[RFC PATCH 07/12] [WIP] powerpc/tm: Add TM_KERNEL_ENTRY in more delicate exception pathes
Cyril Bur
cyrilbur at gmail.com
Tue Feb 20 11:22:36 AEDT 2018
---
arch/powerpc/kernel/entry_64.S | 15 ++++++++++++++-
arch/powerpc/kernel/exceptions-64s.S | 31 ++++++++++++++++++++++++++++---
2 files changed, 42 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 107c15c6f48b..32e8d8f7e091 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -967,7 +967,20 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
bl __check_irq_replay
cmpwi cr0,r3,0
beq .Lrestore_no_replay
-
+
+ /*
+ * We decide VERY late if we need to replay interrupts, theres
+ * not much which can be done about that so this will have to
+ * do
+ */
+ TM_KERNEL_ENTRY
+ /*
+ * This will restore r3 that TM_KERNEL_ENTRY clobbered.
+ * Clearly not ideal! I wonder if we could change the trap
+ * value beforehand...
+ */
+ bl __check_irq_replay
+
/*
* We need to re-emit an interrupt. We do so by re-using our
* existing exception frame. We first change the trap value,
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 3ac87e53b3da..c8899bf77fb0 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -504,6 +504,11 @@ EXC_COMMON_BEGIN(data_access_common)
li r5,0x300
std r3,_DAR(r1)
std r4,_DSISR(r1)
+ /*
+ * Can't do TM_KERNEL_ENTRY here as do_hash_page might jump to
+ * very late in the expection exit code, well after any
+ * possiblity of doing a recheckpoint
+ */
BEGIN_MMU_FTR_SECTION
b do_hash_page /* Try to handle as hpte fault */
MMU_FTR_SECTION_ELSE
@@ -548,6 +553,11 @@ EXC_COMMON_BEGIN(instruction_access_common)
li r5,0x400
std r3,_DAR(r1)
std r4,_DSISR(r1)
+ /*
+ * Can't do TM_KERNEL_ENTRY here as do_hash_page might jump to
+ * very late in the expection exit code, well after any
+ * possiblity of doing a recheckpoint
+ */
BEGIN_MMU_FTR_SECTION
b do_hash_page /* Try to handle as hpte fault */
MMU_FTR_SECTION_ELSE
@@ -761,6 +771,7 @@ EXC_COMMON_BEGIN(alignment_common)
std r4,_DSISR(r1)
bl save_nvgprs
RECONCILE_IRQ_STATE(r10, r11)
+ TM_KERNEL_ENTRY
addi r3,r1,STACK_FRAME_OVERHEAD
bl alignment_exception
b ret_from_except
@@ -1668,7 +1679,9 @@ do_hash_page:
/* Here we have a page fault that hash_page can't handle. */
handle_page_fault:
-11: andis. r0,r4,DSISR_DABRMATCH at h
+11: TM_KERNEL_ENTRY
+ ld r4,_DSISR(r1)
+ andis. r0,r4,DSISR_DABRMATCH at h
bne- handle_dabr_fault
ld r4,_DAR(r1)
ld r5,_DSISR(r1)
@@ -1685,6 +1698,10 @@ handle_page_fault:
/* We have a data breakpoint exception - handle it */
handle_dabr_fault:
+ /*
+ * Don't need to do TM_KERNEL_ENTRY here as we'll
+ * come from handle_page_fault: which has done it already
+ */
bl save_nvgprs
ld r4,_DAR(r1)
ld r5,_DSISR(r1)
@@ -1698,7 +1715,14 @@ handle_dabr_fault:
* the PTE insertion
*/
13: bl save_nvgprs
- mr r5,r3
+ /*
+ * Use a non-volatile as the TM code will call, r3 is the
+ * return value from __hash_page() so not exactly easy to get
+ * again.
+ */
+ mr r31,r3
+ TM_KERNEL_ENTRY
+ mr r5, r31
addi r3,r1,STACK_FRAME_OVERHEAD
ld r4,_DAR(r1)
bl low_hash_fault
@@ -1713,7 +1737,8 @@ handle_dabr_fault:
* the access, or panic if there isn't a handler.
*/
77: bl save_nvgprs
- mr r4,r3
+ TM_KERNEL_ENTRY
+ ld r4,_DAR(r1)
addi r3,r1,STACK_FRAME_OVERHEAD
li r5,SIGSEGV
bl bad_page_fault
--
2.16.2
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