From: Hongbo Zhang hongbo.zhang@nxp.com
There are issues of legacy fuction psci_get_cpu_stack_top:
First, the current algorithm arranges stacks from an fixed adress towards psci_text_end, if there are more CPUs, the stacks will overlap with psci text segment and even other segments. This patch places stacks from psci text segment towards highter address, and all the stack space is reserved, so overlap can be avoided.
Second, even there is one word reserved in each stack for saving target PC, but this reserved space isn't used at all, the target PC is still saved to where the stack top pointer points. This patch doesn't reserve this word as before, new way of saving target PC will be introduced in following patch.
Signed-off-by: Hongbo Zhang hongbo.zhang@nxp.com Signed-off-by: Wang Dongsheng dongsheng.wang@nxp.com --- arch/arm/cpu/armv7/psci.S | 10 +++++----- arch/arm/cpu/armv7/virt-dt.c | 9 +++++++-- arch/arm/include/asm/psci.h | 3 +++ 3 files changed, 15 insertions(+), 7 deletions(-)
diff --git a/arch/arm/cpu/armv7/psci.S b/arch/arm/cpu/armv7/psci.S index 8e25300..91a1dd1 100644 --- a/arch/arm/cpu/armv7/psci.S +++ b/arch/arm/cpu/armv7/psci.S @@ -274,16 +274,16 @@ ENDPROC(psci_cpu_off_common)
@ expects CPU ID in r0 and returns stack top in r0 ENTRY(psci_get_cpu_stack_top) - mov r5, #0x400 @ 1kB of stack per CPU - mul r0, r0, r5 + mov r5, #PSCI_PERCPU_STACK_SIZE @ 1kB of stack per CPU + add r0, r0, #1 + mul r0, r0, r5 @ offset of each stack
ldr r5, =psci_text_end @ end of monitor text - add r5, r5, #0x2000 @ Skip two pages + add r5, r5, #0x1000 @ Skip one page lsr r5, r5, #12 @ Align to start of page lsl r5, r5, #12 - sub r5, r5, #4 @ reserve 1 word for target PC - sub r0, r5, r0 @ here's our stack!
+ add r0, r5, r0 @ here's our stack! bx lr ENDPROC(psci_get_cpu_stack_top)
diff --git a/arch/arm/cpu/armv7/virt-dt.c b/arch/arm/cpu/armv7/virt-dt.c index 5e31891..4fe6f58 100644 --- a/arch/arm/cpu/armv7/virt-dt.c +++ b/arch/arm/cpu/armv7/virt-dt.c @@ -127,14 +127,19 @@ int armv7_apply_memory_carveout(u64 *start, u64 *size)
int psci_update_dt(void *fdt) { + size_t sec_sz = __secure_end - __secure_start; +#ifdef CONFIG_ARMV7_PSCI + sec_sz += CONFIG_MAX_CPUS * PSCI_PERCPU_STACK_SIZE; + /* margin to align psci_text_end to page end*/ + sec_sz += 0x1000; +#endif #ifdef CONFIG_ARMV7_NONSEC if (!armv7_boot_nonsec()) return 0; #endif #ifndef CONFIG_ARMV7_SECURE_BASE /* secure code lives in RAM, keep it alive */ - fdt_add_mem_rsv(fdt, (unsigned long)__secure_start, - __secure_end - __secure_start); + fdt_add_mem_rsv(fdt, (unsigned long)__secure_start, sec_sz); #endif
return fdt_psci(fdt); diff --git a/arch/arm/include/asm/psci.h b/arch/arm/include/asm/psci.h index 2367ec0..76c3c92 100644 --- a/arch/arm/include/asm/psci.h +++ b/arch/arm/include/asm/psci.h @@ -63,6 +63,9 @@ #define ARM_PSCI_1_0_FN_STAT_RESIDENCY ARM_PSCI_0_2_FN(16) #define ARM_PSCI_1_0_FN_STAT_COUNT ARM_PSCI_0_2_FN(17)
+/* size of percpu stack, 1kB */ +#define PSCI_PERCPU_STACK_SIZE 0x400 + #ifndef __ASSEMBLY__ int psci_update_dt(void *fdt); void psci_board_init(void);