| Message ID | 20190308011619.22402-2-mpe@ellerman.id.au (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v5,01/10] powerpc/powernv/idle: Restore IAMR after idle | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | Successfully applied on branch next (9580b71b5a7863c24a9bd18bcd2ad759b86b1eff) |
| snowpatch_ozlabs/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 51 lines checked |
On Fri, Mar 08, 2019 at 12:16:11PM +1100, Michael Ellerman wrote: > In order to implement KUAP (Kernel Userspace Access Protection) on > Power9 we will be using the AMR, and therefore indirectly the > UAMOR/AMOR. > > So save/restore these regs in the idle code. > > Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> > --- > v5: Unchanged. > v4: New. > > arch/powerpc/kernel/idle_book3s.S | 27 +++++++++++++++++++++++---- > 1 file changed, 23 insertions(+), 4 deletions(-) Opps.. i posted a comment on the v4. It would be good if we can make AMOR/UAMOR/AMR save-restore code power9 only.
Akshay Adiga <akshay.adiga@linux.vnet.ibm.com> writes: > On Fri, Mar 08, 2019 at 12:16:11PM +1100, Michael Ellerman wrote: >> In order to implement KUAP (Kernel Userspace Access Protection) on >> Power9 we will be using the AMR, and therefore indirectly the >> UAMOR/AMOR. >> >> So save/restore these regs in the idle code. >> >> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> >> --- >> v5: Unchanged. >> v4: New. >> >> arch/powerpc/kernel/idle_book3s.S | 27 +++++++++++++++++++++++---- >> 1 file changed, 23 insertions(+), 4 deletions(-) > > Opps.. i posted a comment on the v4. > > It would be good if we can make AMOR/UAMOR/AMR save-restore > code power9 only. Yes that would be a good optimisation. If you can send an incremental patch against this one I'll squash it in. If not I'll try and get it done at some point before merging. cheers
diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S index 36178000a2f2..4a860d3b9229 100644 --- a/arch/powerpc/kernel/idle_book3s.S +++ b/arch/powerpc/kernel/idle_book3s.S @@ -170,8 +170,11 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300) bne- core_idle_lock_held blr -/* Reuse an unused pt_regs slot for IAMR */ +/* Reuse some unused pt_regs slots for AMR/IAMR/UAMOR/UAMOR */ +#define PNV_POWERSAVE_AMR _TRAP #define PNV_POWERSAVE_IAMR _DAR +#define PNV_POWERSAVE_UAMOR _DSISR +#define PNV_POWERSAVE_AMOR RESULT /* * Pass requested state in r3: @@ -205,8 +208,16 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300) SAVE_NVGPRS(r1) BEGIN_FTR_SECTION + mfspr r4, SPRN_AMR mfspr r5, SPRN_IAMR + mfspr r6, SPRN_UAMOR + std r4, PNV_POWERSAVE_AMR(r1) std r5, PNV_POWERSAVE_IAMR(r1) + std r6, PNV_POWERSAVE_UAMOR(r1) +BEGIN_FTR_SECTION_NESTED(42) + mfspr r7, SPRN_AMOR + std r7, PNV_POWERSAVE_AMOR(r1) +END_FTR_SECTION_NESTED_IFSET(CPU_FTR_HVMODE, 42) END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) mfcr r5 @@ -935,12 +946,20 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) REST_GPR(2, r1) BEGIN_FTR_SECTION - /* IAMR was saved in pnv_powersave_common() */ + /* These regs were saved in pnv_powersave_common() */ + ld r4, PNV_POWERSAVE_AMR(r1) ld r5, PNV_POWERSAVE_IAMR(r1) + ld r6, PNV_POWERSAVE_UAMOR(r1) + mtspr SPRN_AMR, r4 mtspr SPRN_IAMR, r5 + mtspr SPRN_UAMOR, r6 +BEGIN_FTR_SECTION_NESTED(42) + ld r7, PNV_POWERSAVE_AMOR(r1) + mtspr SPRN_AMOR, r7 +END_FTR_SECTION_NESTED_IFSET(CPU_FTR_HVMODE, 42) /* - * We don't need an isync here because the upcoming mtmsrd is - * execution synchronizing. + * We don't need an isync here after restoring IAMR because the upcoming + * mtmsrd is execution synchronizing. */ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
In order to implement KUAP (Kernel Userspace Access Protection) on Power9 we will be using the AMR, and therefore indirectly the UAMOR/AMOR. So save/restore these regs in the idle code. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> --- v5: Unchanged. v4: New. arch/powerpc/kernel/idle_book3s.S | 27 +++++++++++++++++++++++---- 1 file changed, 23 insertions(+), 4 deletions(-)