Le 05/11/2020 à 15:34, Nicholas Piggin a écrit :
Make mm fault handlers all just take the pt_regs * argument and load
DAR/DSISR from that. Make those that return a value return long.
This is done to make the function signatures match other handlers, which
will help with a future patch to add wrappers. Explicit arguments could
be added for performance but that would require more wrapper macro
variants.
Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
arch/powerpc/include/asm/asm-prototypes.h | 4 ++--
arch/powerpc/include/asm/bug.h | 4 ++--
arch/powerpc/kernel/exceptions-64e.S | 2 --
arch/powerpc/kernel/exceptions-64s.S | 14 ++------------
arch/powerpc/kernel/head_40x.S | 10 +++++-----
arch/powerpc/kernel/head_8xx.S | 6 +++---
arch/powerpc/kernel/head_book3s_32.S | 6 ++----
arch/powerpc/kernel/head_booke.h | 4 +---
arch/powerpc/mm/book3s64/hash_utils.c | 8 +++++---
arch/powerpc/mm/book3s64/slb.c | 11 +++++++----
arch/powerpc/mm/fault.c | 16 +++++++++-------
11 files changed, 38 insertions(+), 47 deletions(-)
diff --git a/arch/powerpc/include/asm/asm-prototypes.h
b/arch/powerpc/include/asm/asm-prototypes.h
index d0b832cbbec8..22c9d08fa3a4 100644
--- a/arch/powerpc/include/asm/asm-prototypes.h
+++ b/arch/powerpc/include/asm/asm-prototypes.h
@@ -82,8 +82,8 @@ void kernel_bad_stack(struct pt_regs *regs);
void system_reset_exception(struct pt_regs *regs);
void machine_check_exception(struct pt_regs *regs);
void emulation_assist_interrupt(struct pt_regs *regs);
-long do_slb_fault(struct pt_regs *regs, unsigned long ea);
-void do_bad_slb_fault(struct pt_regs *regs, unsigned long ea, long err);
+long do_slb_fault(struct pt_regs *regs);
+void do_bad_slb_fault(struct pt_regs *regs);
/* signals, syscalls and interrupts */
long sys_swapcontext(struct ucontext __user *old_ctx,
diff --git a/arch/powerpc/include/asm/bug.h b/arch/powerpc/include/asm/bug.h
index d714d83bbc7c..2fa0cf6c6011 100644
--- a/arch/powerpc/include/asm/bug.h
+++ b/arch/powerpc/include/asm/bug.h
@@ -111,8 +111,8 @@
#ifndef __ASSEMBLY__
struct pt_regs;
-extern int do_page_fault(struct pt_regs *, unsigned long, unsigned long);
-extern int hash__do_page_fault(struct pt_regs *, unsigned long, unsigned long);
+extern long do_page_fault(struct pt_regs *);
+extern long hash__do_page_fault(struct pt_regs *);
extern is pointless
extern void bad_page_fault(struct pt_regs *, unsigned long, int);
extern void _exception(int, struct pt_regs *, int, unsigned long);
extern void _exception_pkey(struct pt_regs *, unsigned long, int);
diff --git a/arch/powerpc/kernel/exceptions-64e.S
b/arch/powerpc/kernel/exceptions-64e.S
index f579ce46eef2..25fa7d5a643c 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -1011,8 +1011,6 @@ storage_fault_common:
std r14,_DAR(r1)
std r15,_DSISR(r1)
addi r3,r1,STACK_FRAME_OVERHEAD
- mr r4,r14
- mr r5,r15
ld r14,PACA_EXGEN+EX_R14(r13)
ld r15,PACA_EXGEN+EX_R15(r13)
bl do_page_fault
