[U-Boot] [PATCH v2 01/12] ARM: Factor out reusable psci_cpu_off_common

Jan Kiszka
2015-02-16T12:54:38Z

Move parts of sunxi's psci_cpu_off into psci_cpu_off_common, namely
cache disabling and flushing, clrex and the disabling of SMP for the
dying CPU. These steps are apparently generic for ARMv7 and will be
reused for Tegra124 support.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
arch/arm/cpu/armv7/psci.S | 71 +++++++++++++++++++++++++++++++++++++++++
arch/arm/cpu/armv7/sunxi/psci.S | 63 +-----------------------------------
2 files changed, 72 insertions(+), 62 deletions(-)

diff --git a/arch/arm/cpu/armv7/psci.S b/arch/arm/cpu/armv7/psci.S
index bf11a34..d688607 100644
--- a/arch/arm/cpu/armv7/psci.S
+++ b/arch/arm/cpu/armv7/psci.S
@@ -99,4 +99,75 @@ _smc_psci:
pop {r4-r7, lr}
movs pc, lr @ Return to the kernel

+/* Imported from Linux kernel */
+LENTRY(v7_flush_dcache_all)
+ dmb @ ensure ordering with previous memory accesses
+ mrc p15, 1, r0, c0, c0, 1 @ read clidr
+ ands r3, r0, #0x7000000 @ extract loc from clidr
+ mov r3, r3, lsr #23 @ left align loc bit field
+ beq finished @ if loc is 0, then no need to clean
+ mov r10, #0 @ start clean at cache level 0
+flush_levels:
+ add r2, r10, r10, lsr #1 @ work out 3x current cache level
+ mov r1, r0, lsr r2 @ extract cache type bits from clidr
+ and r1, r1, #7 @ mask of the bits for current cache only
+ cmp r1, #2 @ see what cache we have at this level
+ blt skip @ skip if no cache, or just i-cache
+ mrs r9, cpsr @ make cssr&csidr read atomic
+ mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr
+ isb @ isb to sych the new cssr&csidr
+ mrc p15, 1, r1, c0, c0, 0 @ read the new csidr
+ msr cpsr_c, r9
+ and r2, r1, #7 @ extract the length of the cache lines
+ add r2, r2, #4 @ add 4 (line length offset)
+ ldr r4, =0x3ff
+ ands r4, r4, r1, lsr #3 @ find maximum number on the way size
+ clz r5, r4 @ find bit position of way size increment
+ ldr r7, =0x7fff
+ ands r7, r7, r1, lsr #13 @ extract max number of the index size
+loop1:
+ mov r9, r7 @ create working copy of max index
+loop2:
+ orr r11, r10, r4, lsl r5 @ factor way and cache number into r11
+ orr r11, r11, r9, lsl r2 @ factor index number into r11
+ mcr p15, 0, r11, c7, c14, 2 @ clean & invalidate by set/way
+ subs r9, r9, #1 @ decrement the index
+ bge loop2
+ subs r4, r4, #1 @ decrement the way
+ bge loop1
+skip:
+ add r10, r10, #2 @ increment cache number
+ cmp r3, r10
+ bgt flush_levels
+finished:
+ mov r10, #0 @ swith back to cache level 0
+ mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr
+ dsb st
+ isb
+ bx lr
+ENDPROC(v7_flush_dcache_all)
+
+ENTRY(psci_cpu_off_common)
+ push {lr}
+
+ mrc p15, 0, r0, c1, c0, 0 @ SCTLR
+ bic r0, r0, #(1 << 2) @ Clear C bit
+ mcr p15, 0, r0, c1, c0, 0 @ SCTLR
+ isb
+ dsb
+
+ bl v7_flush_dcache_all
+
+ clrex @ Why???
+
+ mrc p15, 0, r0, c1, c0, 1 @ ACTLR
+ bic r0, r0, #(1 << 6) @ Clear SMP bit
+ mcr p15, 0, r0, c1, c0, 1 @ ACTLR
+ isb
+ dsb
+
+ pop {lr}
+ bx lr
+ENDPROC(psci_cpu_off_common)
+
.popsection
diff --git a/arch/arm/cpu/armv7/sunxi/psci.S b/arch/arm/cpu/armv7/sunxi/psci.S
index 5be497b..6785fdd 100644
--- a/arch/arm/cpu/armv7/sunxi/psci.S
+++ b/arch/arm/cpu/armv7/sunxi/psci.S
@@ -199,53 +199,6 @@ psci_cpu_on:
_target_pc:
.word 0

-/* Imported from Linux kernel */
-v7_flush_dcache_all:
- dmb @ ensure ordering with previous memory accesses
- mrc p15, 1, r0, c0, c0, 1 @ read clidr
- ands r3, r0, #0x7000000 @ extract loc from clidr
- mov r3, r3, lsr #23 @ left align loc bit field
- beq finished @ if loc is 0, then no need to clean
- mov r10, #0 @ start clean at cache level 0
-flush_levels:
- add r2, r10, r10, lsr #1 @ work out 3x current cache level
- mov r1, r0, lsr r2 @ extract cache type bits from clidr
- and r1, r1, #7 @ mask of the bits for current cache only
- cmp r1, #2 @ see what cache we have@this level
- blt skip @ skip if no cache, or just i-cache
- mrs r9, cpsr @ make cssr&csidr read atomic
- mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr
- isb @ isb to sych the new cssr&csidr
- mrc p15, 1, r1, c0, c0, 0 @ read the new csidr
- msr cpsr_c, r9
- and r2, r1, #7 @ extract the length of the cache lines
- add r2, r2, #4 @ add 4 (line length offset)
- ldr r4, =0x3ff
- ands r4, r4, r1, lsr #3 @ find maximum number on the way size
- clz r5, r4 @ find bit position of way size increment
- ldr r7, =0x7fff
- ands r7, r7, r1, lsr #13 @ extract max number of the index size
-loop1:
- mov r9, r7 @ create working copy of max index
-loop2:
- orr r11, r10, r4, lsl r5 @ factor way and cache number into r11
- orr r11, r11, r9, lsl r2 @ factor index number into r11
- mcr p15, 0, r11, c7, c14, 2 @ clean & invalidate by set/way
- subs r9, r9, #1 @ decrement the index
- bge loop2
- subs r4, r4, #1 @ decrement the way
- bge loop1
-skip:
- add r10, r10, #2 @ increment cache number
- cmp r3, r10
- bgt flush_levels
-finished:
- mov r10, #0 @ swith back to cache level 0
- mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr
- dsb st
- isb
- bx lr
-
_sunxi_cpu_entry:
@ Set SMP bit
mrc p15, 0, r0, c1, c0, 1
@@ -262,21 +215,7 @@ _sunxi_cpu_entry:

.globl psci_cpu_off
psci_cpu_off:
- mrc p15, 0, r0, c1, c0, 0 @ SCTLR
- bic r0, r0, #(1 << 2) @ Clear C bit
- mcr p15, 0, r0, c1, c0, 0 @ SCTLR
- isb
- dsb
-
- bl v7_flush_dcache_all
-
- clrex @ Why???
-
- mrc p15, 0, r0, c1, c0, 1 @ ACTLR
- bic r0, r0, #(1 << 6) @ Clear SMP bit
- mcr p15, 0, r0, c1, c0, 1 @ ACTLR
- isb
- dsb
+ bl psci_cpu_off_common

@ Ask CPU0 to pull the rug...
movw r0, #(GICD_BASE & 0xffff)
--
2.1.4