x86-64 move thread_info into task_struct

PATCH In review Benjamin LaHaise 1 participant 1 message Nov 30, 2005

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Benjamin LaHaise

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2005-11-30 04:26 UTC #0 lore raw

PATCH 7/9 x86-64 move thread_info into task_struct

On x86-64, move thread_info from the stack into task_struct. This has benefits for the use of registers in entry.S when current is moved into a register. Take the easy approach of making GET_THREAD_INFO() return a pointer to current and make the asm-offset.c aware of this new usage.

---

 arch/i386/oprofile/nmi_int.c         |    1 +
 arch/x86_64/kernel/asm-offsets.c     |    2 +-
 arch/x86_64/kernel/genapic_cluster.c |    1 +
 arch/x86_64/kernel/genapic_flat.c    |    1 +
 arch/x86_64/kernel/setup64.c         |    2 +-
 include/asm-x86_64/desc.h            |    1 +
 include/asm-x86_64/processor.h       |   10 +++-------
 include/asm-x86_64/system.h          |    6 ++----
 include/asm-x86_64/thread_info.h     |   31 ++++++++++++++-----------------
 9 files changed, 25 insertions(+), 30 deletions(-)

applies-to: 747a43be5747e1c8e25f5769bdb9e4a1b8029138 bb489ebe1733165426cbbaba24a2ed51d6952d88

arch/i386/oprofile/nmi_int.c +1 -0

index 0493e8b..1e91d22 100644
@@ -13,6 +13,7 @@
 #include <linux/oprofile.h>
 #include <linux/sysdev.h>
 #include <linux/slab.h>
+#include <linux/sched.h>
 #include <asm/nmi.h>
 #include <asm/msr.h>
 #include <asm/apic.h>

arch/x86_64/kernel/asm-offsets.c +1 -1

index aaa6d38..66ebe60 100644
@@ -29,7 +29,7 @@ int main(void)
 	ENTRY(pid);
 	BLANK();
 #undef ENTRY
-#define ENTRY(entry) DEFINE(threadinfo_ ## entry, offsetof(struct thread_info, entry))
+#define ENTRY(entry) DEFINE(threadinfo_ ## entry, offsetof(struct task_struct, thread.info.entry))
 	ENTRY(flags);
 	ENTRY(addr_limit);
 	ENTRY(preempt_count);

arch/x86_64/kernel/genapic_cluster.c +1 -0

index a472d62..42531a9 100644
@@ -16,6 +16,7 @@
 #include <linux/kernel.h>
 #include <linux/ctype.h>
 #include <linux/init.h>
+#include <linux/sched.h>
 #include <asm/smp.h>
 #include <asm/ipi.h>

arch/x86_64/kernel/genapic_flat.c +1 -0

index 9da3edb..28b775f 100644
@@ -15,6 +15,7 @@
 #include <linux/kernel.h>
 #include <linux/ctype.h>
 #include <linux/init.h>
+#include <linux/sched.h>
 #include <asm/smp.h>
 #include <asm/ipi.h>

arch/x86_64/kernel/setup64.c +1 -1

index 06dc354..3e81a04 100644
@@ -126,7 +126,7 @@ void pda_init(int cpu)
 	pda->cpunumber = cpu; 
 	pda->irqcount = -1;
 	pda->kernelstack = 
-		(unsigned long)stack_thread_info() - PDA_STACKOFFSET + THREAD_SIZE; 
+		(unsigned long)current->thread_info - PDA_STACKOFFSET + THREAD_SIZE; 
 	pda->active_mm = &init_mm;
 	pda->mmu_state = 0;

include/asm-x86_64/desc.h +1 -0

index 3376486..ece54d4 100644
@@ -9,6 +9,7 @@
 
 #include <linux/string.h>
 #include <linux/smp.h>
+#include <linux/sched.h>
 
 #include <asm/segment.h>
 #include <asm/mmu.h>

include/asm-x86_64/processor.h +3 -7

index 4861246..7f24beb 100644
@@ -20,6 +20,7 @@
 #include <asm/mmsegment.h>
 #include <asm/percpu.h>
 #include <linux/personality.h>
+#include <linux/thread_info.h>
 
