -42,16 +42,18 @@
 #define EX_R11		16
 #define EX_R12		24
 #define EX_R13		32
-#define EX_DAR		40
-#define EX_DSISR	48
-#define EX_CCR		52
-#define EX_CFAR		56
-#define EX_PPR		64
+#define EX_R14		40
+#define EX_DAR		48
+#define EX_DSISR	56
+#define EX_CCR		60
+#define EX_CFAR		64
+#define EX_PPR		72
+
 #if defined(CONFIG_RELOCATABLE)
-#define EX_CTR		72
-#define EX_SIZE		10	/* size in u64 units */
+#define EX_CTR		80
+#define EX_SIZE		11	/* size in u64 units */
 #else
-#define EX_SIZE		9	/* size in u64 units */
+#define EX_SIZE		10	/* size in u64 units */
 #endif
 
 /*
@@ -77,9 +79,8 @@
 #ifdef CONFIG_RELOCATABLE
 #define __EXCEPTION_RELON_PROLOG_PSERIES_1(label, h)			\
 	mfspr	r11,SPRN_##h##SRR0;	/* save SRR0 */			\
-	LOAD_HANDLER(r12,label);					\
-	mtctr	r12;							\
-	mfspr	r12,SPRN_##h##SRR1;	/* and SRR1 */			\
+	LOAD_HANDLER(r10,label);					\
+	mtctr	r10;							\
 	li	r10,MSR_RI;						\
 	mtmsrd 	r10,1;			/* Set RI (EE=0) */		\
 	bctr;
@@ -87,7 +88,6 @@
 /* If not relocatable, we can jump directly -- and save messing with LR */
 #define __EXCEPTION_RELON_PROLOG_PSERIES_1(label, h)			\
 	mfspr	r11,SPRN_##h##SRR0;	/* save SRR0 */			\
-	mfspr	r12,SPRN_##h##SRR1;	/* and SRR1 */			\
 	li	r10,MSR_RI;						\
 	mtmsrd 	r10,1;			/* Set RI (EE=0) */		\
 	b	label;
@@ -102,7 +102,7 @@
  */
 #define EXCEPTION_RELON_PROLOG_PSERIES(area, label, h, extra, vec)	\
 	EXCEPTION_PROLOG_0(area);					\
-	EXCEPTION_PROLOG_1(area, extra, vec);				\
+	EXCEPTION_PROLOG_1(area, h, extra, vec);				\
 	EXCEPTION_RELON_PROLOG_PSERIES_1(label, h)
 
 /*
@@ -198,17 +198,21 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 	std	r10,area+EX_R10(r13);	/* save r10 - r12 */		\
 	OPT_GET_SPR(r10, SPRN_CFAR, CPU_FTR_CFAR)
 
-#define __EXCEPTION_PROLOG_1_PRE(area)					\
+#define __EXCEPTION_PROLOG_1(area, h)					\
+	std	r11,area+EX_R11(r13);					\
+	std	r12,area+EX_R12(r13);					\
+	mfspr	r12,SPRN_##h##SRR1;	/* and SRR1 */			\
+	GET_SCRATCH0(r11);						\
 	OPT_SAVE_REG_TO_PACA(area+EX_PPR, r9, CPU_FTR_HAS_PPR);		\
 	OPT_SAVE_REG_TO_PACA(area+EX_CFAR, r10, CPU_FTR_CFAR);		\
 	SAVE_CTR(r10, area);						\
-	mfcr	r9;
-
-#define __EXCEPTION_PROLOG_1_POST(area)					\
-	std	r11,area+EX_R11(r13);					\
-	std	r12,area+EX_R12(r13);					\
-	GET_SCRATCH0(r10);						\
-	std	r10,area+EX_R13(r13)
+	mfcr	r9;							\
+	std	r11,area+EX_R13(r13);					\
+	std	r14,area+EX_R14(r13);					\
+	andi.	r10,r12,MSR_PR;						\
+	beq	1f;							\
+	ld	r14,PACA_R14(r13);					\
+1:
 
 /*
  * This version of the EXCEPTION_PROLOG_1 will carry
@@ -216,30 +220,27 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
  * checking of the interrupt maskable level in the SOFTEN_TEST.
  * Intended to be used in MASKABLE_EXCPETION_* macros.
  */
-#define MASKABLE_EXCEPTION_PROLOG_1(area, extra, vec, bitmask)			\
-	__EXCEPTION_PROLOG_1_PRE(area);					\
-	extra(vec, bitmask);						\
-	__EXCEPTION_PROLOG_1_POST(area);
+#define MASKABLE_EXCEPTION_PROLOG_1(area, h, extra, vec, bitmask)	\
+	__EXCEPTION_PROLOG_1(area, h);					\
+	extra(vec, bitmask);
 
 /*
  * This version of the EXCEPTION_PROLOG_1 is intended
  * to be used in STD_EXCEPTION* macros
  */
-#define _EXCEPTION_PROLOG_1(area, extra, vec)				\
-	__EXCEPTION_PROLOG_1_PRE(area);					\
-	extra(vec);							\
-	__EXCEPTION_PROLOG_1_POST(area);
+#define _EXCEPTION_PROLOG_1(area, h, extra, vec)			\
+	__EXCEPTION_PROLOG_1(area, h);					\
+	extra(vec);
 
-#define EXCEPTION_PROLOG_1(area, extra, vec)				\
-	_EXCEPTION_PROLOG_1(area, extra, vec)
+#define EXCEPTION_PROLOG_1(area, h, extra, vec)				\
+	_EXCEPTION_PROLOG_1(area, h, extra, vec)
 
 #define __EXCEPTION_PROLOG_PSERIES_1(label, h)				\
-	ld	r10,PACAKMSR(r13);	/* get MSR value for kernel */	\
 	mfspr	r11,SPRN_##h##SRR0;	/* save SRR0 */			\
-	LOAD_HANDLER(r12,label)						\
-	mtspr	SPRN_##h##SRR0,r12;					\
-	mfspr	r12,SPRN_##h##SRR1;	/* and SRR1 */			\
+	ld	r10,PACAKMSR(r13);	/* get MSR value for kernel */	\
 	mtspr	SPRN_##h##SRR1,r10;					\
+	LOAD_HANDLER(r10,label)						\
+	mtspr	SPRN_##h##SRR0,r10;					\
 	h##rfid;							\
 	b	.	/* prevent speculative execution */
 #define EXCEPTION_PROLOG_PSERIES_1(label, h)				\
@@ -247,13 +248,12 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 
 /* _NORI variant keeps MSR_RI clear */
 #define __EXCEPTION_PROLOG_PSERIES_1_NORI(label, h)			\
+	mfspr	r11,SPRN_##h##SRR0;	/* save SRR0 */			\
 	ld	r10,PACAKMSR(r13);	/* get MSR value for kernel */	\
 	xori	r10,r10,MSR_RI;		/* Clear MSR_RI */		\
-	mfspr	r11,SPRN_##h##SRR0;	/* save SRR0 */			\
-	LOAD_HANDLER(r12,label)						\
-	mtspr	SPRN_##h##SRR0,r12;					\
-	mfspr	r12,SPRN_##h##SRR1;	/* and SRR1 */			\
 	mtspr	SPRN_##h##SRR1,r10;					\
+	LOAD_HANDLER(r10,label)						\
+	mtspr	SPRN_##h##SRR0,r10;					\
 	h##rfid;							\
 	b	.	/* prevent speculative execution */
 
@@ -262,7 +262,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 
 #define EXCEPTION_PROLOG_PSERIES(area, label, h, extra, vec)		\
 	EXCEPTION_PROLOG_0(area);					\
-	EXCEPTION_PROLOG_1(area, extra, vec);				\
+	EXCEPTION_PROLOG_1(area, h, extra, vec);			\
 	EXCEPTION_PROLOG_PSERIES_1(label, h);
 
 #define __KVMTEST(h, n)							\
@@ -336,7 +336,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 /* Do not enable RI */
 #define EXCEPTION_PROLOG_PSERIES_NORI(area, label, h, extra, vec)	\
 	EXCEPTION_PROLOG_0(area);					\
-	EXCEPTION_PROLOG_1(area, extra, vec);				\
+	EXCEPTION_PROLOG_1(area, h, extra, vec);			\
 	EXCEPTION_PROLOG_PSERIES_1_NORI(label, h);
 
 
@@ -349,8 +349,9 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 	ld	r10,area+EX_PPR(r13);					\
 	std	r10,HSTATE_PPR(r13);					\
 	END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,948);	\
+	ld	r10,area+EX_R12(r13);					\
+	std	r10,HSTATE_SCRATCH0(r13);				\
 	ld	r10,area+EX_R10(r13);					\
-	std	r12,HSTATE_SCRATCH0(r13);				\
 	sldi	r12,r9,32;						\
 	ori	r12,r12,(n);						\
 	/* This reloads r9 before branching to kvmppc_interrupt */	\
@@ -363,8 +364,9 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 	ld	r10,area+EX_PPR(r13);					\
 	std	r10,HSTATE_PPR(r13);					\
 	END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,948);	\
+	ld	r10,area+EX_R12(r13);					\
+	std	r10,HSTATE_SCRATCH0(r13);				\
 	ld	r10,area+EX_R10(r13);					\
-	std	r12,HSTATE_SCRATCH0(r13);				\
 	sldi	r12,r9,32;						\
 	ori	r12,r12,(n);						\
 	/* This reloads r9 before branching to kvmppc_interrupt */	\
@@ -372,6 +374,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 89:	mtocrf	0x80,r9;						\
 	ld	r9,area+EX_R9(r13);					\
 	ld	r10,area+EX_R10(r13);					\
+	ld	r12,area+EX_R12(r13);					\
 	b	kvmppc_skip_##h##interrupt
 
 #ifdef CONFIG_KVM_BOOK3S_64_HANDLER
@@ -393,7 +396,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 	std	r12,_MSR(r1);		/* save SRR1 in stackframe	*/ \
 	std	r10,0(r1);		/* make stack chain pointer	*/ \
 	std	r0,GPR0(r1);		/* save r0 in stackframe	*/ \
-	std	r10,GPR1(r1);		/* save r1 in stackframe	*/ \
+	std	r10,GPR1(r1)		/* save r1 in stackframe	*/
 
 
 /*
@@ -430,16 +433,18 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 
 /* Save original regs values from save area to stack frame. */
 #define EXCEPTION_PROLOG_COMMON_2(area)					   \
-	ld	r9,area+EX_R9(r13);	/* move r9, r10 to stackframe	*/ \
+	ld	r9,area+EX_R9(r13);	/* move r9-r14 to stackframe	*/ \
 	ld	r10,area+EX_R10(r13);					   \
 	std	r9,GPR9(r1);						   \
 	std	r10,GPR10(r1);						   \
-	ld	r9,area+EX_R11(r13);	/* move r11 - r13 to stackframe	*/ \
+	ld	r9,area+EX_R11(r13);					   \
 	ld	r10,area+EX_R12(r13);					   \
-	ld	r11,area+EX_R13(r13);					   \
 	std	r9,GPR11(r1);						   \
 	std	r10,GPR12(r1);						   \
-	std	r11,GPR13(r1);						   \
+	ld	r9,area+EX_R13(r13);					   \
+	ld	r10,area+EX_R14(r13);					   \
+	std	r9,GPR13(r1);						   \
+	std	r10,GPR14(r1);						   \
 	BEGIN_FTR_SECTION_NESTED(66);					   \
 	ld	r10,area+EX_CFAR(r13);					   \
 	std	r10,ORIG_GPR3(r1);					   \
@@ -480,7 +485,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 	b hdlr;
 
