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arch: arm: cortex_m: pm_s2ram: use macros to access struct __cpu_context

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Use macros to wrap the interaction between the assembly code and the
struct __cpu_context. This helps making the assembly more readable.

Signed-off-by: Mathieu Choplain <mathieu.choplain@st.com>
This commit is contained in:
Mathieu Choplain 2024-11-04 13:17:57 +01:00 • committed by Anas Nashif
commit 041714cb37
1 changed files with 40 additions and 32 deletions
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72
arch/arm/core/cortex_m/pm_s2ram.S
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@ -14,6 +14,30 @@
#include <zephyr/arch/cpu.h>
#include <zephyr/arch/common/pm_s2ram.h>
/**
* Macro expanding to an integer literal equal to the offset of
* field `sr_name` in `struct __cpu_context`. This macro has to
* be implemented in C, because GEN_OFFSET_SYM provides offsets
* as C preprocessor definitions - there are not visible to the
* assembler.
*
* See also: `arch/arm/core/offsets/offsets_aarch32.c`
*/
#define CPU_CTX_SR_OFFSET(sr_name) \
___cpu_context_t_ ## sr_name ## _OFFSET
/**
* Macros used to save / load a special register in __cpu_context.
* These also have to be implemented in C due to CPU_CTX_SR_OFFSET.
*/
#define SAVE_SPECIAL_REG(sr_name, cpu_ctx_reg, tmp_reg) \
mrs tmp_reg, sr_name; \
str tmp_reg, [cpu_ctx_reg, # CPU_CTX_SR_OFFSET(sr_name)];
#define RESTORE_SPECIAL_REG(sr_name, cpu_ctx_reg, tmp_reg) \
ldr tmp_reg, [cpu_ctx_reg, # CPU_CTX_SR_OFFSET(sr_name)]; \
msr sr_name, tmp_reg;
_ASM_FILE_PROLOGUE
GTEXT(pm_s2ram_mark_set)
@ -34,29 +58,21 @@ SECTION_FUNC(TEXT, arch_pm_s2ram_suspend)
/* Store CPU context */
ldr r1, =_cpu_context
mrs r2, msp
str r2, [r1, #___cpu_context_t_msp_OFFSET]
SAVE_SPECIAL_REG(msp, r1, r2)
mrs r2, msplim
str r2, [r1, #___cpu_context_t_msplim_OFFSET]
SAVE_SPECIAL_REG(msplim, r1, r2)
mrs r2, psp
str r2, [r1, #___cpu_context_t_psp_OFFSET]
SAVE_SPECIAL_REG(psp, r1, r2)
mrs r2, psplim
str r2, [r1, #___cpu_context_t_psplim_OFFSET]
SAVE_SPECIAL_REG(psplim, r1, r2)
mrs r2, primask
str r2, [r1, #___cpu_context_t_primask_OFFSET]
SAVE_SPECIAL_REG(primask, r1, r2)
mrs r2, faultmask
str r2, [r1, #___cpu_context_t_faultmask_OFFSET]
SAVE_SPECIAL_REG(faultmask, r1, r2)
mrs r2, basepri
str r2, [r1, #___cpu_context_t_basepri_OFFSET]
SAVE_SPECIAL_REG(basepri, r1, r2)
mrs r2, control
str r2, [r1, #___cpu_context_t_control_OFFSET]
SAVE_SPECIAL_REG(control, r1, r2)
/*
* Mark entering suspend to RAM.
@ -108,29 +124,21 @@ resume:
*/
ldr r0, =_cpu_context
ldr r1, [r0, #___cpu_context_t_msp_OFFSET]
msr msp, r1
RESTORE_SPECIAL_REG(msp, r0, r1)
ldr r1, [r0, #___cpu_context_t_msplim_OFFSET]
msr msplim, r1
RESTORE_SPECIAL_REG(msplim, r0, r1)
ldr r1, [r0, #___cpu_context_t_psp_OFFSET]
msr psp, r1
RESTORE_SPECIAL_REG(psp, r0, r1)
ldr r1, [r0, #___cpu_context_t_psplim_OFFSET]
msr psplim, r1
RESTORE_SPECIAL_REG(psplim, r0, r1)
ldr r1, [r0, #___cpu_context_t_primask_OFFSET]
msr primask, r1
RESTORE_SPECIAL_REG(primask, r0, r1)
ldr r1, [r0, #___cpu_context_t_faultmask_OFFSET]
msr faultmask, r1
RESTORE_SPECIAL_REG(faultmask, r0, r1)
ldr r1, [r0, #___cpu_context_t_basepri_OFFSET]
msr basepri, r1
RESTORE_SPECIAL_REG(basepri, r0, r1)
ldr r1, [r0, #___cpu_context_t_control_OFFSET]
msr control, r1
RESTORE_SPECIAL_REG(control, r0, r1)
isb
pop {r4-r12, lr}