 #define TF_MASK		0x00000100
 #define IF_MASK		0x00000200

@@ -230,6 +231,7 @@ DECLARE_PER_CPU(struct tss_struct,init_t
 #define ARCH_MIN_TASKALIGN	16
 
 struct thread_struct {
+	struct thread_info info;
 	unsigned long	rsp0;
 	unsigned long	rsp;
 	unsigned long 	userrsp;	/* Copy from PDA */

@@ -257,6 +259,7 @@ struct thread_struct {
 } __attribute__((aligned(16)));
 
 #define INIT_THREAD  { \
+	.info = INIT_THREAD_INFO(init_task), \
 	.rsp0 = (unsigned long)&init_stack + sizeof(init_stack) \
 }

@@ -467,13 +470,6 @@ static inline void __mwait(unsigned long
 		: :"a" (eax), "c" (ecx));
 }
 
-#define stack_current() \
-({								\
-	struct thread_info *ti;					\
-	asm("andq %%rsp,%0; ":"=r" (ti) : "0" (CURRENT_MASK));	\
-	ti->task;					\
-})
-
 #define cache_line_size() (boot_cpu_data.x86_cache_alignment)
 
 extern unsigned long boot_option_idle_override;

include/asm-x86_64/system.h +2 -4

index 85348e0..d2cbbc3 100644
@@ -34,17 +34,15 @@
 		     ".globl thread_return\n"					\
 		     "thread_return:\n\t"					    \
 		     "movq %%gs:%P[pda_pcurrent],%%rsi\n\t"			  \
-		     "movq %P[thread_info](%%rsi),%%r8\n\t"			  \
-		     LOCK "btr  %[tif_fork],%P[ti_flags](%%r8)\n\t"		  \
+		     LOCK "btr  %[tif_fork],%P[ti_flags](%%rsi)\n\t"		  \
 		     "movq %%rax,%%rdi\n\t" 					  \
 		     "jc   ret_from_fork\n\t"					  \
 		     RESTORE_CONTEXT						    \
 		     : "=a" (last)					  	  \
 		     : [next] "S" (next), [prev] "D" (prev),			  \
 		       [threadrsp] "i" (offsetof(struct task_struct, thread.rsp)), \
-		       [ti_flags] "i" (offsetof(struct thread_info, flags)),\
+		       [ti_flags] "i" (offsetof(struct task_struct, thread.info.flags)),\
 		       [tif_fork] "i" (TIF_FORK),			  \
-		       [thread_info] "i" (offsetof(struct task_struct, thread_info)), \
 		       [pda_pcurrent] "i" (offsetof(struct x8664_pda, pcurrent))   \
 		     : "memory", "cc" __EXTRA_CLOBBER)

include/asm-x86_64/thread_info.h +14 ~~-17~~

index 08eb6e4..0c90a18 100644
@@ -57,20 +57,16 @@ struct thread_info {
 #define init_thread_info	(init_thread_union.thread_info)
 #define init_stack		(init_thread_union.stack)
 
-static inline struct thread_info *current_thread_info(void)
-{ 
-	struct thread_info *ti;
-	ti = (void *)(read_pda(kernelstack) + PDA_STACKOFFSET - THREAD_SIZE);
-	return ti; 
-}
-
-/* do not use in interrupt context */
-static inline struct thread_info *stack_thread_info(void)
-{
-	struct thread_info *ti;
-	__asm__("andq %%rsp,%0; ":"=r" (ti) : "0" (~(THREAD_SIZE - 1)));
-	return ti;
-}
+#define task_thread_info(t)	(&(t)->thread.info)
+#define current_thread_info()	task_thread_info(current)
+
+#define setup_thread_stack(p, org) ({			\
+	task_thread_info(p)->task = (p);		\
+})
+
+#define end_of_stack(p)		((unsigned long *)(p)->thread_info + 1)
+
+#define __HAVE_THREAD_FUNCTIONS
 
 /* thread information allocation */
 #define alloc_thread_info(tsk) \

@@ -81,10 +77,11 @@ static inline struct thread_info *stack_
 
 #else /* !__ASSEMBLY__ */
 
-/* how to get the thread information struct from ASM */
+/* How to get the thread information struct from ASM.  We use a pointer to
+ * current and make the asm offsets point to * ->thread.info.<field>
+ */
 #define GET_THREAD_INFO(reg) \
-	movq %gs:pda_kernelstack,reg ; \
-	subq $(THREAD_SIZE-PDA_STACKOFFSET),reg
+	movq %gs:pda_pcurrent,reg
 
 #endif

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0.99.9.GIT