 #define STD_EXCEPTION_PSERIES_OOL(vec, label)			\
-	EXCEPTION_PROLOG_1(PACA_EXGEN, KVMTEST_PR, vec);	\
+	EXCEPTION_PROLOG_1(PACA_EXGEN, EXC_STD, KVMTEST_PR, vec);	\
 	EXCEPTION_PROLOG_PSERIES_1(label, EXC_STD)
 
 #define STD_EXCEPTION_HV(loc, vec, label)			\
@@ -489,7 +494,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 				 EXC_HV, KVMTEST_HV, vec);
 
 #define STD_EXCEPTION_HV_OOL(vec, label)			\
-	EXCEPTION_PROLOG_1(PACA_EXGEN, KVMTEST_HV, vec);	\
+	EXCEPTION_PROLOG_1(PACA_EXGEN, EXC_HV, KVMTEST_HV, vec);	\
 	EXCEPTION_PROLOG_PSERIES_1(label, EXC_HV)
 
 #define STD_RELON_EXCEPTION_PSERIES(loc, vec, label)	\
@@ -498,7 +503,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 	EXCEPTION_RELON_PROLOG_PSERIES(PACA_EXGEN, label, EXC_STD, NOTEST, vec);
 
 #define STD_RELON_EXCEPTION_PSERIES_OOL(vec, label)		\
-	EXCEPTION_PROLOG_1(PACA_EXGEN, NOTEST, vec);		\
+	EXCEPTION_PROLOG_1(PACA_EXGEN, EXC_STD, NOTEST, vec);		\
 	EXCEPTION_RELON_PROLOG_PSERIES_1(label, EXC_STD)
 
 #define STD_RELON_EXCEPTION_HV(loc, vec, label)		\
@@ -507,7 +512,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 				       EXC_HV, KVMTEST_HV, vec);
 
 #define STD_RELON_EXCEPTION_HV_OOL(vec, label)			\
-	EXCEPTION_PROLOG_1(PACA_EXGEN, KVMTEST_HV, vec);	\
+	EXCEPTION_PROLOG_1(PACA_EXGEN, EXC_HV, KVMTEST_HV, vec);	\
 	EXCEPTION_RELON_PROLOG_PSERIES_1(label, EXC_HV)
 
 /* This associate vector numbers with bits in paca->irq_happened */
@@ -548,7 +553,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 #define __MASKABLE_EXCEPTION_PSERIES(vec, label, h, extra, bitmask)	\
 	SET_SCRATCH0(r13);    /* save r13 */				\
 	EXCEPTION_PROLOG_0(PACA_EXGEN);					\
-	MASKABLE_EXCEPTION_PROLOG_1(PACA_EXGEN, extra, vec, bitmask);	\
+	MASKABLE_EXCEPTION_PROLOG_1(PACA_EXGEN, h, extra, vec, bitmask);\
 	EXCEPTION_PROLOG_PSERIES_1(label, h);
 
 #define _MASKABLE_EXCEPTION_PSERIES(vec, label, h, extra, bitmask)	\
@@ -559,7 +564,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 				    EXC_STD, SOFTEN_TEST_PR, bitmask)
 
 #define MASKABLE_EXCEPTION_PSERIES_OOL(vec, label, bitmask)		\
-	MASKABLE_EXCEPTION_PROLOG_1(PACA_EXGEN, SOFTEN_TEST_PR, vec, bitmask);\
+	MASKABLE_EXCEPTION_PROLOG_1(PACA_EXGEN, EXC_STD, SOFTEN_TEST_PR, vec, bitmask);\
 	EXCEPTION_PROLOG_PSERIES_1(label, EXC_STD)
 
 #define MASKABLE_EXCEPTION_HV(loc, vec, label, bitmask)			\
@@ -567,13 +572,13 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 				    EXC_HV, SOFTEN_TEST_HV, bitmask)
 
 #define MASKABLE_EXCEPTION_HV_OOL(vec, label, bitmask)			\
-	MASKABLE_EXCEPTION_PROLOG_1(PACA_EXGEN, SOFTEN_TEST_HV, vec, bitmask);\
+	MASKABLE_EXCEPTION_PROLOG_1(PACA_EXGEN, EXC_HV, SOFTEN_TEST_HV, vec, bitmask);\
 	EXCEPTION_PROLOG_PSERIES_1(label, EXC_HV)
 
 #define __MASKABLE_RELON_EXCEPTION_PSERIES(vec, label, h, extra, bitmask) \
 	SET_SCRATCH0(r13);    /* save r13 */				\
 	EXCEPTION_PROLOG_0(PACA_EXGEN);					\
-	MASKABLE_EXCEPTION_PROLOG_1(PACA_EXGEN, extra, vec, bitmask);	\
+	MASKABLE_EXCEPTION_PROLOG_1(PACA_EXGEN, h, extra, vec, bitmask);\
 	EXCEPTION_RELON_PROLOG_PSERIES_1(label, h)
 
 #define _MASKABLE_RELON_EXCEPTION_PSERIES(vec, label, h, extra, bitmask)\
@@ -584,7 +589,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 					  EXC_STD, SOFTEN_NOTEST_PR, bitmask)
 
 #define MASKABLE_RELON_EXCEPTION_PSERIES_OOL(vec, label, bitmask)	\
-	MASKABLE_EXCEPTION_PROLOG_1(PACA_EXGEN, SOFTEN_NOTEST_PR, vec, bitmask);\
+	MASKABLE_EXCEPTION_PROLOG_1(PACA_EXGEN, EXC_STD, SOFTEN_NOTEST_PR, vec, bitmask);\
 	EXCEPTION_PROLOG_PSERIES_1(label, EXC_STD);
 
 #define MASKABLE_RELON_EXCEPTION_HV(loc, vec, label, bitmask)		\
@@ -592,7 +597,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 					  EXC_HV, SOFTEN_TEST_HV, bitmask)
 
 #define MASKABLE_RELON_EXCEPTION_HV_OOL(vec, label, bitmask)		\
-	MASKABLE_EXCEPTION_PROLOG_1(PACA_EXGEN, SOFTEN_NOTEST_HV, vec, bitmask);\
+	MASKABLE_EXCEPTION_PROLOG_1(PACA_EXGEN, EXC_HV, SOFTEN_NOTEST_HV, vec, bitmask);\
 	EXCEPTION_RELON_PROLOG_PSERIES_1(label, EXC_HV)
 
 /*
arch/powerpc/include/asm/paca.h +4 -1
index e2ee193eb24d..cd6a9a010895 100644
@@ -34,6 +34,9 @@
 #include <asm/cpuidle.h>
 
 register struct paca_struct *local_paca asm("r13");
+#ifdef CONFIG_PPC_BOOK3S
+register u64 local_r14 asm("r14");
+#endif
 
 #if defined(CONFIG_DEBUG_PREEMPT) && defined(CONFIG_SMP)
 extern unsigned int debug_smp_processor_id(void); /* from linux/smp.h */
@@ -65,7 +68,6 @@ struct paca_struct {
 	 * read-only (after boot) fields in the first cacheline to
 	 * avoid cacheline bouncing.
 	 */
-
 	struct lppaca *lppaca_ptr;	/* Pointer to LpPaca for PLIC */
 #endif /* CONFIG_PPC_BOOK3S */
 	/*
@@ -104,6 +106,7 @@ struct paca_struct {
 	 */
 	/* used for most interrupts/exceptions */
 	u64 exgen[EX_SIZE] __attribute__((aligned(0x80)));
+	u64 r14;
 	u64 exslb[EX_SIZE];	/* used for SLB/segment table misses
  				 * on the linear mapping */
 	/* SLB related definitions */
arch/powerpc/kernel/asm-offsets.c +2 -1
index db8407483c9e..32d393f55a96 100644
@@ -218,8 +218,9 @@ int main(void)
 	OFFSET(PACACONTEXTSLLP, paca_struct, mm_ctx_sllp);
 #endif /* CONFIG_PPC_MM_SLICES */
 	OFFSET(PACA_EXGEN, paca_struct, exgen);
-	OFFSET(PACA_EXMC, paca_struct, exmc);
+	OFFSET(PACA_R14, paca_struct, r14);
 	OFFSET(PACA_EXSLB, paca_struct, exslb);
+	OFFSET(PACA_EXMC, paca_struct, exmc);
 	OFFSET(PACA_EXNMI, paca_struct, exnmi);
 	OFFSET(PACALPPACAPTR, paca_struct, lppaca_ptr);
 	OFFSET(PACA_SLBSHADOWPTR, paca_struct, slb_shadow_ptr);
arch/powerpc/kernel/entry_64.S +23 -0
index b9bf44635b10..592e4b36065f 100644
@@ -37,6 +37,11 @@
 #include <asm/tm.h>
 #include <asm/ppc-opcode.h>
 #include <asm/export.h>
+#ifdef CONFIG_PPC_BOOK3S
+#include <asm/exception-64s.h>
+#else
+#include <asm/exception-64e.h>
+#endif
 
 /*
  * System calls.
@@ -65,11 +70,18 @@ END_FTR_SECTION_IFSET(CPU_FTR_TM)
 	addi	r1,r1,-INT_FRAME_SIZE
 	beq-	1f
 	ld	r1,PACAKSAVE(r13)
+#ifdef CONFIG_PPC_BOOK3S
+	ld	r14,PACA_R14(r13)
+#endif
 1:	std	r10,0(r1)
 	std	r11,_NIP(r1)
 	std	r12,_MSR(r1)
 	std	r0,GPR0(r1)
 	std	r10,GPR1(r1)
+#ifdef CONFIG_PPC_BOOK3S
+	ld	r10,PACA_EXGEN+EX_R14(r13)
+	std	r10,GPR14(r1)
+#endif
 	beq	2f			/* if from kernel mode */
 	ACCOUNT_CPU_USER_ENTRY(r13, r10, r11)
 2:	std	r2,GPR2(r1)
@@ -250,6 +262,11 @@ system_call_exit:
 BEGIN_FTR_SECTION
 	stdcx.	r0,0,r1			/* to clear the reservation */
 END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
+	LOAD_REG_IMMEDIATE(r10, 0xdeadbeefULL << 32)
+	mfspr	r11,SPRN_PIR
+	or	r10,r10,r11
+	tdne	r10,r14
+
 	andi.	r6,r8,MSR_PR
 	ld	r4,_LINK(r1)
 
