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

[Hongbo Zhang]

On Mon, Jun 6, 2016 at 11:43 AM, Chen-Yu Tsai <wens at csie.org> wrote:
> Hi,
>
> On Mon, Jun 6, 2016 at 11:27 AM, Hongbo Zhang <macro.wave.z at gmail.com> wrote:
>> 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.
>
> CONFIG_MAX_CPUS is not defined for all platforms.
>
> On sunxi and mx7, we use CONFIG_ARMV7_PSCI_NR_CPUS.
>
> ChenYu
>

Hi,
Thanks for pointing it out, I see.
That means we don't have a unique macro for number of CPUs, it is time
to define it now, CONFIG_ARMV7_PSCI_NR_CPUS is better?

>
>>
>> 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