> -----Original Message----- > From: linux-omap-owner@xxxxxxxxxxxxxxx [mailto:linux-omap- > owner@xxxxxxxxxxxxxxx] On Behalf Of jean.pihet@xxxxxxxxxxxxxx > Sent: Thursday, December 16, 2010 11:21 PM > To: linux-omap@xxxxxxxxxxxxxxx > Cc: khilman@xxxxxxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; > Jean Pihet > Subject: [PATCH 5/7] OMAP3: rework of the ASM sleep code execution paths > > From: Jean Pihet <j-pihet@xxxxxx> > > - Reworked and simplified the execution paths for better > readability and to avoid duplication of code, > - Added comments on the entry and exit points and the interaction > with the ROM code for OFF mode restore, > - Reworked the existing comments for better readability. > > Tested on N900 and Beagleboard with full RET and OFF modes, > using cpuidle and suspend. > > Signed-off-by: Jean Pihet <j-pihet@xxxxxx> > --- > arch/arm/mach-omap2/control.c | 10 +- > arch/arm/mach-omap2/sleep34xx.S | 309 ++++++++++++++++++++++------------ > ---- > 2 files changed, 188 insertions(+), 131 deletions(-) > > diff --git a/arch/arm/mach-omap2/control.c b/arch/arm/mach-omap2/control.c > index 728f268..5cb7276 100644 > --- a/arch/arm/mach-omap2/control.c > +++ b/arch/arm/mach-omap2/control.c > @@ -239,7 +239,15 @@ void omap3_save_scratchpad_contents(void) > struct omap3_scratchpad_prcm_block prcm_block_contents; > struct omap3_scratchpad_sdrc_block sdrc_block_contents; > > - /* Populate the Scratchpad contents */ > + /* > + * Populate the Scratchpad contents > + * > + * The get_*restore_pointer functions are used to get the resume > + * function pointer to be called by the ROM code when back from WFI > + * in OFF mode. Align your text here. > + * The restore pointer is stored into the scratchpad for later > access > + * by the ROM code. The text needs to be reworked a bit. The "get_*restore_pointer" functions are used to provide a physical restore address where ROM code jumps while waking up from MPU OFF/OSWR state. The restore pointer is stored into the scratchpad > + */ > scratchpad_contents.boot_config_ptr = 0x0; > if (cpu_is_omap3630()) > scratchpad_contents.public_restore_ptr = > diff --git a/arch/arm/mach-omap2/sleep34xx.S b/arch/arm/mach- > omap2/sleep34xx.S > index 426af02..55ddd5a 100644 > --- a/arch/arm/mach-omap2/sleep34xx.S > +++ b/arch/arm/mach-omap2/sleep34xx.S > @@ -70,6 +70,11 @@ > * API functions > */ > > +/* > + * The get_*restore_pointer functions are returning the resume > + * function pointer to be called by the ROM code when back from WFI > + * in OFF mode. Ditto The "get_*restore_pointer" functions are used to provide a physical restore address where ROM code jumps while waking up from MPU OFF/OSWR state. The restore pointer is stored into the scratchpad > + */ > .text > /* Function call to get the restore pointer for resume from OFF */ > ENTRY(get_restore_pointer) > @@ -101,7 +106,7 @@ ENTRY(get_es3_restore_pointer_sz) > /* > * L2 cache needs to be toggled for stable OFF mode functionality on 3630. > * This function sets up a flag that will allow for this toggling to take > - * place on 3630. Hopefully some version in the future maynot need this > + * place on 3630. Hopefully some version in the future maynot need this. 