@@ -261,6 +278,9 @@ BEGIN_FTR_SECTION
 END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 
 	ld	r13,GPR13(r1)	/* only restore r13 if returning to usermode */
+#ifdef CONFIG_PPC_BOOK3S
+	ld	r14,GPR14(r1)	/* only restore r14 if returning to usermode */
+#endif
 1:	ld	r2,GPR2(r1)
 	ld	r1,GPR1(r1)
 	mtlr	r4
@@ -874,6 +894,9 @@ BEGIN_FTR_SECTION
 END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	ACCOUNT_CPU_USER_EXIT(r13, r2, r4)
 	REST_GPR(13, r1)
+#ifdef CONFIG_PPC_BOOK3S
+	REST_GPR(14, r1)
+#endif
 1:
 	mtspr	SPRN_SRR1,r3
 
arch/powerpc/kernel/exceptions-64s.S +23 -22

175 lines not on this page · raw message

arch/powerpc/kernel/head_64.S +5 -0
index 87b2c2264118..5a9ec06eab14 100644
@@ -413,6 +413,11 @@ generic_secondary_common_init:
 	b	kexec_wait		/* next kernel might do better	 */
 
 2:	SET_PACA(r13)
+	LOAD_REG_IMMEDIATE(r14, 0xdeadbeef << 32)
+	mfspr	r3,SPRN_PIR
+	or	r14,r14,r3
+	std	r14,PACA_R14(r13)
+
 #ifdef CONFIG_PPC_BOOK3E
 	addi	r12,r13,PACA_EXTLB	/* and TLB exc frame in another  */
 	mtspr	SPRN_SPRG_TLB_EXFRAME,r12
arch/powerpc/kernel/idle_book3s.S +4 -0
index 5065c4cb5f12..3b6de0ba4e03 100644
@@ -195,6 +195,7 @@ pnv_powersave_common:
 
 	/* Continue saving state */
 	SAVE_GPR(2, r1)
+	SAVE_GPR(14, r1) /* XXX: check if we need to save/restore or can rely on PACA_R14 reload */
 	SAVE_NVGPRS(r1)
 	mfcr	r5
 	std	r5,_CCR(r1)
@@ -464,6 +465,7 @@ power9_dd1_recover_paca:
 	/* Load paca->thread_sibling_pacas[i] into r13 */
 	ldx	r13, r4, r5
 	SET_PACA(r13)
+	/* R14 will be restored */
 	/*
 	 * Indicate that we have lost NVGPR state
 	 * which needs to be restored from the stack.
@@ -926,6 +928,7 @@ fastsleep_workaround_at_exit:
 .global pnv_wakeup_loss
 pnv_wakeup_loss:
 	ld	r1,PACAR1(r13)
+	REST_GPR(14, r1)
 BEGIN_FTR_SECTION
 	CHECK_HMI_INTERRUPT
 END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
@@ -950,6 +953,7 @@ pnv_wakeup_noloss:
 	cmpwi	r0,0
 	bne	pnv_wakeup_loss
 	ld	r1,PACAR1(r13)
+	REST_GPR(14, r1)
 BEGIN_FTR_SECTION
 	CHECK_HMI_INTERRUPT
 END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
arch/powerpc/kernel/paca.c +0 -1
index d6597038931d..2491e9cd8d24 100644
@@ -198,7 +198,6 @@ void setup_paca(struct paca_struct *new_paca)
 		mtspr(SPRN_SPRG_HPACA, local_paca);
 #endif
 	mtspr(SPRN_SPRG_PACA, local_paca);
-
 }
 
 static int __initdata paca_size;
arch/powerpc/kernel/setup_64.c +3 -0
index a4408a7e6f14..9a4c5bf35d92 100644
@@ -192,6 +192,9 @@ static void __init fixup_boot_paca(void)
 	get_paca()->data_offset = 0;
 	/* Mark interrupts disabled in PACA */
 	irq_soft_mask_set(IRQ_SOFT_MASK_STD);
+	/* Set r14 and paca_r14 to debug value */
+	get_paca()->r14 = (0xdeadbeefULL << 32) | mfspr(SPRN_PIR);
+	local_r14 = get_paca()->r14;
 }
 
 static void __init configure_exceptions(void)
arch/powerpc/lib/sstep.c +1 -0
index 70274b7b4773..b1b8f9f88083 100644
@@ -3073,6 +3073,7 @@ int emulate_step(struct pt_regs *regs, unsigned int instr)
 		regs->gpr[11] = regs->nip + 4;
 		regs->gpr[12] = regs->msr & MSR_MASK;
 		regs->gpr[13] = (unsigned long) get_paca();
+		regs->gpr[14] = local_r14;
 		regs->nip = (unsigned long) &system_call_common;
 		regs->msr = MSR_KERNEL;
 		return 1;
Signature · 1 line
2.15.0
author reviewer
#3 lore raw

RFC PATCH 3/8 powerpc/64s: put the per-cpu data_offset in r14

In reply to Nicholas Piggin

Shifted left by 16 bits, so the low 16 bits of r14 remain available. This allows per-cpu pointers to be dereferenced with a single extra shift whereas previously it was a load and add.

---
 arch/powerpc/include/asm/paca.h   |  5 +++++
 arch/powerpc/include/asm/percpu.h |  2 +-
 arch/powerpc/kernel/entry_64.S    |  5 -----
 arch/powerpc/kernel/head_64.S     |  5 +----
 arch/powerpc/kernel/setup_64.c    | 11 +++++++++--
 5 files changed, 16 insertions(+), 12 deletions(-)
arch/powerpc/include/asm/paca.h +5 -0
index cd6a9a010895..4dd4ac69e84f 100644
@@ -35,6 +35,11 @@
 
 register struct paca_struct *local_paca asm("r13");
 #ifdef CONFIG_PPC_BOOK3S
+/*
+ * The top 32-bits of r14 is used as the per-cpu offset, shifted by PAGE_SHIFT.
+ * The per-cpu could be moved completely to vmalloc space if we had large
+ * vmalloc page mapping? (no, must access it in real mode).
+ */
 register u64 local_r14 asm("r14");
 #endif
 
arch/powerpc/include/asm/percpu.h +1 -1
index dce863a7635c..1e0d79d30eac 100644
@@ -12,7 +12,7 @@
 
 #include <asm/paca.h>
 
-#define __my_cpu_offset local_paca->data_offset
+#define __my_cpu_offset (local_r14 >> 16)
 
 #endif /* CONFIG_SMP */
 #endif /* __powerpc64__ */
arch/powerpc/kernel/entry_64.S +0 -5
index 592e4b36065f..6b0e3ac311e8 100644
@@ -262,11 +262,6 @@ system_call_exit:
 BEGIN_FTR_SECTION
 	stdcx.	r0,0,r1			/* to clear the reservation */
 END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
-	LOAD_REG_IMMEDIATE(r10, 0xdeadbeefULL << 32)
-	mfspr	r11,SPRN_PIR
-	or	r10,r10,r11
-	tdne	r10,r14
-
 	andi.	r6,r8,MSR_PR
 	ld	r4,_LINK(r1)
 
arch/powerpc/kernel/head_64.S +1 -4
index 5a9ec06eab14..cdb710f43681 100644
@@ -413,10 +413,7 @@ generic_secondary_common_init:
 	b	kexec_wait		/* next kernel might do better	 */
 
 2:	SET_PACA(r13)
-	LOAD_REG_IMMEDIATE(r14, 0xdeadbeef << 32)
-	mfspr	r3,SPRN_PIR
-	or	r14,r14,r3
-	std	r14,PACA_R14(r13)
+	ld	r14,PACA_R14(r13)
 
 #ifdef CONFIG_PPC_BOOK3E
 	addi	r12,r13,PACA_EXTLB	/* and TLB exc frame in another  */
arch/powerpc/kernel/setup_64.c +9 -2
index 9a4c5bf35d92..f4a96ebb523a 100644
@@ -192,8 +192,8 @@ static void __init fixup_boot_paca(void)
 	get_paca()->data_offset = 0;
 	/* Mark interrupts disabled in PACA */
 	irq_soft_mask_set(IRQ_SOFT_MASK_STD);
-	/* Set r14 and paca_r14 to debug value */
-	get_paca()->r14 = (0xdeadbeefULL << 32) | mfspr(SPRN_PIR);
+	/* Set r14 and paca_r14 to zero */
+	get_paca()->r14 = 0;
 	local_r14 = get_paca()->r14;
 }
 
@@ -761,7 +761,14 @@ void __init setup_per_cpu_areas(void)
 	for_each_possible_cpu(cpu) {
                 __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
 		paca[cpu].data_offset = __per_cpu_offset[cpu];
+
+		BUG_ON(paca[cpu].data_offset & (PAGE_SIZE-1));
+		BUG_ON(paca[cpu].data_offset >= (1UL << (64 - 16)));
+
+		/* The top 48 bits are used for per-cpu data */
+		paca[cpu].r14 |= paca[cpu].data_offset << 16;
 	}
+	local_r14 = paca[smp_processor_id()].r14;
 }
 #endif
 
Signature · 1 line
2.15.0
#4 lore raw

Re: [RFC PATCH 3/8] powerpc/64s: put the per-cpu data_offset in r14

Quoted 16 lines · Nicholas Piggin

Shifted left by 16 bits, so the low 16 bits of r14 remain available. This allows per-cpu pointers to be dereferenced with a single extra shift whereas previously it was a load and add.

---
 arch/powerpc/include/asm/paca.h   |  5 +++++
 arch/powerpc/include/asm/percpu.h |  2 +-
 arch/powerpc/kernel/entry_64.S    |  5 -----
 arch/powerpc/kernel/head_64.S     |  5 +----
 arch/powerpc/kernel/setup_64.c    | 11 +++++++++--
 5 files changed, 16 insertions(+), 12 deletions(-)
arch/powerpc/include/asm/paca.h +0 -0
index cd6a9a010895..4dd4ac69e84f 100644

arch/powerpc/include/asm/paca.h line 39

Quoted 5 lines
arch/powerpc/include/asm/paca.h +2 -0
@@ -35,6 +35,11 @@
 
 register struct paca_struct *local_paca asm("r13");
 #ifdef CONFIG_PPC_BOOK3S
+/*
+ * The top 32-bits of r14 is used as the per-cpu offset, shifted by PAGE_SHIFT.

Top 32, really? It's 48 in later comments.

