* [PATCH v2 21/43] powerpc/32: Provide a name to exception prolog continuation in virtual mode
From: Christophe Leroy @ 2021-03-09 12:09 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615291471.git.christophe.leroy@csgroup.eu>
Now that the prolog continuation is separated in .text, give it a name
and mark it _ASM_NOKPROBE_SYMBOL.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/head_32.h | 12 +++++++-----
arch/powerpc/kernel/head_40x.S | 22 ++++++++++++----------
arch/powerpc/kernel/head_8xx.S | 10 +++++-----
arch/powerpc/kernel/head_book3s_32.S | 14 +++++++-------
4 files changed, 31 insertions(+), 27 deletions(-)
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 3c0aa4538514..160ebd573c37 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -10,10 +10,10 @@
* We assume sprg3 has the physical address of the current
* task's thread_struct.
*/
-.macro EXCEPTION_PROLOG handle_dar_dsisr=0
+.macro EXCEPTION_PROLOG name handle_dar_dsisr=0
EXCEPTION_PROLOG_0 handle_dar_dsisr=\handle_dar_dsisr
EXCEPTION_PROLOG_1
- EXCEPTION_PROLOG_2 handle_dar_dsisr=\handle_dar_dsisr
+ EXCEPTION_PROLOG_2 \name handle_dar_dsisr=\handle_dar_dsisr
.endm
.macro EXCEPTION_PROLOG_0 handle_dar_dsisr=0
@@ -56,7 +56,7 @@
#endif
.endm
-.macro EXCEPTION_PROLOG_2 handle_dar_dsisr=0
+.macro EXCEPTION_PROLOG_2 name handle_dar_dsisr=0
#ifdef CONFIG_PPC_8xx
.if \handle_dar_dsisr
li r11, RPN_PATTERN
@@ -72,6 +72,7 @@
rfi
.text
+\name\()_virt:
1:
stw r11,GPR1(r1)
stw r11,0(r1)
@@ -109,6 +110,7 @@
stw r10,8(r11)
SAVE_4GPRS(3, r11)
SAVE_2GPRS(7, r11)
+_ASM_NOKPROBE_SYMBOL(\name\()_virt)
.endm
.macro SYSCALL_ENTRY trapno
@@ -180,7 +182,7 @@
#define EXCEPTION(n, label, hdlr, xfer) \
START_EXCEPTION(n, label) \
- EXCEPTION_PROLOG; \
+ EXCEPTION_PROLOG label; \
addi r3,r1,STACK_FRAME_OVERHEAD; \
xfer(n, hdlr)
@@ -212,7 +214,7 @@
#endif
lwz r1, emergency_ctx@l(r1)
addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE
- EXCEPTION_PROLOG_2
+ EXCEPTION_PROLOG_2 vmap_stack_overflow
SAVE_NVGPRS(r11)
addi r3, r1, STACK_FRAME_OVERHEAD
EXC_XFER_STD(0, stack_overflow_exception)
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index e7d8856714d3..86883ccb3dc5 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -104,7 +104,7 @@ _ENTRY(crit_esr)
* Instead we use a couple of words of memory at low physical addresses.
* This is OK since we don't support SMP on these processors.
*/
-.macro CRITICAL_EXCEPTION_PROLOG
+.macro CRITICAL_EXCEPTION_PROLOG name
stw r10,crit_r10@l(0) /* save two registers to work with */
stw r11,crit_r11@l(0)
mfspr r10,SPRN_SRR0
@@ -135,6 +135,7 @@ _ENTRY(crit_esr)
.text
1:
+\name\()_virt:
lwz r11,crit_r1@l(0)
stw r11,GPR1(r1)
stw r11,0(r1)
@@ -162,6 +163,7 @@ _ENTRY(crit_esr)
stw r10, 8(r11)
SAVE_4GPRS(3, r11)
SAVE_2GPRS(7, r11)
+_ASM_NOKPROBE_SYMBOL(\name\()_virt)
.endm
/*
@@ -182,7 +184,7 @@ _ENTRY(crit_esr)
*/
#define CRITICAL_EXCEPTION(n, label, hdlr) \
START_EXCEPTION(n, label); \
- CRITICAL_EXCEPTION_PROLOG; \
+ CRITICAL_EXCEPTION_PROLOG label; \
addi r3,r1,STACK_FRAME_OVERHEAD; \
EXC_XFER_TEMPLATE(hdlr, n+2, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \
crit_transfer_to_handler, ret_from_crit_exc)
@@ -205,7 +207,7 @@ _ENTRY(crit_esr)
* if they can't resolve the lightweight TLB fault.
*/
START_EXCEPTION(0x0300, DataStorage)
- EXCEPTION_PROLOG handle_dar_dsisr=1
+ EXCEPTION_PROLOG DataStorage handle_dar_dsisr=1
EXC_XFER_LITE(0x300, handle_page_fault)
/*
@@ -213,7 +215,7 @@ _ENTRY(crit_esr)
* This is caused by a fetch from non-execute or guarded pages.
*/
START_EXCEPTION(0x0400, InstructionAccess)
- EXCEPTION_PROLOG
+ EXCEPTION_PROLOG InstructionAccess
li r5,0
stw r5, _ESR(r11) /* Zero ESR */
stw r12, _DEAR(r11) /* SRR0 as DEAR */
@@ -224,13 +226,13 @@ _ENTRY(crit_esr)
/* 0x0600 - Alignment Exception */
START_EXCEPTION(0x0600, Alignment)
- EXCEPTION_PROLOG handle_dar_dsisr=1
+ EXCEPTION_PROLOG Alignment handle_dar_dsisr=1
addi r3,r1,STACK_FRAME_OVERHEAD
EXC_XFER_STD(0x600, alignment_exception)
/* 0x0700 - Program Exception */
START_EXCEPTION(0x0700, ProgramCheck)
- EXCEPTION_PROLOG handle_dar_dsisr=1
+ EXCEPTION_PROLOG ProgramCheck handle_dar_dsisr=1
addi r3,r1,STACK_FRAME_OVERHEAD
EXC_XFER_STD(0x700, program_check_exception)
@@ -450,7 +452,7 @@ _ENTRY(crit_esr)
*/
/* 0x2000 - Debug Exception */
START_EXCEPTION(0x2000, DebugTrap)
- CRITICAL_EXCEPTION_PROLOG
+ CRITICAL_EXCEPTION_PROLOG DebugTrap
/*
* If this is a single step or branch-taken exception in an
@@ -500,7 +502,7 @@ _ENTRY(crit_esr)
/* Programmable Interval Timer (PIT) Exception. (from 0x1000) */
__HEAD
Decrementer:
- EXCEPTION_PROLOG
+ EXCEPTION_PROLOG Decrementer
lis r0,TSR_PIS@h
mtspr SPRN_TSR,r0 /* Clear the PIT exception */
addi r3,r1,STACK_FRAME_OVERHEAD
@@ -509,14 +511,14 @@ Decrementer:
/* Fixed Interval Timer (FIT) Exception. (from 0x1010) */
__HEAD
FITException:
- EXCEPTION_PROLOG
+ EXCEPTION_PROLOG FITException
addi r3,r1,STACK_FRAME_OVERHEAD;
EXC_XFER_STD(0x1010, unknown_exception)
/* Watchdog Timer (WDT) Exception. (from 0x1020) */
__HEAD
WDTException:
- CRITICAL_EXCEPTION_PROLOG;
+ CRITICAL_EXCEPTION_PROLOG WDTException
addi r3,r1,STACK_FRAME_OVERHEAD;
EXC_XFER_TEMPLATE(WatchdogException, 0x1020+2,
(MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)),
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index d16d0ec71bb2..932702a38234 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -122,7 +122,7 @@ instruction_counter:
/* Machine check */
START_EXCEPTION(0x200, MachineCheck)
- EXCEPTION_PROLOG handle_dar_dsisr=1
+ EXCEPTION_PROLOG MachineCheck handle_dar_dsisr=1
addi r3,r1,STACK_FRAME_OVERHEAD
EXC_XFER_STD(0x200, machine_check_exception)
@@ -131,7 +131,7 @@ instruction_counter:
/* Alignment exception */
START_EXCEPTION(0x600, Alignment)
- EXCEPTION_PROLOG handle_dar_dsisr=1
+ EXCEPTION_PROLOG Alignment handle_dar_dsisr=1
addi r3,r1,STACK_FRAME_OVERHEAD
EXC_XFER_STD(0x600, alignment_exception)
@@ -294,7 +294,7 @@ instruction_counter:
* addresses. There is nothing to do but handle a big time error fault.
*/
START_EXCEPTION(0x1300, InstructionTLBError)
- EXCEPTION_PROLOG
+ EXCEPTION_PROLOG InstructionTLBError
andis. r5,r9,DSISR_SRR1_MATCH_32S@h /* Filter relevant SRR1 bits */
andis. r10,r9,SRR1_ISI_NOPT@h
beq+ .Litlbie
@@ -316,7 +316,7 @@ instruction_counter:
beq- cr1, FixupDAR /* must be a buggy dcbX, icbi insn. */
DARFixed:/* Return from dcbx instruction bug workaround */
EXCEPTION_PROLOG_1
- EXCEPTION_PROLOG_2 handle_dar_dsisr=1
+ EXCEPTION_PROLOG_2 DataTLBError handle_dar_dsisr=1
lwz r4, _DAR(r11)
lwz r5, _DSISR(r11)
andis. r10,r5,DSISR_NOHPTE@h
@@ -347,7 +347,7 @@ DARFixed:/* Return from dcbx instruction bug workaround */
rfi
1: EXCEPTION_PROLOG_1
- EXCEPTION_PROLOG_2 handle_dar_dsisr=1
+ EXCEPTION_PROLOG_2 DataBreakpoint handle_dar_dsisr=1
addi r3,r1,STACK_FRAME_OVERHEAD
mfspr r4,SPRN_BAR
stw r4,_DAR(r11)
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 56d7bc212866..24cb245e1c5b 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -266,7 +266,7 @@ __secondary_hold_acknowledge:
mfspr r1, SPRN_SPRG_SCRATCH2
#endif /* CONFIG_PPC_CHRP */
EXCEPTION_PROLOG_1
-7: EXCEPTION_PROLOG_2
+7: EXCEPTION_PROLOG_2 MachineCheck
addi r3,r1,STACK_FRAME_OVERHEAD
#ifdef CONFIG_PPC_CHRP
beq cr1, 1f
@@ -296,7 +296,7 @@ ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_HPTE_TABLE)
#endif
1: EXCEPTION_PROLOG_0 handle_dar_dsisr=1
EXCEPTION_PROLOG_1
- EXCEPTION_PROLOG_2 handle_dar_dsisr=1
+ EXCEPTION_PROLOG_2 DataAccess handle_dar_dsisr=1
lwz r5, _DSISR(r11)
andis. r0, r5, DSISR_DABRMATCH@h
bne- 1f
@@ -325,7 +325,7 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
andi. r11, r11, MSR_PR
EXCEPTION_PROLOG_1
- EXCEPTION_PROLOG_2
+ EXCEPTION_PROLOG_2 InstructionAccess
andis. r5,r9,DSISR_SRR1_MATCH_32S@h /* Filter relevant SRR1 bits */
stw r5, _DSISR(r11)
stw r12, _DAR(r11)
@@ -336,7 +336,7 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
/* Alignment exception */
START_EXCEPTION(0x600, Alignment)
- EXCEPTION_PROLOG handle_dar_dsisr=1
+ EXCEPTION_PROLOG Alignment handle_dar_dsisr=1
addi r3,r1,STACK_FRAME_OVERHEAD
EXC_XFER_STD(0x600, alignment_exception)
@@ -353,7 +353,7 @@ BEGIN_FTR_SECTION
*/
b ProgramCheck
END_FTR_SECTION_IFSET(CPU_FTR_FPU_UNAVAILABLE)
- EXCEPTION_PROLOG
+ EXCEPTION_PROLOG FPUnavailable
beq 1f
bl load_up_fpu /* if from user, just load it up */
b fast_exception_return
@@ -713,7 +713,7 @@ fast_hash_page_return:
__HEAD
AltiVecUnavailable:
- EXCEPTION_PROLOG
+ EXCEPTION_PROLOG AltiVecUnavailable
#ifdef CONFIG_ALTIVEC
beq 1f
bl load_up_altivec /* if from user, just load it up */
@@ -724,7 +724,7 @@ AltiVecUnavailable:
__HEAD
PerformanceMonitor:
- EXCEPTION_PROLOG
+ EXCEPTION_PROLOG PerformanceMonitor
addi r3,r1,STACK_FRAME_OVERHEAD
EXC_XFER_STD(0xf00, performance_monitor_exception)
--
2.25.0
^ permalink raw reply related
* [PATCH v2 20/43] powerpc/32: Move exception prolog code into .text once MMU is back on
From: Christophe Leroy @ 2021-03-09 12:09 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615291471.git.christophe.leroy@csgroup.eu>
The space in the head section is rather constrained by the fact that
exception vectors are spread every 0x100 bytes and sometimes we
need to have "out of line" code because it doesn't fit.
Now that we are enabling MMU early in the prolog, take that opportunity
to jump somewhere else in the .text section where we don't have any
space constraint.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/head_32.h | 5 ++++
arch/powerpc/kernel/head_40x.S | 6 +++++
arch/powerpc/kernel/head_8xx.S | 25 ++++++++------------
arch/powerpc/kernel/head_book3s_32.S | 34 ++++++++++++----------------
4 files changed, 36 insertions(+), 34 deletions(-)
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index d97ec94b34da..3c0aa4538514 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -70,6 +70,8 @@
mtspr SPRN_SRR0, r11
mfspr r11, SPRN_SPRG_SCRATCH2
rfi
+
+ .text
1:
stw r11,GPR1(r1)
stw r11,0(r1)
@@ -163,12 +165,14 @@
*/
#ifdef CONFIG_PPC_BOOK3S
#define START_EXCEPTION(n, label) \
+ __HEAD; \
. = n; \
DO_KVM n; \
label:
#else
#define START_EXCEPTION(n, label) \
+ __HEAD; \
. = n; \
label:
@@ -196,6 +200,7 @@
ret_from_except)
.macro vmap_stack_overflow_exception
+ __HEAD
vmap_stack_overflow:
#ifdef CONFIG_SMP
mfspr r1, SPRN_SPRG_THREAD
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index c14a71e0d6d3..e7d8856714d3 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -132,6 +132,8 @@ _ENTRY(crit_esr)
ori r11, r11, 1f@l
mtspr SPRN_SRR0, r11
rfi
+
+ .text
1:
lwz r11,crit_r1@l(0)
stw r11,GPR1(r1)
@@ -496,6 +498,7 @@ _ENTRY(crit_esr)
crit_transfer_to_handler, ret_from_crit_exc)
/* Programmable Interval Timer (PIT) Exception. (from 0x1000) */
+ __HEAD
Decrementer:
EXCEPTION_PROLOG
lis r0,TSR_PIS@h
@@ -504,12 +507,14 @@ Decrementer:
EXC_XFER_LITE(0x1000, timer_interrupt)
/* Fixed Interval Timer (FIT) Exception. (from 0x1010) */
+ __HEAD
FITException:
EXCEPTION_PROLOG
addi r3,r1,STACK_FRAME_OVERHEAD;
EXC_XFER_STD(0x1010, unknown_exception)
/* Watchdog Timer (WDT) Exception. (from 0x1020) */
+ __HEAD
WDTException:
CRITICAL_EXCEPTION_PROLOG;
addi r3,r1,STACK_FRAME_OVERHEAD;
@@ -523,6 +528,7 @@ WDTException:
* reserved.
*/
+ __HEAD
/* Damn, I came up one instruction too many to fit into the
* exception space :-). Both the instruction and data TLB
* miss get to this point to load the TLB.
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 11789a077d76..d16d0ec71bb2 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -133,7 +133,7 @@ instruction_counter:
START_EXCEPTION(0x600, Alignment)
EXCEPTION_PROLOG handle_dar_dsisr=1
addi r3,r1,STACK_FRAME_OVERHEAD
- b .Lalignment_exception_ool
+ EXC_XFER_STD(0x600, alignment_exception)
/* Program check exception */
EXCEPTION(0x700, ProgramCheck, program_check_exception, EXC_XFER_STD)
@@ -141,11 +141,6 @@ instruction_counter:
/* Decrementer */
EXCEPTION(0x900, Decrementer, timer_interrupt, EXC_XFER_LITE)
- /* With VMAP_STACK there's not enough room for this at 0x600 */
- . = 0xa00
-.Lalignment_exception_ool:
- EXC_XFER_STD(0x600, alignment_exception)
-
/* System call */
START_EXCEPTION(0xc00, SystemCall)
SYSCALL_ENTRY 0xc00
@@ -339,26 +334,25 @@ DARFixed:/* Return from dcbx instruction bug workaround */
* support of breakpoints and such. Someday I will get around to
* using them.
