Hi Hongbo,
On 03/16/2016 03:47 PM, Hongbo Zhang wrote:
Hi Dongsheng,
-----Original Message-----
From: Chenhui Zhao
Sent: Wednesday, March 16, 2016 3:05 PM
To: Hongbo Zhang <hongbo.zh...@nxp.com>
Cc: tr...@konsulko.com; sba...@denx.de; i...@hellion.org.uk;
hdego...@redhat.com; twar...@nvidia.com; Huan Wang
<alison.w...@nxp.com>; york sun <york....@nxp.com>;
jan.kis...@siemens.com; Frank Li <frank...@nxp.com>; Peng Fan
<peng....@nxp.com>; Zhengxiong Jin <jason....@nxp.com>;
o...@buserror.net; u-boot@lists.denx.de; albert.u.b...@aribaud.net
Subject: Re: [PATCH 3/9] ARM: ARMv7: PSCI: move target PC in each CPU stack
no longer is shared
Add Hongbo.
Thanks,
Chenhui
________________________________________
From: Dongsheng Wang <dongsheng.w...@nxp.com>
Sent: Monday, January 18, 2016 12:27 PM
To: albert.u.b...@aribaud.net
Cc: tr...@konsulko.com; sba...@denx.de; i...@hellion.org.uk;
hdego...@redhat.com; twar...@nvidia.com; Huan Wang; york sun;
jan.kis...@siemens.com; Frank Li; Peng Fan; Zhengxiong Jin; Chenhui Zhao;
o...@buserror.net; u-boot@lists.denx.de; Dongsheng Wang
Subject: [PATCH 3/9] ARM: ARMv7: PSCI: move target PC in each CPU stack no
longer is shared
From: Wang Dongsheng <dongsheng.w...@nxp.com>
All of cpu share the same targetPC space that is unsafe. So move target PC save
space into CPU stack.
Signed-off-by: Wang Dongsheng <dongsheng.w...@nxp.com>
---
arch/arm/cpu/armv7/ls102xa/psci.S | 4 +--
arch/arm/cpu/armv7/mx7/psci.S | 4 +--
arch/arm/cpu/armv7/psci.S | 51 ++++++++++++++++++++++++++++----
---
arch/arm/cpu/armv7/sunxi/psci_sun6i.S | 4 +--
arch/arm/cpu/armv7/sunxi/psci_sun7i.S | 4 +--
arch/arm/cpu/armv7/virt-dt.c | 3 ++-
arch/arm/include/asm/psci.h | 4 +++
arch/arm/mach-tegra/psci.S | 4 +--
8 files changed, 53 insertions(+), 25 deletions(-)
diff --git a/arch/arm/cpu/armv7/ls102xa/psci.S
b/arch/arm/cpu/armv7/ls102xa/psci.S
index 0b067d9..3a34064 100644
--- a/arch/arm/cpu/armv7/ls102xa/psci.S
+++ b/arch/arm/cpu/armv7/ls102xa/psci.S
@@ -36,9 +36,7 @@ psci_cpu_on:
and r1, r1, #0xff
mov r0, r1
- bl psci_get_cpu_stack_top
- str r2, [r0]
- dsb
+ bl psci_save_target_pc
@ Get DCFG base address
movw r4, #(CONFIG_SYS_FSL_GUTS_ADDR & 0xffff)
diff --git a/arch/arm/cpu/armv7/mx7/psci.S b/arch/arm/cpu/armv7/mx7/psci.S
index 34c6ab3..cb39f27 100644
--- a/arch/arm/cpu/armv7/mx7/psci.S
+++ b/arch/arm/cpu/armv7/mx7/psci.S
@@ -30,9 +30,7 @@ psci_cpu_on:
push {lr}
mov r0, r1
- bl psci_get_cpu_stack_top
- str r2, [r0]
- dsb
+ bl psci_save_target_pc
ldr r2, =psci_cpu_entry
bl imx_cpu_on
diff --git a/arch/arm/cpu/armv7/psci.S b/arch/arm/cpu/armv7/psci.S index
2425f6a..0e0f98e 100644
--- a/arch/arm/cpu/armv7/psci.S
+++ b/arch/arm/cpu/armv7/psci.S
@@ -20,6 +20,8 @@
#include <asm/macro.h>
#include <asm/psci.h>
+#define SAVE_SPACE_TARGET_PC_OFFSET 0x0
+
.pushsection ._secure.text, "ax"
.arch_extension sec
@@ -196,27 +198,58 @@ 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
-
+ @ Align psci_text_end minumum page size. Even if page is greater than
+ @ 4K, we still can ensure that data is always safe access by the CPU.
ldr r5, =psci_text_end @ end of monitor text
- add r5, r5, #0x2000 @ Skip two pages
- lsr r5, r5, #12 @ Align to start of page
+ @ Detect page border
+ lsl r4, r5, #20
Why do you shift it 20 bits? I guess you wanted to shift 12 bits instead.
Shift left 20bits will get the low of 12bits that is page border. if the
12 bits of value is 0,
this means that we stand in the page border. And not need to do align page.
+ cmp r4, #0
+ beq out_psci_stack_align
+ add r5, r5, #PSCI_STACK_ALIGN_SIZE
+ lsr r5, r5, #12
lsl r5, r5, #12
- sub r5, r5, #4 @ reserve 1 word for target PC
- sub r0, r5, r0 @ here's our stack!
+
+out_psci_stack_align:
+ mov r4, #PSCI_PERCPU_STACK_SIZE
+ add r0, r0, #1
+ mul r0, r0, r4
+ add r0, r0, r5
bx lr
ENDPROC(psci_get_cpu_stack_top)
+@ Save space in percpu stack tail.
+@ expects CPU ID in r0 and returns save space address in r0.
+ENTRY(psci_get_cpu_save_space)
It is better to use term "reserve" here instead of "save"
s/save/reserve/, thanks.
+ mov r10, lr
+
+ bl psci_get_cpu_stack_top
+ sub r0, r0, #PSCI_PERCPU_STACK_SIZE
(r0 - PSCI_PERCPU_STACK_SIZE ) is stack top of next CPU's stack.
(r0 - PSCI_PERCPU_STACK_SIZE +1 ) is the stack tail you want, right?
Yes, :)
Regards,
-Dongsheng
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