diff --git a/arch/powerpc/kernel/exceptions-64s.S
b/arch/powerpc/kernel/exceptions-64s.S
index f830b893fe03..1f34cfd1887c 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1437,8 +1437,6 @@ EXC_VIRT_BEGIN(data_access, 0x4300, 0x80)
EXC_VIRT_END(data_access, 0x4300, 0x80)
EXC_COMMON_BEGIN(data_access_common)
GEN_COMMON data_access
- ld r4,_DAR(r1)
- ld r5,_DSISR(r1)
addi r3,r1,STACK_FRAME_OVERHEAD
BEGIN_MMU_FTR_SECTION
bl do_hash_fault
@@ -1491,10 +1489,9 @@ EXC_VIRT_BEGIN(data_access_slb, 0x4380, 0x80)
EXC_VIRT_END(data_access_slb, 0x4380, 0x80)
EXC_COMMON_BEGIN(data_access_slb_common)
GEN_COMMON data_access_slb
- ld r4,_DAR(r1)
- addi r3,r1,STACK_FRAME_OVERHEAD
BEGIN_MMU_FTR_SECTION
/* HPT case, do SLB fault */
+ addi r3,r1,STACK_FRAME_OVERHEAD
bl do_slb_fault
cmpdi r3,0
bne- 1f
@@ -1506,8 +1503,6 @@ MMU_FTR_SECTION_ELSE
ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
std r3,RESULT(r1)
RECONCILE_IRQ_STATE(r10, r11)
- ld r4,_DAR(r1)
- ld r5,RESULT(r1)
addi r3,r1,STACK_FRAME_OVERHEAD
bl do_bad_slb_fault
b interrupt_return
@@ -1542,8 +1537,6 @@ EXC_VIRT_BEGIN(instruction_access, 0x4400, 0x80)
EXC_VIRT_END(instruction_access, 0x4400, 0x80)
EXC_COMMON_BEGIN(instruction_access_common)
GEN_COMMON instruction_access
- ld r4,_DAR(r1)
- ld r5,_DSISR(r1)
addi r3,r1,STACK_FRAME_OVERHEAD
BEGIN_MMU_FTR_SECTION
bl do_hash_fault
@@ -1587,10 +1580,9 @@ EXC_VIRT_BEGIN(instruction_access_slb, 0x4480, 0x80)
EXC_VIRT_END(instruction_access_slb, 0x4480, 0x80)
EXC_COMMON_BEGIN(instruction_access_slb_common)
GEN_COMMON instruction_access_slb
- ld r4,_DAR(r1)
- addi r3,r1,STACK_FRAME_OVERHEAD
BEGIN_MMU_FTR_SECTION
/* HPT case, do SLB fault */
+ addi r3,r1,STACK_FRAME_OVERHEAD
bl do_slb_fault
cmpdi r3,0
bne- 1f
@@ -1602,8 +1594,6 @@ MMU_FTR_SECTION_ELSE
ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
std r3,RESULT(r1)
RECONCILE_IRQ_STATE(r10, r11)
- ld r4,_DAR(r1)
- ld r5,RESULT(r1)
addi r3,r1,STACK_FRAME_OVERHEAD
bl do_bad_slb_fault
b interrupt_return
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 44c9018aed1b..ea31f75e9692 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -179,9 +179,9 @@ _ENTRY(saved_ksp_limit)
*/
START_EXCEPTION(0x0300, DataStorage)
EXCEPTION_PROLOG
- mfspr r5, SPRN_ESR /* Grab the ESR, save it, pass arg3 */
+ mfspr r5, SPRN_ESR /* Grab the ESR, save it */
stw r5, _ESR(r11)
- mfspr r4, SPRN_DEAR /* Grab the DEAR, save it, pass arg2 */
+ mfspr r4, SPRN_DEAR /* Grab the DEAR, save it */
stw r4, _DEAR(r11)
EXC_XFER_LITE(0x300, handle_page_fault)
@@ -191,9 +191,9 @@ _ENTRY(saved_ksp_limit)
*/
START_EXCEPTION(0x0400, InstructionAccess)
EXCEPTION_PROLOG
- mr r4,r12 /* Pass SRR0 as arg2 */
- stw r4, _DEAR(r11)
- li r5,0 /* Pass zero as arg3 */
+ li r5,0
+ stw r5, _ESR(r11) /* Zero ESR */
+ stw r12, _DEAR(r11) /* SRR0 as DEAR */
I think we should avoid this, see below
EXC_XFER_LITE(0x400, handle_page_fault)
/* 0x0500 - External Interrupt Exception */
