arm: socfpga: fix fetching cpu1start_addr for system with > 2GB of ram
Subsystems (3)
PATCH v2 1/1 arm: socfpga: fix fetching cpu1start_addr for system with > 2GB of ram
From: Dinh Nguyen <[email protected]>
When CPU1 is brought out of reset, it's MMU is not turned yet, so it will only be able to use physical addresses. For systems with 1GB or less, clearing 0x40000000 will work just fine, as it was just converting the virtual address of &cpu1start_addr into a physical address. But for systems with > 2BG, bit clearing 0x40000000 is not enough to get the physical address of &cpu1start_addr correctly.
This patch fixes the secondary_trampoline code to correctly fetch the physical address of cpu1start_addr directly.
While at it, change the name of cpu1start_addr to socfpga_cpu1start_addr to avoid any future naming collisions for multiplatform image.
---
v2: Correctly get the physical address instead of just a BIC hack.
--- arch/arm/mach-socfpga/core.h | 2 +- arch/arm/mach-socfpga/headsmp.S | 13 +++++-------- arch/arm/mach-socfpga/platsmp.c | 5 +++-- arch/arm/mach-socfpga/socfpga.c | 3 +-- 4 files changed, 10 insertions(+), 13 deletions(-)
arch/arm/mach-socfpga/core.h +1 -1
@@ -40,7 +40,7 @@ extern void __iomem *rst_manager_base_addr;extern struct smp_operations socfpga_smp_ops;extern char secondary_trampoline, secondary_trampoline_end; -extern unsigned long cpu1start_addr; +extern unsigned long socfpga_cpu1start_addr;#define SOCFPGA_SCU_VIRT_BASE 0xfffec000
arch/arm/mach-socfpga/headsmp.S +5 -8
@@ -13,17 +13,14 @@ .arch armv7-a ENTRY(secondary_trampoline) - movw r2, #:lower16:cpu1start_addr - movt r2, #:upper16:cpu1start_addr - - /* The socfpga VT cannot handle a 0xC0000000 page offset when loading - the cpu1start_addr, we bit clear it. Tested on HW and VT. */ - bic r2, r2, #0x40000000 - - ldr r0, [r2] + ldr r0, 1f ldr r1, [r0] bx r1 + .globl socfpga_cpu1start_addr +socfpga_cpu1start_addr: +1: .space 4 + ENTRY(secondary_trampoline_end) ENTRY(socfpga_secondary_startup)
arch/arm/mach-socfpga/platsmp.c +3 -2
@@ -33,11 +33,12 @@ static int socfpga_boot_secondary(unsigned int cpu, struct task_struct *idle) {int trampoline_size = &secondary_trampoline_end - &secondary_trampoline; -if (cpu1start_addr) { +if (socfpga_cpu1start_addr) {memcpy (phys_to_virt (0 ), &secondary_trampoline, trampoline_size);__raw_writel (virt_to_phys (socfpga_secondary_startup), - (sys_manager_base_addr + (cpu1start_addr &0x000000ff ))); + (sys_manager_base_addr + (socfpga_cpu1start_addr + &0x000000ff )));flush_cache_all ();smp_wmb ();
arch/arm/mach-socfpga/socfpga.c +1 -2
@@ -29,7 +29,6 @@void __iomem *socfpga_scu_base_addr = ((void __iomem *)(SOCFPGA_SCU_VIRT_BASE ));void __iomem *sys_manager_base_addr;void __iomem *rst_manager_base_addr; -unsigned long cpu1start_addr;static struct map_desc scu_io_desc__initdata = { .virtual =SOCFPGA_SCU_VIRT_BASE ,
@@ -70,7 +69,7 @@ void __init socfpga_sysmgr_init(void) np =of_find_compatible_node (NULL ,NULL ,"altr,sys-mgr" );if (of_property_read_u32 (np,"cpu1-start-addr" , - (u32 *) &cpu1start_addr)) + (u32 *) &socfpga_cpu1start_addr))pr_err ("SMP: Need cpu1-start-addr in device tree.\n" ); sys_manager_base_addr =of_iomap (np,0 );
Signature · 1 line
2.0.3
PATCH v2 1/1 arm: socfpga: fix fetching cpu1start_addr for system with > 2GB of ram
Quoted 9 lines · dinguyen at opensource.altera.com
From: Dinh Nguyen <[email protected]>
When CPU1 is brought out of reset, it's MMU is not turned yet, so it will only be able to use physical addresses. For systems with 1GB or less, clearing
0x40000000will work just fine, as it was just converting the virtual address of&cpu1start_addrinto a physical address. But for systems with > 2BG, bit clearing0x40000000is not enough to get the physical address of&cpu1start_addrcorrectly.
Quoted 5 lines
This patch fixes the
secondary_trampolinecode to correctly fetch the physical address ofcpu1start_addrdirectly.While at it, change the name of
cpu1start_addrtosocfpga_cpu1start_addrto avoid any future naming collisions for multiplatform image.
I'm still not happy with this. I see why my suggestion didn't work, but this is still pretty dire - and will break when we add read-only text support to the kernel (you are writing into the text segment.)
The reason my suggestion broke is because you aren't executing the code in the kernel, you're copying it into SRAM and executing it there. I think you need to come up with some way to locate the physical address in the SRAM, either before or after the function you're copying there.
Signature · 2 lines
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PATCH v2 1/1 arm: socfpga: fix fetching cpu1start_addr for system with > 2GB of ram
Hi Russell,
Quoted 16 lines · Russell King - ARM Linux
Quoted 9 lines · dinguyen at opensource.altera.com
From: Dinh Nguyen <[email protected]>
When CPU1 is brought out of reset, it's MMU is not turned yet, so it will only be able to use physical addresses. For systems with 1GB or less, clearing
0x40000000will work just fine, as it was just converting the virtual address of&cpu1start_addrinto a physical address. But for systems with > 2BG, bit clearing0x40000000is not enough to get the physical address of&cpu1start_addrcorrectly.Quoted 5 lines
This patch fixes the
secondary_trampolinecode to correctly fetch the physical address ofcpu1start_addrdirectly.While at it, change the name of
cpu1start_addrtosocfpga_cpu1start_addrto avoid any future naming collisions for multiplatform image.
Quoted 9 lines
I'm still not happy with this. I see why my suggestion didn't work, but this is still pretty dire - and will break when we add read-only text support to the kernel (you are writing into the text segment.)
The reason my suggestion broke is because you aren't executing the code in the kernel, you're copying it into SRAM and executing it there. I think you need to come up with some way to locate the physical address in the SRAM, either before or after the function you're copying there.
This seems to also work. What do you think?
ENTRY(secondary_trampoline)
adr r0, 1f
ldmia r0, {r1, r2}
sub r2, r2, #PAGE_OFFSET
ldr r3, [r2]
ldr r4, [r3]
bx r4 .align
1: .long .
.long cpu1start_addrENTRY(secondary_trampoline_end)