*/
-do_databreakpoint:
- EXCEPTION_PROLOG_1
- EXCEPTION_PROLOG_2 handle_dar_dsisr=1
- addi r3,r1,STACK_FRAME_OVERHEAD
- mfspr r4,SPRN_BAR
- stw r4,_DAR(r11)
- EXC_XFER_STD(0x1c00, do_break)
-
START_EXCEPTION(0x1c00, DataBreakpoint)
EXCEPTION_PROLOG_0 handle_dar_dsisr=1
mfspr r11, SPRN_SRR0
cmplwi cr1, r11, (.Ldtlbie - PAGE_OFFSET)@l
cmplwi cr7, r11, (.Litlbie - PAGE_OFFSET)@l
cror 4*cr1+eq, 4*cr1+eq, 4*cr7+eq
- bne cr1, do_databreakpoint
+ bne cr1, 1f
mtcr r10
mfspr r10, SPRN_SPRG_SCRATCH0
mfspr r11, SPRN_SPRG_SCRATCH1
rfi
+1: EXCEPTION_PROLOG_1
+ EXCEPTION_PROLOG_2 handle_dar_dsisr=1
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ mfspr r4,SPRN_BAR
+ stw r4,_DAR(r11)
+ EXC_XFER_STD(0x1c00, do_break)
+
#ifdef CONFIG_PERF_EVENTS
START_EXCEPTION(0x1d00, InstructionBreakpoint)
mtspr SPRN_SPRG_SCRATCH0, r10
@@ -376,6 +370,7 @@ do_databreakpoint:
EXCEPTION(0x1e00, Trap_1e, unknown_exception, EXC_XFER_STD)
EXCEPTION(0x1f00, Trap_1f, unknown_exception, EXC_XFER_STD)
+ __HEAD
. = 0x2000
/* This is the procedure to calculate the data EA for buggy dcbx,dcbi instructions
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 8f5c8c8da63d..56d7bc212866 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -269,11 +269,10 @@ __secondary_hold_acknowledge:
7: EXCEPTION_PROLOG_2
addi r3,r1,STACK_FRAME_OVERHEAD
#ifdef CONFIG_PPC_CHRP
- beq cr1, machine_check_tramp
+ beq cr1, 1f
twi 31, 0, 0
-#else
- b machine_check_tramp
#endif
+1: EXC_XFER_STD(0x200, machine_check_exception)
/* Data access exception. */
START_EXCEPTION(0x300, DataAccess)
@@ -297,7 +296,13 @@ ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_HPTE_TABLE)
#endif
1: EXCEPTION_PROLOG_0 handle_dar_dsisr=1
EXCEPTION_PROLOG_1
- b handle_page_fault_tramp_1
+ EXCEPTION_PROLOG_2 handle_dar_dsisr=1
+ lwz r5, _DSISR(r11)
+ andis. r0, r5, DSISR_DABRMATCH@h
+ bne- 1f
+ EXC_XFER_LITE(0x300, handle_page_fault)
+1: EXC_XFER_STD(0x300, do_break)
+
/* Instruction access exception. */
START_EXCEPTION(0x400, InstructionAccess)
@@ -333,7 +338,7 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
START_EXCEPTION(0x600, Alignment)
EXCEPTION_PROLOG handle_dar_dsisr=1
addi r3,r1,STACK_FRAME_OVERHEAD
- b alignment_exception_tramp
+ EXC_XFER_STD(0x600, alignment_exception)
/* Program check exception */
EXCEPTION(0x700, ProgramCheck, program_check_exception, EXC_XFER_STD)
@@ -385,6 +390,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_FPU_UNAVAILABLE)
START_EXCEPTION(0xf20, AltiVecUnavailableTrap)
b AltiVecUnavailable
+ __HEAD
/*
* Handle TLB miss for instruction on 603/603e.
* Note: we get an alternate set of r0 - r3 to use automatically.
@@ -624,22 +630,9 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_NEED_DTLB_SW_LRU)
EXCEPTION(0x2e00, Trap_2e, unknown_exception, EXC_XFER_STD)
EXCEPTION(0x2f00, Trap_2f, unknown_exception, EXC_XFER_STD)
+ __HEAD
. = 0x3000
-machine_check_tramp:
- EXC_XFER_STD(0x200, machine_check_exception)
-
-alignment_exception_tramp:
- EXC_XFER_STD(0x600, alignment_exception)
-
-handle_page_fault_tramp_1:
- EXCEPTION_PROLOG_2 handle_dar_dsisr=1
- lwz r5, _DSISR(r11)
- andis. r0, r5, DSISR_DABRMATCH@h
- bne- 1f
- EXC_XFER_LITE(0x300, handle_page_fault)
-1: EXC_XFER_STD(0x300, do_break)
-
#ifdef CONFIG_PPC_BOOK3S_604
.macro save_regs_thread thread
stw r0, THR0(\thread)
@@ -718,6 +711,7 @@ fast_hash_page_return:
vmap_stack_overflow_exception
#endif
+ __HEAD
AltiVecUnavailable:
EXCEPTION_PROLOG
#ifdef CONFIG_ALTIVEC
@@ -728,12 +722,14 @@ AltiVecUnavailable:
1: addi r3,r1,STACK_FRAME_OVERHEAD
EXC_XFER_LITE(0xf20, altivec_unavailable_exception)
+ __HEAD
PerformanceMonitor:
EXCEPTION_PROLOG
addi r3,r1,STACK_FRAME_OVERHEAD
EXC_XFER_STD(0xf00, performance_monitor_exception)
+ __HEAD
/*
* This code is jumped to from the startup code to copy
* the kernel image to physical address PHYSICAL_START.
--
2.25.0
^ permalink raw reply related
* [PATCH v2 19/43] powerpc/32: Use START_EXCEPTION() as much as possible
From: Christophe Leroy @ 2021-03-09 12:09 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615291471.git.christophe.leroy@csgroup.eu>
Everywhere where it is possible, use START_EXCEPTION().
This will help for proper exception init in future patches.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/head_40x.S | 12 +++++------
arch/powerpc/kernel/head_8xx.S | 27 +++++++++----------------
arch/powerpc/kernel/head_book3s_32.S | 30 ++++++++--------------------
3 files changed, 22 insertions(+), 47 deletions(-)
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 55fa99c5085c..c14a71e0d6d3 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -247,17 +247,15 @@ _ENTRY(crit_esr)
EXCEPTION(0x0F00, Trap_0F, unknown_exception, EXC_XFER_STD)
/* 0x1000 - Programmable Interval Timer (PIT) Exception */
- . = 0x1000
+ START_EXCEPTION(0x1000, DecrementerTrap)
b Decrementer
-/* 0x1010 - Fixed Interval Timer (FIT) Exception
-*/
- . = 0x1010
+/* 0x1010 - Fixed Interval Timer (FIT) Exception */
+ START_EXCEPTION(0x1010, FITExceptionTrap)
b FITException
-/* 0x1020 - Watchdog Timer (WDT) Exception
-*/
- . = 0x1020
+/* 0x1020 - Watchdog Timer (WDT) Exception */
+ START_EXCEPTION(0x1020, WDTExceptionTrap)
b WDTException
/* 0x1100 - Data TLB Miss Exception
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index b63445c55f4d..11789a077d76 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -121,8 +121,7 @@ instruction_counter:
EXCEPTION(0x100, Reset, system_reset_exception, EXC_XFER_STD)
/* Machine check */
- . = 0x200
-MachineCheck:
+ START_EXCEPTION(0x200, MachineCheck)
EXCEPTION_PROLOG handle_dar_dsisr=1
addi r3,r1,STACK_FRAME_OVERHEAD
EXC_XFER_STD(0x200, machine_check_exception)
@@ -131,8 +130,7 @@ MachineCheck:
EXCEPTION(0x500, HardwareInterrupt, do_IRQ, EXC_XFER_LITE)
/* Alignment exception */
- . = 0x600
-Alignment:
+ START_EXCEPTION(0x600, Alignment)
EXCEPTION_PROLOG handle_dar_dsisr=1
addi r3,r1,STACK_FRAME_OVERHEAD
b .Lalignment_exception_ool
@@ -149,8 +147,7 @@ Alignment:
EXC_XFER_STD(0x600, alignment_exception)
/* System call */
- . = 0xc00
-SystemCall:
+ START_EXCEPTION(0xc00, SystemCall)
SYSCALL_ENTRY 0xc00
/* Single step - not used on 601 */
@@ -161,7 +158,6 @@ SystemCall:
*/
EXCEPTION(0x1000, SoftEmu, emulation_assist_interrupt, EXC_XFER_STD)
- . = 0x1100
/*
* For the MPC8xx, this is a software tablewalk to load the instruction
* TLB. The task switch loads the M_TWB register with the pointer to the first
@@ -183,7 +179,7 @@ SystemCall:
#define INVALIDATE_ADJACENT_PAGES_CPU15(addr, tmp)
#endif
-InstructionTLBMiss:
+ START_EXCEPTION(0x1100, InstructionTLBMiss)
mtspr SPRN_SPRG_SCRATCH2, r10
mtspr SPRN_M_TW, r11
@@ -239,8 +235,7 @@ InstructionTLBMiss:
rfi
#endif
- . = 0x1200
-DataStoreTLBMiss:
+ START_EXCEPTION(0x1200, DataStoreTLBMiss)
mtspr SPRN_SPRG_SCRATCH2, r10
mtspr SPRN_M_TW, r11
mfcr r11
@@ -303,8 +298,7 @@ DataStoreTLBMiss:
* to many reasons, such as executing guarded memory or illegal instruction
* addresses. There is nothing to do but handle a big time error fault.
*/
- . = 0x1300
-InstructionTLBError:
+ START_EXCEPTION(0x1300, InstructionTLBError)
EXCEPTION_PROLOG
andis. r5,r9,DSISR_SRR1_MATCH_32S@h /* Filter relevant SRR1 bits */
andis. r10,r9,SRR1_ISI_NOPT@h
@@ -320,8 +314,7 @@ InstructionTLBError:
* many reasons, including a dirty update to a pte. We bail out to
* a higher level function that can handle it.
*/
- . = 0x1400
-DataTLBError:
+ START_EXCEPTION(0x1400, DataTLBError)
EXCEPTION_PROLOG_0 handle_dar_dsisr=1
mfspr r11, SPRN_DAR
cmpwi cr1, r11, RPN_PATTERN
@@ -354,8 +347,7 @@ do_databreakpoint:
stw r4,_DAR(r11)
EXC_XFER_STD(0x1c00, do_break)
- . = 0x1c00
-DataBreakpoint:
+ START_EXCEPTION(0x1c00, DataBreakpoint)
EXCEPTION_PROLOG_0 handle_dar_dsisr=1
mfspr r11, SPRN_SRR0
cmplwi cr1, r11, (.Ldtlbie - PAGE_OFFSET)@l
@@ -368,8 +360,7 @@ DataBreakpoint:
rfi
#ifdef CONFIG_PERF_EVENTS
- . = 0x1d00
-InstructionBreakpoint:
+ START_EXCEPTION(0x1d00, InstructionBreakpoint)
mtspr SPRN_SPRG_SCRATCH0, r10
lwz r10, (instruction_counter - PAGE_OFFSET)@l(0)
addi r10, r10, -1
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 9dc05890477d..8f5c8c8da63d 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -255,9 +255,7 @@ __secondary_hold_acknowledge:
* pointer when we take an exception from supervisor mode.)
* -- paulus.
*/
- . = 0x200
- DO_KVM 0x200
-MachineCheck:
+ START_EXCEPTION(0x200, MachineCheck)
EXCEPTION_PROLOG_0
#ifdef CONFIG_PPC_CHRP
mtspr SPRN_SPRG_SCRATCH2,r1
@@ -278,9 +276,7 @@ MachineCheck:
#endif
/* Data access exception. */
- . = 0x300
- DO_KVM 0x300
-DataAccess:
+ START_EXCEPTION(0x300, DataAccess)
#ifdef CONFIG_PPC_BOOK3S_604
BEGIN_MMU_FTR_SECTION
mtspr SPRN_SPRG_SCRATCH2,r10
@@ -304,9 +300,7 @@ ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_HPTE_TABLE)
b handle_page_fault_tramp_1
/* Instruction access exception. */
- . = 0x400
- DO_KVM 0x400
-InstructionAccess:
+ START_EXCEPTION(0x400, InstructionAccess)
mtspr SPRN_SPRG_SCRATCH0,r10
mtspr SPRN_SPRG_SCRATCH1,r11
mfspr r10, SPRN_SPRG_THREAD
@@ -336,9 +330,7 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
EXCEPTION(0x500, HardwareInterrupt, do_IRQ, EXC_XFER_LITE)
/* Alignment exception */
- . = 0x600
- DO_KVM 0x600
-Alignment:
+ START_EXCEPTION(0x600, Alignment)
EXCEPTION_PROLOG handle_dar_dsisr=1
addi r3,r1,STACK_FRAME_OVERHEAD
b alignment_exception_tramp
@@ -347,9 +339,7 @@ Alignment:
EXCEPTION(0x700, ProgramCheck, program_check_exception, EXC_XFER_STD)
/* Floating-point unavailable */
- . = 0x800
- DO_KVM 0x800
-FPUnavailable:
+ START_EXCEPTION(0x800, FPUnavailable)
#ifdef CONFIG_PPC_FPU
BEGIN_FTR_SECTION
/*
@@ -375,9 +365,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_FPU_UNAVAILABLE)
EXCEPTION(0xb00, Trap_0b, unknown_exception, EXC_XFER_STD)
/* System call */
- . = 0xc00
- DO_KVM 0xc00
-SystemCall:
+ START_EXCEPTION(0xc00, SystemCall)
SYSCALL_ENTRY 0xc00
EXCEPTION(0xd00, SingleStep, single_step_exception, EXC_XFER_STD)
@@ -391,12 +379,10 @@ SystemCall:
* non-altivec kernel running on a machine with altivec just
* by executing an altivec instruction.
*/
- . = 0xf00
- DO_KVM 0xf00
+ START_EXCEPTION(0xf00, PerformanceMonitorTrap)
b PerformanceMonitor
- . = 0xf20
- DO_KVM 0xf20
+ START_EXCEPTION(0xf20, AltiVecUnavailableTrap)
b AltiVecUnavailable
/*
--
2.25.0
^ permalink raw reply related
* [PATCH v2 18/43] powerpc/32: Add vmap_stack_overflow label inside the macro
From: Christophe Leroy @ 2021-03-09 12:09 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615291471.git.christophe.leroy@csgroup.eu>
For consistency, add in the macro the label used by exception prolog
to branch to stack overflow processing.
While at it, enclose the macro in #ifdef CONFIG_VMAP_STACK on the 8xx
as already done on book3s/32.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/head_32.h | 3 ++-
arch/powerpc/kernel/head_8xx.S | 3 ++-
arch/powerpc/kernel/head_book3s_32.S | 1 -
3 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 15c6fc7cbbf5..d97ec94b34da 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -52,7 +52,7 @@
1:
#ifdef CONFIG_VMAP_STACK
mtcrf 0x3f, r1
- bt 32 - THREAD_ALIGN_SHIFT, stack_overflow
+ bt 32 - THREAD_ALIGN_SHIFT, vmap_stack_overflow
#endif
.endm
@@ -196,6 +196,7 @@
ret_from_except)
.macro vmap_stack_overflow_exception
+vmap_stack_overflow:
#ifdef CONFIG_SMP
mfspr r1, SPRN_SPRG_THREAD
lwz r1, TASK_CPU - THREAD(r1)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index cdbfa9d41353..b63445c55f4d 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -338,8 +338,9 @@ DARFixed:/* Return from dcbx instruction bug workaround */
/* 0x300 is DataAccess exception, needed by bad_page_fault() */
EXC_XFER_LITE(0x300, handle_page_fault)
-stack_overflow:
+#ifdef CONFIG_VMAP_STACK
vmap_stack_overflow_exception
+#endif
/* On the MPC8xx, these next four traps are used for development
* support of breakpoints and such. Someday I will get around to
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 59efbee7c080..9dc05890477d 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -729,7 +729,6 @@ fast_hash_page_return:
#endif /* CONFIG_PPC_BOOK3S_604 */
#ifdef CONFIG_VMAP_STACK
-stack_overflow:
vmap_stack_overflow_exception
#endif
--
2.25.0
^ permalink raw reply related
* [PATCH v2 17/43] powerpc/32: Statically initialise first emergency context
From: Christophe Leroy @ 2021-03-09 12:09 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615291471.git.christophe.leroy@csgroup.eu>
The check of the emergency context initialisation in
vmap_stack_overflow is buggy for the SMP case, as it
compares r1 with 0 while in the SMP case r1 is offseted
by the CPU id.
Instead of fixing it, just perform static initialisation
of the first emergency context.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/head_32.h | 6 +-----
arch/powerpc/kernel/setup_32.c | 2 +-
2 files changed, 2 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 88b02bd91e8e..15c6fc7cbbf5 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -205,11 +205,7 @@
lis r1, emergency_ctx@ha
#endif
lwz r1, emergency_ctx@l(r1)
- cmpwi cr1, r1, 0
- bne cr1, 1f
- lis r1, init_thread_union@ha
- addi r1, r1, init_thread_union@l
-1: addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE
+ addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE
EXCEPTION_PROLOG_2
SAVE_NVGPRS(r11)
addi r3, r1, STACK_FRAME_OVERHEAD
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index 8ba49a6bf515..d7c1f92152af 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -164,7 +164,7 @@ void __init irqstack_early_init(void)
}
#ifdef CONFIG_VMAP_STACK
-void *emergency_ctx[NR_CPUS] __ro_after_init;
+void *emergency_ctx[NR_CPUS] __ro_after_init = {[0] = &init_stack};
void __init emergency_stack_init(void)
{
--
2.25.0
^ permalink raw reply related
* [PATCH v2 16/43] powerpc/32: Enable instruction translation at the same time as data translation
From: Christophe Leroy @ 2021-03-09 12:09 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615291471.git.christophe.leroy@csgroup.eu>
On 40x and 8xx, kernel text is pinned.
On book3s/32, kernel text is mapped by BATs.
Enable instruction translation at the same time as data translation, it
makes things simpler.