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 9f359d3fba74..0cd95b633e2b 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -356,14 +356,14 @@ DataStoreTLBMiss:
. = 0x1300
InstructionTLBError:
EXCEPTION_PROLOG
- mr r4,r12
andis. r5,r9,DSISR_SRR1_MATCH_32S@h /* Filter relevant SRR1 bits */
Could avoid this, see below
andis. r10,r9,SRR1_ISI_NOPT@h
beq+ .Litlbie
- tlbie r4
+ tlbie r12
/* 0x400 is InstructionAccess exception, needed by bad_page_fault() */
.Litlbie:
- stw r4, _DAR(r11)
+ stw r12, _DAR(r11)
+ stw r5, _DSISR(r11)
And this
EXC_XFER_LITE(0x400, handle_page_fault)
/* This is the data TLB error on the MPC8xx. This could be due to
diff --git a/arch/powerpc/kernel/head_book3s_32.S
b/arch/powerpc/kernel/head_book3s_32.S
index 5eb9eedac920..81c69769cec6 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -369,9 +369,9 @@ BEGIN_MMU_FTR_SECTION
bl hash_page
END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
#endif /* CONFIG_VMAP_STACK */
-1: mr r4,r12
andis. r5,r9,DSISR_SRR1_MATCH_32S@h /* Filter relevant SRR1 bits */
- stw r4, _DAR(r11)
+ stw r5, _DSISR(r11)
+ stw r12, _DAR(r11)
And this including the andis.
EXC_XFER_LITE(0x400, handle_page_fault)
/* External interrupt */
@@ -698,8 +698,6 @@ handle_page_fault_tramp_1:
#ifdef CONFIG_VMAP_STACK
EXCEPTION_PROLOG_2 handle_dar_dsisr=1
#endif
- lwz r4, _DAR(r11)
- lwz r5, _DSISR(r11)
/* fall through */
handle_page_fault_tramp_2:
EXC_XFER_LITE(0x300, handle_page_fault)
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 71c359d438b5..1da0c1d1b0a1 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -477,9 +477,7 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
NORMAL_EXCEPTION_PROLOG(INST_STORAGE); \
mfspr r5,SPRN_ESR; /* Grab the ESR and save it */ \
stw r5,_ESR(r11); \
- mr r4,r12; /* Pass SRR0 as arg2 */ \
- stw r4, _DEAR(r11); \
- li r5,0; /* Pass zero as arg3 */ \
+ stw r12, _DEAR(r11); /* Pass SRR0 as arg2 */ \
And this
EXC_XFER_LITE(0x0400, handle_page_fault)
#define ALIGNMENT_EXCEPTION \
diff --git a/arch/powerpc/mm/book3s64/hash_utils.c
b/arch/powerpc/mm/book3s64/hash_utils.c
index bfa1b1966218..0f0bd4af4b2d 100644
--- a/arch/powerpc/mm/book3s64/hash_utils.c
+++ b/arch/powerpc/mm/book3s64/hash_utils.c
@@ -1510,13 +1510,15 @@ int hash_page(unsigned long ea, unsigned long access,
unsigned long trap,
}
EXPORT_SYMBOL_GPL(hash_page);
-int do_hash_fault(struct pt_regs *regs, unsigned long ea, unsigned long dsisr)
+long do_hash_fault(struct pt_regs *regs)
{
+ unsigned long ea = regs->dar;
+ unsigned long dsisr = regs->dsisr;
unsigned long access = _PAGE_PRESENT | _PAGE_READ;
unsigned long flags = 0;
struct mm_struct *mm;
unsigned int region_id;
- int err;
+ long err;
if (unlikely(dsisr & (DSISR_BAD_FAULT_64S | DSISR_DABRMATCH | DSISR_KEYFAULT)))
goto _do_page_fault;
@@ -1580,7 +1582,7 @@ int do_hash_fault(struct pt_regs *regs, unsigned long ea,
unsigned long dsisr)