Gabriel

Quoted 83 lines
arch/powerpc/include/asm/paca.h +3 -0
+ * The per-cpu could be moved completely to vmalloc space if we had large
+ * vmalloc page mapping? (no, must access it in real mode).
+ */
 register u64 local_r14 asm("r14");
 #endif
 
arch/powerpc/include/asm/percpu.h +1 -1
index dce863a7635c..1e0d79d30eac 100644
@@ -12,7 +12,7 @@
 
 #include <asm/paca.h>
 
-#define __my_cpu_offset local_paca->data_offset
+#define __my_cpu_offset (local_r14 >> 16)
 
 #endif /* CONFIG_SMP */
 #endif /* __powerpc64__ */
arch/powerpc/kernel/entry_64.S +0 -5
index 592e4b36065f..6b0e3ac311e8 100644
@@ -262,11 +262,6 @@ system_call_exit:
 BEGIN_FTR_SECTION
 	stdcx.	r0,0,r1			/* to clear the reservation */
 END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
-	LOAD_REG_IMMEDIATE(r10, 0xdeadbeefULL << 32)
-	mfspr	r11,SPRN_PIR
-	or	r10,r10,r11
-	tdne	r10,r14
-
 	andi.	r6,r8,MSR_PR
 	ld	r4,_LINK(r1)
 
arch/powerpc/kernel/head_64.S +1 -4
index 5a9ec06eab14..cdb710f43681 100644
@@ -413,10 +413,7 @@ generic_secondary_common_init:
 	b	kexec_wait		/* next kernel might do better	 */
 
 2:	SET_PACA(r13)
-	LOAD_REG_IMMEDIATE(r14, 0xdeadbeef << 32)
-	mfspr	r3,SPRN_PIR
-	or	r14,r14,r3
-	std	r14,PACA_R14(r13)
+	ld	r14,PACA_R14(r13)
 
 #ifdef CONFIG_PPC_BOOK3E
 	addi	r12,r13,PACA_EXTLB	/* and TLB exc frame in another  */
arch/powerpc/kernel/setup_64.c +9 -2
index 9a4c5bf35d92..f4a96ebb523a 100644
@@ -192,8 +192,8 @@ static void __init fixup_boot_paca(void)
 	get_paca()->data_offset = 0;
 	/* Mark interrupts disabled in PACA */
 	irq_soft_mask_set(IRQ_SOFT_MASK_STD);
-	/* Set r14 and paca_r14 to debug value */
-	get_paca()->r14 = (0xdeadbeefULL << 32) | mfspr(SPRN_PIR);
+	/* Set r14 and paca_r14 to zero */
+	get_paca()->r14 = 0;
 	local_r14 = get_paca()->r14;
 }
 
@@ -761,7 +761,14 @@ void __init setup_per_cpu_areas(void)
 	for_each_possible_cpu(cpu) {
                 __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
 		paca[cpu].data_offset = __per_cpu_offset[cpu];
+
+		BUG_ON(paca[cpu].data_offset & (PAGE_SIZE-1));
+		BUG_ON(paca[cpu].data_offset >= (1UL << (64 - 16)));
+
+		/* The top 48 bits are used for per-cpu data */
+		paca[cpu].r14 |= paca[cpu].data_offset << 16;
 	}
+	local_r14 = paca[smp_processor_id()].r14;
 }
 #endif
 
Signature · 1 line
2.15.0
author reviewer
#5 lore raw

Re: [RFC PATCH 3/8] powerpc/64s: put the per-cpu data_offset in r14

Quoted 18 lines · On Wed, 20 Dec 2017 18:53:24 +0100 Gabriel Paubert <[email protected]> wrote:
Quoted 17 lines · Nicholas Piggin

Shifted left by 16 bits, so the low 16 bits of r14 remain available. This allows per-cpu pointers to be dereferenced with a single extra shift whereas previously it was a load and add.

---
 arch/powerpc/include/asm/paca.h   |  5 +++++
 arch/powerpc/include/asm/percpu.h |  2 +-
 arch/powerpc/kernel/entry_64.S    |  5 -----
 arch/powerpc/kernel/head_64.S     |  5 +----
 arch/powerpc/kernel/setup_64.c    | 11 +++++++++--
 5 files changed, 16 insertions(+), 12 deletions(-)
arch/powerpc/include/asm/paca.h +0 -0
index cd6a9a010895..4dd4ac69e84f 100644
@@ -35,6 +35,11 @@
 
Quoted 6 lines

arch/powerpc/include/asm/paca.h line 39

Quoted 4 lines
arch/powerpc/include/asm/paca.h +2 -0
 register struct paca_struct *local_paca asm("r13");
 #ifdef CONFIG_PPC_BOOK3S
+/*
+ * The top 32-bits of r14 is used as the per-cpu offset, shifted by PAGE_SHIFT.  

Top 32, really? It's 48 in later comments.

Yep, I used 32 to start with but it wasn't enough. Will fix.

Thanks,
Nick

author reviewer
#6 lore raw

RFC PATCH 4/8 powerpc/64s: put io_sync bit into r14

In reply to Nicholas Piggin

This simplifies spin unlock code and mmio primitives. This may not be the best use of an r14 bit, but it was a simple first proof of concept after the per-cpu data_offset, and so it can stay until we get low on bits.

---
 arch/powerpc/include/asm/io.h       | 11 ++++------
 arch/powerpc/include/asm/paca.h     | 44 ++++++++++++++++++++++++++++++++++++-
 arch/powerpc/include/asm/spinlock.h | 21 ++++++++++--------
 arch/powerpc/xmon/xmon.c            |  1 -
 4 files changed, 59 insertions(+), 18 deletions(-)
arch/powerpc/include/asm/io.h +4 -7
index 422f99cf9924..c817f3a83fcc 100644
@@ -104,8 +104,8 @@ extern bool isa_io_special;
  *
  */
 
-#ifdef CONFIG_PPC64
-#define IO_SET_SYNC_FLAG()	do { local_paca->io_sync = 1; } while(0)
+#if defined(CONFIG_PPC64) && defined(CONFIG_SMP)
+#define IO_SET_SYNC_FLAG()	do { r14_set_bits(R14_BIT_IO_SYNC); } while(0)
 #else
 #define IO_SET_SYNC_FLAG()
 #endif
@@ -673,11 +673,8 @@ static inline void name at					\
  */
 static inline void mmiowb(void)
 {
-	unsigned long tmp;
-
-	__asm__ __volatile__("sync; li %0,0; stb %0,%1(13)"
-	: "=&r" (tmp) : "i" (offsetof(struct paca_struct, io_sync))
-	: "memory");
+	__asm__ __volatile__("sync" : : : "memory");
+	r14_clear_bits(R14_BIT_IO_SYNC);
 }
 #endif /* !CONFIG_PPC32 */
 
arch/powerpc/include/asm/paca.h +43 -1

62 lines not on this page · raw message

arch/powerpc/include/asm/spinlock.h +12 -9
index b9ebc3085fb7..182bb9304c79 100644
@@ -40,16 +40,9 @@
 #endif
 
 #if defined(CONFIG_PPC64) && defined(CONFIG_SMP)
-#define CLEAR_IO_SYNC	(get_paca()->io_sync = 0)
-#define SYNC_IO		do {						\
-				if (unlikely(get_paca()->io_sync)) {	\
-					mb();				\
-					get_paca()->io_sync = 0;	\
-				}					\
-			} while (0)
+#define CLEAR_IO_SYNC	do { r14_clear_bits(R14_BIT_IO_SYNC); } while(0)
 #else
 #define CLEAR_IO_SYNC
-#define SYNC_IO
 #endif
 
 #ifdef CONFIG_PPC_PSERIES
@@ -165,9 +158,19 @@ void arch_spin_lock_flags(arch_spinlock_t *lock, unsigned long flags)
 
 static inline void arch_spin_unlock(arch_spinlock_t *lock)
 {
-	SYNC_IO;
+#if defined(CONFIG_PPC64) && defined(CONFIG_SMP)
+	bool io_sync = local_r14 & R14_BIT_IO_SYNC;
+	if (unlikely(io_sync)) {
+		mb();
+		CLEAR_IO_SYNC;
+	} else {
+		__asm__ __volatile__("# arch_spin_unlock\n\t"
+				PPC_RELEASE_BARRIER: : :"memory");
+	}
+#else
 	__asm__ __volatile__("# arch_spin_unlock\n\t"
 				PPC_RELEASE_BARRIER: : :"memory");
+#endif
 	lock->slock = 0;
 }
 
arch/powerpc/xmon/xmon.c +0 -1
index a53454f61d09..40f0d02ae92d 100644
@@ -2393,7 +2393,6 @@ static void dump_one_paca(int cpu)
 	DUMP(p, trap_save, "x");
 	DUMP(p, irq_soft_mask, "x");
 	DUMP(p, irq_happened, "x");
-	DUMP(p, io_sync, "x");
 	DUMP(p, irq_work_pending, "x");
 	DUMP(p, nap_state_lost, "x");
 	DUMP(p, sprg_vdso, "llx");
Signature · 1 line
2.15.0
#7 lore raw

Re: [RFC PATCH 4/8] powerpc/64s: put io_sync bit into r14

Hello Nicholas,

Just a small comment about syntax. I'm afraid I can't comment much about the substance of the patch.

Quoted 6 lines · Nicholas Piggin
arch/powerpc/include/asm/spinlock.h +0 -0
index b9ebc3085fb7..182bb9304c79 100644
@@ -40,16 +40,9 @@
 #endif

arch/powerpc/include/asm/spinlock.h line 43

Quoted 10 lines
arch/powerpc/include/asm/spinlock.h +1 -7
 
 #if defined(CONFIG_PPC64) && defined(CONFIG_SMP)
-#define CLEAR_IO_SYNC	(get_paca()->io_sync = 0)
-#define SYNC_IO		do {						\
-				if (unlikely(get_paca()->io_sync)) {	\
-					mb();				\
-					get_paca()->io_sync = 0;	\
-				}					\
-			} while (0)
+#define CLEAR_IO_SYNC	do { r14_clear_bits(R14_BIT_IO_SYNC); } while(0)

Is there a reason for the do { } while(0) idiom here? If r14_clear_bits() is an inline function, isn't it a single statement already?

Signature · 2 lines
Thiago Jung Bauermann
IBM Linux Technology Center
author reviewer
#8 lore raw

RFC PATCH 5/8 powerpc/64s: put work_pending bit into r14

In reply to Nicholas Piggin

Similarly, may not be worth an r14 bit, but...

