[PATCH V3 2/2] powerpc/kexec: Reset HILE before entering target kernel
Samuel Mendoza-Jonas
sam.mj at au1.ibm.com
Fri Jul 10 15:19:59 AEST 2015
On powernv secondary cpus are returned to OPAL, and will then enter the
target kernel in big-endian. However if it is set the HILE bit will persist,
causing the first exception in the target kernel to be delivered in
litte-endian regardless of the current endianess.
If running on top of OPAL make sure the HILE bit is reset before any
thread branches into the target kernel.
Signed-off-by: Samuel Mendoza-Jonas <sam.mj at au1.ibm.com>
---
arch/powerpc/kernel/machine_kexec_64.c | 6 ++++--
arch/powerpc/kernel/misc_64.S | 19 +++++++++++++++++--
2 files changed, 21 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
index 1a74446..60bb626 100644
--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -29,6 +29,7 @@
#include <asm/prom.h>
#include <asm/smp.h>
#include <asm/hw_breakpoint.h>
+#include <asm/firmware.h>
int default_machine_kexec_prepare(struct kimage *image)
{
@@ -313,7 +314,8 @@ struct paca_struct kexec_paca;
/* Our assembly helper, in misc_64.S */
extern void kexec_sequence(void *newstack, unsigned long start,
void *image, void *control,
- void (*clear_all)(void)) __noreturn;
+ void (*clear_all)(void),
+ unsigned long features) __noreturn;
/* too late to fail here */
void default_machine_kexec(struct kimage *image)
@@ -361,7 +363,7 @@ void default_machine_kexec(struct kimage *image)
*/
kexec_sequence(&kexec_stack, image->start, image,
page_address(image->control_code_page),
- ppc_md.hpte_clear_all);
+ ppc_md.hpte_clear_all, powerpc_firmware_features);
/* NOTREACHED */
}
diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index 6e4168c..abde07d 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -19,6 +19,7 @@
#include <asm/errno.h>
#include <asm/processor.h>
#include <asm/page.h>
+#include <asm/opal.h>
#include <asm/cache.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
@@ -539,7 +540,7 @@ real_mode: /* assume normal blr return */
/*
- * kexec_sequence(newstack, start, image, control, clear_all())
+ * kexec_sequence(newstack, start, image, control, clear_all(), features)
*
* does the grungy work with stack switching and real mode switches
* also does simple calls to other code
@@ -575,7 +576,7 @@ _GLOBAL(kexec_sequence)
mr r29,r5 /* image (virt) */
mr r28,r6 /* control, unused */
mr r27,r7 /* clear_all() fn desc */
- mr r26,r8 /* spare */
+ mr r26,r8 /* powerpc_firmware_features */
lhz r25,PACAHWCPUID(r13) /* get our phys cpu from paca */
/* disable interrupts, we are overwriting kernel data next */
@@ -590,6 +591,20 @@ _GLOBAL(kexec_sequence)
/* turn off mmu */
bl real_mode
+#if defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_PPC_POWERNV)
+ li r3,(FW_FEATURE_OPAL >> 16)
+ rldicr r3,r3,16,63
+ and. r3,r3,r26
+ cmpwi r3,0
+ beq 99f
+
+ /* Reset HILE bit now that interrupts are disabled */
+ li r3,1
+ li r0,OPAL_REINIT_CPUS
+ bl opal_call_realmode
+99:
+#endif
+
/* copy 0x100 bytes starting at start to 0 */
li r3,0
mr r4,r30 /* start, aka phys mem offset */
--
2.4.5
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