[RFC] powerpc: add kexec support on Book-E
Sebastian Andrzej Siewior
sebastian at breakpoint.cc
Wed Oct 1 17:20:22 EDT 2008
From: Sebastian Andrzej Siewior <bigeasy at linutronix.de>
The relocate_new_kernel() code usually disables the MMU and the small code
operates on physicall addresses while moving the kernel to its final
position. Book-E doesn't support this so a 1:1 mapping must be created.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy at linutronix.de>
---
arch/powerpc/include/asm/kexec.h | 4 +
arch/powerpc/kernel/machine_kexec_32.c | 16 +++-
arch/powerpc/kernel/misc_32.S | 139 ++++++++++++++++++++++++++++++-
3 files changed, 151 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index 3736d9b..3907b24 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -31,6 +31,9 @@
#define KEXEC_ARCH KEXEC_ARCH_PPC
#endif
+#define KEXEC_MODE_NOMMU 1
+#define KEXEC_MODE_BOOKE 2
+
#ifndef __ASSEMBLY__
#include <linux/cpumask.h>
@@ -124,6 +127,7 @@ struct kimage;
struct pt_regs;
extern void default_machine_kexec(struct kimage *image);
extern int default_machine_kexec_prepare(struct kimage *image);
+extern int booke_machine_kexec_prepare(struct kimage *image);
extern void default_machine_crash_shutdown(struct pt_regs *regs);
extern int crash_shutdown_register(crash_shutdown_t handler);
extern int crash_shutdown_unregister(crash_shutdown_t handler);
diff --git a/arch/powerpc/kernel/machine_kexec_32.c b/arch/powerpc/kernel/machine_kexec_32.c
index ae63a96..6611002 100644
--- a/arch/powerpc/kernel/machine_kexec_32.c
+++ b/arch/powerpc/kernel/machine_kexec_32.c
@@ -16,11 +16,13 @@
#include <asm/hw_irq.h>
#include <asm/io.h>
-typedef NORET_TYPE void (*relocate_new_kernel_t)(
+typedef void (*relocate_new_kernel_t)(
unsigned long indirection_page,
unsigned long reboot_code_buffer,
- unsigned long start_address) ATTRIB_NORET;
+ unsigned long start_address,
+ unsigned long mmu_mode);
+static unsigned long mmu_mode;
/*
* This is a generic machine_kexec function suitable at least for
* non-OpenFirmware embedded platforms.
@@ -56,10 +58,18 @@ void default_machine_kexec(struct kimage *image)
/* now call it */
rnk = (relocate_new_kernel_t) reboot_code_buffer;
- (*rnk)(page_list, reboot_code_buffer_phys, image->start);
+ (*rnk)(page_list, reboot_code_buffer_phys, image->start, mmu_mode);
+ BUG();
}
int default_machine_kexec_prepare(struct kimage *image)
{
+ mmu_mode = KEXEC_MODE_NOMMU;
+ return 0;
+}
+
+int booke_machine_kexec_prepare(struct kimage *image)
+{
+ mmu_mode = KEXEC_MODE_BOOKE;
return 0;
}
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index 7a6dfbc..519d752 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -877,9 +877,131 @@ relocate_new_kernel:
/* r3 = page_list */
/* r4 = reboot_code_buffer */
/* r5 = start_address */
+ /* r6 = mmu handling */
- li r0, 0
+ mflr r28
+ mr r29, r3
+ mr r30, r4
+ mr r31, r5
+
+ li r0, KEXEC_MODE_NOMMU
+ cmpw r0, r6
+ beq disable_mmu
+
+ li r0, KEXEC_MODE_BOOKE
+ cmpw r0, r6
+ beq create_linear_mapping
+
+ blr
+create_linear_mapping:
+ li r25, 0 /* phys kernel start (low) */
+
+/* 1. Find the index of the entry we're executing in */
+ bl invstr /* Find our address */
+invstr:
+ mflr r6 /* Make it accessible */
+ mfmsr r7
+ rlwinm r4,r7,27,31,31 /* extract MSR[IS] */
+ mfspr r7, SPRN_PID0
+ slwi r7,r7,16
+ or r7,r7,r4
+ mtspr SPRN_MAS6,r7
+ tlbsx 0,r6 /* search MSR[IS], SPID=PID0 */
+ mfspr r7,SPRN_MAS1
+ andis. r7,r7,MAS1_VALID at h
+ bne match_TLB
+
+ /*
+ * We search just in PID0 because kernel's global mapping has to be
+ * there. We simply return to the caller if we didn't find the mapping
+ * since we didn't (yet) pass the point of no return. This should not
+ * happen.
