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ARM: pm: omap3: run the ASM sleep code from DDR 

Most of the ASM sleep code (in arch/arm/mach-omap2/sleep34xx.S)
is copied to internal SRAM at boot and after wake-up from CORE OFF
mode.  However only a small part of the code really needs to run from
internal SRAM.

This fix lets most of the ASM idle code run from the DDR in order to
minimize the SRAM usage and the overhead in the code copy.

The only pieces of code that are mandatory in SRAM are:
- the i443 erratum WA,
- the i581 erratum WA,
- the security extension code.

SRAM usage:
- original code:
  . 560 bytes for omap3_sram_configure_core_dpll (used by DVFS),
  . 852 bytes for omap_sram_idle (used by suspend/resume in RETention),
  . 124 bytes for es3_sdrc_fix (used by suspend/resume in OFF mode on ES3.x),
  . 108 bytes for save_secure_ram_context (used on HS parts only).

With this fix the usage for suspend/resume in RETention goes down 288
bytes, so the gain in SRAM usage for suspend/resume is 564 bytes.

Also fixed the SRAM initialization sequence to avoid an unnecessary
copy to SRAM at boot time and for readability.

Tested on Beagleboard (ES2.x) in idle with full RET and OFF modes.

Kevin Hilman tested retention and off on 3430/n900, 3530/Overo and
3630/Zoom3

Signed-off-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Jean Pihet 2011-06-29 18:40:23 +02:00 committed by Russell King
parent 0853f96f13
commit 46e130d298
4 changed files with 208 additions and 154 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
arch/arm/mach-omap2/pm.h
View File

@ -88,18 +88,28 @@ extern int pm_dbg_regset_init(int reg_set);
#define pm_dbg_regset_init(reg_set) do {} while (0);
#endif /* CONFIG_PM_DEBUG */
/* 24xx */
extern void omap24xx_idle_loop_suspend(void);
extern unsigned int omap24xx_idle_loop_suspend_sz;
extern void omap24xx_cpu_suspend(u32 dll_ctrl, void __iomem *sdrc_dlla_ctrl,
void __iomem *sdrc_power);
extern void omap34xx_cpu_suspend(u32 *addr, int save_state);
extern int save_secure_ram_context(u32 *addr);
extern void omap3_save_scratchpad_contents(void);
extern unsigned int omap24xx_idle_loop_suspend_sz;
extern unsigned int save_secure_ram_context_sz;
extern unsigned int omap24xx_cpu_suspend_sz;
extern unsigned int omap34xx_cpu_suspend_sz;
/* 3xxx */
extern void omap34xx_cpu_suspend(u32 *addr, int save_state);
/* omap3_do_wfi function pointer and size, for copy to SRAM */
extern void omap3_do_wfi(void);
extern unsigned int omap3_do_wfi_sz;
/* ... and its pointer from SRAM after copy */
extern void (*omap3_do_wfi_sram)(void);
/* save_secure_ram_context function pointer and size, for copy to SRAM */
extern int save_secure_ram_context(u32 *addr);
extern unsigned int save_secure_ram_context_sz;
extern void omap3_save_scratchpad_contents(void);
#define PM_RTA_ERRATUM_i608 (1 << 0)
#define PM_SDRC_WAKEUP_ERRATUM_i583 (1 << 1)

20
arch/arm/mach-omap2/pm34xx.c
View File

@ -78,9 +78,8 @@ struct power_state {
static LIST_HEAD(pwrst_list);
static void (*_omap_sram_idle)(u32 *addr, int save_state);
static int (*_omap_save_secure_sram)(u32 *addr);
void (*omap3_do_wfi_sram)(void);
static struct powerdomain *mpu_pwrdm, *neon_pwrdm;
static struct powerdomain *core_pwrdm, *per_pwrdm;
@ -309,7 +308,7 @@ static irqreturn_t prcm_interrupt_handler (int irq, void *dev_id)
static void omap34xx_do_sram_idle(unsigned long save_state)
{
_omap_sram_idle(omap3_arm_context, save_state);
omap34xx_cpu_suspend(omap3_arm_context, save_state);
}
void omap_sram_idle(void)
@ -328,9 +327,6 @@ void omap_sram_idle(void)
int core_prev_state, per_prev_state;
u32 sdrc_pwr = 0;
if (!_omap_sram_idle)
return;
pwrdm_clear_all_prev_pwrst(mpu_pwrdm);
pwrdm_clear_all_prev_pwrst(neon_pwrdm);
pwrdm_clear_all_prev_pwrst(core_pwrdm);
@ -826,10 +822,17 @@ static int __init clkdms_setup(struct clockdomain *clkdm, void *unused)
return 0;
}
/*
* Push functions to SRAM
*
* The minimum set of functions is pushed to SRAM for execution:
* - omap3_do_wfi for erratum i581 WA,
* - save_secure_ram_context for security extensions.
*/
void omap_push_sram_idle(void)
{
_omap_sram_idle = omap_sram_push(omap34xx_cpu_suspend,
omap34xx_cpu_suspend_sz);
omap3_do_wfi_sram = omap_sram_push(omap3_do_wfi, omap3_do_wfi_sz);
if (omap_type() != OMAP2_DEVICE_TYPE_GP)
_omap_save_secure_sram = omap_sram_push(save_secure_ram_context,
save_secure_ram_context_sz);
@ -894,7 +897,6 @@ static int __init omap3_pm_init(void)
per_clkdm = clkdm_lookup("per_clkdm");
core_clkdm = clkdm_lookup("core_clkdm");
omap_push_sram_idle();
#ifdef CONFIG_SUSPEND
suspend_set_ops(&omap_pm_ops);
#endif /* CONFIG_SUSPEND */

