Re: [PATCH] powerpc/32: Add missing context synchronisation with CONFIG_VMAP_STACK
Michael Ellerman a écrit : Christophe Leroy writes: Michael Ellerman a écrit : Christophe Leroy writes: ... diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h index 73a035b40dbf..a6a5fbbf8504 100644 --- a/arch/powerpc/kernel/head_32.h +++ b/arch/powerpc/kernel/head_32.h @@ -43,6 +43,7 @@ .ifeq \for_rtas li r11, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */ mtmsr r11 + isync Actually this one leads to: /home/michael/linux/arch/powerpc/kernel/head_8xx.S: Assembler messages: /home/michael/linux/arch/powerpc/kernel/head_8xx.S:151: Error: attempt to move .org backwards make[3]: *** [/home/michael/linux/scripts/Makefile.build:348: arch/powerpc/kernel/head_8xx.o] Error 1 For mpc885_ads_defconfig. That's the alignment exception overflowing into the program check handler: /* Alignment exception */ . = 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 */ addir3,r1,STACK_FRAME_OVERHEAD EXC_XFER_STD(0x600, alignment_exception) /* Program check exception */ EXCEPTION(0x700, ProgramCheck, program_check_exception, EXC_XFER_STD) Can't see an obvious/easy way to fix it. Argh ! I think the easiest is to move the EXC_XFER_STD(0x600, alignment_exception) somewhere else and branch to it. There is some space at .0xa00 That works, or builds at least. I'm not setup to boot test it. Does this look OK? Yes it looks ok, Thanks Christophe cheers From 40e7d671aa27cf4411188f978b2cd06b30a9cb6c Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Sun, 26 Jan 2020 00:20:16 +1100 Subject: [PATCH] powerpc/8xx: Move tail of alignment exception out of line When we enable VMAP_STACK there will not be enough room for the alignment handler at 0x600 in head_8xx.S. For now move the tail of the alignment handler out of line, and branch to it. Suggested-by: Christophe Leroy Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/head_8xx.S | 7 ++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index 477933b36bde..9922306ae512 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -145,7 +145,7 @@ _ENTRY(_start); li r6, RPN_PATTERN mtspr SPRN_DAR, r6/* Tag DAR, to be used in DTLB Error */ addir3,r1,STACK_FRAME_OVERHEAD - EXC_XFER_STD(0x600, alignment_exception) + b .Lalignment_exception_ool /* Program check exception */ EXCEPTION(0x700, ProgramCheck, program_check_exception, EXC_XFER_STD) @@ -153,6 +153,11 @@ _ENTRY(_start); /* 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 */ . = 0xc00 SystemCall: -- 2.21.1
Re: [PATCH] powerpc/32: Add missing context synchronisation with CONFIG_VMAP_STACK
Christophe Leroy writes: > Michael Ellerman a écrit : >> Christophe Leroy writes: ... >>> diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h >>> index 73a035b40dbf..a6a5fbbf8504 100644 >>> --- a/arch/powerpc/kernel/head_32.h >>> +++ b/arch/powerpc/kernel/head_32.h >>> @@ -43,6 +43,7 @@ >>> .ifeq \for_rtas >>> li r11, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */ >>> mtmsr r11 >>> + isync >> >> Actually this one leads to: >> >> /home/michael/linux/arch/powerpc/kernel/head_8xx.S: Assembler messages: >> /home/michael/linux/arch/powerpc/kernel/head_8xx.S:151: Error: >> attempt to move .org backwards >> make[3]: *** [/home/michael/linux/scripts/Makefile.build:348: >> arch/powerpc/kernel/head_8xx.o] Error 1 >> >> For mpc885_ads_defconfig. >> >> That's the alignment exception overflowing into the program check >> handler: >> >> /* Alignment exception */ >> . = 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 */ >> addir3,r1,STACK_FRAME_OVERHEAD >> EXC_XFER_STD(0x600, alignment_exception) >> >> /* Program check exception */ >> EXCEPTION(0x700, ProgramCheck, program_check_exception, EXC_XFER_STD) >> >> >> Can't see an obvious/easy way to fix it. > > Argh ! > > I think the easiest is to move the EXC_XFER_STD(0x600, > alignment_exception) somewhere else and branch to it. There is some > space at .0xa00 That works, or builds at least. I'm not setup to boot test it. Does this look OK? cheers >From 40e7d671aa27cf4411188f978b2cd06b30a9cb6c Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Sun, 26 Jan 2020 00:20:16 +1100 Subject: [PATCH] powerpc/8xx: Move tail of alignment exception out of line When we enable VMAP_STACK there will not be enough room for the alignment handler at 0x600 in head_8xx.S. For now move the tail of the alignment handler out of line, and branch to it. Suggested-by: Christophe Leroy Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/head_8xx.S | 7 ++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index 477933b36bde..9922306ae512 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -145,7 +145,7 @@ _ENTRY(_start); li r6, RPN_PATTERN mtspr SPRN_DAR, r6/* Tag DAR, to be used in DTLB Error */ addir3,r1,STACK_FRAME_OVERHEAD - EXC_XFER_STD(0x600, alignment_exception) + b .Lalignment_exception_ool /* Program check exception */ EXCEPTION(0x700, ProgramCheck, program_check_exception, EXC_XFER_STD) @@ -153,6 +153,11 @@ _ENTRY(_start); /* 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 */ . = 0xc00 SystemCall: -- 2.21.1
Re: [PATCH] powerpc/32: Add missing context synchronisation with CONFIG_VMAP_STACK
Michael Ellerman a écrit : Christophe Leroy writes: After reactivation of data translation by modifying MSR[DR], a isync is required to ensure the translation is effective. Signed-off-by: Christophe Leroy --- Rebased on powerpc/merge-test @mpe: If not too late: - change to head_32.h should be squashed into "powerpc/32: prepare for CONFIG_VMAP_STACK" - change to head_32.S should be squashed into "powerpc/32s: Enable CONFIG_VMAP_STACK" Signed-off-by: Christophe Leroy --- arch/powerpc/kernel/head_32.S | 1 + arch/powerpc/kernel/head_32.h | 2 ++ 2 files changed, 3 insertions(+) diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h index 73a035b40dbf..a6a5fbbf8504 100644 --- a/arch/powerpc/kernel/head_32.h +++ b/arch/powerpc/kernel/head_32.h @@ -43,6 +43,7 @@ .ifeq \for_rtas li r11, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */ mtmsr r11 + isync Actually this one leads to: /home/michael/linux/arch/powerpc/kernel/head_8xx.S: Assembler messages: /home/michael/linux/arch/powerpc/kernel/head_8xx.S:151: Error: attempt to move .org backwards make[3]: *** [/home/michael/linux/scripts/Makefile.build:348: arch/powerpc/kernel/head_8xx.o] Error 1 For mpc885_ads_defconfig. That's the alignment exception overflowing into the program check handler: /* Alignment exception */ . = 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 */ addir3,r1,STACK_FRAME_OVERHEAD EXC_XFER_STD(0x600, alignment_exception) /* Program check exception */ EXCEPTION(0x700, ProgramCheck, program_check_exception, EXC_XFER_STD) Can't see an obvious/easy way to fix it. Argh ! I think the easiest is to move the EXC_XFER_STD(0x600, alignment_exception) somewhere else and branch to it. There is some space at .0xa00 Christophe PS: I'm afk until monday
Re: [PATCH] powerpc/32: Add missing context synchronisation with CONFIG_VMAP_STACK