In syscall handler, MSR_RI can also be set at the same time because
srr0/srr1 are already saved and r1 is set properly.
On booke, translation is always on, so at the end all PPC32
have translation on early. Just update msr.
Also update comment in power_save_ppc32_restore().
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/entry_32.S | 30 ++++++++++++------------------
arch/powerpc/kernel/head_32.h | 13 ++++++++-----
arch/powerpc/kernel/head_40x.S | 10 +++++++---
arch/powerpc/kernel/head_booke.h | 6 ++++--
4 files changed, 31 insertions(+), 28 deletions(-)
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 33e97032ca25..01a064c8a96a 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -153,19 +153,11 @@ transfer_to_handler:
transfer_to_handler_cont:
3:
mflr r9
- tovirt(r9, r9)
lwz r11,0(r9) /* virtual address of handler */
lwz r9,4(r9) /* where to go when done */
-#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
- mtspr SPRN_NRI, r0
-#endif
- mtspr SPRN_SRR0,r11
- mtspr SPRN_SRR1,r10
+ mtctr r11
mtlr r9
- rfi /* jump to handler, enable MMU */
-#ifdef CONFIG_40x
- b . /* Prevent prefetch past rfi */
-#endif
+ bctr /* jump to handler */
#if defined (CONFIG_PPC_BOOK3S_32) || defined(CONFIG_E500)
4: rlwinm r12,r12,0,~_TLF_NAPPING
@@ -444,8 +436,6 @@ fee_restarts:
li r10,-1
stw r10,_TRAP(r11)
addi r3,r1,STACK_FRAME_OVERHEAD
- lis r10,MSR_KERNEL@h
- ori r10,r10,MSR_KERNEL@l
bl transfer_to_handler_full
.long unrecoverable_exception
.long ret_from_except
@@ -945,16 +935,20 @@ _GLOBAL(enter_rtas)
mtspr SPRN_SRR1,r9
rfi
1:
- li r0, MSR_KERNEL & ~MSR_IR /* can take DTLB miss */
- mtmsr r0
- isync
+ lis r8, 1f@h
+ ori r8, r8, 1f@l
+ LOAD_REG_IMMEDIATE(r9,MSR_KERNEL)
+ mtspr SPRN_SRR0,r8
+ mtspr SPRN_SRR1,r9
+ rfi /* Reactivate MMU translation */
+1:
lwz r8,INT_FRAME_SIZE+4(r1) /* get return address */
lwz r9,8(r1) /* original msr value */
addi r1,r1,INT_FRAME_SIZE
li r0,0
stw r0, THREAD + RTAS_SP(r2)
- mtspr SPRN_SRR0,r8
- mtspr SPRN_SRR1,r9
- rfi /* return to caller */
+ mtlr r8
+ mtmsr r9
+ blr /* return to caller */
_ASM_NOKPROBE_SYMBOL(enter_rtas)
#endif /* CONFIG_PPC_RTAS */
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 910f86642eec..88b02bd91e8e 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -63,10 +63,14 @@
mtspr SPRN_DAR, r11 /* Tag DAR, to be used in DTLB Error */
.endif
#endif
- LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_IR | MSR_RI)) /* can take DTLB miss */
- mtmsr r11
- isync
+ LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~MSR_RI) /* re-enable MMU */
+ mtspr SPRN_SRR1, r11
+ lis r11, 1f@h
+ ori r11, r11, 1f@l
+ mtspr SPRN_SRR0, r11
mfspr r11, SPRN_SPRG_SCRATCH2
+ rfi
+1:
stw r11,GPR1(r1)
stw r11,0(r1)
mr r11, r1
@@ -94,7 +98,7 @@
#elif defined(CONFIG_PPC_8xx)
mtspr SPRN_EID, r2 /* Set MSR_RI */
#else
- li r10, MSR_KERNEL & ~MSR_IR /* can take exceptions */
+ li r10, MSR_KERNEL /* can take exceptions */
mtmsr r10 /* (except for mach check in rtas) */
#endif
stw r0,GPR0(r11)
@@ -179,7 +183,6 @@
#define EXC_XFER_TEMPLATE(hdlr, trap, msr, tfer, ret) \
li r10,trap; \
stw r10,_TRAP(r11); \
- LOAD_REG_IMMEDIATE(r10, msr); \
bl tfer; \
.long hdlr; \
.long ret
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 7da673ec63ef..55fa99c5085c 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -126,9 +126,13 @@ _ENTRY(crit_esr)
lwz r11,TASK_STACK-THREAD(r11) /* this thread's kernel stack */
1: stw r1,crit_r1@l(0)
addi r1,r11,THREAD_SIZE-INT_FRAME_SIZE /* Alloc an excpt frm */
- LOAD_REG_IMMEDIATE(r11,MSR_KERNEL & ~(MSR_IR | MSR_RI))
- mtmsr r11
- isync
+ LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)) /* re-enable MMU */
+ mtspr SPRN_SRR1, r11
+ lis r11, 1f@h
+ ori r11, r11, 1f@l
+ mtspr SPRN_SRR0, r11
+ rfi
+1:
lwz r11,crit_r1@l(0)
stw r11,GPR1(r1)
stw r11,0(r1)
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 4a5f0c9b652b..f712b9bc6d62 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -53,6 +53,8 @@ END_BTB_FLUSH_SECTION
mfspr r11, SPRN_SRR1; \
DO_KVM BOOKE_INTERRUPT_##intno SPRN_SRR1; \
andi. r11, r11, MSR_PR; /* check whether user or kernel */\
+ LOAD_REG_IMMEDIATE(r11, MSR_KERNEL); \
+ mtmsr r11; \
mr r11, r1; \
beq 1f; \
BOOKE_CLEAR_BTB(r11) \
@@ -192,6 +194,8 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
DO_KVM BOOKE_INTERRUPT_##intno exc_level_srr1; \
BOOKE_CLEAR_BTB(r10) \
andi. r11,r11,MSR_PR; \
+ LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)); \
+ mtmsr r11; \
mfspr r11,SPRN_SPRG_THREAD; /* if from user, start at top of */\
lwz r11, TASK_STACK - THREAD(r11); /* this thread's kernel stack */\
addi r11,r11,EXC_LVL_FRAME_OVERHEAD; /* allocate stack frame */\
@@ -282,8 +286,6 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
#define EXC_XFER_TEMPLATE(hdlr, trap, msr, tfer, ret) \
li r10,trap; \
stw r10,_TRAP(r11); \
- lis r10,msr@h; \
- ori r10,r10,msr@l; \
bl tfer; \
.long hdlr; \
.long ret
--
2.25.0
^ permalink raw reply related
* [PATCH v2 15/43] powerpc/32: Tag DAR in EXCEPTION_PROLOG_2 for the 8xx
From: Christophe Leroy @ 2021-03-09 12:09 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615291471.git.christophe.leroy@csgroup.eu>
8xx requires to tag the DAR with a magic value in order to
fixup DAR on faults generated by 'dcbX', as the 8xx
forgets to update the DAR for those faults.
Do the tagging as early as possible, that is before enabling MMU.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/head_32.h | 6 ++++++
arch/powerpc/kernel/head_8xx.S | 18 ++++++------------
2 files changed, 12 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 1b707755c68e..910f86642eec 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -57,6 +57,12 @@
.endm
.macro EXCEPTION_PROLOG_2 handle_dar_dsisr=0
+#ifdef CONFIG_PPC_8xx
+ .if \handle_dar_dsisr
+ li r11, RPN_PATTERN
+ mtspr SPRN_DAR, r11 /* Tag DAR, to be used in DTLB Error */
+ .endif
+#endif
LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_IR | MSR_RI)) /* can take DTLB miss */
mtmsr r11
isync
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 792e2fd86479..cdbfa9d41353 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -30,6 +30,12 @@
#include <asm/export.h>
#include <asm/code-patching-asm.h>
+/*
+ * Value for the bits that have fixed value in RPN entries.
+ * Also used for tagging DAR for DTLBerror.
+ */
+#define RPN_PATTERN 0x00f0
+
#include "head_32.h"
.macro compare_to_kernel_boundary scratch, addr
@@ -42,12 +48,6 @@
#endif
.endm
-/*
- * Value for the bits that have fixed value in RPN entries.
- * Also used for tagging DAR for DTLBerror.
- */
-#define RPN_PATTERN 0x00f0
-
#define PAGE_SHIFT_512K 19
#define PAGE_SHIFT_8M 23
@@ -124,8 +124,6 @@ instruction_counter:
. = 0x200
MachineCheck:
EXCEPTION_PROLOG handle_dar_dsisr=1
- li r6, RPN_PATTERN
- mtspr SPRN_DAR, r6 /* Tag DAR, to be used in DTLB Error */
addi r3,r1,STACK_FRAME_OVERHEAD
EXC_XFER_STD(0x200, machine_check_exception)
@@ -136,8 +134,6 @@ MachineCheck:
. = 0x600
Alignment:
EXCEPTION_PROLOG handle_dar_dsisr=1
- li r6, RPN_PATTERN
- mtspr SPRN_DAR, r6 /* Tag DAR, to be used in DTLB Error */
addi r3,r1,STACK_FRAME_OVERHEAD
b .Lalignment_exception_ool
@@ -331,8 +327,6 @@ DataTLBError:
cmpwi cr1, r11, RPN_PATTERN
beq- cr1, FixupDAR /* must be a buggy dcbX, icbi insn. */
DARFixed:/* Return from dcbx instruction bug workaround */
- li r11, RPN_PATTERN
- mtspr SPRN_DAR, r11 /* Tag DAR, to be used in DTLB Error */
EXCEPTION_PROLOG_1
EXCEPTION_PROLOG_2 handle_dar_dsisr=1
lwz r4, _DAR(r11)
--
2.25.0
^ permalink raw reply related
* [PATCH v2 14/43] powerpc/32: Always enable data translation in exception prolog
From: Christophe Leroy @ 2021-03-09 12:09 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615291471.git.christophe.leroy@csgroup.eu>
If the code can use a stack in vm area, it can also use a
stack in linear space.
Simplify code by removing old non VMAP stack code on PPC32.
That means the data translation is now re-enabled early in
exception prolog in all cases, not only when using VMAP stacks.
While we are touching EXCEPTION_PROLOG macros, remove the
unused for_rtas parameter in EXCEPTION_PROLOG_1.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/include/asm/processor.h | 4 +-
arch/powerpc/kernel/asm-offsets.c | 2 -
arch/powerpc/kernel/entry_32.S | 19 +++----
arch/powerpc/kernel/fpu.S | 2 -
arch/powerpc/kernel/head_32.h | 85 +---------------------------
arch/powerpc/kernel/head_40x.S | 23 --------
arch/powerpc/kernel/head_8xx.S | 19 +------
arch/powerpc/kernel/head_book3s_32.S | 47 +--------------
arch/powerpc/kernel/idle_6xx.S | 12 +---
arch/powerpc/kernel/idle_e500.S | 4 +-
arch/powerpc/kernel/vector.S | 2 -
arch/powerpc/mm/book3s32/hash_low.S | 14 -----
12 files changed, 17 insertions(+), 216 deletions(-)
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 43cbd9281055..eae16facc390 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -147,11 +147,9 @@ struct thread_struct {
#ifdef CONFIG_PPC_RTAS
unsigned long rtas_sp; /* stack pointer for when in RTAS */
#endif
-#endif
#if defined(CONFIG_PPC_BOOK3S_32) && defined(CONFIG_PPC_KUAP)
unsigned long kuap; /* opened segments for user access */
#endif
-#ifdef CONFIG_VMAP_STACK
unsigned long srr0;
unsigned long srr1;
unsigned long dar;
@@ -160,7 +158,7 @@ struct thread_struct {
unsigned long r0, r3, r4, r5, r6, r8, r9, r11;
unsigned long lr, ctr;
#endif
-#endif
+#endif /* CONFIG_PPC32 */
/* Debug Registers */
struct debug_reg debug;
#ifdef CONFIG_PPC_FPU_REGS
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 73620536c801..85ba2b0bc8d8 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -131,7 +131,6 @@ int main(void)
OFFSET(KSP_VSID, thread_struct, ksp_vsid);
#else /* CONFIG_PPC64 */
OFFSET(PGDIR, thread_struct, pgdir);
-#ifdef CONFIG_VMAP_STACK
OFFSET(SRR0, thread_struct, srr0);
OFFSET(SRR1, thread_struct, srr1);
OFFSET(DAR, thread_struct, dar);
@@ -148,7 +147,6 @@ int main(void)
OFFSET(THLR, thread_struct, lr);
OFFSET(THCTR, thread_struct, ctr);
#endif
-#endif
#ifdef CONFIG_SPE
OFFSET(THREAD_EVR0, thread_struct, evr[0]);
OFFSET(THREAD_ACC, thread_struct, acc);
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 66198e6e25e7..33e97032ca25 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -129,7 +129,7 @@ transfer_to_handler:
stw r12,_CTR(r11)
stw r2,_XER(r11)
mfspr r12,SPRN_SPRG_THREAD
- tovirt_vmstack r12, r12
+ tovirt(r12, r12)
beq 2f /* if from user, fix up THREAD.regs */
addi r2, r12, -THREAD
addi r11,r1,STACK_FRAME_OVERHEAD
@@ -153,8 +153,7 @@ transfer_to_handler:
transfer_to_handler_cont:
3:
mflr r9
- tovirt_novmstack r2, r2 /* set r2 to current */
- tovirt_vmstack r9, r9
+ tovirt(r9, r9)
lwz r11,0(r9) /* virtual address of handler */
lwz r9,4(r9) /* where to go when done */
#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
@@ -933,7 +932,6 @@ _GLOBAL(enter_rtas)
lis r6,1f@ha /* physical return address for rtas */
addi r6,r6,1f@l
tophys(r6,r6)
- tophys_novmstack r7, r1
lwz r8,RTASENTRY(r4)
lwz r4,RTASBASE(r4)
mfmsr r9
@@ -942,22 +940,19 @@ _GLOBAL(enter_rtas)
mtmsr r0 /* disable interrupts so SRR0/1 don't get trashed */
li r9,MSR_KERNEL & ~(MSR_IR|MSR_DR)
mtlr r6
- stw r7, THREAD + RTAS_SP(r2)
+ stw r1, THREAD + RTAS_SP(r2)
mtspr SPRN_SRR0,r8
mtspr SPRN_SRR1,r9
rfi
-1: tophys_novmstack r9, r1
-#ifdef CONFIG_VMAP_STACK
+1:
li r0, MSR_KERNEL & ~MSR_IR /* can take DTLB miss */
mtmsr r0
isync
-#endif
- lwz r8,INT_FRAME_SIZE+4(r9) /* get return address */
- lwz r9,8(r9) /* original msr value */
+ lwz r8,INT_FRAME_SIZE+4(r1) /* get return address */
+ lwz r9,8(r1) /* original msr value */
addi r1,r1,INT_FRAME_SIZE
li r0,0
- tophys_novmstack r7, r2
- stw r0, THREAD + RTAS_SP(r7)
+ stw r0, THREAD + RTAS_SP(r2)
mtspr SPRN_SRR0,r8
mtspr SPRN_SRR1,r9
rfi /* return to caller */
diff --git a/arch/powerpc/kernel/fpu.S b/arch/powerpc/kernel/fpu.S
index 3ff9a8fafa46..2c57ece6671c 100644
--- a/arch/powerpc/kernel/fpu.S
+++ b/arch/powerpc/kernel/fpu.S
@@ -92,9 +92,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
/* enable use of FP after return */
#ifdef CONFIG_PPC32
mfspr r5,SPRN_SPRG_THREAD /* current task's THREAD (phys) */
-#ifdef CONFIG_VMAP_STACK
tovirt(r5, r5)
-#endif
lwz r4,THREAD_FPEXC_MODE(r5)
ori r9,r9,MSR_FP /* enable FP for current */
or r9,r9,r4
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 25ee6b26ef5a..1b707755c68e 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -19,7 +19,6 @@
.macro EXCEPTION_PROLOG_0 handle_dar_dsisr=0
mtspr SPRN_SPRG_SCRATCH0,r10
mtspr SPRN_SPRG_SCRATCH1,r11
-#ifdef CONFIG_VMAP_STACK
mfspr r10, SPRN_SPRG_THREAD
.if \handle_dar_dsisr
#ifdef CONFIG_40x
@@ -37,17 +36,13 @@
.endif
mfspr r11, SPRN_SRR0
stw r11, SRR0(r10)
-#endif
mfspr r11, SPRN_SRR1 /* check whether user or kernel */
-#ifdef CONFIG_VMAP_STACK
stw r11, SRR1(r10)
-#endif
mfcr r10
andi. r11, r11, MSR_PR
.endm
-.macro EXCEPTION_PROLOG_1 for_rtas=0
-#ifdef CONFIG_VMAP_STACK
+.macro EXCEPTION_PROLOG_1
mtspr SPRN_SPRG_SCRATCH2,r1
subi r1, r1, INT_FRAME_SIZE /* use r1 if kernel */
beq 1f
@@ -55,20 +50,13 @@
lwz r1,TASK_STACK-THREAD(r1)
addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE
1:
+#ifdef CONFIG_VMAP_STACK
mtcrf 0x3f, r1
bt 32 - THREAD_ALIGN_SHIFT, stack_overflow
-#else
- subi r11, r1, INT_FRAME_SIZE /* use r1 if kernel */
- beq 1f
- mfspr r11,SPRN_SPRG_THREAD
- lwz r11,TASK_STACK-THREAD(r11)
- addi r11, r11, THREAD_SIZE - INT_FRAME_SIZE
-1: tophys(r11, r11)
#endif
.endm
.macro EXCEPTION_PROLOG_2 handle_dar_dsisr=0
-#ifdef CONFIG_VMAP_STACK
LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_IR | MSR_RI)) /* can take DTLB miss */
mtmsr r11
isync
@@ -76,11 +64,6 @@
stw r11,GPR1(r1)
stw r11,0(r1)
mr r11, r1
-#else
- stw r1,GPR1(r11)
- stw r1,0(r11)
- tovirt(r1, r11) /* set new kernel sp */
-#endif
stw r10,_CCR(r11) /* save registers */
stw r12,GPR12(r11)
stw r9,GPR9(r11)
@@ -90,7 +73,6 @@
stw r12,GPR11(r11)
mflr r10
stw r10,_LINK(r11)
-#ifdef CONFIG_VMAP_STACK
mfspr r12, SPRN_SPRG_THREAD
tovirt(r12, r12)
.if \handle_dar_dsisr
@@ -101,20 +83,12 @@
.endif
lwz r9, SRR1(r12)
lwz r12, SRR0(r12)
-#else
- mfspr r12,SPRN_SRR0
- mfspr r9,SPRN_SRR1
-#endif
#ifdef CONFIG_40x
rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */
#elif defined(CONFIG_PPC_8xx)
mtspr SPRN_EID, r2 /* Set MSR_RI */
#else
-#ifdef CONFIG_VMAP_STACK
li r10, MSR_KERNEL & ~MSR_IR /* can take exceptions */
-#else
- li r10,MSR_KERNEL & ~(MSR_IR|MSR_DR) /* can take exceptions */
-#endif
mtmsr r10 /* (except for mach check in rtas) */
#endif
stw r0,GPR0(r11)
@@ -166,59 +140,6 @@
b transfer_to_syscall /* jump to handler */
.endm
-.macro save_dar_dsisr_on_stack reg1, reg2, sp
-#ifndef CONFIG_VMAP_STACK
-#ifdef CONFIG_40x
- mfspr \reg1, SPRN_DEAR
- mfspr \reg2, SPRN_ESR
-#else
- mfspr \reg1, SPRN_DAR
- mfspr \reg2, SPRN_DSISR
-#endif
- stw \reg1, _DAR(\sp)
- stw \reg2, _DSISR(\sp)
-#endif
-.endm
-
-.macro get_and_save_dar_dsisr_on_stack reg1, reg2, sp
-#ifdef CONFIG_VMAP_STACK
- lwz \reg1, _DAR(\sp)
- lwz \reg2, _DSISR(\sp)
-#else
- save_dar_dsisr_on_stack \reg1, \reg2, \sp
-#endif
-.endm
-
-.macro tovirt_vmstack dst, src
-#ifdef CONFIG_VMAP_STACK
- tovirt(\dst, \src)
-#else
- .ifnc \dst, \src
- mr \dst, \src
- .endif
-#endif
-.endm
-
-.macro tovirt_novmstack dst, src
-#ifndef CONFIG_VMAP_STACK
- tovirt(\dst, \src)
-#else
- .ifnc \dst, \src
- mr \dst, \src
- .endif
-#endif
-.endm
-
-.macro tophys_novmstack dst, src
-#ifndef CONFIG_VMAP_STACK
- tophys(\dst, \src)
-#else
- .ifnc \dst, \src
- mr \dst, \src
- .endif
-#endif
-.endm
-
/*
* Note: code which follows this uses cr0.eq (set if from kernel),
* r11, r12 (SRR0), and r9 (SRR1).