---
 arch/powerpc/include/asm/paca.h |  4 ++--
 arch/powerpc/kernel/time.c      | 15 +++------------
 arch/powerpc/xmon/xmon.c        |  1 -
 3 files changed, 5 insertions(+), 15 deletions(-)
arch/powerpc/include/asm/paca.h +2 -2
index 408fa079e00d..cd3637f4ee4e 100644
@@ -36,7 +36,8 @@
 register struct paca_struct *local_paca asm("r13");
 #ifdef CONFIG_PPC_BOOK3S
 
-#define R14_BIT_IO_SYNC	0x0001
+#define R14_BIT_IO_SYNC			0x0001
+#define R14_BIT_IRQ_WORK_PENDING	0x0002 /* IRQ_WORK interrupt while soft-disable */
 
 /*
  * The top 32-bits of r14 is used as the per-cpu offset, shifted by PAGE_SHIFT.
@@ -212,7 +213,6 @@ struct paca_struct {
 	u16 trap_save;			/* Used when bad stack is encountered */
 	u8 irq_soft_mask;		/* mask for irq soft masking */
 	u8 irq_happened;		/* irq happened while soft-disabled */
-	u8 irq_work_pending;		/* IRQ_WORK interrupt while soft-disable */
 	u8 nap_state_lost;		/* NV GPR values lost in power7_idle */
 	u64 sprg_vdso;			/* Saved user-visible sprg */
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
arch/powerpc/kernel/time.c +3 -12
index 8d32ce95ec88..fac30152723f 100644
@@ -488,26 +488,17 @@ EXPORT_SYMBOL(profile_pc);
 #ifdef CONFIG_PPC64
 static inline unsigned long test_irq_work_pending(void)
 {
-	unsigned long x;
-
-	asm volatile("lbz %0,%1(13)"
-		: "=r" (x)
-		: "i" (offsetof(struct paca_struct, irq_work_pending)));
-	return x;
+	return local_r14 & R14_BIT_IRQ_WORK_PENDING;
 }
 
 static inline void set_irq_work_pending_flag(void)
 {
-	asm volatile("stb %0,%1(13)" : :
-		"r" (1),
-		"i" (offsetof(struct paca_struct, irq_work_pending)));
+	r14_set_bits(R14_BIT_IRQ_WORK_PENDING);
 }
 
 static inline void clear_irq_work_pending(void)
 {
-	asm volatile("stb %0,%1(13)" : :
-		"r" (0),
-		"i" (offsetof(struct paca_struct, irq_work_pending)));
+	r14_clear_bits(R14_BIT_IRQ_WORK_PENDING);
 }
 
 #else /* 32-bit */
arch/powerpc/xmon/xmon.c +0 -1
index 40f0d02ae92d..7d2bb26ff333 100644
@@ -2393,7 +2393,6 @@ static void dump_one_paca(int cpu)
 	DUMP(p, trap_save, "x");
 	DUMP(p, irq_soft_mask, "x");
 	DUMP(p, irq_happened, "x");
-	DUMP(p, irq_work_pending, "x");
 	DUMP(p, nap_state_lost, "x");
 	DUMP(p, sprg_vdso, "llx");
 
Signature · 1 line
2.15.0
author reviewer
#9 lore raw

RFC PATCH 6/8 powerpc/64s: put irq_soft_mask bits into r14

In reply to Nicholas Piggin

Put the STD and PMI interrupt mask bits into r14. This benefits IRQ disabling (enabling to a lesser extent), and soft mask check in the interrupt entry handler.

---
 arch/powerpc/include/asm/exception-64s.h |  6 +-
 arch/powerpc/include/asm/hw_irq.h        | 98 ++++++++++++--------------------
 arch/powerpc/include/asm/irqflags.h      |  9 +--
 arch/powerpc/include/asm/kvm_ppc.h       |  2 +-
 arch/powerpc/include/asm/paca.h          | 18 +++++-
 arch/powerpc/kernel/asm-offsets.c        |  7 ++-
 arch/powerpc/kernel/entry_64.S           | 19 +++----
 arch/powerpc/kernel/idle_book3s.S        |  3 +
 arch/powerpc/kernel/irq.c                | 12 ++--
 arch/powerpc/kernel/optprobes_head.S     |  3 +-
 arch/powerpc/kernel/process.c            |  2 +-
 arch/powerpc/kernel/setup_64.c           | 11 ++--
 arch/powerpc/kvm/book3s_hv_rmhandlers.S  |  3 +-
 arch/powerpc/xmon/xmon.c                 |  5 +-
 14 files changed, 95 insertions(+), 103 deletions(-)
arch/powerpc/include/asm/exception-64s.h +2 -4
index dadaa7471755..5602454ae56f 100644
@@ -459,9 +459,8 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 	mflr	r9;			/* Get LR, later save to stack	*/ \
 	ld	r2,PACATOC(r13);	/* get kernel TOC into r2	*/ \
 	std	r9,_LINK(r1);						   \
-	lbz	r10,PACAIRQSOFTMASK(r13);				   \
 	mfspr	r11,SPRN_XER;		/* save XER in stackframe	*/ \
-	std	r10,SOFTE(r1);						   \
+	std	r14,SOFTE(r1);		/* full r14 not just softe XXX	*/ \
 	std	r11,_XER(r1);						   \
 	li	r9,(n)+1;						   \
 	std	r9,_TRAP(r1);		/* set trap number		*/ \
@@ -526,8 +525,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 #define SOFTEN_VALUE_0xf00	PACA_IRQ_PMI
 
 #define __SOFTEN_TEST(h, vec, bitmask)					\
-	lbz	r10,PACAIRQSOFTMASK(r13);				\
-	andi.	r10,r10,bitmask;					\
+	andi.	r10,r14,bitmask;					\
 	li	r10,SOFTEN_VALUE_##vec;					\
 	bne	masked_##h##interrupt
 
arch/powerpc/include/asm/hw_irq.h +37 -61

154 lines not on this page · raw message

arch/powerpc/include/asm/irqflags.h +3 -6
index 492b0a9fa352..19a2752868f8 100644
@@ -47,14 +47,12 @@
  * be clobbered.
  */
 #define RECONCILE_IRQ_STATE(__rA, __rB)		\
-	lbz	__rA,PACAIRQSOFTMASK(r13);	\
 	lbz	__rB,PACAIRQHAPPENED(r13);	\
-	andi.	__rA,__rA,IRQ_SOFT_MASK_STD;	\
-	li	__rA,IRQ_SOFT_MASK_STD;		\
+	andi.	__rA,r14,IRQ_SOFT_MASK_STD;	\
+	ori	r14,r14,IRQ_SOFT_MASK_STD;	\
 	ori	__rB,__rB,PACA_IRQ_HARD_DIS;	\
 	stb	__rB,PACAIRQHAPPENED(r13);	\
 	bne	44f;				\
-	stb	__rA,PACAIRQSOFTMASK(r13);	\
 	TRACE_DISABLE_INTS;			\
 44:
 
@@ -64,9 +62,8 @@
 
 #define RECONCILE_IRQ_STATE(__rA, __rB)		\
 	lbz	__rA,PACAIRQHAPPENED(r13);	\
-	li	__rB,IRQ_SOFT_MASK_STD;		\
+	ori	r14,r14,IRQ_SOFT_MASK_STD;	\
 	ori	__rA,__rA,PACA_IRQ_HARD_DIS;	\
-	stb	__rB,PACAIRQSOFTMASK(r13);	\
 	stb	__rA,PACAIRQHAPPENED(r13)
 #endif
 #endif
arch/powerpc/include/asm/kvm_ppc.h +1 -1
index 08053e596753..028b7cefe089 100644
@@ -873,7 +873,7 @@ static inline void kvmppc_fix_ee_before_entry(void)
 
 	/* Only need to enable IRQs by hard enabling them after this */
 	local_paca->irq_happened = 0;
-	irq_soft_mask_set(IRQ_SOFT_MASK_NONE);
+	__irq_soft_mask_clear(IRQ_SOFT_MASK_ALL);
 #endif
 }
 
arch/powerpc/include/asm/paca.h +15 -3
index cd3637f4ee4e..dbf80fff2f53 100644
@@ -36,8 +36,10 @@
 register struct paca_struct *local_paca asm("r13");
 #ifdef CONFIG_PPC_BOOK3S
 
-#define R14_BIT_IO_SYNC			0x0001
-#define R14_BIT_IRQ_WORK_PENDING	0x0002 /* IRQ_WORK interrupt while soft-disable */
+#define R14_BIT_IRQ_SOFT_MASK_SHIFT	0
+#define R14_BIT_IRQ_SOFT_MASK		(0x3 << R14_BIT_IRQ_SOFT_MASK_SHIFT)
+#define R14_BIT_IO_SYNC			0x0004
+#define R14_BIT_IRQ_WORK_PENDING	0x0008 /* IRQ_WORK interrupt while soft-disable */
 
 /*
  * The top 32-bits of r14 is used as the per-cpu offset, shifted by PAGE_SHIFT.
@@ -79,6 +81,17 @@ static inline void r14_flip_bits(unsigned long mask)
 				: "0" (local_r14), "r" (mask));
 }
 
+static inline void r14_insert_bits(unsigned long source, unsigned long mask)
+{
+	unsigned long first = ffs(mask) - 1;
+	unsigned long last = fls64(mask) - 1;
+
+	mask >>= first;
+	asm volatile("rldimi	%0,%2,%3,%4\n"
+			: "=r" (local_r14)
+			: "0" (local_r14), "r" (source), "i" (first), "i" (63 - last));
+}
+
 static inline void r14_clear_bits(unsigned long mask)
 {
 	asm volatile("andc	%0,%0,%2\n"
@@ -211,7 +224,6 @@ struct paca_struct {
 	u64 saved_r1;			/* r1 save for RTAS calls or PM */
 	u64 saved_msr;			/* MSR saved here by enter_rtas */
 	u16 trap_save;			/* Used when bad stack is encountered */
-	u8 irq_soft_mask;		/* mask for irq soft masking */
 	u8 irq_happened;		/* irq happened while soft-disabled */
 	u8 nap_state_lost;		/* NV GPR values lost in power7_idle */
 	u64 sprg_vdso;			/* Saved user-visible sprg */
arch/powerpc/kernel/asm-offsets.c +6 -1
index 32d393f55a96..c5c005d354b0 100644
@@ -83,6 +83,12 @@ int main(void)
 #ifdef CONFIG_PPC64
 	DEFINE(SIGSEGV, SIGSEGV);
 	DEFINE(NMI_MASK, NMI_MASK);
+	DEFINE(R14_BIT_IRQ_SOFT_MASK_SHIFT, R14_BIT_IRQ_SOFT_MASK_SHIFT);
+	DEFINE(R14_BIT_IRQ_SOFT_MASK, R14_BIT_IRQ_SOFT_MASK);
+	DEFINE(IRQ_SOFT_MASK_STD, IRQ_SOFT_MASK_STD);
+	DEFINE(IRQ_SOFT_MASK_PMU, IRQ_SOFT_MASK_PMU);
+	DEFINE(IRQ_SOFT_MASK_ALL, IRQ_SOFT_MASK_ALL);
+
 	OFFSET(TASKTHREADPPR, task_struct, thread.ppr);
 #else
 	OFFSET(THREAD_INFO, task_struct, stack);
@@ -178,7 +184,6 @@ int main(void)
 	OFFSET(PACATOC, paca_struct, kernel_toc);
 	OFFSET(PACAKBASE, paca_struct, kernelbase);
 	OFFSET(PACAKMSR, paca_struct, kernel_msr);
-	OFFSET(PACAIRQSOFTMASK, paca_struct, irq_soft_mask);
 	OFFSET(PACAIRQHAPPENED, paca_struct, irq_happened);
 #ifdef CONFIG_PPC_BOOK3S
 	OFFSET(PACACONTEXTID, paca_struct, mm_ctx_id);
arch/powerpc/kernel/entry_64.S +9 -10
index 6b0e3ac311e8..dd06f8f874f3 100644
@@ -141,8 +141,8 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR)
 	 * is correct
 	 */
 #if defined(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG) && defined(CONFIG_BUG)
-	lbz	r10,PACAIRQSOFTMASK(r13)
-1:	tdnei	r10,IRQ_SOFT_MASK_NONE
+	andi.	r10,r14,R14_BIT_IRQ_SOFT_MASK
+1:	tdnei	r10,0
 	EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING
 #endif
 
@@ -158,7 +158,7 @@ system_call:			/* label this so stack traces look sane */
 	/* We do need to set SOFTE in the stack frame or the return
 	 * from interrupt will be painful
 	 */
-	li	r10,IRQ_SOFT_MASK_NONE
+	li	r10,0
 	std	r10,SOFTE(r1)
 
