OMAP3: PM: Remove un-necessary cp15 registers form low power cpu context

The current code saves few un-necessary registers which are read-only or
write-only, unused CP15 registers.

Remove them and keep only necessary CP15 registers part of
low power context save/restore.

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>

1 files changed, 40 insertions, 116 deletions

diff --git a/arch/arm/mach-omap2/sleep34xx.S b/arch/arm/mach-omap2/sleep34xx.S
index f75a166f0a21..99e43cc5a503 100644
--- a/arch/arm/mach-omap2/sleep34xx.S
+++ b/arch/arm/mach-omap2/sleep34xx.S
@@ -214,66 +214,29 @@ save_context_wfi:
         beq     clean_caches
 
 l1_logic_lost:
-        /* Store sp and spsr to SDRAM */
-        mov     r4, sp
-        mrs     r5, spsr
-        mov     r6, lr
+        mov     r4, sp                  @ Store sp
+        mrs     r5, spsr                @ Store spsr
+        mov     r6, lr                  @ Store 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,
-         * 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
+
+        mrc     p15, 0, r4, c1, c0, 2   @ Coprocessor access control register
+        mrc     p15, 0, r5, c2, c0, 0   @ TTBR0
+        mrc     p15, 0, r6, c2, c0, 1   @ TTBR1
+        mrc     p15, 0, r7, c2, c0, 2   @ TTBCR
         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, c3, c0, 0   @ Domain access Control Register
+        mrc     p15, 0, r5, c10, c2, 0  @ PRRR
+        mrc     p15, 0, r6, c10, c2, 1  @ NMRR
+        stmia   r8!,{r4-r6}
+
+        mrc     p15, 0, r4, c13, c0, 1  @ Context ID
+        mrc     p15, 0, r5, c13, c0, 2  @ User r/w thread and process ID
+        mrc     p15, 0, r6, c12, c0, 0  @ Secure or NS vector base address
+        mrs     r7, cpsr                @ Store current cpsr
+        stmia   r8!, {r4-r7}
 
-        mrc     p15, 0, r4, c1, c0, 0
-        /* save control register */
+        mrc     p15, 0, r4, c1, c0, 0   @ save control register
         stmia   r8!, {r4}
 
 clean_caches:
@@ -489,68 +452,29 @@ skipl2reen:
         ldr     r4, scratchpad_base
         ldr     r3, [r4,#0xBC]
         adds    r3, r3, #16
+
         ldmia   r3!, {r4-r6}
-        mov     sp, r4
-        msr     spsr_cxsf, r5
-        mov     lr, r6
-
-        ldmia   r3!, {r4-r9}
-        /* Coprocessor access Control Register */
-        mcr p15, 0, r4, c1, c0, 2
-
-        /* TTBR0 */
-        MCR p15, 0, r5, c2, c0, 0
-        /* TTBR1 */
-        MCR p15, 0, r6, c2, c0, 1
-        /* Translation table base control register */
-        MCR p15, 0, r7, c2, c0, 2
-        /* Domain access Control Register */
-        MCR p15, 0, r8, c3, c0, 0
-        /* Data fault status Register */
-        MCR p15, 0, r9, c5, c0, 0
-
-        ldmia   r3!,{r4-r8}
-        /* Instruction fault status Register */
-        MCR p15, 0, r4, c5, c0, 1
-        /* Data Auxiliary Fault Status Register */
-        MCR p15, 0, r5, c5, c1, 0
-        /* Instruction Auxiliary Fault Status Register*/
-        MCR p15, 0, r6, c5, c1, 1
-        /* Data Fault Address Register */
-        MCR p15, 0, r7, c6, c0, 0
-        /* Instruction Fault Address Register*/
-        MCR p15, 0, r8, c6, c0, 2
-        ldmia   r3!,{r4-r7}
+        mov     sp, r4                  @ Restore sp
+        msr     spsr_cxsf, r5           @ Restore spsr
+        mov     lr, r6                  @ Restore lr
 
-        /* User r/w thread and process ID */
-        MCR p15, 0, r4, c13, c0, 2
-        /* User ro thread and process ID */
-        MCR p15, 0, r5, c13, c0, 3
-        /* Privileged only thread and process ID */
-        MCR p15, 0, r6, c13, c0, 4
-        /* Cache size selection */
-        MCR p15, 2, r7, c0, c0, 0
-        ldmia   r3!,{r4-r8}
-        /* Data TLB lockdown registers */
-        MCR p15, 0, r4, c10, c0, 0
-        /* Instruction TLB lockdown registers */
-        MCR p15, 0, r5, c10, c0, 1
-        /* Secure or Nonsecure Vector Base Address */
-        MCR p15, 0, r6, c12, c0, 0
-        /* FCSE PID */
-        MCR p15, 0, r7, c13, c0, 0
-        /* Context PID */
-        MCR p15, 0, r8, c13, c0, 1
-
-        ldmia   r3!,{r4-r5}
-        /* Primary memory remap register */
-        MCR p15, 0, r4, c10, c2, 0
-        /* Normal memory remap register */
-        MCR p15, 0, r5, c10, c2, 1
-
-        /* Restore cpsr */
-        ldmia   r3!,{r4}                @ load CPSR from SDRAM
-        msr     cpsr, r4                @ store cpsr
+        ldmia   r3!, {r4-r7}
+        mcr     p15, 0, r4, c1, c0, 2   @ Coprocessor access Control Register
+        mcr     p15, 0, r5, c2, c0, 0   @ TTBR0
+        mcr     p15, 0, r6, c2, c0, 1   @ TTBR1
+        mcr     p15, 0, r7, c2, c0, 2   @ TTBCR
+
+        ldmia   r3!,{r4-r6}
+        mcr     p15, 0, r4, c3, c0, 0   @ Domain access Control Register
+        mcr     p15, 0, r5, c10, c2, 0  @ PRRR
+        mcr     p15, 0, r6, c10, c2, 1  @ NMRR
+
+
+        ldmia   r3!,{r4-r7}
+        mcr     p15, 0, r4, c13, c0, 1  @ Context ID
+        mcr     p15, 0, r5, c13, c0, 2  @ User r/w thread and process ID
+        mrc     p15, 0, r6, c12, c0, 0  @ Secure or NS vector base address
+        msr     cpsr, r7                @ store cpsr
 
         /* Enabling MMU here */
         mrc     p15, 0, r7, c2, c0, 2   @ Read TTBRControl