@@ -266,7 +187,6 @@
ret_from_except)
.macro vmap_stack_overflow_exception
-#ifdef CONFIG_VMAP_STACK
#ifdef CONFIG_SMP
mfspr r1, SPRN_SPRG_THREAD
lwz r1, TASK_CPU - THREAD(r1)
@@ -285,7 +205,6 @@
SAVE_NVGPRS(r11)
addi r3, r1, STACK_FRAME_OVERHEAD
EXC_XFER_STD(0, stack_overflow_exception)
-#endif
.endm
#endif /* __HEAD_32_H__ */
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 72e4962902de..7da673ec63ef 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -111,12 +111,10 @@ _ENTRY(crit_esr)
mfspr r11,SPRN_SRR1
stw r10,crit_srr0@l(0)
stw r11,crit_srr1@l(0)
-#ifdef CONFIG_VMAP_STACK
mfspr r10,SPRN_DEAR
mfspr r11,SPRN_ESR
stw r10,crit_dear@l(0)
stw r11,crit_esr@l(0)
-#endif
mfcr r10 /* save CR in r10 for now */
mfspr r11,SPRN_SRR3 /* check whether user or kernel */
andi. r11,r11,MSR_PR
@@ -126,7 +124,6 @@ _ENTRY(crit_esr)
/* COMING FROM USER MODE */
mfspr r11,SPRN_SPRG_THREAD /* if from user, start at top of */
lwz r11,TASK_STACK-THREAD(r11) /* this thread's kernel stack */
-#ifdef CONFIG_VMAP_STACK
1: stw r1,crit_r1@l(0)
addi r1,r11,THREAD_SIZE-INT_FRAME_SIZE /* Alloc an excpt frm */
LOAD_REG_IMMEDIATE(r11,MSR_KERNEL & ~(MSR_IR | MSR_RI))
@@ -136,35 +133,18 @@ _ENTRY(crit_esr)
stw r11,GPR1(r1)
stw r11,0(r1)
mr r11,r1
-#else
-1: addi r11,r11,THREAD_SIZE-INT_FRAME_SIZE /* Alloc an excpt frm */
- tophys(r11,r11)
- stw r1,GPR1(r11)
- stw r1,0(r11)
- tovirt(r1,r11)
-#endif
stw r10,_CCR(r11) /* save various registers */
stw r12,GPR12(r11)
stw r9,GPR9(r11)
mflr r10
stw r10,_LINK(r11)
-#ifdef CONFIG_VMAP_STACK
lis r9,PAGE_OFFSET@ha
lwz r10,crit_r10@l(r9)
lwz r12,crit_r11@l(r9)
-#else
- lwz r10,crit_r10@l(0)
- lwz r12,crit_r11@l(0)
-#endif
stw r10,GPR10(r11)
stw r12,GPR11(r11)
-#ifdef CONFIG_VMAP_STACK
lwz r12,crit_dear@l(r9)
lwz r9,crit_esr@l(r9)
-#else
- mfspr r12,SPRN_DEAR /* save DEAR and ESR in the frame */
- mfspr r9,SPRN_ESR /* in them at the point where the */
-#endif
stw r12,_DEAR(r11) /* since they may have had stuff */
stw r9,_ESR(r11) /* exception was taken */
mfspr r12,SPRN_SRR2
@@ -220,7 +200,6 @@ _ENTRY(crit_esr)
*/
START_EXCEPTION(0x0300, DataStorage)
EXCEPTION_PROLOG handle_dar_dsisr=1
- save_dar_dsisr_on_stack r4, r5, r11
EXC_XFER_LITE(0x300, handle_page_fault)
/*
@@ -240,14 +219,12 @@ _ENTRY(crit_esr)
/* 0x0600 - Alignment Exception */
START_EXCEPTION(0x0600, Alignment)
EXCEPTION_PROLOG handle_dar_dsisr=1
- save_dar_dsisr_on_stack r4, r5, r11
addi r3,r1,STACK_FRAME_OVERHEAD
EXC_XFER_STD(0x600, alignment_exception)
/* 0x0700 - Program Exception */
START_EXCEPTION(0x0700, ProgramCheck)
EXCEPTION_PROLOG handle_dar_dsisr=1
- save_dar_dsisr_on_stack r4, r5, r11
addi r3,r1,STACK_FRAME_OVERHEAD
EXC_XFER_STD(0x700, program_check_exception)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 46dff3f9c31f..792e2fd86479 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -124,7 +124,6 @@ instruction_counter:
. = 0x200
MachineCheck:
EXCEPTION_PROLOG handle_dar_dsisr=1
- save_dar_dsisr_on_stack r4, r5, r11
li r6, RPN_PATTERN
mtspr SPRN_DAR, r6 /* Tag DAR, to be used in DTLB Error */
addi r3,r1,STACK_FRAME_OVERHEAD
@@ -137,7 +136,6 @@ MachineCheck:
. = 0x600
Alignment:
EXCEPTION_PROLOG handle_dar_dsisr=1
- save_dar_dsisr_on_stack r4, r5, r11
li r6, RPN_PATTERN
mtspr SPRN_DAR, r6 /* Tag DAR, to be used in DTLB Error */
addi r3,r1,STACK_FRAME_OVERHEAD
@@ -333,21 +331,16 @@ DataTLBError:
cmpwi cr1, r11, RPN_PATTERN
beq- cr1, FixupDAR /* must be a buggy dcbX, icbi insn. */
DARFixed:/* Return from dcbx instruction bug workaround */
-#ifdef CONFIG_VMAP_STACK
li r11, RPN_PATTERN
mtspr SPRN_DAR, r11 /* Tag DAR, to be used in DTLB Error */
-#endif
EXCEPTION_PROLOG_1
EXCEPTION_PROLOG_2 handle_dar_dsisr=1
- get_and_save_dar_dsisr_on_stack r4, r5, r11
+ lwz r4, _DAR(r11)
+ lwz r5, _DSISR(r11)
andis. r10,r5,DSISR_NOHPTE@h
beq+ .Ldtlbie
tlbie r4
.Ldtlbie:
-#ifndef CONFIG_VMAP_STACK
- li r10,RPN_PATTERN
- mtspr SPRN_DAR,r10 /* Tag DAR, to be used in DTLB Error */
-#endif
/* 0x300 is DataAccess exception, needed by bad_page_fault() */
EXC_XFER_LITE(0x300, handle_page_fault)
@@ -364,10 +357,6 @@ do_databreakpoint:
addi r3,r1,STACK_FRAME_OVERHEAD
mfspr r4,SPRN_BAR
stw r4,_DAR(r11)
-#ifndef CONFIG_VMAP_STACK
- mfspr r5,SPRN_DSISR
- stw r5,_DSISR(r11)
-#endif
EXC_XFER_STD(0x1c00, do_break)
. = 0x1c00
@@ -510,14 +499,10 @@ FixupDAR:/* Entry point for dcbx workaround. */
152:
mfdar r11
mtctr r11 /* restore ctr reg from DAR */
-#ifdef CONFIG_VMAP_STACK
mfspr r11, SPRN_SPRG_THREAD
stw r10, DAR(r11)
mfspr r10, SPRN_DSISR
stw r10, DSISR(r11)
-#else
- mtdar r10 /* save fault EA to DAR */
-#endif
mfspr r10,SPRN_M_TW
b DARFixed /* Go back to normal TLB handling */
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 727fdab557c9..59efbee7c080 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -260,21 +260,14 @@ __secondary_hold_acknowledge:
MachineCheck:
EXCEPTION_PROLOG_0
#ifdef CONFIG_PPC_CHRP
-#ifdef CONFIG_VMAP_STACK
mtspr SPRN_SPRG_SCRATCH2,r1
mfspr r1, SPRN_SPRG_THREAD
lwz r1, RTAS_SP(r1)
cmpwi cr1, r1, 0
bne cr1, 7f
mfspr r1, SPRN_SPRG_SCRATCH2
-#else
- mfspr r11, SPRN_SPRG_THREAD
- lwz r11, RTAS_SP(r11)
- cmpwi cr1, r11, 0
- bne cr1, 7f
-#endif
#endif /* CONFIG_PPC_CHRP */
- EXCEPTION_PROLOG_1 for_rtas=1
+ EXCEPTION_PROLOG_1
7: EXCEPTION_PROLOG_2
addi r3,r1,STACK_FRAME_OVERHEAD
#ifdef CONFIG_PPC_CHRP
@@ -288,7 +281,6 @@ MachineCheck:
. = 0x300
DO_KVM 0x300
DataAccess:
-#ifdef CONFIG_VMAP_STACK
#ifdef CONFIG_PPC_BOOK3S_604
BEGIN_MMU_FTR_SECTION
mtspr SPRN_SPRG_SCRATCH2,r10
@@ -310,29 +302,11 @@ ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_HPTE_TABLE)
1: EXCEPTION_PROLOG_0 handle_dar_dsisr=1
EXCEPTION_PROLOG_1
b handle_page_fault_tramp_1
-#else /* CONFIG_VMAP_STACK */
- EXCEPTION_PROLOG handle_dar_dsisr=1
- get_and_save_dar_dsisr_on_stack r4, r5, r11
-#ifdef CONFIG_PPC_BOOK3S_604
-BEGIN_MMU_FTR_SECTION
- andis. r0, r5, (DSISR_BAD_FAULT_32S | DSISR_DABRMATCH)@h
- bne handle_page_fault_tramp_2 /* if not, try to put a PTE */
- rlwinm r3, r5, 32 - 15, 21, 21 /* DSISR_STORE -> _PAGE_RW */
- bl hash_page
- b handle_page_fault_tramp_1
-MMU_FTR_SECTION_ELSE
-#endif
- b handle_page_fault_tramp_2
-#ifdef CONFIG_PPC_BOOK3S_604
-ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_HPTE_TABLE)
-#endif
-#endif /* CONFIG_VMAP_STACK */
/* Instruction access exception. */
. = 0x400
DO_KVM 0x400
InstructionAccess:
-#ifdef CONFIG_VMAP_STACK
mtspr SPRN_SPRG_SCRATCH0,r10
mtspr SPRN_SPRG_SCRATCH1,r11
mfspr r10, SPRN_SPRG_THREAD
@@ -353,18 +327,6 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
EXCEPTION_PROLOG_1
EXCEPTION_PROLOG_2
-#else /* CONFIG_VMAP_STACK */
- EXCEPTION_PROLOG
- andis. r0,r9,SRR1_ISI_NOPT@h /* no pte found? */
- beq 1f /* if so, try to put a PTE */
- li r3,0 /* into the hash table */
- mr r4,r12 /* SRR0 is fault address */
-#ifdef CONFIG_PPC_BOOK3S_604
-BEGIN_MMU_FTR_SECTION
- bl hash_page
-END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
-#endif
-#endif /* CONFIG_VMAP_STACK */
andis. r5,r9,DSISR_SRR1_MATCH_32S@h /* Filter relevant SRR1 bits */
stw r5, _DSISR(r11)
stw r12, _DAR(r11)
@@ -378,7 +340,6 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
DO_KVM 0x600
Alignment:
EXCEPTION_PROLOG handle_dar_dsisr=1
- save_dar_dsisr_on_stack r4, r5, r11
addi r3,r1,STACK_FRAME_OVERHEAD
b alignment_exception_tramp
@@ -686,18 +647,13 @@ alignment_exception_tramp:
EXC_XFER_STD(0x600, alignment_exception)
handle_page_fault_tramp_1:
-#ifdef CONFIG_VMAP_STACK
EXCEPTION_PROLOG_2 handle_dar_dsisr=1
-#endif
lwz r5, _DSISR(r11)
- /* fall through */
-handle_page_fault_tramp_2:
andis. r0, r5, DSISR_DABRMATCH@h
bne- 1f
EXC_XFER_LITE(0x300, handle_page_fault)
1: EXC_XFER_STD(0x300, do_break)
-#ifdef CONFIG_VMAP_STACK
#ifdef CONFIG_PPC_BOOK3S_604
.macro save_regs_thread thread
stw r0, THR0(\thread)
@@ -772,6 +728,7 @@ fast_hash_page_return:
rfi
#endif /* CONFIG_PPC_BOOK3S_604 */
+#ifdef CONFIG_VMAP_STACK
stack_overflow:
vmap_stack_overflow_exception
#endif
diff --git a/arch/powerpc/kernel/idle_6xx.S b/arch/powerpc/kernel/idle_6xx.S
index 69df840f7253..153366e178c4 100644
--- a/arch/powerpc/kernel/idle_6xx.S
+++ b/arch/powerpc/kernel/idle_6xx.S
@@ -145,9 +145,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
/*
* Return from NAP/DOZE mode, restore some CPU specific registers,
- * we are called with DR/IR still off and r2 containing physical
- * address of current. R11 points to the exception frame (physical
- * address). We have to preserve r10.
+ * R11 points to the exception frame. We have to preserve r10.
*/
_GLOBAL(power_save_ppc32_restore)
lwz r9,_LINK(r11) /* interrupted in ppc6xx_idle: */
@@ -166,11 +164,7 @@ BEGIN_FTR_SECTION
mfspr r9,SPRN_HID0
andis. r9,r9,HID0_NAP@h
beq 1f
-#ifdef CONFIG_VMAP_STACK
addis r9, r11, nap_save_msscr0@ha
-#else
- addis r9,r11,(nap_save_msscr0-KERNELBASE)@ha
-#endif
lwz r9,nap_save_msscr0@l(r9)
mtspr SPRN_MSSCR0, r9
sync
@@ -178,11 +172,7 @@ BEGIN_FTR_SECTION
1:
END_FTR_SECTION_IFSET(CPU_FTR_NAP_DISABLE_L2_PR)
BEGIN_FTR_SECTION
-#ifdef CONFIG_VMAP_STACK
addis r9, r11, nap_save_hid1@ha
-#else
- addis r9,r11,(nap_save_hid1-KERNELBASE)@ha
-#endif
lwz r9,nap_save_hid1@l(r9)
mtspr SPRN_HID1, r9
END_FTR_SECTION_IFSET(CPU_FTR_DUAL_PLL_750FX)
diff --git a/arch/powerpc/kernel/idle_e500.S b/arch/powerpc/kernel/idle_e500.S
index 72c85b6f3898..7795727e7f08 100644
--- a/arch/powerpc/kernel/idle_e500.S
+++ b/arch/powerpc/kernel/idle_e500.S
@@ -74,8 +74,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
/*
* Return from NAP/DOZE mode, restore some CPU specific registers,
- * r2 containing physical address of current.