 	CURRENT_THREAD_INFO(r11, r1)
@@ -793,13 +793,12 @@ restore:
 	 * are about to re-enable interrupts
 	 */
 	ld	r5,SOFTE(r1)
-	lbz	r6,PACAIRQSOFTMASK(r13)
 	andi.	r5,r5,IRQ_SOFT_MASK_STD
 	bne	.Lrestore_irq_off
 
 	/* We are enabling, were we already enabled ? Yes, just return */
-	andi.	r6,r6,IRQ_SOFT_MASK_STD
-	beq	cr0,.Ldo_restore
+	andi.	r5,r14,IRQ_SOFT_MASK_STD
+	beq	.Ldo_restore
 
 	/*
 	 * We are about to soft-enable interrupts (we are hard disabled
@@ -817,8 +816,8 @@ restore:
 	 */
 .Lrestore_no_replay:
 	TRACE_ENABLE_INTS
-	li	r0,IRQ_SOFT_MASK_NONE
-	stb	r0,PACAIRQSOFTMASK(r13);
+	li	r0,R14_BIT_IRQ_SOFT_MASK
+	andc	r14,r14,r0
 
 	/*
 	 * Final return path. BookE is handled in a different file
@@ -1056,8 +1055,8 @@ _GLOBAL(enter_rtas)
 	/* There is no way it is acceptable to get here with interrupts enabled,
 	 * check it with the asm equivalent of WARN_ON
 	 */
-	lbz	r0,PACAIRQSOFTMASK(r13)
-1:	tdeqi	r0,IRQ_SOFT_MASK_NONE
+	andi.	r0,r14,R14_BIT_IRQ_SOFT_MASK
+1:	tdeqi	r0,0
 	EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING
 #endif
 
arch/powerpc/kernel/idle_book3s.S +3 -0
index 3b6de0ba4e03..0a7de4e13cf8 100644
@@ -510,12 +510,15 @@ pnv_powersave_wakeup:
 BEGIN_FTR_SECTION
 BEGIN_FTR_SECTION_NESTED(70)
 	bl	power9_dd1_recover_paca
+	ld	r14,PACA_R14(r13)
 END_FTR_SECTION_NESTED_IFSET(CPU_FTR_POWER9_DD1, 70)
 	bl	pnv_restore_hyp_resource_arch300
 FTR_SECTION_ELSE
 	bl	pnv_restore_hyp_resource_arch207
 ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300)
 
+	ori	r14,r14,PACA_IRQ_HARD_DIS
+
 	li	r0,PNV_THREAD_RUNNING
 	stb	r0,PACA_THREAD_IDLE_STATE(r13)	/* Clear thread state */
 
arch/powerpc/kernel/irq.c +8 -4
index e7619d144c15..2341029653e4 100644
@@ -230,10 +230,13 @@ notrace void arch_local_irq_restore(unsigned long mask)
 	unsigned int replay;
 
 	/* Write the new soft-enabled value */
-	irq_soft_mask_set(mask);
+	__irq_soft_mask_insert(mask);
+	/* any bits still disabled */
 	if (mask)
 		return;
 
+	barrier();
+
 	/*
 	 * From this point onward, we can take interrupts, preempt,
 	 * etc... unless we got hard-disabled. We check if an event
@@ -261,6 +264,7 @@ notrace void arch_local_irq_restore(unsigned long mask)
 	 * then we are already hard disabled (there are other less
 	 * common cases that we'll ignore for now), so we skip the
 	 * (expensive) mtmsrd.
+	 * XXX: why not test & IRQ_HARD_DIS?
 	 */
 	if (unlikely(irq_happened != PACA_IRQ_HARD_DIS))
 		__hard_irq_disable();
@@ -277,7 +281,7 @@ notrace void arch_local_irq_restore(unsigned long mask)
 	}
 #endif
 
-	irq_soft_mask_set(IRQ_SOFT_MASK_ALL);
+	__irq_soft_mask_set(IRQ_SOFT_MASK_ALL);
 	trace_hardirqs_off();
 
 	/*
@@ -289,7 +293,7 @@ notrace void arch_local_irq_restore(unsigned long mask)
 
 	/* We can soft-enable now */
 	trace_hardirqs_on();
-	irq_soft_mask_set(IRQ_SOFT_MASK_NONE);
+	__irq_soft_mask_clear(IRQ_SOFT_MASK_ALL);
 
 	/*
 	 * And replay if we have to. This will return with interrupts
@@ -364,7 +368,7 @@ bool prep_irq_for_idle(void)
 	 * of entering the low power state.
 	 */
 	local_paca->irq_happened &= ~PACA_IRQ_HARD_DIS;
-	irq_soft_mask_set(IRQ_SOFT_MASK_NONE);
+	__irq_soft_mask_clear(IRQ_SOFT_MASK_ALL);
 
 	/* Tell the caller to enter the low power state */
 	return true;
arch/powerpc/kernel/optprobes_head.S +1 -2
index 98a3aeeb3c8c..c8f106e6bc70 100644
@@ -58,8 +58,7 @@ optprobe_template_entry:
 	std	r5,_XER(r1)
 	mfcr	r5
 	std	r5,_CCR(r1)
-	lbz     r5,PACAIRQSOFTMASK(r13)
-	std     r5,SOFTE(r1)
+	std     r14,SOFTE(r1)
 
 	/*
 	 * We may get here from a module, so load the kernel TOC in r2.
arch/powerpc/kernel/process.c +1 -1
index f56e42f06f24..5914da5db7d9 100644
@@ -1675,7 +1675,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 			childregs->gpr[FIRST_NVGPR] = ppc_function_entry((void *)usp);
 #ifdef CONFIG_PPC64
 		clear_tsk_thread_flag(p, TIF_32BIT);
-		childregs->softe = IRQ_SOFT_MASK_NONE;
+		childregs->softe = 0;
 #endif
 		childregs->gpr[FIRST_NVGPR + 1] = kthread_arg;
 		p->thread.regs = NULL;	/* no user register state */
arch/powerpc/kernel/setup_64.c +6 -5
index f4a96ebb523a..6e4f4e46b76b 100644
@@ -190,11 +190,12 @@ static void __init fixup_boot_paca(void)
 	get_paca()->cpu_start = 1;
 	/* Allow percpu accesses to work until we setup percpu data */
 	get_paca()->data_offset = 0;
-	/* Mark interrupts disabled in PACA */
-	irq_soft_mask_set(IRQ_SOFT_MASK_STD);
 	/* Set r14 and paca_r14 to zero */
 	get_paca()->r14 = 0;
 	local_r14 = get_paca()->r14;
+
+	/* Mark interrupts disabled in PACA or r14 */
+	__irq_soft_mask_set(IRQ_SOFT_MASK_STD);
 }
 
 static void __init configure_exceptions(void)
@@ -356,8 +357,8 @@ void __init early_setup(unsigned long dt_ptr)
 #ifdef CONFIG_SMP
 void early_setup_secondary(void)
 {
-	/* Mark interrupts disabled in PACA */
-	irq_soft_mask_set(IRQ_SOFT_MASK_STD);
+	/* Mark interrupts disabled in r14 */
+	__irq_soft_mask_set(IRQ_SOFT_MASK_STD);
 
 	/* Initialize the hash table or TLB handling */
 	early_init_mmu_secondary();
@@ -768,7 +769,7 @@ void __init setup_per_cpu_areas(void)
 		/* The top 48 bits are used for per-cpu data */
 		paca[cpu].r14 |= paca[cpu].data_offset << 16;
 	}
-	local_r14 = paca[smp_processor_id()].r14;
+	local_r14 |= paca[smp_processor_id()].r14;
 }
 #endif
 
arch/powerpc/kvm/book3s_hv_rmhandlers.S +1 -2
index a92ad8500917..88455123352c 100644
@@ -3249,11 +3249,10 @@ kvmppc_bad_host_intr:
 	mfctr	r4
 #endif
 	mfxer	r5
-	lbz	r6, PACAIRQSOFTMASK(r13)
 	std	r3, _LINK(r1)
 	std	r4, _CTR(r1)
 	std	r5, _XER(r1)
-	std	r6, SOFTE(r1)
+	std	r14, SOFTE(r1)
 	ld	r2, PACATOC(r13)
 	LOAD_REG_IMMEDIATE(3, 0x7265677368657265)
 	std	r3, STACK_FRAME_OVERHEAD-16(r1)
arch/powerpc/xmon/xmon.c +2 -3
index 7d2bb26ff333..d7d3885035f2 100644
@@ -1622,8 +1622,8 @@ static void excprint(struct pt_regs *fp)
 
 	printf("  current = 0x%lx\n", current);
 #ifdef CONFIG_PPC64
-	printf("  paca    = 0x%lx\t softe: %d\t irq_happened: 0x%02x\n",
-	       local_paca, local_paca->irq_soft_mask, local_paca->irq_happened);
+	printf("  paca    = 0x%lx\t r14: 0x%lx\t irq_happened: 0x%02x\n",
+	       local_paca, local_r14, local_paca->irq_happened);
 #endif
 	if (current) {
 		printf("    pid   = %ld, comm = %s\n",
@@ -2391,7 +2391,6 @@ static void dump_one_paca(int cpu)
 	DUMP(p, stab_rr, "lx");
 	DUMP(p, saved_r1, "lx");
 	DUMP(p, trap_save, "x");
-	DUMP(p, irq_soft_mask, "x");
 	DUMP(p, irq_happened, "x");
 	DUMP(p, nap_state_lost, "x");
 	DUMP(p, sprg_vdso, "llx");
Signature · 1 line
2.15.0
author reviewer
#10 lore raw

RFC PATCH 7/8 powerpc/64s: put irq_soft_mask and irq_happened bits into r14

In reply to Nicholas Piggin

This should be split into two patches. irq_happened and soft_mask. It may not be worth putting all irq_happened bits into r14, just a single "an irq did happen" bit may be good enough to then load a paca variable.

