| Message ID | 20210315220402.260594-13-npiggin@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | powerpc/64: fast interrupt exits | expand |
| Related | show |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | warning | Failed to apply on branch powerpc/merge (91966823812efbd175f904599e5cf2a854b39809) |
| snowpatch_ozlabs/apply_patch | warning | Failed to apply on branch powerpc/next (fe07bfda2fb9cdef8a4d4008a409bb02f35f1bd8) |
| snowpatch_ozlabs/apply_patch | warning | Failed to apply on branch linus/master (280d542f6ffac0e6d65dc267f92191d509b13b64) |
| snowpatch_ozlabs/apply_patch | warning | Failed to apply on branch powerpc/fixes (5c88a17e15795226b56d83f579cbb9b7a4864f79) |
| snowpatch_ozlabs/apply_patch | warning | Failed to apply on branch linux-next (7a7fd0de4a9804299793e564a555a49c1fc924cb) |
| snowpatch_ozlabs/apply_patch | fail | Failed to apply to any branch |
Le 15/03/2021 à 23:04, Nicholas Piggin a écrit : > This extends the MSR[RI]=0 window a little further into the system > call in order to pair RI and EE enabling with a single mtmsrd. Time ago, I proposed to delay that on PPC32 and Michael objected, see https://patchwork.ozlabs.org/project/linuxppc-dev/patch/9f9dd859d571e324c7412ed9db9da8cfba678257.1548956511.git.christophe.leroy@c-s.fr/ > > Signed-off-by: Nicholas Piggin <npiggin@gmail.com> > --- > arch/powerpc/kernel/exceptions-64s.S | 2 -- > arch/powerpc/kernel/interrupt_64.S | 6 +++--- > 2 files changed, 3 insertions(+), 5 deletions(-) > > diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S > index bd0c82ac9de5..2f14ac3c377c 100644 > --- a/arch/powerpc/kernel/exceptions-64s.S > +++ b/arch/powerpc/kernel/exceptions-64s.S > @@ -1999,8 +1999,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_REAL_LE) > mtctr r10 > bctr > .else > - li r10,MSR_RI > - mtmsrd r10,1 /* Set RI (EE=0) */ > #ifdef CONFIG_RELOCATABLE > __LOAD_HANDLER(r10, system_call_common) > mtctr r10 > diff --git a/arch/powerpc/kernel/interrupt_64.S b/arch/powerpc/kernel/interrupt_64.S > index f28f41a1a85a..eef61800f734 100644 > --- a/arch/powerpc/kernel/interrupt_64.S > +++ b/arch/powerpc/kernel/interrupt_64.S > @@ -311,10 +311,10 @@ END_BTB_FLUSH_SECTION > * nothing pending. system_call_exception() will call > * trace_hardirqs_off(). > */ > - li r11,IRQS_ALL_DISABLED > - li r12,PACA_IRQ_HARD_DIS > + li r11,IRQS_DISABLED > + li r12,-1 /* Set MSR_EE and MSR_RI */ > stb r11,PACAIRQSOFTMASK(r13) > - stb r12,PACAIRQHAPPENED(r13) > + mtmsrd r12,1 > > ENTER_KERNEL_SECURITY_FALLBACK > >
Excerpts from Christophe Leroy's message of March 16, 2021 5:21 pm: > > > Le 15/03/2021 à 23:04, Nicholas Piggin a écrit : >> This extends the MSR[RI]=0 window a little further into the system >> call in order to pair RI and EE enabling with a single mtmsrd. > > Time ago, I proposed to delay that on PPC32 and Michael objected, see > https://patchwork.ozlabs.org/project/linuxppc-dev/patch/9f9dd859d571e324c7412ed9db9da8cfba678257.1548956511.git.christophe.leroy@c-s.fr/ Yeah, it is a concern. The speedup should be at least 5% I think on 64s (have not measured in isolation yet), so might be worth it. We'll see. Thanks, Nick
Christophe Leroy <christophe.leroy@csgroup.eu> writes: > Le 15/03/2021 à 23:04, Nicholas Piggin a écrit : >> This extends the MSR[RI]=0 window a little further into the system >> call in order to pair RI and EE enabling with a single mtmsrd. > > Time ago, I proposed to delay that on PPC32 and Michael objected, see > https://patchwork.ozlabs.org/project/linuxppc-dev/patch/9f9dd859d571e324c7412ed9db9da8cfba678257.1548956511.git.christophe.leroy@c-s.fr/ I don't think I objected, I was just curious about what the added exposure to RI=0 was :) cheers >> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S >> index bd0c82ac9de5..2f14ac3c377c 100644 >> --- a/arch/powerpc/kernel/exceptions-64s.S >> +++ b/arch/powerpc/kernel/exceptions-64s.S >> @@ -1999,8 +1999,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_REAL_LE) >> mtctr r10 >> bctr >> .else >> - li r10,MSR_RI >> - mtmsrd r10,1 /* Set RI (EE=0) */ >> #ifdef CONFIG_RELOCATABLE >> __LOAD_HANDLER(r10, system_call_common) >> mtctr r10 >> diff --git a/arch/powerpc/kernel/interrupt_64.S b/arch/powerpc/kernel/interrupt_64.S >> index f28f41a1a85a..eef61800f734 100644 >> --- a/arch/powerpc/kernel/interrupt_64.S >> +++ b/arch/powerpc/kernel/interrupt_64.S >> @@ -311,10 +311,10 @@ END_BTB_FLUSH_SECTION >> * nothing pending. system_call_exception() will call >> * trace_hardirqs_off(). >> */ >> - li r11,IRQS_ALL_DISABLED >> - li r12,PACA_IRQ_HARD_DIS >> + li r11,IRQS_DISABLED >> + li r12,-1 /* Set MSR_EE and MSR_RI */ >> stb r11,PACAIRQSOFTMASK(r13) >> - stb r12,PACAIRQHAPPENED(r13) >> + mtmsrd r12,1 >> >> ENTER_KERNEL_SECURITY_FALLBACK >> >>
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index bd0c82ac9de5..2f14ac3c377c 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -1999,8 +1999,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_REAL_LE) mtctr r10 bctr .else - li r10,MSR_RI - mtmsrd r10,1 /* Set RI (EE=0) */ #ifdef CONFIG_RELOCATABLE __LOAD_HANDLER(r10, system_call_common) mtctr r10 diff --git a/arch/powerpc/kernel/interrupt_64.S b/arch/powerpc/kernel/interrupt_64.S index f28f41a1a85a..eef61800f734 100644 --- a/arch/powerpc/kernel/interrupt_64.S +++ b/arch/powerpc/kernel/interrupt_64.S @@ -311,10 +311,10 @@ END_BTB_FLUSH_SECTION * nothing pending. system_call_exception() will call * trace_hardirqs_off(). */ - li r11,IRQS_ALL_DISABLED - li r12,PACA_IRQ_HARD_DIS + li r11,IRQS_DISABLED + li r12,-1 /* Set MSR_EE and MSR_RI */ stb r11,PACAIRQSOFTMASK(r13) - stb r12,PACAIRQHAPPENED(r13) + mtmsrd r12,1 ENTER_KERNEL_SECURITY_FALLBACK
This extends the MSR[RI]=0 window a little further into the system call in order to pair RI and EE enabling with a single mtmsrd. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- arch/powerpc/kernel/exceptions-64s.S | 2 -- arch/powerpc/kernel/interrupt_64.S | 6 +++--- 2 files changed, 3 insertions(+), 5 deletions(-)