- * r11 points to the exception frame (physical address).
+ * r2 containing address of current.
+ * r11 points to the exception frame.
* We have to preserve r10.
*/
_GLOBAL(power_save_ppc32_restore)
diff --git a/arch/powerpc/kernel/vector.S b/arch/powerpc/kernel/vector.S
index 801dc28fdcca..f5a52f444e36 100644
--- a/arch/powerpc/kernel/vector.S
+++ b/arch/powerpc/kernel/vector.S
@@ -67,9 +67,7 @@ _GLOBAL(load_up_altivec)
#ifdef CONFIG_PPC32
mfspr r5,SPRN_SPRG_THREAD /* current task's THREAD (phys) */
oris r9,r9,MSR_VEC@h
-#ifdef CONFIG_VMAP_STACK
tovirt(r5, r5)
-#endif
#else
ld r4,PACACURRENT(r13)
addi r5,r4,THREAD /* Get THREAD */
diff --git a/arch/powerpc/mm/book3s32/hash_low.S b/arch/powerpc/mm/book3s32/hash_low.S
index 0e6dc830c38b..fb4233a5bdf7 100644
--- a/arch/powerpc/mm/book3s32/hash_low.S
+++ b/arch/powerpc/mm/book3s32/hash_low.S
@@ -140,10 +140,6 @@ _GLOBAL(hash_page)
bne- .Lretry /* retry if someone got there first */
mfsrin r3,r4 /* get segment reg for segment */
-#ifndef CONFIG_VMAP_STACK
- mfctr r0
- stw r0,_CTR(r11)
-#endif
bl create_hpte /* add the hash table entry */
#ifdef CONFIG_SMP
@@ -152,17 +148,7 @@ _GLOBAL(hash_page)
li r0,0
stw r0, (mmu_hash_lock - PAGE_OFFSET)@l(r8)
#endif
-
-#ifdef CONFIG_VMAP_STACK
b fast_hash_page_return
-#else
- /* Return from the exception */
- lwz r5,_CTR(r11)
- mtctr r5
- lwz r0,GPR0(r11)
- lwz r8,GPR8(r11)
- b fast_exception_return
-#endif
#ifdef CONFIG_SMP
.Lhash_page_out:
--
2.25.0
^ permalink raw reply related
* [PATCH v2 13/43] powerpc/32: Remove ksp_limit
From: Christophe Leroy @ 2021-03-09 12:09 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615291471.git.christophe.leroy@csgroup.eu>
ksp_limit is there to help detect stack overflows.
That is specific to ppc32 as it was removed from ppc64 in
commit cbc9565ee826 ("powerpc: Remove ksp_limit on ppc64").
There are other means for detecting stack overflows.
As ppc64 has proven to not need it, ppc32 should be able to do
without it too.
Lets remove it and simplify exception handling.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/include/asm/processor.h | 2 -
arch/powerpc/kernel/asm-offsets.c | 2 -
arch/powerpc/kernel/entry_32.S | 68 +---------------------------
arch/powerpc/kernel/head_40x.S | 2 -
arch/powerpc/kernel/head_booke.h | 1 -
arch/powerpc/kernel/misc_32.S | 14 ------
arch/powerpc/kernel/process.c | 3 --
arch/powerpc/kernel/traps.c | 9 ----
arch/powerpc/lib/sstep.c | 9 ----
9 files changed, 2 insertions(+), 108 deletions(-)
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 8acc3590c971..43cbd9281055 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -144,7 +144,6 @@ struct thread_struct {
#endif
#ifdef CONFIG_PPC32
void *pgdir; /* root of page-table tree */
- unsigned long ksp_limit; /* if ksp <= ksp_limit stack overflow */
#ifdef CONFIG_PPC_RTAS
unsigned long rtas_sp; /* stack pointer for when in RTAS */
#endif
@@ -282,7 +281,6 @@ struct thread_struct {
#ifdef CONFIG_PPC32
#define INIT_THREAD { \
.ksp = INIT_SP, \
- .ksp_limit = INIT_SP_LIMIT, \
.pgdir = swapper_pg_dir, \
.fpexc_mode = MSR_FE0 | MSR_FE1, \
SPEFSCR_INIT \
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index f3a662201a9f..73620536c801 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -91,7 +91,6 @@ int main(void)
DEFINE(SIGSEGV, SIGSEGV);
DEFINE(NMI_MASK, NMI_MASK);
#else
- OFFSET(KSP_LIMIT, thread_struct, ksp_limit);
#ifdef CONFIG_PPC_RTAS
OFFSET(RTAS_SP, thread_struct, rtas_sp);
#endif
@@ -381,7 +380,6 @@ int main(void)
DEFINE(_CSRR1, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, csrr1));
DEFINE(_DSRR0, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, dsrr0));
DEFINE(_DSRR1, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, dsrr1));
- DEFINE(SAVED_KSP_LIMIT, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, saved_ksp_limit));
#endif
#endif
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 4ffbcf3df72e..66198e6e25e7 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -94,12 +94,6 @@ crit_transfer_to_handler:
mfspr r0,SPRN_SRR1
stw r0,_SRR1(r11)
- /* set the stack limit to the current stack */
- mfspr r8,SPRN_SPRG_THREAD
- lwz r0,KSP_LIMIT(r8)
- stw r0,SAVED_KSP_LIMIT(r11)
- rlwinm r0,r1,0,0,(31 - THREAD_SHIFT)
- stw r0,KSP_LIMIT(r8)
/* fall through */
_ASM_NOKPROBE_SYMBOL(crit_transfer_to_handler)
#endif
@@ -107,12 +101,6 @@ _ASM_NOKPROBE_SYMBOL(crit_transfer_to_handler)
#ifdef CONFIG_40x
.globl crit_transfer_to_handler
crit_transfer_to_handler:
- /* set the stack limit to the current stack */
- mfspr r8,SPRN_SPRG_THREAD
- lwz r0,KSP_LIMIT(r8)
- stw r0,saved_ksp_limit@l(0)
- rlwinm r0,r1,0,0,(31 - THREAD_SHIFT)
- stw r0,KSP_LIMIT(r8)
/* fall through */
_ASM_NOKPROBE_SYMBOL(crit_transfer_to_handler)
#endif
@@ -151,17 +139,10 @@ transfer_to_handler:
#endif
b 3f
-2: /* if from kernel, check interrupted DOZE/NAP mode and
- * check for stack overflow
- */
+ /* if from kernel, check interrupted DOZE/NAP mode */
+2:
kuap_save_and_lock r11, r12, r9, r2, r6
addi r2, r12, -THREAD
-#ifndef CONFIG_VMAP_STACK
- lwz r9,KSP_LIMIT(r12)
- cmplw r1,r9 /* if r1 <= ksp_limit */
- ble- stack_ovf /* then the kernel stack overflowed */
-#endif
-5:
#if defined(CONFIG_PPC_BOOK3S_32) || defined(CONFIG_E500)
lwz r12,TI_LOCAL_FLAGS(r2)
mtcrf 0x01,r12
@@ -204,37 +185,6 @@ transfer_to_handler_cont:
_ASM_NOKPROBE_SYMBOL(transfer_to_handler)
_ASM_NOKPROBE_SYMBOL(transfer_to_handler_cont)
-#ifndef CONFIG_VMAP_STACK
-/*
- * On kernel stack overflow, load up an initial stack pointer
- * and call StackOverflow(regs), which should not return.
- */
-stack_ovf:
- /* sometimes we use a statically-allocated stack, which is OK. */
- lis r12,_end@h
- ori r12,r12,_end@l
- cmplw r1,r12
- ble 5b /* r1 <= &_end is OK */
- SAVE_NVGPRS(r11)
- addi r3,r1,STACK_FRAME_OVERHEAD
- lis r1,init_thread_union@ha
- addi r1,r1,init_thread_union@l
- addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
- lis r9,StackOverflow@ha
- addi r9,r9,StackOverflow@l
- LOAD_REG_IMMEDIATE(r10,MSR_KERNEL)
-#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
- mtspr SPRN_NRI, r0
-#endif
- mtspr SPRN_SRR0,r9
- mtspr SPRN_SRR1,r10
- rfi
-#ifdef CONFIG_40x
- b . /* Prevent prefetch past rfi */
-#endif
-_ASM_NOKPROBE_SYMBOL(stack_ovf)
-#endif
-
.globl transfer_to_syscall
transfer_to_syscall:
SAVE_NVGPRS(r1)
@@ -815,11 +765,6 @@ _ASM_NOKPROBE_SYMBOL(exc_exit_restart)
#ifdef CONFIG_40x
.globl ret_from_crit_exc
ret_from_crit_exc:
- mfspr r9,SPRN_SPRG_THREAD
- lis r10,saved_ksp_limit@ha;
- lwz r10,saved_ksp_limit@l(r10);
- tovirt(r9,r9);
- stw r10,KSP_LIMIT(r9)
lis r9,crit_srr0@ha;
lwz r9,crit_srr0@l(r9);
lis r10,crit_srr1@ha;
@@ -833,9 +778,6 @@ _ASM_NOKPROBE_SYMBOL(ret_from_crit_exc)
#ifdef CONFIG_BOOKE
.globl ret_from_crit_exc
ret_from_crit_exc:
- mfspr r9,SPRN_SPRG_THREAD
- lwz r10,SAVED_KSP_LIMIT(r1)
- stw r10,KSP_LIMIT(r9)
RESTORE_xSRR(SRR0,SRR1);
RESTORE_MMU_REGS;
RET_FROM_EXC_LEVEL(SPRN_CSRR0, SPRN_CSRR1, PPC_RFCI)
@@ -843,9 +785,6 @@ _ASM_NOKPROBE_SYMBOL(ret_from_crit_exc)
.globl ret_from_debug_exc
ret_from_debug_exc:
- mfspr r9,SPRN_SPRG_THREAD
- lwz r10,SAVED_KSP_LIMIT(r1)
- stw r10,KSP_LIMIT(r9)
RESTORE_xSRR(SRR0,SRR1);
RESTORE_xSRR(CSRR0,CSRR1);
RESTORE_MMU_REGS;
@@ -854,9 +793,6 @@ _ASM_NOKPROBE_SYMBOL(ret_from_debug_exc)
.globl ret_from_mcheck_exc
ret_from_mcheck_exc:
- mfspr r9,SPRN_SPRG_THREAD
- lwz r10,SAVED_KSP_LIMIT(r1)
- stw r10,KSP_LIMIT(r9)
RESTORE_xSRR(SRR0,SRR1);
RESTORE_xSRR(CSRR0,CSRR1);
RESTORE_xSRR(DSRR0,DSRR1);
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 4bf0aee858eb..72e4962902de 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -95,8 +95,6 @@ _ENTRY(crit_dear)
.space 4
_ENTRY(crit_esr)
.space 4
-_ENTRY(saved_ksp_limit)
- .space 4
/*
* Exception prolog for critical exceptions. This is a little different
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 47857795f50a..4a5f0c9b652b 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -481,7 +481,6 @@ struct exception_regs {
unsigned long csrr1;
unsigned long dsrr0;
unsigned long dsrr1;
- unsigned long saved_ksp_limit;
};
/* ensure this structure is always sized to a multiple of the stack alignment */
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index 717e658b90fd..acc410043b96 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -27,23 +27,14 @@
.text
-/*
- * We store the saved ksp_limit in the unused part
- * of the STACK_FRAME_OVERHEAD
- */
_GLOBAL(call_do_softirq)
mflr r0
stw r0,4(r1)
- lwz r10,THREAD+KSP_LIMIT(r2)
- stw r3, THREAD+KSP_LIMIT(r2)
stwu r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r3)
mr r1,r3
- stw r10,8(r1)
bl __do_softirq
- lwz r10,8(r1)
lwz r1,0(r1)
lwz r0,4(r1)
- stw r10,THREAD+KSP_LIMIT(r2)
mtlr r0
blr
@@ -53,16 +44,11 @@ _GLOBAL(call_do_softirq)
_GLOBAL(call_do_irq)
mflr r0
stw r0,4(r1)
- lwz r10,THREAD+KSP_LIMIT(r2)
- stw r4, THREAD+KSP_LIMIT(r2)
stwu r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r4)
mr r1,r4
- stw r10,8(r1)
bl __do_irq
- lwz r10,8(r1)
lwz r1,0(r1)
lwz r0,4(r1)
- stw r10,THREAD+KSP_LIMIT(r2)
mtlr r0
blr
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 3231c2df9e26..5d5d64be2679 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1724,9 +1724,6 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
kregs = (struct pt_regs *) sp;
sp -= STACK_FRAME_OVERHEAD;
p->thread.ksp = sp;
-#ifdef CONFIG_PPC32
- p->thread.ksp_limit = (unsigned long)end_of_stack(p);
-#endif
#ifdef CONFIG_HAVE_HW_BREAKPOINT
for (i = 0; i < nr_wp_slots(); i++)
p->thread.ptrace_bps[i] = NULL;
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index d5c9d9ddd186..7c4ab872004d 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1606,15 +1606,6 @@ DEFINE_INTERRUPT_HANDLER(alignment_exception)
bad_page_fault(regs, sig);
}
-DEFINE_INTERRUPT_HANDLER(StackOverflow)
-{
- pr_crit("Kernel stack overflow in process %s[%d], r1=%lx\n",
- current->comm, task_pid_nr(current), regs->gpr[1]);
- debugger(regs);
- show_regs(regs);
- panic("kernel stack overflow");
-}
-
DEFINE_INTERRUPT_HANDLER(stack_overflow_exception)
{
die("Kernel stack overflow", regs, SIGSEGV);
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index bb5c20d4ca91..212012f49f10 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -3086,15 +3086,6 @@ NOKPROBE_SYMBOL(analyse_instr);
*/
static nokprobe_inline int handle_stack_update(unsigned long ea, struct pt_regs *regs)
{
-#ifdef CONFIG_PPC32
- /*
- * Check if we will touch kernel stack overflow
- */
- if (ea - STACK_INT_FRAME_SIZE <= current->thread.ksp_limit) {
- printk(KERN_CRIT "Can't kprobe this since kernel stack would overflow.\n");
- return -EINVAL;
- }
-#endif /* CONFIG_PPC32 */
/*
* Check if we already set since that means we'll
* lose the previous value.
--
2.25.0
^ permalink raw reply related
* [PATCH v2 12/43] powerpc/32: Use fast instruction to set MSR RI in exception prolog on 8xx
From: Christophe Leroy @ 2021-03-09 12:09 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615291471.git.christophe.leroy@csgroup.eu>
8xx has registers SPRN_NRI, SPRN_EID and SPRN_EIE for changing
MSR EE and RI.
Use SPRN_EID in exception prolog to set RI.
On an 8xx, it reduces the null_syscall test by 3 cycles.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/head_32.h | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index ac6b391f1493..25ee6b26ef5a 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -107,6 +107,8 @@
#endif
#ifdef CONFIG_40x
rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */
+#elif defined(CONFIG_PPC_8xx)
+ mtspr SPRN_EID, r2 /* Set MSR_RI */
#else
#ifdef CONFIG_VMAP_STACK
li r10, MSR_KERNEL & ~MSR_IR /* can take exceptions */
--
2.25.0
^ permalink raw reply related
* [PATCH v2 11/43] powerpc/32: Handle bookE debugging in C in exception entry
From: Christophe Leroy @ 2021-03-09 12:09 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615291471.git.christophe.leroy@csgroup.eu>
The handling of SPRN_DBCR0 and other registers can easily
be done in C instead of ASM.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/include/asm/interrupt.h | 2 ++
arch/powerpc/kernel/entry_32.S | 23 -----------------------
2 files changed, 2 insertions(+), 23 deletions(-)
diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index c35368adbe71..861e6eadc98c 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -65,6 +65,8 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrup
if (user_mode(regs))
account_cpu_user_entry();
#endif
+
+ booke_restore_dbcr0();
}
/*
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 0f3f1bdd909e..4ffbcf3df72e 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -146,32 +146,9 @@ transfer_to_handler:
addi r2, r12, -THREAD
addi r11,r1,STACK_FRAME_OVERHEAD
stw r11,PT_REGS(r12)
-#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
- /* Check to see if the dbcr0 register is set up to debug. Use the
- internal debug mode bit to do this. */
- lwz r12,THREAD_DBCR0(r12)
- andis. r12,r12,DBCR0_IDM@h
-#endif
#ifdef CONFIG_PPC_BOOK3S_32
kuep_lock r11, r12
#endif
-#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
- beq+ 3f
- /* From user and task is ptraced - load up global dbcr0 */
- li r12,-1 /* clear all pending debug events */
- mtspr SPRN_DBSR,r12
- lis r11,global_dbcr0@ha
- tophys_novmstack r11,r11
- addi r11,r11,global_dbcr0@l
-#ifdef CONFIG_SMP
- lwz r9,TASK_CPU(r2)
- slwi r9,r9,2
- add r11,r11,r9
-#endif
- lwz r12,0(r11)
- mtspr SPRN_DBCR0,r12
-#endif
-
b 3f
2: /* if from kernel, check interrupted DOZE/NAP mode and
--
2.25.0
^ permalink raw reply related
* [PATCH v2 09/43] powerpc/32: Reconcile interrupts in C
From: Christophe Leroy @ 2021-03-09 12:09 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615291471.git.christophe.leroy@csgroup.eu>
There is no need for this to be in asm anymore,
use the new interrupt entry wrapper.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/include/asm/interrupt.h | 4 ++
arch/powerpc/kernel/entry_32.S | 58 ----------------------------
2 files changed, 4 insertions(+), 58 deletions(-)
diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 232a4847f596..b2f69e5dcb50 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -29,6 +29,10 @@ static inline void booke_restore_dbcr0(void)
static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrupt_state *state)
{
+#ifdef CONFIG_PPC32
+ if (!arch_irq_disabled_regs(regs))
+ trace_hardirqs_off();
+#endif
/*
* Book3E reconciles irq soft mask in asm
*/
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 535c55f4393a..0f18fe14649c 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -202,22 +202,6 @@ transfer_to_handler_cont:
lwz r9,4(r9) /* where to go when done */
#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
mtspr SPRN_NRI, r0
-#endif
-#ifdef CONFIG_TRACE_IRQFLAGS
- /*
- * When tracing IRQ state (lockdep) we enable the MMU before we call
- * the IRQ tracing functions as they might access vmalloc space or
- * perform IOs for console output.