303
arch/arm/mach-omap2/sleep34xx.S
View File

@ -139,8 +139,10 @@ ENTRY(save_secure_ram_context_sz)
*
*
* Notes:
* - this code gets copied to internal SRAM at boot and after wake-up
* from OFF mode. The execution pointer in SRAM is _omap_sram_idle.
* - only the minimum set of functions gets copied to internal SRAM at boot
* and after wake-up from OFF mode, cf. omap_push_sram_idle. The function
* pointers in SDRAM or SRAM are called depending on the desired low power
* target state.
* - when the OMAP wakes up it continues at different execution points
* depending on the low power mode (non-OFF vs OFF modes),
* cf. 'Resume path for xxx mode' comments.
@ -158,9 +160,15 @@ ENTRY(omap34xx_cpu_suspend)
* 3 - Both L1 and L2 lost and logic lost
*/
/* Directly jump to WFI is the context save is not required */
cmp r1, #0x0
beq omap3_do_wfi
/*
* For OFF mode: save context and jump to WFI in SDRAM (omap3_do_wfi)
* For non-OFF modes: jump to the WFI code in SRAM (omap3_do_wfi_sram)
*/
ldr r4, omap3_do_wfi_sram_addr
ldr r5, [r4]
cmp r1, #0x0 @ If no context save required,
bxeq r5 @ jump to the WFI code in SRAM
/* Otherwise fall through to the save context code */
save_context_wfi:
@ -213,7 +221,32 @@ save_context_wfi:
THUMB( nop )
.arm
omap3_do_wfi:
b omap3_do_wfi
/*
* Local variables
*/
omap3_do_wfi_sram_addr:
.word omap3_do_wfi_sram
kernel_flush:
.word v7_flush_dcache_all
/* ===================================
* == WFI instruction => Enter idle ==
* ===================================
*/
/*
* Do WFI instruction
* Includes the resume path for non-OFF modes
*
* This code gets copied to internal SRAM and is accessible
* from both SDRAM and SRAM:
* - executed from SRAM for non-off modes (omap3_do_wfi_sram),
* - executed from SDRAM for OFF mode (omap3_do_wfi).
*/
.align 3
ENTRY(omap3_do_wfi)
ldr r4, sdrc_power @ read the SDRC_POWER register
ldr r5, [r4] @ read the contents of SDRC_POWER
orr r5, r5, #0x40 @ enable self refresh on idle req
@ -245,8 +278,86 @@ omap3_do_wfi:
nop
nop
nop
bl wait_sdrc_ok
/*
* This function implements the erratum ID i581 WA:
* SDRC state restore before accessing the SDRAM
*
* Only used at return from non-OFF mode. For OFF
* mode the ROM code configures the SDRC and
* the DPLL before calling the restore code directly
* from DDR.
*/
/* Make sure SDRC accesses are ok */
wait_sdrc_ok:
/* DPLL3 must be locked before accessing the SDRC. Maybe the HW ensures this */
ldr r4, cm_idlest_ckgen
wait_dpll3_lock:
ldr r5, [r4]
tst r5, #1
beq wait_dpll3_lock
ldr r4, cm_idlest1_core
wait_sdrc_ready:
ldr r5, [r4]
tst r5, #0x2
bne wait_sdrc_ready
/* allow DLL powerdown upon hw idle req */
ldr r4, sdrc_power
ldr r5, [r4]
bic r5, r5, #0x40
str r5, [r4]
/*
* PC-relative stores lead to undefined behaviour in Thumb-2: use a r7 as a
* base instead.
* Be careful not to clobber r7 when maintaing this code.
*/
is_dll_in_lock_mode:
/* Is dll in lock mode? */
ldr r4, sdrc_dlla_ctrl
ldr r5, [r4]
tst r5, #0x4
bne exit_nonoff_modes @ Return if locked
/* wait till dll locks */
adr r7, kick_counter
wait_dll_lock_timed:
ldr r4, wait_dll_lock_counter
add r4, r4, #1