---
 arch/powerpc/include/asm/hw_irq.h    | 23 +++++++++----
 arch/powerpc/include/asm/irqflags.h  | 21 +++++-------
 arch/powerpc/include/asm/kvm_ppc.h   |  4 +--
 arch/powerpc/include/asm/paca.h      |  7 ++--
 arch/powerpc/kernel/asm-offsets.c    |  9 +++++-
 arch/powerpc/kernel/entry_64.S       | 13 ++++----
 arch/powerpc/kernel/exceptions-64s.S |  4 +--
 arch/powerpc/kernel/head_64.S        | 15 ++-------
 arch/powerpc/kernel/irq.c            | 62 ++++++++++++++----------------------
 arch/powerpc/kvm/book3s_hv.c         |  6 ++--
 arch/powerpc/xmon/xmon.c             |  4 +--
 11 files changed, 76 insertions(+), 92 deletions(-)
arch/powerpc/include/asm/hw_irq.h +16 -7
index 9ba445de989d..f492a7779ea3 100644
@@ -22,6 +22,7 @@
  * and allow a proper replay. Additionally, PACA_IRQ_HARD_DIS
  * is set whenever we manually hard disable.
  */
+#ifdef CONFIG_PPC_BOOK3E
 #define PACA_IRQ_HARD_DIS	0x01
 #define PACA_IRQ_DBELL		0x02
 #define PACA_IRQ_EE		0x04
@@ -30,14 +31,22 @@
 #define PACA_IRQ_HMI		0x20
 #define PACA_IRQ_PMI		0x40
 
+#else /* CONFIG_PPC_BOOK3E */
 /*
- * 64s uses r14 rather than paca for irq_soft_mask
+ * 64s uses r14 rather than paca for irq_soft_mask and irq_happened
  */
-#ifdef CONFIG_PPC_BOOK3S
+
+#define PACA_IRQ_HARD_DIS	(0x01 << R14_BIT_IRQ_HAPPENED_SHIFT)
+#define PACA_IRQ_DBELL		(0x02 << R14_BIT_IRQ_HAPPENED_SHIFT)
+#define PACA_IRQ_EE		(0x04 << R14_BIT_IRQ_HAPPENED_SHIFT)
+#define PACA_IRQ_DEC		(0x08 << R14_BIT_IRQ_HAPPENED_SHIFT)
+#define PACA_IRQ_HMI		(0x10 << R14_BIT_IRQ_HAPPENED_SHIFT)
+#define PACA_IRQ_PMI		(0x20 << R14_BIT_IRQ_HAPPENED_SHIFT)
+
 #define IRQ_SOFT_MASK_STD	(0x01 << R14_BIT_IRQ_SOFT_MASK_SHIFT)
 #define IRQ_SOFT_MASK_PMU	(0x02 << R14_BIT_IRQ_SOFT_MASK_SHIFT)
 #define IRQ_SOFT_MASK_ALL	(0x03 << R14_BIT_IRQ_SOFT_MASK_SHIFT)
-#endif /* CONFIG_PPC_BOOK3S */
+#endif /* CONFIG_PPC_BOOK3E */
 
 #endif /* CONFIG_PPC64 */
 
@@ -206,14 +215,14 @@ static inline bool arch_irqs_disabled(void)
 	unsigned long flags;						\
 	__hard_irq_disable();						\
 	flags = irq_soft_mask_set_return(IRQ_SOFT_MASK_ALL);		\
-	local_paca->irq_happened |= PACA_IRQ_HARD_DIS;			\
+	r14_set_bits(PACA_IRQ_HARD_DIS);				\
 	if (!arch_irqs_disabled_flags(flags))				\
 		trace_hardirqs_off();					\
 } while(0)
 
 static inline bool lazy_irq_pending(void)
 {
-	return !!(get_paca()->irq_happened & ~PACA_IRQ_HARD_DIS);
+	return !!(local_r14 & R14_BIT_IRQ_HAPPENED_MASK & ~PACA_IRQ_HARD_DIS);
 }
 
 /*
@@ -223,8 +232,8 @@ static inline bool lazy_irq_pending(void)
  */
 static inline void may_hard_irq_enable(void)
 {
-	get_paca()->irq_happened &= ~PACA_IRQ_HARD_DIS;
-	if (!(get_paca()->irq_happened & PACA_IRQ_EE))
+	r14_clear_bits(PACA_IRQ_HARD_DIS);
+	if (!(local_r14 & PACA_IRQ_EE))
 		__hard_irq_enable();
 }
 
arch/powerpc/include/asm/irqflags.h +8 -13
index 19a2752868f8..140e51b9f436 100644
@@ -45,26 +45,21 @@
  *
  * NB: This may call C code, so the caller must be prepared for volatiles to
  * be clobbered.
+ * XXX: could make this single-register now
  */
-#define RECONCILE_IRQ_STATE(__rA, __rB)		\
-	lbz	__rB,PACAIRQHAPPENED(r13);	\
-	andi.	__rA,r14,IRQ_SOFT_MASK_STD;	\
-	ori	r14,r14,IRQ_SOFT_MASK_STD;	\
-	ori	__rB,__rB,PACA_IRQ_HARD_DIS;	\
-	stb	__rB,PACAIRQHAPPENED(r13);	\
-	bne	44f;				\
-	TRACE_DISABLE_INTS;			\
+#define RECONCILE_IRQ_STATE(__rA, __rB)					\
+	andi.	__rA,r14,IRQ_SOFT_MASK_STD;				\
+	ori	r14,r14,(PACA_IRQ_HARD_DIS | IRQ_SOFT_MASK_STD);	\
+	bne	44f;							\
+	TRACE_DISABLE_INTS;						\
 44:
 
 #else
 #define TRACE_ENABLE_INTS
 #define TRACE_DISABLE_INTS
 
-#define RECONCILE_IRQ_STATE(__rA, __rB)		\
-	lbz	__rA,PACAIRQHAPPENED(r13);	\
-	ori	r14,r14,IRQ_SOFT_MASK_STD;	\
-	ori	__rA,__rA,PACA_IRQ_HARD_DIS;	\
-	stb	__rA,PACAIRQHAPPENED(r13)
+#define RECONCILE_IRQ_STATE(__rA, __rB)					\
+	ori	r14,r14,(PACA_IRQ_HARD_DIS | IRQ_SOFT_MASK_STD)
 #endif
 #endif
 
arch/powerpc/include/asm/kvm_ppc.h +2 -2
index 028b7cefe089..45202e124003 100644
@@ -869,10 +869,10 @@ static inline void kvmppc_fix_ee_before_entry(void)
 	 * To avoid races, the caller must have gone directly from having
 	 * interrupts fully-enabled to hard-disabled.
 	 */
-	WARN_ON(local_paca->irq_happened != PACA_IRQ_HARD_DIS);
+	WARN_ON((local_r14 & R14_BIT_IRQ_HAPPENED_MASK) != PACA_IRQ_HARD_DIS);
 
 	/* Only need to enable IRQs by hard enabling them after this */
-	local_paca->irq_happened = 0;
+	r14_clear_bits(R14_BIT_IRQ_HAPPENED_MASK);
 	__irq_soft_mask_clear(IRQ_SOFT_MASK_ALL);
 #endif
 }
arch/powerpc/include/asm/paca.h +4 -3
index dbf80fff2f53..4edfcdecb268 100644
@@ -38,8 +38,10 @@ register struct paca_struct *local_paca asm("r13");
 
 #define R14_BIT_IRQ_SOFT_MASK_SHIFT	0
 #define R14_BIT_IRQ_SOFT_MASK		(0x3 << R14_BIT_IRQ_SOFT_MASK_SHIFT)
-#define R14_BIT_IO_SYNC			0x0004
-#define R14_BIT_IRQ_WORK_PENDING	0x0008 /* IRQ_WORK interrupt while soft-disable */
+#define R14_BIT_IRQ_HAPPENED_SHIFT	2
+#define R14_BIT_IRQ_HAPPENED_MASK	(0x3f << R14_BIT_IRQ_HAPPENED_SHIFT) /* irq happened while soft-disabled */
+#define R14_BIT_IO_SYNC			0x0100
+#define R14_BIT_IRQ_WORK_PENDING	0x0200 /* IRQ_WORK interrupt while soft-disable */
 
 /*
  * The top 32-bits of r14 is used as the per-cpu offset, shifted by PAGE_SHIFT.
@@ -224,7 +226,6 @@ struct paca_struct {
 	u64 saved_r1;			/* r1 save for RTAS calls or PM */
 	u64 saved_msr;			/* MSR saved here by enter_rtas */
 	u16 trap_save;			/* Used when bad stack is encountered */
-	u8 irq_happened;		/* irq happened while soft-disabled */
 	u8 nap_state_lost;		/* NV GPR values lost in power7_idle */
 	u64 sprg_vdso;			/* Saved user-visible sprg */
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
arch/powerpc/kernel/asm-offsets.c +8 -1
index c5c005d354b0..2f03f778baf2 100644
@@ -88,6 +88,14 @@ int main(void)
 	DEFINE(IRQ_SOFT_MASK_STD, IRQ_SOFT_MASK_STD);
 	DEFINE(IRQ_SOFT_MASK_PMU, IRQ_SOFT_MASK_PMU);
 	DEFINE(IRQ_SOFT_MASK_ALL, IRQ_SOFT_MASK_ALL);
+	DEFINE(R14_BIT_IRQ_HAPPENED_SHIFT, R14_BIT_IRQ_HAPPENED_SHIFT);
+	DEFINE(R14_BIT_IRQ_HAPPENED_MASK, R14_BIT_IRQ_HAPPENED_MASK);
+	DEFINE(PACA_IRQ_HARD_DIS, PACA_IRQ_HARD_DIS);
+	DEFINE(PACA_IRQ_EE, PACA_IRQ_EE);
+	DEFINE(PACA_IRQ_DBELL, PACA_IRQ_DBELL);
+	DEFINE(PACA_IRQ_DEC, PACA_IRQ_DEC);
+	DEFINE(PACA_IRQ_HMI, PACA_IRQ_HMI);
+	DEFINE(PACA_IRQ_PMI, PACA_IRQ_PMI);
 
 	OFFSET(TASKTHREADPPR, task_struct, thread.ppr);
 #else
@@ -184,7 +192,6 @@ int main(void)
 	OFFSET(PACATOC, paca_struct, kernel_toc);
 	OFFSET(PACAKBASE, paca_struct, kernelbase);
 	OFFSET(PACAKMSR, paca_struct, kernel_msr);
-	OFFSET(PACAIRQHAPPENED, paca_struct, irq_happened);
 #ifdef CONFIG_PPC_BOOK3S
 	OFFSET(PACACONTEXTID, paca_struct, mm_ctx_id);
 #ifdef CONFIG_PPC_MM_SLICES
arch/powerpc/kernel/entry_64.S +6 -7
index dd06f8f874f3..33e596d587fb 100644
@@ -805,8 +805,7 @@ restore:
 	 * at this point). We check if there's anything that needs to
 	 * be replayed first.
 	 */
-	lbz	r0,PACAIRQHAPPENED(r13)
-	cmpwi	cr0,r0,0
+	andi.	r0,r14,R14_BIT_IRQ_HAPPENED_MASK
 	bne-	.Lrestore_check_irq_replay
 