'maynot' ..... may not > */ > ENTRY(enable_omap3630_toggle_l2_on_restore) > stmfd sp!, {lr} @ save registers on stack > @@ -143,34 +148,156 @@ ENTRY(save_secure_ram_context_sz) > .word . - save_secure_ram_context > > /* > + * ====================== > + * == Idle entry point == > + * ====================== > + */ > + > +/* > * Forces OMAP into idle state > * > - * omap34xx_suspend() - This bit of code just executes the WFI > - * for normal idles. > + * omap34xx_suspend() - This bit of code saves the CPU context if needed > + * and executes the WFI instruction > * > - * Note: This code get's copied to internal SRAM at boot. When the OMAP > - * wakes up it continues execution at the point it went to sleep. > + * Notes: > + * - this code gets copied to internal SRAM at boot. > + * - 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. > */ > ENTRY(omap34xx_cpu_suspend) > stmfd sp!, {r0-r12, lr} @ save registers on stack > > - /* r0 contains restore pointer in sdram */ > - /* r1 contains information about saving context */ > - 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 > - str r5, [r4] @ write back to SDRC_POWER register > + /* > + * r0 contains restore pointer in sdram > + * r1 contains information about saving context: > + * 0 - No context lost > + * 1 - Only L1 and logic lost > + * 2 - Only L2 lost > + * 3 - Both L1 and L2 lost > + */ > > + /* Save context only if required */ > cmp r1, #0x0 > - /* If context save is required, do that and execute wfi */ > - bne save_context_wfi > + beq omap3_do_wfi > + > +save_context_wfi: > + mov r8, r0 @ Store SDRAM address in r8 > + mrc p15, 0, r5, c1, c0, 1 @ Read Auxiliary Control Register > + mov r4, #0x1 @ Number of parameters for restore call > + stmia r8!, {r4-r5} @ Push parameters for restore call > + mrc p15, 1, r5, c9, c0, 2 @ Read L2 AUX ctrl register > + stmia r8!, {r4-r5} @ Push parameters for restore call > + > + /* Check what that target sleep state is from r1 */ > + cmp r1, #0x2 @ Only L2 lost, no need to save context > + beq clean_caches > + > +l1_logic_lost: > + /* Store sp and spsr to SDRAM */ > + mov r4, sp > + mrs r5, spsr > + mov r6, lr > + stmia r8!, {r4-r6} > + /* Save all ARM registers */ > + /* Coprocessor access control register */ You might want to fix above commenting style as well > + mrc p15, 0, r6, c1, c0, 2 > + stmia r8!, {r6} > + /* TTBR0, TTBR1 and Translation table base control */ > + mrc p15, 0, r4, c2, c0, 0 > + mrc p15, 0, r5, c2, c0, 1 > + mrc p15, 0, r6, c2, c0, 2 > + stmia r8!, {r4-r6} > + /* > + * Domain access control register, data fault status register, > + * and instruction fault status register > + */ > + mrc p15, 0, r4, c3, c0, 0 > + mrc p15, 0, r5, c5, c0, 0 > + mrc p15, 0, r6, c5, c0, 1 > + stmia r8!, {r4-r6} > + /* > + * Data aux fault status register, instruction aux fault status, > + * data fault address register and instruction fault address > register > + */ > + mrc p15, 0, r4, c5, c1, 0 > + mrc p15, 0, r5, c5, c1, 1 > + mrc p15, 0, r6, c6, c0, 0 > + mrc p15, 0, r7, c6, c0, 2 > + stmia r8!, {r4-r7} > + /* > + * user r/w thread and process ID, user r/o thread and process ID, > + * priv only thread and process ID, cache size selection > + */ > + mrc p15, 0, r4, c13, c0, 2 > + mrc p15, 0, r5, c13, c0, 3 > + mrc p15, 0, r6, c13, c0, 4 > + mrc p15, 2, r7, c0, c0, 0 > + stmia r8!, {r4-r7} > + /* Data TLB lockdown, instruction TLB lockdown registers */ > + mrc p15, 0, r5, c10, c0, 0 > + mrc p15, 0, r6, c10, c0, 1 > + stmia r8!, {r5-r6} > + /* Secure or non secure vector base address, FCSE PID, Context PID*/ > + mrc p15, 0, r4, c12, c0, 0 > + mrc p15, 0, r5, c13, c0, 0 > + mrc p15, 0, r6, c13, c0, 1 > + stmia r8!, {r4-r6} > + /* Primary remap, normal remap registers */ > + mrc p15, 