Christophe Leroy writes: > After reactivation of data translation by modifying MSR[DR], a isync > is required to ensure the translation is effective. > > Signed-off-by: Christophe Leroy > --- > Rebased on powerpc/merge-test > > @mpe: If not too late: > - change to head_32.h should be squashed into "powerpc/32: prepare for > CONFIG_VMAP_STACK" > - change to head_32.S should be squashed into "powerpc/32s: Enable > CONFIG_VMAP_STACK" > > Signed-off-by: Christophe Leroy > --- > arch/powerpc/kernel/head_32.S | 1 + > arch/powerpc/kernel/head_32.h | 2 ++ > 2 files changed, 3 insertions(+) > > diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h > index 73a035b40dbf..a6a5fbbf8504 100644 > --- a/arch/powerpc/kernel/head_32.h > +++ b/arch/powerpc/kernel/head_32.h > @@ -43,6 +43,7 @@ > .ifeq \for_rtas > li r11, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */ > mtmsr r11 > + isync Actually this one leads to: /home/michael/linux/arch/powerpc/kernel/head_8xx.S: Assembler messages: /home/michael/linux/arch/powerpc/kernel/head_8xx.S:151: Error: attempt to move .org backwards make[3]: *** [/home/michael/linux/scripts/Makefile.build:348: arch/powerpc/kernel/head_8xx.o] Error 1 For mpc885_ads_defconfig. That's the alignment exception overflowing into the program check handler: /* Alignment exception */ . = 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 */ addir3,r1,STACK_FRAME_OVERHEAD EXC_XFER_STD(0x600, alignment_exception) /* Program check exception */ EXCEPTION(0x700, ProgramCheck, program_check_exception, EXC_XFER_STD) Can't see an obvious/easy way to fix it. cheers > .endif > subir11, r1, INT_FRAME_SIZE /* use r1 if kernel */ > #else
Re: [PATCH] powerpc/32: Add missing context synchronisation with CONFIG_VMAP_STACK
Christophe Leroy writes: > After reactivation of data translation by modifying MSR[DR], a isync > is required to ensure the translation is effective. > > Signed-off-by: Christophe Leroy > --- > Rebased on powerpc/merge-test > > @mpe: If not too late: > - change to head_32.h should be squashed into "powerpc/32: prepare for > CONFIG_VMAP_STACK" > - change to head_32.S should be squashed into "powerpc/32s: Enable > CONFIG_VMAP_STACK" Done. Thanks. cheers
[PATCH] powerpc/32: Add missing context synchronisation with CONFIG_VMAP_STACK
After reactivation of data translation by modifying MSR[DR], a isync is required to ensure the translation is effective. Signed-off-by: Christophe Leroy --- Rebased on powerpc/merge-test @mpe: If not too late: - change to head_32.h should be squashed into "powerpc/32: prepare for CONFIG_VMAP_STACK" - change to head_32.S should be squashed into "powerpc/32s: Enable CONFIG_VMAP_STACK" Signed-off-by: Christophe Leroy --- arch/powerpc/kernel/head_32.S | 1 + arch/powerpc/kernel/head_32.h | 2 ++ 2 files changed, 3 insertions(+) diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S index cb7864091641..0493fcac6409 100644 --- a/arch/powerpc/kernel/head_32.S +++ b/arch/powerpc/kernel/head_32.S @@ -277,6 +277,7 @@ MachineCheck: #ifdef CONFIG_VMAP_STACK li r11, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */ mtmsr r11 + isync #endif #ifdef CONFIG_PPC_CHRP mfspr r11, SPRN_SPRG_THREAD diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h index 73a035b40dbf..a6a5fbbf8504 100644 --- a/arch/powerpc/kernel/head_32.h +++ b/arch/powerpc/kernel/head_32.h @@ -43,6 +43,7 @@ .ifeq \for_rtas li r11, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */ mtmsr r11 + isync .endif subir11, r1, INT_FRAME_SIZE /* use r1 if kernel */ #else @@ -123,6 +124,7 @@ #ifdef CONFIG_VMAP_STACK li r9, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */ mtmsr r9 + isync #endif tovirt_vmstack r12, r12 tophys_novmstack r11, r11 -- 2.25.0