- *
- * To speed up the syscall path where interrupts stay on, let's check
- * first if we are changing the MSR value at all.
- */
- tophys_novmstack r12, r1
- lwz r12,_MSR(r12)
- andi. r12,r12,MSR_EE
- bne 1f
-
- /* MSR isn't changing, just transition directly */
#endif
mtspr SPRN_SRR0,r11
mtspr SPRN_SRR1,r10
@@ -244,48 +228,6 @@ transfer_to_handler_cont:
_ASM_NOKPROBE_SYMBOL(transfer_to_handler)
_ASM_NOKPROBE_SYMBOL(transfer_to_handler_cont)
-#ifdef CONFIG_TRACE_IRQFLAGS
-1: /* MSR is changing, re-enable MMU so we can notify lockdep. We need to
- * keep interrupts disabled at this point otherwise we might risk
- * taking an interrupt before we tell lockdep they are enabled.
- */
- lis r12,reenable_mmu@h
- ori r12,r12,reenable_mmu@l
- LOAD_REG_IMMEDIATE(r0, MSR_KERNEL)
- mtspr SPRN_SRR0,r12
- mtspr SPRN_SRR1,r0
- rfi
-#ifdef CONFIG_40x
- b . /* Prevent prefetch past rfi */
-#endif
-
-reenable_mmu:
- /*
- * We save a bunch of GPRs,
- * r3 can be different from GPR3(r1) at this point, r9 and r11
- * contains the old MSR and handler address respectively,
- * r0, r4-r8, r12, CCR, CTR, XER etc... are left
- * clobbered as they aren't useful past this point.
- */
-
- stwu r1,-32(r1)
- stw r9,8(r1)
- stw r11,12(r1)
- stw r3,16(r1)
-
- /* If we are disabling interrupts (normal case), simply log it with
- * lockdep
- */
-1: bl trace_hardirqs_off
- lwz r3,16(r1)
- lwz r11,12(r1)
- lwz r9,8(r1)
- addi r1,r1,32
- mtctr r11
- mtlr r9
- bctr /* jump to handler */
-#endif /* CONFIG_TRACE_IRQFLAGS */
-
#ifndef CONFIG_VMAP_STACK
/*
* On kernel stack overflow, load up an initial stack pointer
--
2.25.0
^ permalink raw reply related
* [PATCH v2 10/43] powerpc/32: Entry cpu time accounting in C
From: Christophe Leroy @ 2021-03-09 12:09 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615291471.git.christophe.leroy@csgroup.eu>
There is no need for this to be in asm,
use the new interrupt entry wrapper.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/include/asm/interrupt.h | 3 +++
arch/powerpc/include/asm/ppc_asm.h | 10 ----------
arch/powerpc/kernel/entry_32.S | 1 -
3 files changed, 3 insertions(+), 11 deletions(-)
diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index b2f69e5dcb50..c35368adbe71 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -32,6 +32,9 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrup
#ifdef CONFIG_PPC32
if (!arch_irq_disabled_regs(regs))
trace_hardirqs_off();
+
+ if (user_mode(regs))
+ account_cpu_user_entry();
#endif
/*
* Book3E reconciles irq soft mask in asm
diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
index 3dceb64fc9af..8998122fc7e2 100644
--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -23,18 +23,8 @@
*/
#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
-#define ACCOUNT_CPU_USER_ENTRY(ptr, ra, rb)
#define ACCOUNT_CPU_USER_EXIT(ptr, ra, rb)
#else
-#define ACCOUNT_CPU_USER_ENTRY(ptr, ra, rb) \
- MFTB(ra); /* get timebase */ \
- PPC_LL rb, ACCOUNT_STARTTIME_USER(ptr); \
- PPC_STL ra, ACCOUNT_STARTTIME(ptr); \
- subf rb,rb,ra; /* subtract start value */ \
- PPC_LL ra, ACCOUNT_USER_TIME(ptr); \
- add ra,ra,rb; /* add on to user time */ \
- PPC_STL ra, ACCOUNT_USER_TIME(ptr); \
-
#define ACCOUNT_CPU_USER_EXIT(ptr, ra, rb) \
MFTB(ra); /* get timebase */ \
PPC_LL rb, ACCOUNT_STARTTIME(ptr); \
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 0f18fe14649c..0f3f1bdd909e 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -152,7 +152,6 @@ transfer_to_handler:
lwz r12,THREAD_DBCR0(r12)
andis. r12,r12,DBCR0_IDM@h
#endif
- ACCOUNT_CPU_USER_ENTRY(r2, r11, r12)
#ifdef CONFIG_PPC_BOOK3S_32
kuep_lock r11, r12
#endif
--
2.25.0
^ permalink raw reply related
* [PATCH v2 08/43] powerpc/40x: Prepare normal exception handler for enabling MMU early
From: Christophe Leroy @ 2021-03-09 12:09 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615291471.git.christophe.leroy@csgroup.eu>
Ensure normal exception handler are able to manage stuff with
MMU enabled. For that we use CONFIG_VMAP_STACK related code
allthough there is no intention to really activate CONFIG_VMAP_STACK
on powerpc 40x for the moment.
40x uses SPRN_DEAR instead of SPRN_DAR and SPRN_ESR instead of
SPRN_DSISR. Take it into account in common macros.
40x MSR value doesn't fit on 15 bits, use LOAD_REG_IMMEDIATE() in
common macros that will be used also with 40x.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/entry_32.S | 2 +-
arch/powerpc/kernel/head_32.h | 15 ++++++++++++++-
arch/powerpc/kernel/head_40x.S | 17 ++++++-----------
3 files changed, 21 insertions(+), 13 deletions(-)
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 8528b4c7f9d3..535c55f4393a 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -162,7 +162,7 @@ transfer_to_handler:
li r12,-1 /* clear all pending debug events */
mtspr SPRN_DBSR,r12
lis r11,global_dbcr0@ha
- tophys(r11,r11)
+ tophys_novmstack r11,r11
addi r11,r11,global_dbcr0@l
#ifdef CONFIG_SMP
lwz r9,TASK_CPU(r2)
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 5d4706c14572..ac6b391f1493 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -22,9 +22,17 @@
#ifdef CONFIG_VMAP_STACK
mfspr r10, SPRN_SPRG_THREAD
.if \handle_dar_dsisr
+#ifdef CONFIG_40x
+ mfspr r11, SPRN_DEAR
+#else
mfspr r11, SPRN_DAR
+#endif
stw r11, DAR(r10)
+#ifdef CONFIG_40x
+ mfspr r11, SPRN_ESR
+#else
mfspr r11, SPRN_DSISR
+#endif
stw r11, DSISR(r10)
.endif
mfspr r11, SPRN_SRR0
@@ -61,7 +69,7 @@
.macro EXCEPTION_PROLOG_2 handle_dar_dsisr=0
#ifdef CONFIG_VMAP_STACK
- li r11, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */
+ LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_IR | MSR_RI)) /* can take DTLB miss */
mtmsr r11
isync
mfspr r11, SPRN_SPRG_SCRATCH2
@@ -158,8 +166,13 @@
.macro save_dar_dsisr_on_stack reg1, reg2, sp
#ifndef CONFIG_VMAP_STACK
+#ifdef CONFIG_40x
+ mfspr \reg1, SPRN_DEAR
+ mfspr \reg2, SPRN_ESR
+#else
mfspr \reg1, SPRN_DAR
mfspr \reg2, SPRN_DSISR
+#endif
stw \reg1, _DAR(\sp)
stw \reg2, _DSISR(\sp)
#endif
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 1468f38c3860..4bf0aee858eb 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -221,11 +221,8 @@ _ENTRY(saved_ksp_limit)
* if they can't resolve the lightweight TLB fault.
*/
START_EXCEPTION(0x0300, DataStorage)
- EXCEPTION_PROLOG
- mfspr r5, SPRN_ESR /* Grab the ESR, save it */
- stw r5, _ESR(r11)
- mfspr r4, SPRN_DEAR /* Grab the DEAR, save it */
- stw r4, _DEAR(r11)
+ EXCEPTION_PROLOG handle_dar_dsisr=1
+ save_dar_dsisr_on_stack r4, r5, r11
EXC_XFER_LITE(0x300, handle_page_fault)
/*
@@ -244,17 +241,15 @@ _ENTRY(saved_ksp_limit)
/* 0x0600 - Alignment Exception */
START_EXCEPTION(0x0600, Alignment)
- EXCEPTION_PROLOG
- mfspr r4,SPRN_DEAR /* Grab the DEAR and save it */
- stw r4,_DEAR(r11)
+ EXCEPTION_PROLOG handle_dar_dsisr=1
+ save_dar_dsisr_on_stack r4, r5, r11
addi r3,r1,STACK_FRAME_OVERHEAD
EXC_XFER_STD(0x600, alignment_exception)
/* 0x0700 - Program Exception */
START_EXCEPTION(0x0700, ProgramCheck)
- EXCEPTION_PROLOG
- mfspr r4,SPRN_ESR /* Grab the ESR and save it */
- stw r4,_ESR(r11)
+ EXCEPTION_PROLOG handle_dar_dsisr=1
+ save_dar_dsisr_on_stack r4, r5, r11
addi r3,r1,STACK_FRAME_OVERHEAD
EXC_XFER_STD(0x700, program_check_exception)
--
2.25.0
^ permalink raw reply related
* [PATCH v2 07/43] powerpc/40x: Prepare for enabling MMU in critical exception prolog
From: Christophe Leroy @ 2021-03-09 12:09 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615291471.git.christophe.leroy@csgroup.eu>
In order the enable MMU early in exception prolog, implement
CONFIG_VMAP_STACK principles in critical exception prolog.
There is no intention to use CONFIG_VMAP_STACK on 40x,
but related code will be used to enable MMU early in exception
in a later patch.
Also address (critirq_ctx - PAGE_OFFSET) directly instead of
using tophys() in order to win one instruction.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/head_40x.S | 40 +++++++++++++++++++++++++++++++---
1 file changed, 37 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 5b337bf49bcb..1468f38c3860 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -89,6 +89,12 @@ _ENTRY(crit_srr0)
.space 4
_ENTRY(crit_srr1)
.space 4
+_ENTRY(crit_r1)
+ .space 4
+_ENTRY(crit_dear)
+ .space 4
+_ENTRY(crit_esr)
+ .space 4
_ENTRY(saved_ksp_limit)
.space 4
@@ -107,32 +113,60 @@ _ENTRY(saved_ksp_limit)
mfspr r11,SPRN_SRR1
stw r10,crit_srr0@l(0)
stw r11,crit_srr1@l(0)
+#ifdef CONFIG_VMAP_STACK
+ mfspr r10,SPRN_DEAR
+ mfspr r11,SPRN_ESR
+ stw r10,crit_dear@l(0)
+ stw r11,crit_esr@l(0)
+#endif
mfcr r10 /* save CR in r10 for now */
mfspr r11,SPRN_SRR3 /* check whether user or kernel */
andi. r11,r11,MSR_PR
- lis r11,critirq_ctx@ha
- tophys(r11,r11)
- lwz r11,critirq_ctx@l(r11)
+ lis r11,(critirq_ctx-PAGE_OFFSET)@ha
+ lwz r11,(critirq_ctx-PAGE_OFFSET)@l(r11)
beq 1f
/* COMING FROM USER MODE */
mfspr r11,SPRN_SPRG_THREAD /* if from user, start at top of */
lwz r11,TASK_STACK-THREAD(r11) /* this thread's kernel stack */
+#ifdef CONFIG_VMAP_STACK
+1: stw r1,crit_r1@l(0)
+ addi r1,r11,THREAD_SIZE-INT_FRAME_SIZE /* Alloc an excpt frm */
+ LOAD_REG_IMMEDIATE(r11,MSR_KERNEL & ~(MSR_IR | MSR_RI))
+ mtmsr r11
+ isync
+ lwz r11,crit_r1@l(0)
+ stw r11,GPR1(r1)
+ stw r11,0(r1)
+ mr r11,r1
+#else
1: addi r11,r11,THREAD_SIZE-INT_FRAME_SIZE /* Alloc an excpt frm */
tophys(r11,r11)
stw r1,GPR1(r11)
stw r1,0(r11)
tovirt(r1,r11)
+#endif
stw r10,_CCR(r11) /* save various registers */
stw r12,GPR12(r11)
stw r9,GPR9(r11)
mflr r10
stw r10,_LINK(r11)
+#ifdef CONFIG_VMAP_STACK
+ lis r9,PAGE_OFFSET@ha
+ lwz r10,crit_r10@l(r9)
+ lwz r12,crit_r11@l(r9)
+#else
lwz r10,crit_r10@l(0)
lwz r12,crit_r11@l(0)
+#endif
stw r10,GPR10(r11)
stw r12,GPR11(r11)
+#ifdef CONFIG_VMAP_STACK
+ lwz r12,crit_dear@l(r9)
+ lwz r9,crit_esr@l(r9)
+#else
mfspr r12,SPRN_DEAR /* save DEAR and ESR in the frame */
mfspr r9,SPRN_ESR /* in them at the point where the */
+#endif
stw r12,_DEAR(r11) /* since they may have had stuff */
stw r9,_ESR(r11) /* exception was taken */
mfspr r12,SPRN_SRR2
--
2.25.0
^ permalink raw reply related
* [PATCH v2 05/43] powerpc/40x: Save SRR0/SRR1 and r10/r11 earlier in critical exception
From: Christophe Leroy @ 2021-03-09 12:09 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615291471.git.christophe.leroy@csgroup.eu>
In order to be able to switch MMU on in exception prolog, save
SRR0 and SRR1 earlier.
Also save r10 and r11 into stack earlier to better match with the
normal exception prolog.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/entry_32.S | 9 ---------
arch/powerpc/kernel/head_40x.S | 8 ++++++++
2 files changed, 8 insertions(+), 9 deletions(-)
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 78c430b7f9d9..8528b4c7f9d3 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -107,15 +107,6 @@ _ASM_NOKPROBE_SYMBOL(crit_transfer_to_handler)
#ifdef CONFIG_40x
.globl crit_transfer_to_handler
crit_transfer_to_handler:
- lwz r0,crit_r10@l(0)
- stw r0,GPR10(r11)
- lwz r0,crit_r11@l(0)
- stw r0,GPR11(r11)
- mfspr r0,SPRN_SRR0
- stw r0,crit_srr0@l(0)
- mfspr r0,SPRN_SRR1
- stw r0,crit_srr1@l(0)
-
/* set the stack limit to the current stack */
mfspr r8,SPRN_SPRG_THREAD
lwz r0,KSP_LIMIT(r8)
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 9cef423d574b..067ae1302c1c 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -103,6 +103,10 @@ _ENTRY(saved_ksp_limit)
.macro CRITICAL_EXCEPTION_PROLOG
stw r10,crit_r10@l(0) /* save two registers to work with */
stw r11,crit_r11@l(0)
+ mfspr r10,SPRN_SRR0
+ mfspr r11,SPRN_SRR1
+ stw r10,crit_srr0@l(0)
+ stw r11,crit_srr1@l(0)
mfcr r10 /* save CR in r10 for now */
mfspr r11,SPRN_SRR3 /* check whether user or kernel */
andi. r11,r11,MSR_PR
@@ -120,6 +124,10 @@ _ENTRY(saved_ksp_limit)
stw r9,GPR9(r11)
mflr r10
stw r10,_LINK(r11)
+ lwz r10,crit_r10@l(0)
+ lwz r12,crit_r11@l(0)
+ stw r10,GPR10(r11)
+ stw r12,GPR11(r11)
mfspr r12,SPRN_DEAR /* save DEAR and ESR in the frame */
stw r12,_DEAR(r11) /* since they may have had stuff */
mfspr r9,SPRN_ESR /* in them at the point where the */
--
2.25.0
^ permalink raw reply related
* [PATCH v2 06/43] powerpc/40x: Reorder a few instructions in critical exception prolog
From: Christophe Leroy @ 2021-03-09 12:09 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615291471.git.christophe.leroy@csgroup.eu>
In order to ease preparation for CONFIG_VMAP_STACK, reorder
a few instruction, especially save r1 into stack frame earlier.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/head_40x.S | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 067ae1302c1c..5b337bf49bcb 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -119,6 +119,9 @@ _ENTRY(saved_ksp_limit)
lwz r11,TASK_STACK-THREAD(r11) /* this thread's kernel stack */
1: addi r11,r11,THREAD_SIZE-INT_FRAME_SIZE /* Alloc an excpt frm */
tophys(r11,r11)
+ stw r1,GPR1(r11)
+ stw r1,0(r11)
+ tovirt(r1,r11)
stw r10,_CCR(r11) /* save various registers */
stw r12,GPR12(r11)
stw r9,GPR9(r11)
@@ -129,14 +132,11 @@ _ENTRY(saved_ksp_limit)
stw r10,GPR10(r11)
stw r12,GPR11(r11)
mfspr r12,SPRN_DEAR /* save DEAR and ESR in the frame */
- stw r12,_DEAR(r11) /* since they may have had stuff */
mfspr r9,SPRN_ESR /* in them at the point where the */
+ stw r12,_DEAR(r11) /* since they may have had stuff */
stw r9,_ESR(r11) /* exception was taken */
mfspr r12,SPRN_SRR2
- stw r1,GPR1(r11)
mfspr r9,SPRN_SRR3
- stw r1,0(r11)
- tovirt(r1,r11)
rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */
stw r0,GPR0(r11)
lis r10, STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
--
2.25.0
^ permalink raw reply related
* [PATCH v2 04/43] powerpc/40x: Change CRITICAL_EXCEPTION_PROLOG macro to a gas macro
From: Christophe Leroy @ 2021-03-09 12:09 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615291471.git.christophe.leroy@csgroup.eu>
Change CRITICAL_EXCEPTION_PROLOG macro to a gas macro to
remove the ugly ; and \ on each line.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/head_40x.S | 71 +++++++++++++++++-----------------
1 file changed, 36 insertions(+), 35 deletions(-)
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 383238a98f77..9cef423d574b 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -100,42 +100,43 @@ _ENTRY(saved_ksp_limit)
* Instead we use a couple of words of memory at low physical addresses.