0, r4, c10, c2, 0 > + mrc p15, 0, r5, c10, c2, 1 > + stmia r8!,{r4-r5} > + > + /* Store current cpsr*/ > + mrs r2, cpsr > + stmia r8!, {r2} > + > + mrc p15, 0, r4, c1, c0, 0 > + /* save control register */ > + stmia r8!, {r4} > + > +clean_caches: > + /* Clean Data or unified cache to POU*/ > + /* How to invalidate only L1 cache???? - #FIX_ME# */ > + /* mcr p15, 0, r11, c7, c11, 1 */ And this one too... > + cmp r1, #0x1 @ Check whether L2 inval is required > + beq omap3_do_wfi > + > +clean_l2: > + /* > + * jump out to kernel flush routine > + * - reuse that code is better > + * - it executes in a cached space so is faster than refetch per- > block > + * - should be faster and will change with kernel > + * - 'might' have to copy address, load and jump to it > + */ > + ldr r1, kernel_flush > + mov lr, pc > + bx r1 > + > +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 > + str r5, [r4] @ write back to SDRC_POWER register > + > /* Data memory barrier and Data sync barrier */ > mov r1, #0 > mcr p15, 0, r1, c7, c10, 4 > mcr p15, 0, r1, c7, c10, 5 > > +/* > + * =================================== > + * == WFI instruction => Enter idle == > + * =================================== > + */ > wfi @ wait for interrupt > > +/* > + * =================================== > + * == Resume path for non-OFF modes == > + * =================================== > + */ > nop > nop > nop > @@ -183,7 +310,29 @@ ENTRY(omap34xx_cpu_suspend) > nop > bl wait_sdrc_ok > > - ldmfd sp!, {r0-r12, pc} @ restore regs and return > +/* > + * =================================== > + * == Exit point from non-OFF modes == > + * =================================== > + */ > + ldmfd sp!, {r0-r12, pc} @ restore regs and return > + > + > +/* > + * ============================== > + * == Resume path for OFF mode == > + * ============================== > + */ > + > +/* > + * The restore_* functions are called by the ROM code > + * when back from WFI in OFF mode. > + * Cf. the get_*restore_pointer functions. > + * > + * restore_es3: applies to 34xx >= ES3.0 > + * restore_3630: applies to 36xx > + * restore: common code for 3xxx > + */ > restore_es3: > ldr r5, pm_prepwstst_core_p > ldr r4, [r5] > @@ -213,12 +362,17 @@ restore_3630: > ldr r1, control_mem_rta > mov r2, #OMAP36XX_RTA_DISABLE > str r2, [r1] > - /* Fall thru for the remaining logic */ > + > + /* Fall thru to common code for the remaining logic */ > + > restore: > - /* Check what was the reason for mpu reset and store the reason > in r9*/ > - /* 1 - Only L1 and logic lost */ > - /* 2 - Only L2 lost - In this case, we wont be here */ > - /* 3 - Both L1 and L2 lost */ > + /* > + * Check what was the reason for mpu reset and store the reason in > r9: > + * 0 - No context lost > + * 1 - Only L1 and logic lost > + * 2 - Only L2 lost - In this case, we wont be here > + * 3 - Both L1 and L2 lost > + */ > ldr r1, pm_pwstctrl_mpu > ldr r2, [r1] > and r2, r2, #0x3 > @@ -421,118 +575,12 @@ usettbr0: > and r4, r2 > mcr p15, 0, r4, c1, c0, 0 > > +/* > + * ============================== > + * == Exit point from OFF mode == > + * ============================== > + */ > ldmfd sp!, {r0-r12, pc} @ restore regs and return > -save_context_wfi: > - mov r8, r0 /* Store SDRAM address in r8 */ > - mrc p15, 0, r5, c1, c0, 1 @ Read Auxiliary Control Register > - mov r4, #0x1 @ Number of parameters for restore call > - stmia r8!, {r4-r5} @ Push parameters for restore call > - mrc p15, 1, r5, c9, c0, 2 @ Read L2 AUX ctrl