ARM: pm: add generic CPU suspend/resume support
This adds core support for saving and restoring CPU coprocessor
registers for suspend/resume support. This contains support for suspend
with ARM920, ARM926, SA11x0, PXA25x, PXA27x, PXA3xx, V6 and V7 CPUs.
Tested on Assabet and Tegra 2.
Tested-by: Colin Cross <ccross@android.com>
Tested-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index 185ee82..74554f1 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -29,6 +29,7 @@
obj-$(CONFIG_ARTHUR) += arthur.o
obj-$(CONFIG_ISA_DMA) += dma-isa.o
obj-$(CONFIG_PCI) += bios32.o isa.o
+obj-$(CONFIG_PM) += sleep.o
obj-$(CONFIG_HAVE_SCHED_CLOCK) += sched_clock.o
obj-$(CONFIG_SMP) += smp.o smp_tlb.o
obj-$(CONFIG_HAVE_ARM_SCU) += smp_scu.o
diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c
index 5302a91..927522c 100644
--- a/arch/arm/kernel/asm-offsets.c
+++ b/arch/arm/kernel/asm-offsets.c
@@ -13,6 +13,7 @@
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/dma-mapping.h>
+#include <asm/cacheflush.h>
#include <asm/glue-df.h>
#include <asm/glue-pf.h>
#include <asm/mach/arch.h>
@@ -116,6 +117,14 @@
#ifdef MULTI_PABORT
DEFINE(PROCESSOR_PABT_FUNC, offsetof(struct processor, _prefetch_abort));
#endif
+#ifdef MULTI_CPU
+ DEFINE(CPU_SLEEP_SIZE, offsetof(struct processor, suspend_size));
+ DEFINE(CPU_DO_SUSPEND, offsetof(struct processor, do_suspend));
+ DEFINE(CPU_DO_RESUME, offsetof(struct processor, do_resume));
+#endif
+#ifdef MULTI_CACHE
+ DEFINE(CACHE_FLUSH_KERN_ALL, offsetof(struct cpu_cache_fns, flush_kern_all));
+#endif
BLANK();
DEFINE(DMA_BIDIRECTIONAL, DMA_BIDIRECTIONAL);
DEFINE(DMA_TO_DEVICE, DMA_TO_DEVICE);
diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S
new file mode 100644
index 0000000..2ba1794
--- /dev/null
+++ b/arch/arm/kernel/sleep.S
@@ -0,0 +1,109 @@
+#include <linux/linkage.h>
+#include <asm/asm-offsets.h>
+#include <asm/assembler.h>
+#include <asm/glue-cache.h>
+#include <asm/glue-proc.h>
+#include <asm/system.h>
+ .text
+
+/*
+ * Save CPU state for a suspend
+ * r1 = v:p offset
+ * r3 = virtual return function
+ * Note: sp is decremented to allocate space for CPU state on stack
+ * r0-r3,r9,r10,lr corrupted
+ */
+ENTRY(cpu_suspend)
+ mov r9, lr
+#ifdef MULTI_CPU
+ ldr r10, =processor
+ mov r2, sp @ current virtual SP
+ ldr r0, [r10, #CPU_SLEEP_SIZE] @ size of CPU sleep state
+ ldr ip, [r10, #CPU_DO_RESUME] @ virtual resume function
+ sub sp, sp, r0 @ allocate CPU state on stack
+ mov r0, sp @ save pointer
+ add ip, ip, r1 @ convert resume fn to phys
+ stmfd sp!, {r1, r2, r3, ip} @ save v:p, virt SP, retfn, phys resume fn
+ ldr r3, =sleep_save_sp
+ add r2, sp, r1 @ convert SP to phys
+ str r2, [r3] @ save phys SP
+ mov lr, pc
+ ldr pc, [r10, #CPU_DO_SUSPEND] @ save CPU state
+#else
+ mov r2, sp @ current virtual SP
+ ldr r0, =cpu_suspend_size
+ sub sp, sp, r0 @ allocate CPU state on stack
+ mov r0, sp @ save pointer
+ stmfd sp!, {r1, r2, r3} @ save v:p, virt SP, return fn
+ ldr r3, =sleep_save_sp
+ add r2, sp, r1 @ convert SP to phys
+ str r2, [r3] @ save phys SP
+ bl cpu_do_suspend
+#endif
+
+ @ flush data cache
+#ifdef MULTI_CACHE
+ ldr r10, =cpu_cache
+ mov lr, r9
+ ldr pc, [r10, #CACHE_FLUSH_KERN_ALL]
+#else
+ mov lr, r9
+ b __cpuc_flush_kern_all
+#endif
+ENDPROC(cpu_suspend)
+ .ltorg
+
+/*
+ * r0 = control register value
+ * r1 = v:p offset (preserved by cpu_do_resume)
+ * r2 = phys page table base
+ * r3 = L1 section flags
+ */
+ENTRY(cpu_resume_mmu)
+ adr r4, cpu_resume_turn_mmu_on
+ mov r4, r4, lsr #20
+ orr r3, r3, r4, lsl #20
+ ldr r5, [r2, r4, lsl #2] @ save old mapping
+ str r3, [r2, r4, lsl #2] @ setup 1:1 mapping for mmu code
+ sub r2, r2, r1
+ ldr r3, =cpu_resume_after_mmu
+ bic r1, r0, #CR_C @ ensure D-cache is disabled
+ b cpu_resume_turn_mmu_on
+ENDPROC(cpu_resume_mmu)
+ .ltorg
+ .align 5
+cpu_resume_turn_mmu_on:
+ mcr p15, 0, r1, c1, c0, 0 @ turn on MMU, I-cache, etc
+ mrc p15, 0, r1, c0, c0, 0 @ read id reg
+ mov r1, r1
+ mov r1, r1
+ mov pc, r3 @ jump to virtual address
+ENDPROC(cpu_resume_turn_mmu_on)
+cpu_resume_after_mmu:
+ str r5, [r2, r4, lsl #2] @ restore old mapping
+ mcr p15, 0, r0, c1, c0, 0 @ turn on D-cache
+ mov pc, lr
+ENDPROC(cpu_resume_after_mmu)
+
+/*
+ * Note: Yes, part of the following code is located into the .data section.
+ * This is to allow sleep_save_sp to be accessed with a relative load
+ * while we can't rely on any MMU translation. We could have put
+ * sleep_save_sp in the .text section as well, but some setups might
+ * insist on it to be truly read-only.
+ */
+ .data
+ .align
+ENTRY(cpu_resume)
+ ldr r0, sleep_save_sp @ stack phys addr
+ msr cpsr_c, #PSR_I_BIT | PSR_F_BIT | SVC_MODE @ set SVC, irqs off
+#ifdef MULTI_CPU
+ ldmia r0!, {r1, sp, lr, pc} @ load v:p, stack, return fn, resume fn
+#else
+ ldmia r0!, {r1, sp, lr} @ load v:p, stack, return fn
+ b cpu_do_resume
+#endif
+ENDPROC(cpu_resume)
+
+sleep_save_sp:
+ .word 0 @ preserve stack phys ptr here