} else if (err) {
_do_page_fault:
- err = hash__do_page_fault(regs, ea, dsisr);
+ err = hash__do_page_fault(regs);
}
return err;
diff --git a/arch/powerpc/mm/book3s64/slb.c b/arch/powerpc/mm/book3s64/slb.c
index c30fcbfa0e32..cc34d50874c1 100644
--- a/arch/powerpc/mm/book3s64/slb.c
+++ b/arch/powerpc/mm/book3s64/slb.c
@@ -837,8 +837,9 @@ static long slb_allocate_user(struct mm_struct *mm,
unsigned long ea)
return slb_insert_entry(ea, context, flags, ssize, false);
}
-long do_slb_fault(struct pt_regs *regs, unsigned long ea)
+long do_slb_fault(struct pt_regs *regs)
{
+ unsigned long ea = regs->dar;
unsigned long id = get_region_id(ea);
/* IRQs are not reconciled here, so can't check irqs_disabled */
@@ -889,13 +890,15 @@ long do_slb_fault(struct pt_regs *regs, unsigned long ea)
}
}
-void do_bad_slb_fault(struct pt_regs *regs, unsigned long ea, long err)
+void do_bad_slb_fault(struct pt_regs *regs)
{
+ int err = regs->result;
+
if (err == -EFAULT) {
if (user_mode(regs))
- _exception(SIGSEGV, regs, SEGV_BNDERR, ea);
+ _exception(SIGSEGV, regs, SEGV_BNDERR, regs->dar);
else
- bad_page_fault(regs, ea, SIGSEGV);
+ bad_page_fault(regs, regs->dar, SIGSEGV);
} else if (err == -EINVAL) {
unrecoverable_exception(regs);
} else {
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index e65a49f246ef..390a296b16a3 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -549,11 +549,12 @@ static int __do_page_fault(struct pt_regs *regs, unsigned
long address,
}
NOKPROBE_SYMBOL(__do_page_fault);
-int do_page_fault(struct pt_regs *regs, unsigned long address,
- unsigned long error_code)
+long do_page_fault(struct pt_regs *regs)
{
enum ctx_state prev_state = exception_enter();
- int err;
+ unsigned long address = regs->dar;
+ unsigned long error_code = regs->dsisr;
+ long err;
By doing something more or less like this (need to be tuned for bookE as well):
+ int is_exec = TRAP(regs) == 0x400;
+ unsigned long address = is_exec ? regs->ssr0 : regs->dar;
+ unsigned long error_code = is_exec ? (regs->ssr1 & DSISR_SRR1_MATCH_32S) :
regs->dsisr;
err = __do_page_fault(regs, address, error_code);
@@ -580,11 +581,12 @@ int do_page_fault(struct pt_regs *regs, unsigned long address,
NOKPROBE_SYMBOL(do_page_fault);
#ifdef CONFIG_PPC_BOOK3S_64
-/* Same as do_page_fault but interrupt entry has already run in do_hash_fault
*/
-int hash__do_page_fault(struct pt_regs *regs, unsigned long address,
- unsigned long error_code)
+/* Same as do_page_fault but no interrupt entry */
+long hash__do_page_fault(struct pt_regs *regs)
{
- int err;
+ unsigned long address = regs->dar;
+ unsigned long error_code = regs->dsisr;
+ long err;
err = __do_page_fault(regs, address, error_code);
if (unlikely(err)) {
There is probably also something we can simplify around get_and_save_dar_dsisr_on_stack() macro in
head_32.h, no need to reload DAR, at least for 8xx. Maybe as a followup patch later.
Christophe
