ArmPkg/ArmV7Lib: Add support for Invalid Instruction Cache to Point of Unification

This patch adds support to invalidate Instruction Cache to the Point of Unification (PoU).

Signed-off-by: eugenecohen
Reviewed-by: oliviermartin



git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@13012 6f19259b-4bc3-4df7-8a09-765794883524

ArmPkg/Library/ArmLib/ArmV7/ArmV7Support.asm

@@ -35,6 +35,7 @@
     EXPORT  ArmSetLowVectors
     EXPORT  ArmSetHighVectors
     EXPORT  ArmV7AllDataCachesOperation
+    EXPORT  ArmV7PerformPoUDataCacheOperation
     EXPORT  ArmDataMemoryBarrier
     EXPORT  ArmDataSyncronizationBarrier
     EXPORT  ArmInstructionSynchronizationBarrier
@@ -261,6 +262,55 @@ Finished
   ldmfd SP!, {r4-r12, lr}
   bx    LR
 
+ArmV7PerformPoUDataCacheOperation
+  stmfd SP!,{r4-r12, LR}
+  mov   R1, R0                ; Save Function call in R1
+  mrc   p15, 1, R6, c0, c0, 1 ; Read CLIDR
+  ands  R3, R6, #&38000000    ; Mask out all but Level of Unification (LoU)
+  mov   R3, R3, LSR #26       ; Cache level value (naturally aligned)
+  beq   Finished2
+  mov   R10, #0
+
+Loop4   
+  add   R2, R10, R10, LSR #1    ; Work out 3xcachelevel
+  mov   R12, R6, LSR R2         ; bottom 3 bits are the Cache type for this level
+  and   R12, R12, #7            ; get those 3 bits alone
+  cmp   R12, #2
+  blt   Skip2                   ; no cache or only instruction cache at this level
+  mcr   p15, 2, R10, c0, c0, 0  ; write the Cache Size selection register (CSSELR) // OR in 1 for Instruction
+  isb                           ; isb to sync the change to the CacheSizeID reg 
+  mrc   p15, 1, R12, c0, c0, 0  ; reads current Cache Size ID register (CCSIDR)
+  and   R2, R12, #&7            ; extract the line length field
+  add   R2, R2, #4              ; add 4 for the line length offset (log2 16 bytes)
+  ldr   R4, =0x3FF
+  ands  R4, R4, R12, LSR #3     ; R4 is the max number on the way size (right aligned)
+  clz   R5, R4                  ; R5 is the bit position of the way size increment
+  ldr   R7, =0x00007FFF
+  ands  R7, R7, R12, LSR #13    ; R7 is the max number of the index size (right aligned)
+
+Loop5   
+  mov   R9, R4                  ; R9 working copy of the max way size (right aligned)
+
+Loop6   
+  orr   R0, R10, R9, LSL R5     ; factor in the way number and cache number into R11
+  orr   R0, R0, R7, LSL R2      ; factor in the index number
+
+  blx   R1
+
+  subs  R9, R9, #1              ; decrement the way number
+  bge   Loop6
+  subs  R7, R7, #1              ; decrement the index
+  bge   Loop5
+Skip2  
+  add   R10, R10, #2            ; increment the cache number
+  cmp   R3, R10
+  bgt   Loop4
+  
+Finished2
+  dsb
+  ldmfd SP!, {r4-r12, lr}
+  bx    LR
+
 ArmDataMemoryBarrier
   dmb
   bx      LR