* This is OK since we don't support SMP on these processors.
*/
-#define CRITICAL_EXCEPTION_PROLOG \
- stw r10,crit_r10@l(0); /* save two registers to work with */\
- stw r11,crit_r11@l(0); \
- mfcr r10; /* save CR in r10 for now */\
- mfspr r11,SPRN_SRR3; /* check whether user or kernel */\
- andi. r11,r11,MSR_PR; \
- lis r11,critirq_ctx@ha; \
- tophys(r11,r11); \
- lwz r11,critirq_ctx@l(r11); \
- beq 1f; \
- /* COMING FROM USER MODE */ \
- mfspr r11,SPRN_SPRG_THREAD; /* if from user, start at top of */\
- lwz r11,TASK_STACK-THREAD(r11); /* this thread's kernel stack */\
-1: addi r11,r11,THREAD_SIZE-INT_FRAME_SIZE; /* Alloc an excpt frm */\
- tophys(r11,r11); \
- stw r10,_CCR(r11); /* save various registers */\
- stw r12,GPR12(r11); \
- stw r9,GPR9(r11); \
- mflr r10; \
- stw r10,_LINK(r11); \
- mfspr r12,SPRN_DEAR; /* save DEAR and ESR in the frame */\
- stw r12,_DEAR(r11); /* since they may have had stuff */\
- mfspr r9,SPRN_ESR; /* in them at the point where the */\
- stw r9,_ESR(r11); /* exception was taken */\
- mfspr r12,SPRN_SRR2; \
- stw r1,GPR1(r11); \
- mfspr r9,SPRN_SRR3; \
- stw r1,0(r11); \
- tovirt(r1,r11); \
- rlwinm r9,r9,0,14,12; /* clear MSR_WE (necessary?) */\
- stw r0,GPR0(r11); \
- lis r10, STACK_FRAME_REGS_MARKER@ha; /* exception frame marker */\
- addi r10, r10, STACK_FRAME_REGS_MARKER@l; \
- stw r10, 8(r11); \
- SAVE_4GPRS(3, r11); \
+.macro CRITICAL_EXCEPTION_PROLOG
+ stw r10,crit_r10@l(0) /* save two registers to work with */
+ stw r11,crit_r11@l(0)
+ mfcr r10 /* save CR in r10 for now */
+ mfspr r11,SPRN_SRR3 /* check whether user or kernel */
+ andi. r11,r11,MSR_PR
+ lis r11,critirq_ctx@ha
+ tophys(r11,r11)
+ lwz r11,critirq_ctx@l(r11)
+ beq 1f
+ /* COMING FROM USER MODE */
+ mfspr r11,SPRN_SPRG_THREAD /* if from user, start at top of */
+ lwz r11,TASK_STACK-THREAD(r11) /* this thread's kernel stack */
+1: addi r11,r11,THREAD_SIZE-INT_FRAME_SIZE /* Alloc an excpt frm */
+ tophys(r11,r11)
+ stw r10,_CCR(r11) /* save various registers */
+ stw r12,GPR12(r11)
+ stw r9,GPR9(r11)
+ mflr r10
+ stw r10,_LINK(r11)
+ mfspr r12,SPRN_DEAR /* save DEAR and ESR in the frame */
+ stw r12,_DEAR(r11) /* since they may have had stuff */
+ mfspr r9,SPRN_ESR /* in them at the point where the */
+ stw r9,_ESR(r11) /* exception was taken */
+ mfspr r12,SPRN_SRR2
+ stw r1,GPR1(r11)
+ mfspr r9,SPRN_SRR3
+ stw r1,0(r11)
+ tovirt(r1,r11)
+ rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */
+ stw r0,GPR0(r11)
+ lis r10, STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
+ addi r10, r10, STACK_FRAME_REGS_MARKER@l
+ stw r10, 8(r11)
+ SAVE_4GPRS(3, r11)
SAVE_2GPRS(7, r11)
+.endm
/*
* State at this point:
--
2.25.0
^ permalink raw reply related
* [PATCH v2 03/43] powerpc/40x: Don't use SPRN_SPRG_SCRATCH0/1 in TLB miss handlers
From: Christophe Leroy @ 2021-03-09 12:09 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615291471.git.christophe.leroy@csgroup.eu>
SPRN_SPRG_SCRATCH5 is used to save SPRN_PID.
SPRN_SPRG_SCRATCH6 is already available.
SPRN_PID is only 8 bits. We have r12 that contains CR.
We only need to preserve CR0, so we have space available in r12
to save PID.
Keep PID in r12 and free up SPRN_SPRG_SCRATCH5.
Then In TLB miss handlers, instead of using SPRN_SPRG_SCRATCH0 and
SPRN_SPRG_SCRATCH1, use SPRN_SPRG_SCRATCH5 and SPRN_SPRG_SCRATCH6
to avoid future conflicts with normal exception prologs.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/head_40x.S | 39 ++++++++++++++++------------------
1 file changed, 18 insertions(+), 21 deletions(-)
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 24724a7dad49..383238a98f77 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -249,13 +249,13 @@ _ENTRY(saved_ksp_limit)
* load TLB entries from the page table if they exist.
*/
START_EXCEPTION(0x1100, DTLBMiss)
- mtspr SPRN_SPRG_SCRATCH0, r10 /* Save some working registers */
- mtspr SPRN_SPRG_SCRATCH1, r11
+ mtspr SPRN_SPRG_SCRATCH5, r10 /* Save some working registers */
+ mtspr SPRN_SPRG_SCRATCH6, r11
mtspr SPRN_SPRG_SCRATCH3, r12
mtspr SPRN_SPRG_SCRATCH4, r9
mfcr r12
mfspr r9, SPRN_PID
- mtspr SPRN_SPRG_SCRATCH5, r9
+ rlwimi r12, r9, 0, 0xff
mfspr r10, SPRN_DEAR /* Get faulting address */
/* If we are faulting a kernel address, we have to use the
@@ -316,13 +316,12 @@ _ENTRY(saved_ksp_limit)
/* The bailout. Restore registers to pre-exception conditions
* and call the heavyweights to help us out.
*/
- mfspr r9, SPRN_SPRG_SCRATCH5
- mtspr SPRN_PID, r9
- mtcr r12
+ mtspr SPRN_PID, r12
+ mtcrf 0x80, r12
mfspr r9, SPRN_SPRG_SCRATCH4
mfspr r12, SPRN_SPRG_SCRATCH3
- mfspr r11, SPRN_SPRG_SCRATCH1
- mfspr r10, SPRN_SPRG_SCRATCH0
+ mfspr r11, SPRN_SPRG_SCRATCH6
+ mfspr r10, SPRN_SPRG_SCRATCH5
b DataStorage
/* 0x1200 - Instruction TLB Miss Exception
@@ -330,13 +329,13 @@ _ENTRY(saved_ksp_limit)
* registers and bailout to a different point.
*/
START_EXCEPTION(0x1200, ITLBMiss)
- mtspr SPRN_SPRG_SCRATCH0, r10 /* Save some working registers */
- mtspr SPRN_SPRG_SCRATCH1, r11
+ mtspr SPRN_SPRG_SCRATCH5, r10 /* Save some working registers */
+ mtspr SPRN_SPRG_SCRATCH6, r11
mtspr SPRN_SPRG_SCRATCH3, r12
mtspr SPRN_SPRG_SCRATCH4, r9
mfcr r12
mfspr r9, SPRN_PID
- mtspr SPRN_SPRG_SCRATCH5, r9
+ rlwimi r12, r9, 0, 0xff
mfspr r10, SPRN_SRR0 /* Get faulting address */
/* If we are faulting a kernel address, we have to use the
@@ -397,13 +396,12 @@ _ENTRY(saved_ksp_limit)
/* The bailout. Restore registers to pre-exception conditions
* and call the heavyweights to help us out.
*/
- mfspr r9, SPRN_SPRG_SCRATCH5
- mtspr SPRN_PID, r9
- mtcr r12
+ mtspr SPRN_PID, r12
+ mtcrf 0x80, r12
mfspr r9, SPRN_SPRG_SCRATCH4
mfspr r12, SPRN_SPRG_SCRATCH3
- mfspr r11, SPRN_SPRG_SCRATCH1
- mfspr r10, SPRN_SPRG_SCRATCH0
+ mfspr r11, SPRN_SPRG_SCRATCH6
+ mfspr r10, SPRN_SPRG_SCRATCH5
b InstructionAccess
EXCEPTION(0x1300, Trap_13, unknown_exception, EXC_XFER_STD)
@@ -543,13 +541,12 @@ finish_tlb_load:
/* Done...restore registers and get out of here.
*/
- mfspr r9, SPRN_SPRG_SCRATCH5
- mtspr SPRN_PID, r9
- mtcr r12
+ mtspr SPRN_PID, r12
+ mtcrf 0x80, r12
mfspr r9, SPRN_SPRG_SCRATCH4
mfspr r12, SPRN_SPRG_SCRATCH3
- mfspr r11, SPRN_SPRG_SCRATCH1
- mfspr r10, SPRN_SPRG_SCRATCH0
+ mfspr r11, SPRN_SPRG_SCRATCH6
+ mfspr r10, SPRN_SPRG_SCRATCH5
rfi /* Should sync shadow TLBs */
b . /* prevent prefetch past rfi */
--
2.25.0
^ permalink raw reply related
* [PATCH v2 01/43] powerpc/traps: unrecoverable_exception() is not an interrupt handler
From: Christophe Leroy @ 2021-03-09 12:09 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615291471.git.christophe.leroy@csgroup.eu>
unrecoverable_exception() is called from interrupt handlers or
after an interrupt handler has failed.
Make it a standard function to avoid doubling the actions
performed on interrupt entry (e.g.: user time accounting).
Fixes: 3a96570ffceb ("powerpc: convert interrupt handlers to use wrappers")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/include/asm/interrupt.h | 3 ++-
arch/powerpc/kernel/interrupt.c | 1 -
arch/powerpc/kernel/traps.c | 2 +-
3 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index aedfba29e43a..e8d09a841373 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -410,7 +410,6 @@ DECLARE_INTERRUPT_HANDLER(altivec_assist_exception);
DECLARE_INTERRUPT_HANDLER(CacheLockingException);
DECLARE_INTERRUPT_HANDLER(SPEFloatingPointException);
DECLARE_INTERRUPT_HANDLER(SPEFloatingPointRoundException);
-DECLARE_INTERRUPT_HANDLER(unrecoverable_exception);
DECLARE_INTERRUPT_HANDLER(WatchdogException);
DECLARE_INTERRUPT_HANDLER(kernel_bad_stack);
@@ -437,6 +436,8 @@ DECLARE_INTERRUPT_HANDLER_NMI(hmi_exception_realmode);
DECLARE_INTERRUPT_HANDLER_ASYNC(TAUException);
+void unrecoverable_exception(struct pt_regs *regs);
+
void replay_system_reset(void);
void replay_soft_interrupts(void);
diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
index 398cd86b6ada..b8e7d25be31b 100644
--- a/arch/powerpc/kernel/interrupt.c
+++ b/arch/powerpc/kernel/interrupt.c
@@ -436,7 +436,6 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned
return ret;
}
-void unrecoverable_exception(struct pt_regs *regs);
void preempt_schedule_irq(void);
notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsigned long msr)
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 1583fd1c6010..a44a30b0688c 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -2170,7 +2170,7 @@ DEFINE_INTERRUPT_HANDLER(SPEFloatingPointRoundException)
* in the MSR is 0. This indicates that SRR0/1 are live, and that
* we therefore lost state by taking this exception.
*/
-DEFINE_INTERRUPT_HANDLER(unrecoverable_exception)
+void unrecoverable_exception(struct pt_regs *regs)
{
pr_emerg("Unrecoverable exception %lx at %lx (msr=%lx)\n",
regs->trap, regs->nip, regs->msr);
--
2.25.0
^ permalink raw reply related
* [PATCH v2 00/43] powerpc/32: Switch to interrupt entry/exit in C
From: Christophe Leroy @ 2021-03-09 12:09 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
Cc: linuxppc-dev, linux-kernel
This series aims at porting interrupt entry/exit in C on PPC32, using
the work already merged for PPC64.
First two patches are a fix and an optimisation of unrecoverable_exception() function.
Six following patches do minimal changes in 40x in order to be able to enable MMU
earlier in exception entry.
Second part of the series prepares and switches interrupt exit in C.
Third part moves more and more things in C, ending with KUAP management.
v2 is tested on 8xx and 83xx and qemu, and compile tested via kisskb.
Changes in v2:
- Two first patches are new.
- Mainly build fixes, nothing much new.
Christophe Leroy (43):
powerpc/traps: unrecoverable_exception() is not an interrupt handler
powerpc/traps: Declare unrecoverable_exception() as __noreturn
powerpc/40x: Don't use SPRN_SPRG_SCRATCH0/1 in TLB miss handlers
powerpc/40x: Change CRITICAL_EXCEPTION_PROLOG macro to a gas macro
powerpc/40x: Save SRR0/SRR1 and r10/r11 earlier in critical exception
powerpc/40x: Reorder a few instructions in critical exception prolog
powerpc/40x: Prepare for enabling MMU in critical exception prolog
powerpc/40x: Prepare normal exception handler for enabling MMU early
powerpc/32: Reconcile interrupts in C
powerpc/32: Entry cpu time accounting in C
powerpc/32: Handle bookE debugging in C in exception entry
powerpc/32: Use fast instruction to set MSR RI in exception prolog on
8xx
powerpc/32: Remove ksp_limit
powerpc/32: Always enable data translation in exception prolog
powerpc/32: Tag DAR in EXCEPTION_PROLOG_2 for the 8xx
powerpc/32: Enable instruction translation at the same time as data
translation
powerpc/32: Statically initialise first emergency context
powerpc/32: Add vmap_stack_overflow label inside the macro
powerpc/32: Use START_EXCEPTION() as much as possible
powerpc/32: Move exception prolog code into .text once MMU is back on
powerpc/32: Provide a name to exception prolog continuation in virtual
mode
powerpc/32: Refactor booke critical registers saving
powerpc/32: Perform normal function call in exception entry
powerpc/32: Always save non volatile registers on exception entry
powerpc/32: Replace ASM exception exit by C exception exit from ppc64
powerpc/32: Set regs parameter in r3 in transfer_to_handler
powerpc/32: Call bad_page_fault() from do_page_fault()
powerpc/64e: Call bad_page_fault() from do_page_fault()
powerpc/32: Save trap number on stack in exception prolog
powerpc/32: Add a prepare_transfer_to_handler macro for exception
prologs
powerpc/32: Only restore non volatile registers when required
powerpc/32: Dismantle EXC_XFER_STD/LITE/TEMPLATE
powerpc/32: Remove the xfer parameter in EXCEPTION() macro
powerpc/32: Refactor saving of volatile registers in exception prologs
powerpc/32: Save remaining registers in exception prolog
powerpc/32: Set current->thread.regs in C interrupt entry
powerpc/32: Return directly from power_save_ppc32_restore()
powerpc/32: Only use prepare_transfer_to_handler function on book3s/32
and e500
powerpc/32s: Move KUEP locking/unlocking in C
powerpc/64s: Make kuap_check_amr() and kuap_get_and_check_amr()
generic
powerpc/32s: Create C version of kuap save/restore/check helpers
powerpc/8xx: Create C version of kuap save/restore/check helpers
powerpc/32: Manage KUAP in C
arch/powerpc/include/asm/book3s/32/kup.h | 126 +--
arch/powerpc/include/asm/book3s/64/kup.h | 24 +-
arch/powerpc/include/asm/interrupt.h | 19 +-
arch/powerpc/include/asm/kup.h | 27 +-
arch/powerpc/include/asm/nohash/32/kup-8xx.h | 56 +-
arch/powerpc/include/asm/ppc_asm.h | 10 -
arch/powerpc/include/asm/processor.h | 6 +-
arch/powerpc/include/asm/ptrace.h | 6 +-
arch/powerpc/kernel/asm-offsets.c | 4 -
arch/powerpc/kernel/entry_32.S | 835 ++++---------------
arch/powerpc/kernel/exceptions-64e.S | 8 +-
arch/powerpc/kernel/fpu.S | 2 -
arch/powerpc/kernel/head_32.h | 195 ++---
arch/powerpc/kernel/head_40x.S | 271 +++---
arch/powerpc/kernel/head_44x.S | 10 +-
arch/powerpc/kernel/head_8xx.S | 151 ++--
arch/powerpc/kernel/head_book3s_32.S | 233 +++---
arch/powerpc/kernel/head_booke.h | 188 +++--
arch/powerpc/kernel/head_fsl_booke.S | 64 +-
arch/powerpc/kernel/idle_6xx.S | 14 +-
arch/powerpc/kernel/idle_e500.S | 14 +-
arch/powerpc/kernel/interrupt.c | 40 +-
arch/powerpc/kernel/irq.c | 2 +-
arch/powerpc/kernel/misc_32.S | 14 -
arch/powerpc/kernel/process.c | 6 +-
arch/powerpc/kernel/setup_32.c | 2 +-
arch/powerpc/kernel/traps.c | 15 +-
arch/powerpc/kernel/vector.S | 2 -
arch/powerpc/lib/sstep.c | 9 -
arch/powerpc/mm/book3s32/Makefile | 1 +
arch/powerpc/mm/book3s32/hash_low.S | 14 -
arch/powerpc/mm/book3s32/kuep.c | 38 +
arch/powerpc/mm/fault.c | 17 +-
33 files changed, 885 insertions(+), 1538 deletions(-)
create mode 100644 arch/powerpc/mm/book3s32/kuep.c
--
2.25.0
^ permalink raw reply
* [PATCH v2 02/43] powerpc/traps: Declare unrecoverable_exception() as __noreturn
From: Christophe Leroy @ 2021-03-09 12:09 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615291471.git.christophe.leroy@csgroup.eu>
unrecoverable_exception() is never expected to return, most callers
have an infiniteloop in case it returns.