register > - stmia r8!, {r4-r5} @ Push parameters for restore call > - /* Check what that target sleep state is:stored in r1*/ > - /* 1 - Only L1 and logic lost */ > - /* 2 - Only L2 lost */ > - /* 3 - Both L1 and L2 lost */ > - cmp r1, #0x2 /* Only L2 lost */ > - beq clean_l2 > - cmp r1, #0x1 /* L2 retained */ > - /* r9 stores whether to clean L2 or not*/ > - moveq r9, #0x0 /* Dont Clean L2 */ > - movne r9, #0x1 /* Clean L2 */ > -l1_logic_lost: > - /* Store sp and spsr to SDRAM */ > - mov r4, sp > - mrs r5, spsr > - mov r6, lr > - stmia r8!, {r4-r6} > - /* Save all ARM registers */ > - /* Coprocessor access control register */ > - mrc p15, 0, r6, c1, c0, 2 > - stmia r8!, {r6} > - /* TTBR0, TTBR1 and Translation table base control */ > - mrc p15, 0, r4, c2, c0, 0 > - mrc p15, 0, r5, c2, c0, 1 > - mrc p15, 0, r6, c2, c0, 2 > - stmia r8!, {r4-r6} > - /* Domain access control register, data fault status register, > - and instruction fault status register */ > - mrc p15, 0, r4, c3, c0, 0 > - mrc p15, 0, r5, c5, c0, 0 > - mrc p15, 0, r6, c5, c0, 1 > - stmia r8!, {r4-r6} > - /* Data aux fault status register, instruction aux fault status, > - datat fault address register and instruction fault address > register*/ > - mrc p15, 0, r4, c5, c1, 0 > - mrc p15, 0, r5, c5, c1, 1 > - mrc p15, 0, r6, c6, c0, 0 > - mrc p15, 0, r7, c6, c0, 2 > - stmia r8!, {r4-r7} > - /* user r/w thread and process ID, user r/o thread and process ID, > - priv only thread and process ID, cache size selection */ > - mrc p15, 0, r4, c13, c0, 2 > - mrc p15, 0, r5, c13, c0, 3 > - mrc p15, 0, r6, c13, c0, 4 > - mrc p15, 2, r7, c0, c0, 0 > - stmia r8!, {r4-r7} > - /* Data TLB lockdown, instruction TLB lockdown registers */ > - mrc p15, 0, r5, c10, c0, 0 > - mrc p15, 0, r6, c10, c0, 1 > - stmia r8!, {r5-r6} > - /* Secure or non secure vector base address, FCSE PID, Context PID*/ > - mrc p15, 0, r4, c12, c0, 0 > - mrc p15, 0, r5, c13, c0, 0 > - mrc p15, 0, r6, c13, c0, 1 > - stmia r8!, {r4-r6} > - /* Primary remap, normal remap registers */ > - mrc p15, 0, r4, c10, c2, 0 > - mrc p15, 0, r5, c10, c2, 1 > - stmia r8!,{r4-r5} > - > - /* Store current cpsr*/ > - mrs r2, cpsr > - stmia r8!, {r2} > - > - mrc p15, 0, r4, c1, c0, 0 > - /* save control register */ > - stmia r8!, {r4} > -clean_caches: > - /* Clean Data or unified cache to POU*/ > - /* How to invalidate only L1 cache???? - #FIX_ME# */ > - /* mcr p15, 0, r11, c7, c11, 1 */ > - cmp r9, #1 /* Check whether L2 inval is required or not*/ > - bne skip_l2_inval > -clean_l2: > - /* > - * Jump out to kernel flush routine > - * - reuse that code is better > - * - it executes in a cached space so is faster than refetch per- > block > - * - should be faster and will change with kernel > - * - 'might' have to copy address, load and jump to it > - */ > - ldr r1, kernel_flush > - mov lr, pc > - bx r1 > - > -skip_l2_inval: > - /* Data memory barrier and Data sync barrier */ > - mov r1, #0 > - mcr p15, 0, r1, c7, c10, 4 > - mcr p15, 0, r1, c7, c10, 5 > - > - wfi @ wait for interrupt > - nop > - nop > - nop > - nop > - nop > - nop > - nop > - nop > - nop > - nop > - bl wait_sdrc_ok > - /* restore regs and return */ > - ldmfd sp!, {r0-r12, pc} > > > /* > @@ -682,5 +730,6 @@ kick_counter: > .word 0 > wait_dll_lock_counter: > .word 0 > + > ENTRY(omap34xx_cpu_suspend_sz) > .word . - omap34xx_cpu_suspend > -- > 1.7.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-omap" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