str r4, [r7, #wait_dll_lock_counter - kick_counter]
ldr r4, sdrc_dlla_status
/* Wait 20uS for lock */
mov r6, #8
wait_dll_lock:
subs r6, r6, #0x1
beq kick_dll
ldr r5, [r4]
and r5, r5, #0x4
cmp r5, #0x4
bne wait_dll_lock
b exit_nonoff_modes @ Return when locked
/* disable/reenable DLL if not locked */
kick_dll:
ldr r4, sdrc_dlla_ctrl
ldr r5, [r4]
mov r6, r5
bic r6, #(1<<3) @ disable dll
str r6, [r4]
dsb
orr r6, r6, #(1<<3) @ enable dll
str r6, [r4]
dsb
ldr r4, kick_counter
add r4, r4, #1
str r4, [r7] @ kick_counter
b wait_dll_lock_timed
exit_nonoff_modes:
/* Re-enable C-bit if needed */
mrc p15, 0, r0, c1, c0, 0
tst r0, #(1 << 2) @ Check C bit enabled?
orreq r0, r0, #(1 << 2) @ Enable the C bit if cleared
@ -260,6 +371,31 @@ omap3_do_wfi:
*/
ldmfd sp!, {r4 - r11, pc} @ restore regs and return
/*
* Local variables
*/
sdrc_power:
.word SDRC_POWER_V
cm_idlest1_core:
.word CM_IDLEST1_CORE_V
cm_idlest_ckgen:
.word CM_IDLEST_CKGEN_V
sdrc_dlla_status:
.word SDRC_DLLA_STATUS_V
sdrc_dlla_ctrl:
.word SDRC_DLLA_CTRL_V
/*
* When exporting to userspace while the counters are in SRAM,
* these 2 words need to be at the end to facilitate retrival!
*/
kick_counter:
.word 0
wait_dll_lock_counter:
.word 0
ENTRY(omap3_do_wfi_sz)
.word . - omap3_do_wfi
/*
* ==============================
@ -275,13 +411,17 @@ omap3_do_wfi:
* restore_es3: applies to 34xx >= ES3.0
* restore_3630: applies to 36xx
* restore: common code for 3xxx
*
* Note: when back from CORE and MPU OFF mode we are running
* from SDRAM, without MMU, without the caches and prediction.
* Also the SRAM content has been cleared.
*/
ENTRY(omap3_restore_es3)
ldr r5, pm_prepwstst_core_p
ldr r4, [r5]
and r4, r4, #0x3
cmp r4, #0x0 @ Check if previous power state of CORE is OFF
bne omap3_restore
bne omap3_restore @ Fall through to OMAP3 common code
adr r0, es3_sdrc_fix
ldr r1, sram_base
ldr r2, es3_sdrc_fix_sz
@ -293,7 +433,7 @@ copy_to_sram:
bne copy_to_sram
ldr r1, sram_base
blx r1
b omap3_restore
b omap3_restore @ Fall through to OMAP3 common code
ENDPROC(omap3_restore_es3)
ENTRY(omap3_restore_3630)
@ -301,7 +441,7 @@ ENTRY(omap3_restore_3630)
ldr r2, [r1]
and r2, r2, #0x3
cmp r2, #0x0 @ Check if previous power state of CORE is OFF
bne omap3_restore
bne omap3_restore @ Fall through to OMAP3 common code
/* Disable RTA before giving control */
ldr r1, control_mem_rta
mov r2, #OMAP36XX_RTA_DISABLE
@ -404,11 +544,32 @@ ENDPROC(omap3_restore)
.ltorg
/*
* Local variables
*/
pm_prepwstst_core_p:
.word PM_PREPWSTST_CORE_P
pm_pwstctrl_mpu:
.word PM_PWSTCTRL_MPU_P
scratchpad_base:
.word SCRATCHPAD_BASE_P
sram_base:
.word SRAM_BASE_P + 0x8000
control_stat:
.word CONTROL_STAT
control_mem_rta:
.word CONTROL_MEM_RTA_CTRL
l2dis_3630:
.word 0
/*
* Internal functions
*/
/* This function implements the erratum ID i443 WA, applies to 34xx >= ES3.0 */
/*
* This function implements the erratum ID i443 WA, applies to 34xx >= ES3.0
* Copied to and run from SRAM in order to reconfigure the SDRC parameters.
*/
.text
.align 3
ENTRY(es3_sdrc_fix)
@ -438,6 +599,9 @@ ENTRY(es3_sdrc_fix)
str r5, [r4] @ kick off refreshes
bx lr