 	/*
@@ -919,16 +918,16 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	 */
 .Lrestore_irq_off:
 	ld	r3,_MSR(r1)
-	lbz	r7,PACAIRQHAPPENED(r13)
+	ori	r14,r14,IRQ_SOFT_MASK_STD
 	andi.	r0,r3,MSR_EE
 	beq	1f
-	rlwinm	r7,r7,0,~PACA_IRQ_HARD_DIS
-	stb	r7,PACAIRQHAPPENED(r13)
+	li	r0,PACA_IRQ_HARD_DIS
+	andc	r14,r14,r0
 1:
 #if defined(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG) && defined(CONFIG_BUG)
 	/* The interrupt should not have soft enabled. */
-	lbz	r7,PACAIRQSOFTMASK(r13)
-	tdeqi	r7,IRQ_SOFT_MASK_NONE
+	andi.	r7,r14,R14_BIT_IRQ_SOFT_MASK
+1:	tdeqi	r7,0
 	EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING
 #endif
 	b	.Ldo_restore
arch/powerpc/kernel/exceptions-64s.S +1 -3
index ca962bf85b8a..4da2b586e29e 100644
@@ -1404,9 +1404,7 @@ EXC_COMMON_BEGIN(soft_nmi_common)
  */
 #define MASKED_INTERRUPT(_H)				\
 masked_##_H##interrupt:					\
-	lbz	r11,PACAIRQHAPPENED(r13);		\
-	or	r11,r11,r10;				\
-	stb	r11,PACAIRQHAPPENED(r13);		\
+	or	r14,r14,r10;				\
 	cmpwi	r10,PACA_IRQ_DEC;			\
 	bne	1f;					\
 	lis	r10,0x7fff;				\
arch/powerpc/kernel/head_64.S +3 -12
index cdb710f43681..60de1aa6ef85 100644
@@ -767,10 +767,7 @@ _GLOBAL(pmac_secondary_start)
 	/* Mark interrupts soft and hard disabled (they might be enabled
 	 * in the PACA when doing hotplug)
 	 */
-	li	r0,IRQ_SOFT_MASK_STD
-	stb	r0,PACAIRQSOFTMASK(r13)
-	li	r0,PACA_IRQ_HARD_DIS
-	stb	r0,PACAIRQHAPPENED(r13)
+	ori	r14,r14,(IRQ_SOFT_MASK_STD | PACA_IRQ_HARD_DIS)
 
 	/* Create a temp kernel stack for use before relocation is on.	*/
 	ld	r1,PACAEMERGSP(r13)
@@ -824,10 +821,7 @@ __secondary_start:
 	/* Mark interrupts soft and hard disabled (they might be enabled
 	 * in the PACA when doing hotplug)
 	 */
-	li	r7,IRQ_SOFT_MASK_STD
-	stb	r7,PACAIRQSOFTMASK(r13)
-	li	r0,PACA_IRQ_HARD_DIS
-	stb	r0,PACAIRQHAPPENED(r13)
+	ori	r14,r14,(IRQ_SOFT_MASK_STD | PACA_IRQ_HARD_DIS)
 
 	/* enable MMU and jump to start_secondary */
 	LOAD_REG_ADDR(r3, start_secondary_prolog)
@@ -991,10 +985,7 @@ start_here_common:
 	/* Mark interrupts soft and hard disabled (they might be enabled
 	 * in the PACA when doing hotplug)
 	 */
-	li	r0,IRQ_SOFT_MASK_STD
-	stb	r0,PACAIRQSOFTMASK(r13)
-	li	r0,PACA_IRQ_HARD_DIS
-	stb	r0,PACAIRQHAPPENED(r13)
+	ori	r14,r14,(IRQ_SOFT_MASK_STD | PACA_IRQ_HARD_DIS)
 
 	/* Generic kernel entry */
 	bl	start_kernel
arch/powerpc/kernel/irq.c +24 -38

148 lines not on this page · raw message

arch/powerpc/kvm/book3s_hv.c +3 -3
index 2d46037ce936..870dd835c8b6 100644
@@ -2614,13 +2614,13 @@ static void set_irq_happened(int trap)
 {
 	switch (trap) {
 	case BOOK3S_INTERRUPT_EXTERNAL:
-		local_paca->irq_happened |= PACA_IRQ_EE;
+		r14_set_bits(PACA_IRQ_EE);
 		break;
 	case BOOK3S_INTERRUPT_H_DOORBELL:
-		local_paca->irq_happened |= PACA_IRQ_DBELL;
+		r14_set_bits(PACA_IRQ_DBELL);
 		break;
 	case BOOK3S_INTERRUPT_HMI:
-		local_paca->irq_happened |= PACA_IRQ_HMI;
+		r14_set_bits(PACA_IRQ_HMI);
 		break;
 	case BOOK3S_INTERRUPT_SYSTEM_RESET:
 		replay_system_reset();
arch/powerpc/xmon/xmon.c +1 -3
index d7d3885035f2..df73f8a1f030 100644
@@ -1622,8 +1622,7 @@ static void excprint(struct pt_regs *fp)
 
 	printf("  current = 0x%lx\n", current);
 #ifdef CONFIG_PPC64
-	printf("  paca    = 0x%lx\t r14: 0x%lx\t irq_happened: 0x%02x\n",
-	       local_paca, local_r14, local_paca->irq_happened);
+	printf("  paca    = 0x%lx\t r14: %lx\n", local_paca, local_r14);
 #endif
 	if (current) {
 		printf("    pid   = %ld, comm = %s\n",
@@ -2391,7 +2390,6 @@ static void dump_one_paca(int cpu)
 	DUMP(p, stab_rr, "lx");
 	DUMP(p, saved_r1, "lx");
 	DUMP(p, trap_save, "x");
-	DUMP(p, irq_happened, "x");
 	DUMP(p, nap_state_lost, "x");
 	DUMP(p, sprg_vdso, "llx");
 
Signature · 1 line
2.15.0
author reviewer
#11 lore raw

RFC PATCH 8/8 powerpc/64s: inline local_irq_enable/restore

In reply to Nicholas Piggin

This does increase kernel text size by about 0.4%, but code is often improved by putting the interrupt-replay call out of line, and gcc function "shrink wrapping" can more often avoid setting up a stack frame, e.g., _raw_spin_unlock_irqrestore fastpath before:

	<_raw_spin_unlock_irqrestore>:
	addis   r2,r12,63
	addi    r2,r2,24688
	mflr    r0
	andi.   r9,r14,256
	mr      r9,r3
	std     r0,16(r1)
	stdu    r1,-32(r1)
	bne     c0000000009fd1e0 <_raw_spin_unlock_irqrestore+0x50>
	lwsync
	li      r10,0
	mr      r3,r4
	stw     r10,0(r9)
	bl      c000000000013f98 <arch_local_irq_restore+0x8>

		<arch_local_irq_restore>:
		addis   r2,r12,222
		addi    r2,r2,-3472
		rldimi  r14,r3,0,62
		cmpdi   cr7,r3,0
		bnelr   cr7
		andi.   r9,r14,252
		beqlr

	nop
	addi    r1,r1,32
	ld      r0,16(r1)
	mtlr    r0
	blr

And after:

	<_raw_spin_unlock_irqrestore>:
	addis   r2,r12,64
	addi    r2,r2,-15200
	andi.   r9,r14,256
	bne     c000000000a06dd0 <_raw_spin_unlock_irqrestore+0x70>
	lwsync
	li      r9,0
	stw     r9,0(r3)
	rldimi  r14,r4,0,62
	cmpdi   cr7,r4,0
	bne     cr7,c000000000a06d90 <_raw_spin_unlock_irqrestore+0x30>
	andi.   r9,r14,252
	bne     c000000000a06da0 <_raw_spin_unlock_irqrestore+0x40>
	blr

GCC can still improve code size for the slow paths by avoiding aligning branch targets too, so there is room to reduce the text size cost there.

---
 arch/powerpc/include/asm/hw_irq.h | 15 +++++++++++++--
 arch/powerpc/kernel/irq.c         | 28 ++++++----------------------
 2 files changed, 19 insertions(+), 24 deletions(-)
arch/powerpc/include/asm/hw_irq.h +13 -2
index f492a7779ea3..8690e0d5605d 100644
@@ -132,11 +132,22 @@ static inline void arch_local_irq_disable(void)
 	irq_soft_mask_set(IRQ_SOFT_MASK_STD);
 }
 
-extern void arch_local_irq_restore(unsigned long);
+extern void __arch_local_irq_enable(void);
 
 static inline void arch_local_irq_enable(void)
 {
-	arch_local_irq_restore(0);
+	__irq_soft_mask_clear(IRQ_SOFT_MASK_ALL);
+	if (unlikely(local_r14 & R14_BIT_IRQ_HAPPENED_MASK))
+		__arch_local_irq_enable();
+}
+
+static inline void arch_local_irq_restore(unsigned long flags)
+{
+	__irq_soft_mask_insert(flags);
+	if (!flags) {
+		if (unlikely(local_r14 & R14_BIT_IRQ_HAPPENED_MASK))
+			__arch_local_irq_enable();
+	}
 }
 
 static inline unsigned long arch_local_irq_save(void)
arch/powerpc/kernel/irq.c +6 -22
index ebaf210a7406..e2ff0210477e 100644
@@ -97,11 +97,6 @@ extern int tau_interrupts(int);
 
 int distribute_irqs = 1;
 
-static inline notrace unsigned long get_irq_happened(void)
-{
-	return local_r14 & R14_BIT_IRQ_HAPPENED_MASK;
-}
-
 static inline notrace int decrementer_check_overflow(void)
 {
  	u64 now = get_tb_or_rtc();
@@ -210,19 +205,10 @@ notrace unsigned int __check_irq_replay(void)
 	return 0;
 }
 
-notrace void arch_local_irq_restore(unsigned long mask)
+notrace void __arch_local_irq_enable(void)
 {
-	unsigned char irq_happened;
 	unsigned int replay;
 
-	/* Write the new soft-enabled value */
-	__irq_soft_mask_insert(mask);
-	/* any bits still disabled */
-	if (mask)
-		return;
-
-	barrier();
-
 	/*
 	 * From this point onward, we can take interrupts, preempt,
 	 * etc... unless we got hard-disabled. We check if an event
@@ -236,9 +222,6 @@ notrace void arch_local_irq_restore(unsigned long mask)
 	 * be hard-disabled, so there is no problem, we
 	 * cannot have preempted.
 	 */
-	irq_happened = get_irq_happened();
-	if (!irq_happened)
-		return;
 
 	/*
 	 * We need to hard disable to get a trusted value from
@@ -252,10 +235,11 @@ notrace void arch_local_irq_restore(unsigned long mask)
 	 * (expensive) mtmsrd.
 	 * XXX: why not test & IRQ_HARD_DIS?
 	 */
-	if (unlikely(irq_happened != PACA_IRQ_HARD_DIS))
+	if (unlikely((local_r14 & R14_BIT_IRQ_HAPPENED_MASK) !=
+						PACA_IRQ_HARD_DIS)) {
 		__hard_irq_disable();
 #ifdef CONFIG_PPC_IRQ_SOFT_MASK_DEBUG
-	else {
+	} else {
 		/*
 		 * We should already be hard disabled here. We had bugs
 		 * where that wasn't the case so let's dbl check it and
@@ -264,8 +248,8 @@ notrace void arch_local_irq_restore(unsigned long mask)
 		 */
 		if (WARN_ON(mfmsr() & MSR_EE))
 			__hard_irq_disable();
-	}
 #endif
+	}
 
 	__irq_soft_mask_set(IRQ_SOFT_MASK_ALL);
 	trace_hardirqs_off();
@@ -293,7 +277,7 @@ notrace void arch_local_irq_restore(unsigned long mask)
 	/* Finally, let's ensure we are hard enabled */
 	__hard_irq_enable();
 }
-EXPORT_SYMBOL(arch_local_irq_restore);
+EXPORT_SYMBOL(__arch_local_irq_enable);
 
 /*
  * This is specifically called by assembly code to re-enable interrupts
Signature · 1 line
2.15.0