[U-Boot] [PATCH v4 2/9] ARMv7: PSCI: update function psci_get_cpu_stack_top

[Hongbo Zhang]

Hi York,
Which version of u-boot do you use? I don't have such problem.
I was using the latest u-boot (when I re-worked this patch set), it was
e4a94ce Merge git://git.denx.de/u-boot-dm
but there is some thing wrong that this version of u-boot cannot load
my kernel properly, so I went a little backward to
c7757d4 arm: meson: implement calls to secure monitor
because I need Beniamino's commits.
The above two patch sets are identical, and there is no such compiling
error for me, and I've tested the later.


On Sat, Jun 4, 2016 at 3:44 AM, York Sun <york.sun at nxp.com> wrote:
> On 06/02/2016 01:07 AM, macro.wave.z at gmail.com wrote:
>> From: Hongbo Zhang <hongbo.zhang at 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 at nxp.com>
>> Signed-off-by: Wang Dongsheng <dongsheng.wang at 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
>
> This causes a compiling error
>
> +(mx7dsabresd) ../arch/arm/cpu/armv7/virt-dt.c: In function ‘psci_update_dt’:
> +(mx7dsabresd) ../arch/arm/cpu/armv7/virt-dt.c:132:12: error: ‘CONFIG_MAX_CPUS’
> undeclared (first use in this function)
> +(mx7dsabresd) ../arch/arm/cpu/armv7/virt-dt.c:132:12: note: each undeclared
> identifier is reported only once for each function it appears in
>
> York