/*
* Local variables
*/
.align
sdrc_syscfg:
.word SDRC_SYSCONFIG_P
@ -456,120 +620,3 @@ sdrc_manual_1:
ENDPROC(es3_sdrc_fix)
ENTRY(es3_sdrc_fix_sz)
.word . - es3_sdrc_fix
/*
* This function implements the erratum ID i581 WA:
* SDRC state restore before accessing the SDRAM
*
* Only used at return from non-OFF mode. For OFF
* mode the ROM code configures the SDRC and
* the DPLL before calling the restore code directly
* from DDR.
*/
/* Make sure SDRC accesses are ok */
wait_sdrc_ok:
/* DPLL3 must be locked before accessing the SDRC. Maybe the HW ensures this */
ldr r4, cm_idlest_ckgen
wait_dpll3_lock:
ldr r5, [r4]
tst r5, #1
beq wait_dpll3_lock
ldr r4, cm_idlest1_core
wait_sdrc_ready:
ldr r5, [r4]
tst r5, #0x2
bne wait_sdrc_ready
/* allow DLL powerdown upon hw idle req */
ldr r4, sdrc_power
ldr r5, [r4]
bic r5, r5, #0x40
str r5, [r4]
/*
* PC-relative stores lead to undefined behaviour in Thumb-2: use a r7 as a
* base instead.
* Be careful not to clobber r7 when maintaing this code.
*/
is_dll_in_lock_mode:
/* Is dll in lock mode? */
ldr r4, sdrc_dlla_ctrl
ldr r5, [r4]
tst r5, #0x4
bxne lr @ Return if locked
/* wait till dll locks */
adr r7, kick_counter
wait_dll_lock_timed:
ldr r4, wait_dll_lock_counter
add r4, r4, #1
str r4, [r7, #wait_dll_lock_counter - kick_counter]
ldr r4, sdrc_dlla_status
/* Wait 20uS for lock */
mov r6, #8
wait_dll_lock:
subs r6, r6, #0x1
beq kick_dll
ldr r5, [r4]
and r5, r5, #0x4
cmp r5, #0x4
bne wait_dll_lock
bx lr @ Return when locked
/* disable/reenable DLL if not locked */
kick_dll:
ldr r4, sdrc_dlla_ctrl
ldr r5, [r4]
mov r6, r5
bic r6, #(1<<3) @ disable dll
str r6, [r4]
dsb
orr r6, r6, #(1<<3) @ enable dll
str r6, [r4]
dsb
ldr r4, kick_counter
add r4, r4, #1
str r4, [r7] @ kick_counter
b wait_dll_lock_timed
.align
cm_idlest1_core:
.word CM_IDLEST1_CORE_V
cm_idlest_ckgen:
.word CM_IDLEST_CKGEN_V
sdrc_dlla_status:
.word SDRC_DLLA_STATUS_V
sdrc_dlla_ctrl:
.word SDRC_DLLA_CTRL_V
pm_prepwstst_core_p:
.word PM_PREPWSTST_CORE_P
pm_pwstctrl_mpu:
.word PM_PWSTCTRL_MPU_P
scratchpad_base:
.word SCRATCHPAD_BASE_P
sram_base:
.word SRAM_BASE_P + 0x8000
sdrc_power:
.word SDRC_POWER_V
control_stat:
.word CONTROL_STAT
control_mem_rta:
.word CONTROL_MEM_RTA_CTRL
kernel_flush:
.word v7_flush_dcache_all
l2dis_3630:
.word 0
/*
* When exporting to userspace while the counters are in SRAM,
* these 2 words need to be at the end to facilitate retrival!
*/
kick_counter:
.word 0
wait_dll_lock_counter:
.word 0
ENDPROC(omap34xx_cpu_suspend)
ENTRY(omap34xx_cpu_suspend_sz)
.word . - omap34xx_cpu_suspend

15
arch/arm/plat-omap/sram.c
View File

@ -394,20 +394,15 @@ void omap3_sram_restore_context(void)
}
#endif /* CONFIG_PM */
static int __init omap34xx_sram_init(void)
{
_omap3_sram_configure_core_dpll =
omap_sram_push(omap3_sram_configure_core_dpll,
omap3_sram_configure_core_dpll_sz);
omap_push_sram_idle();
return 0;
}
#else
#endif /* CONFIG_ARCH_OMAP3 */
static inline int omap34xx_sram_init(void)
{
#if defined(CONFIG_ARCH_OMAP3) && defined(CONFIG_PM)
omap3_sram_restore_context();
#endif
return 0;
}
#endif
int __init omap_sram_init(void)
{