Ensure it really never returns by terminating it with a BUG(), and
declare it __no_return.
It always GCC to really simplify functions calling it. In the exemple
below, it avoids the stack frame in the likely fast path and avoids
code duplication for the exit.
With this patch:
00000348 <interrupt_exit_kernel_prepare>:
348: 81 43 00 84 lwz r10,132(r3)
34c: 71 48 00 02 andi. r8,r10,2
350: 41 82 00 2c beq 37c <interrupt_exit_kernel_prepare+0x34>
354: 71 4a 40 00 andi. r10,r10,16384
358: 40 82 00 20 bne 378 <interrupt_exit_kernel_prepare+0x30>
35c: 80 62 00 70 lwz r3,112(r2)
360: 74 63 00 01 andis. r3,r3,1
364: 40 82 00 28 bne 38c <interrupt_exit_kernel_prepare+0x44>
368: 7d 40 00 a6 mfmsr r10
36c: 7c 11 13 a6 mtspr 81,r0
370: 7c 12 13 a6 mtspr 82,r0
374: 4e 80 00 20 blr
378: 48 00 00 00 b 378 <interrupt_exit_kernel_prepare+0x30>
37c: 94 21 ff f0 stwu r1,-16(r1)
380: 7c 08 02 a6 mflr r0
384: 90 01 00 14 stw r0,20(r1)
388: 48 00 00 01 bl 388 <interrupt_exit_kernel_prepare+0x40>
388: R_PPC_REL24 unrecoverable_exception
38c: 38 e2 00 70 addi r7,r2,112
390: 3d 00 00 01 lis r8,1
394: 7c c0 38 28 lwarx r6,0,r7
398: 7c c6 40 78 andc r6,r6,r8
39c: 7c c0 39 2d stwcx. r6,0,r7
3a0: 40 a2 ff f4 bne 394 <interrupt_exit_kernel_prepare+0x4c>
3a4: 38 60 00 01 li r3,1
3a8: 4b ff ff c0 b 368 <interrupt_exit_kernel_prepare+0x20>
Without this patch:
00000348 <interrupt_exit_kernel_prepare>:
348: 94 21 ff f0 stwu r1,-16(r1)
34c: 93 e1 00 0c stw r31,12(r1)
350: 7c 7f 1b 78 mr r31,r3
354: 81 23 00 84 lwz r9,132(r3)
358: 71 2a 00 02 andi. r10,r9,2
35c: 41 82 00 34 beq 390 <interrupt_exit_kernel_prepare+0x48>
360: 71 29 40 00 andi. r9,r9,16384
364: 40 82 00 28 bne 38c <interrupt_exit_kernel_prepare+0x44>
368: 80 62 00 70 lwz r3,112(r2)
36c: 74 63 00 01 andis. r3,r3,1
370: 40 82 00 3c bne 3ac <interrupt_exit_kernel_prepare+0x64>
374: 7d 20 00 a6 mfmsr r9
378: 7c 11 13 a6 mtspr 81,r0
37c: 7c 12 13 a6 mtspr 82,r0
380: 83 e1 00 0c lwz r31,12(r1)
384: 38 21 00 10 addi r1,r1,16
388: 4e 80 00 20 blr
38c: 48 00 00 00 b 38c <interrupt_exit_kernel_prepare+0x44>
390: 7c 08 02 a6 mflr r0
394: 90 01 00 14 stw r0,20(r1)
398: 48 00 00 01 bl 398 <interrupt_exit_kernel_prepare+0x50>
398: R_PPC_REL24 unrecoverable_exception
39c: 80 01 00 14 lwz r0,20(r1)
3a0: 81 3f 00 84 lwz r9,132(r31)
3a4: 7c 08 03 a6 mtlr r0
3a8: 4b ff ff b8 b 360 <interrupt_exit_kernel_prepare+0x18>
3ac: 39 02 00 70 addi r8,r2,112
3b0: 3d 40 00 01 lis r10,1
3b4: 7c e0 40 28 lwarx r7,0,r8
3b8: 7c e7 50 78 andc r7,r7,r10
3bc: 7c e0 41 2d stwcx. r7,0,r8
3c0: 40 a2 ff f4 bne 3b4 <interrupt_exit_kernel_prepare+0x6c>
3c4: 38 60 00 01 li r3,1
3c8: 4b ff ff ac b 374 <interrupt_exit_kernel_prepare+0x2c>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/include/asm/interrupt.h | 2 +-
arch/powerpc/kernel/traps.c | 6 +++++-
2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index e8d09a841373..232a4847f596 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -436,7 +436,7 @@ DECLARE_INTERRUPT_HANDLER_NMI(hmi_exception_realmode);
DECLARE_INTERRUPT_HANDLER_ASYNC(TAUException);
-void unrecoverable_exception(struct pt_regs *regs);
+void __noreturn unrecoverable_exception(struct pt_regs *regs);
void replay_system_reset(void);
void replay_soft_interrupts(void);
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index a44a30b0688c..d5c9d9ddd186 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -2170,11 +2170,15 @@ DEFINE_INTERRUPT_HANDLER(SPEFloatingPointRoundException)
* in the MSR is 0. This indicates that SRR0/1 are live, and that
* we therefore lost state by taking this exception.
*/
-void unrecoverable_exception(struct pt_regs *regs)
+void __noreturn unrecoverable_exception(struct pt_regs *regs)
{
pr_emerg("Unrecoverable exception %lx at %lx (msr=%lx)\n",
regs->trap, regs->nip, regs->msr);
die("Unrecoverable exception", regs, SIGABRT);
+ /* die() should not return */
+ WARN(true, "die() unexpectedly returned");
+ for (;;)
+ ;
}
#if defined(CONFIG_BOOKE_WDT) || defined(CONFIG_40x)
--
2.25.0
^ permalink raw reply related
* Re: [PATCH] powerpc/perf: Fix the threshold event selection for memory events in power10
From: Madhavan Srinivasan @ 2021-03-09 11:28 UTC (permalink / raw)
To: Athira Rajeev, mpe; +Cc: linuxppc-dev
In-Reply-To: <1614840015-1535-1-git-send-email-atrajeev@linux.vnet.ibm.com>
On 3/4/21 12:10 PM, Athira Rajeev wrote:
> Memory events (mem-loads and mem-stores) currently use the threshold
> event selection as issue to finish. Power10 supports issue to complete
> as part of thresholding which is more appropriate for mem-loads and
> mem-stores. Hence fix the event code for memory events to use issue
> to complete.
Changes looks fine to me.
Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
We should also CC stable to include this fix?
> Fixes: a64e697cef23 ("powerpc/perf: power10 Performance Monitoring support")
> Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
> ---
> arch/powerpc/perf/power10-events-list.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/perf/power10-events-list.h b/arch/powerpc/perf/power10-events-list.h
> index e45dafe818ed..93be7197d250 100644
> --- a/arch/powerpc/perf/power10-events-list.h
> +++ b/arch/powerpc/perf/power10-events-list.h
> @@ -75,5 +75,5 @@
> * thresh end (TE)
> */
>
> -EVENT(MEM_LOADS, 0x34340401e0);
> -EVENT(MEM_STORES, 0x343c0401e0);
> +EVENT(MEM_LOADS, 0x35340401e0);
> +EVENT(MEM_STORES, 0x353c0401e0);
^ permalink raw reply
* Re: [PATCH] powerpc/perf: Fix sampled instruction type for larx/stcx
From: Madhavan Srinivasan @ 2021-03-09 11:26 UTC (permalink / raw)
To: Athira Rajeev, mpe; +Cc: linuxppc-dev
In-Reply-To: <1614858937-1485-1-git-send-email-atrajeev@linux.vnet.ibm.com>
On 3/4/21 5:25 PM, Athira Rajeev wrote:
> Sampled Instruction Event Register (SIER) field [46:48]
> identifies the sampled instruction type. ISA v3.1 says value
> of 0b111 for this field as reserved, but in POWER10 it denotes
> LARX/STCX type which will hopefully be fixed in ISA v3.1 update.
>
> Patch fixes the functions to handle type value 7 for
> CPU_FTR_ARCH_31.
Changes looks fine to me.
Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
> Fixes: a64e697cef23 ("powerpc/perf: power10 Performance Monitoring support")
> Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
> ---
> arch/powerpc/perf/isa207-common.c | 30 +++++++++++++++++++++++++++---
> arch/powerpc/perf/isa207-common.h | 1 +
> 2 files changed, 28 insertions(+), 3 deletions(-)
>
> diff --git a/arch/powerpc/perf/isa207-common.c b/arch/powerpc/perf/isa207-common.c
> index e4f577da33d8..754f904d8d69 100644
> --- a/arch/powerpc/perf/isa207-common.c
> +++ b/arch/powerpc/perf/isa207-common.c
> @@ -266,6 +266,8 @@ void isa207_get_mem_data_src(union perf_mem_data_src *dsrc, u32 flags,
> u32 sub_idx;
> u64 sier;
> u64 val;
> + u64 mmcra = mfspr(SPRN_MMCRA);
> + u32 op_type;
>
> /* Skip if no SIER support */
> if (!(flags & PPMU_HAS_SIER)) {
> @@ -275,12 +277,34 @@ void isa207_get_mem_data_src(union perf_mem_data_src *dsrc, u32 flags,
>
> sier = mfspr(SPRN_SIER);
> val = (sier & ISA207_SIER_TYPE_MASK) >> ISA207_SIER_TYPE_SHIFT;
> - if (val == 1 || val == 2) {
> + if (val == 1 || val == 2 || (val == 7 && cpu_has_feature(CPU_FTR_ARCH_31))) {
> idx = (sier & ISA207_SIER_LDST_MASK) >> ISA207_SIER_LDST_SHIFT;
> sub_idx = (sier & ISA207_SIER_DATA_SRC_MASK) >> ISA207_SIER_DATA_SRC_SHIFT;
>
> dsrc->val = isa207_find_source(idx, sub_idx);
> - dsrc->val |= (val == 1) ? P(OP, LOAD) : P(OP, STORE);
> + if (val == 7) {
> + /*
> + * Type 0b111 denotes either larx or stcx instruction. Use the
> + * MMCRA sampling bits [57:59] along with the type value
> + * to determine the exact instruction type. If the sampling
> + * criteria is neither load or store, set the type as default
> + * to NA.
> + */
> + op_type = (mmcra >> MMCRA_SAMP_ELIG_SHIFT) & MMCRA_SAMP_ELIG_MASK;
> + switch (op_type) {
> + case 5:
> + dsrc->val |= P(OP, LOAD);
> + break;
> + case 7:
> + dsrc->val |= P(OP, STORE);
> + break;
> + default:
> + dsrc->val |= P(OP, NA);
> + break;
> + }
> + } else {
> + dsrc->val |= (val == 1) ? P(OP, LOAD) : P(OP, STORE);
> + }
> }
> }
>
> @@ -295,7 +319,7 @@ void isa207_get_mem_weight(u64 *weight)
> if (cpu_has_feature(CPU_FTR_ARCH_31))
> mantissa = P10_MMCRA_THR_CTR_MANT(mmcra);
>
> - if (val == 0 || val == 7)
> + if (val == 0 || (val == 7 && !cpu_has_feature(CPU_FTR_ARCH_31)))
> *weight = 0;
> else
> *weight = mantissa << (2 * exp);
> diff --git a/arch/powerpc/perf/isa207-common.h b/arch/powerpc/perf/isa207-common.h
> index 1af0e8c97ac7..7b0242efe4b9 100644
> --- a/arch/powerpc/perf/isa207-common.h
> +++ b/arch/powerpc/perf/isa207-common.h
> @@ -220,6 +220,7 @@
> /* Bits in MMCRA for PowerISA v2.07 */
> #define MMCRA_SAMP_MODE_SHIFT 1
> #define MMCRA_SAMP_ELIG_SHIFT 4
> +#define MMCRA_SAMP_ELIG_MASK 7
> #define MMCRA_THR_CTL_SHIFT 8
> #define MMCRA_THR_SEL_SHIFT 16
> #define MMCRA_THR_CMP_SHIFT 32
^ permalink raw reply
* Re: [PATCH v4] powerpc/uprobes: Validation for prefixed instruction
From: Naveen N. Rao @ 2021-03-09 11:21 UTC (permalink / raw)
To: Michael Ellerman
Cc: Ravi Bangoria, jniethe5, oleg, rostedt, linux-kernel, paulus,
sandipan, naveen.n.rao, linuxppc-dev
In-Reply-To: <87ft14r6sa.fsf@mpe.ellerman.id.au>
On 2021/03/09 08:54PM, Michael Ellerman wrote:
> Ravi Bangoria <ravi.bangoria@linux.ibm.com> writes:
> > As per ISA 3.1, prefixed instruction should not cross 64-byte
> > boundary. So don't allow Uprobe on such prefixed instruction.
> >
> > There are two ways probed instruction is changed in mapped pages.
> > First, when Uprobe is activated, it searches for all the relevant
> > pages and replace instruction in them. In this case, if that probe
> > is on the 64-byte unaligned prefixed instruction, error out
> > directly. Second, when Uprobe is already active and user maps a
> > relevant page via mmap(), instruction is replaced via mmap() code
> > path. But because Uprobe is invalid, entire mmap() operation can
> > not be stopped. In this case just print an error and continue.
> >
> > Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
> > Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
>
> Do we have a Fixes: tag for this?
Since this is an additional check we are adding, I don't think we should
add a Fixes: tag. Nothing is broken per-se -- we're just adding more
checks to catch simple mistakes. Also, like Oleg pointed out, there are
still many other ways for users to shoot themselves in the foot with
uprobes and prefixed instructions, if they so desire.
However, if you still think we should add a Fixes: tag, we can perhaps
use the below commit since I didn't see any specific commit adding
support for prefixed instructions for uprobes:
Fixes: 650b55b707fdfa ("powerpc: Add prefixed instructions to
instruction data type")
>
> > ---
> > v3: https://lore.kernel.org/r/20210304050529.59391-1-ravi.bangoria@linux.ibm.com
> > v3->v4:
> > - CONFIG_PPC64 check was not required, remove it.
> > - Use SZ_ macros instead of hardcoded numbers.
> >
> > arch/powerpc/kernel/uprobes.c | 7 +++++++
> > 1 file changed, 7 insertions(+)
> >
> > diff --git a/arch/powerpc/kernel/uprobes.c b/arch/powerpc/kernel/uprobes.c
> > index e8a63713e655..4cbfff6e94a3 100644
> > --- a/arch/powerpc/kernel/uprobes.c
> > +++ b/arch/powerpc/kernel/uprobes.c
> > @@ -41,6 +41,13 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe,
> > if (addr & 0x03)
> > return -EINVAL;
> >
> > + if (cpu_has_feature(CPU_FTR_ARCH_31) &&
> > + ppc_inst_prefixed(auprobe->insn) &&
> > + (addr & (SZ_64 - 4)) == SZ_64 - 4) {
> > + pr_info_ratelimited("Cannot register a uprobe on 64 byte unaligned prefixed instruction\n");
> > + return -EINVAL;
>
> I realise we already did the 0x03 check above, but I still think this
> would be clearer simply as:
>
> (addr & 0x3f == 60)
Indeed, I like the use of `60' there -- hex is overrated ;)
- Naveen
^ permalink raw reply
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