+ */
+ mtlr r28
+ blr
+
+match_TLB:
+ mfspr r7,SPRN_MAS0
+ rlwinm r3,r7,16,20,31 /* Extract MAS0(Entry) */
+
+ mfspr r7,SPRN_MAS1 /* Insure IPROT set */
+ oris r7,r7,MAS1_IPROT at h
+ mtspr SPRN_MAS1,r7
+ tlbwe
+
+/* 2. Invalidate all entries except the entry we're executing in */
+ mfspr r9,SPRN_TLB1CFG
+ andi. r9,r9,0xfff
+ li r6,0 /* Set Entry counter to 0 */
+1:
+ lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */
+ rlwimi r7,r6,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r6) */
+ mtspr SPRN_MAS0,r7
+ tlbre
+ mfspr r7,SPRN_MAS1
+ rlwinm r7,r7,0,2,31 /* Clear MAS1 Valid and IPROT */
+ cmpw r3,r6
+ beq skpinv /* Dont update the current execution TLB */
+ mtspr SPRN_MAS1,r7
+ tlbwe
+ isync
+skpinv:
+ addi r6,r6,1 /* Increment */
+ cmpw r6,r9 /* Are we done? */
+ bne 1b /* If not, repeat */
+
+ /* Invalidate TLB0 */
+ li r6,0x04
+ tlbivax 0,r6
+ TLBSYNC
+ /* Invalidate TLB1 */
+ li r6,0x0c
+ tlbivax 0,r6
+ TLBSYNC
+
+/* 3. Setup a temp mapping and jump to it */
+ andi. r5, r3, 0x1 /* Find an entry not used and is non-zero */
+ addi r5, r5, 0x1
+ lis r7, 0x1000 /* Set MAS0(TLBSEL) = 1 */
+ rlwimi r7, r3, 16, 4, 15 /* Setup MAS0 = TLBSEL | ESEL(r3) */
+ mtspr SPRN_MAS0,r7
+ tlbre
+
+ /* Just modify the entry ID and EPN for the temp mapping */
+ lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */
+ rlwimi r7,r5,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r5) */
+ mtspr SPRN_MAS0,r7
+
+ xori r6,r4,1 /* Setup TMP mapping in the other Address space */
+ slwi r6,r6,12
+ oris r6,r6,(MAS1_VALID|MAS1_IPROT)@h
+ ori r6,r6,(MAS1_TSIZE(BOOKE_PAGESZ_1GB))@l
+ mtspr SPRN_MAS1,r6
+
+ lis r7, MAS2_I | MAS2_G
+ mtspr SPRN_MAS2,r7
+
+ li r8, 0
+ ori r8,r25,(MAS3_SX|MAS3_SW|MAS3_SR)
+ mtspr SPRN_MAS3,r8
+
+ tlbwe
+
+ xori r6, r4, 1
+ slwi r5, r6, 4 /* DS setup new context with other address space */
+ slwi r6, r6, 5 /* IS setup new context with other address space */
+ or r6, r6, r5
+
+ /* find our address */
+ addi r7, r30, final_copy_code - relocate_new_kernel
+
+ mtspr SPRN_SRR0,r7
+ mtspr SPRN_SRR1,r6
+ rfi
+
+disable_mmu:
+ li r0, 0
/*
* Set Machine Status Register to a known status,
* switch the MMU off and jump to 1: in a single step.
@@ -888,14 +1010,21 @@ relocate_new_kernel:
mr r8, r0
ori r8, r8, MSR_RI|MSR_ME
mtspr SPRN_SRR1, r8
- addi r8, r4, 1f - relocate_new_kernel
+ addi r8, r4, final_copy_code - relocate_new_kernel
mtspr SPRN_SRR0, r8
sync
rfi
-1:
- /* from this point address translation is turned off */
- /* and interrupts are disabled */
+final_copy_code:
+
+ mr r3, r29
+ mr r4, r30
+ mr r5, r31
+
+ li r0, 0
+
+ /* from this point address translation is turned off or we have */
+ /* a 1:1 mapping and interrupts are disabled */
/* set a new stack at the bottom of our page... */
/* (not really needed now) */
--
1.5.6.5
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