Re: [PATCH 1/2] powerpc/64s: move machine check SLB flushing to mm/slb.c
On Wed, 8 Aug 2018 22:22:52 +0200
Michal Suchánek wrote:
> On Fri, 3 Aug 2018 14:13:49 +1000
> Nicholas Piggin wrote:
>
> > The machine check code that flushes and restores bolted segments in
> > real mode belongs in mm/slb.c. This will be used by pseries machine
> > check and idle code.
> >
> > Signed-off-by: Nicholas Piggin
> > ---
> > arch/powerpc/include/asm/book3s/64/mmu-hash.h | 3 ++
> > arch/powerpc/kernel/mce_power.c | 21 ++
> > arch/powerpc/mm/slb.c | 38
> > +++ 3 files changed, 44 insertions(+), 18 deletions(-)
> >
> > diff --git a/arch/powerpc/include/asm/book3s/64/mmu-hash.h
> > b/arch/powerpc/include/asm/book3s/64/mmu-hash.h index
> > 2f74bdc805e0..d4e398185b3a 100644 ---
> > a/arch/powerpc/include/asm/book3s/64/mmu-hash.h +++
> > b/arch/powerpc/include/asm/book3s/64/mmu-hash.h @@ -497,6 +497,9 @@
> > extern void hpte_init_native(void);
> > extern void slb_initialize(void);
> > extern void slb_flush_and_rebolt(void);
> > +extern void slb_flush_all_realmode(void);
> > +extern void __slb_restore_bolted_realmode(void);
> > +extern void slb_restore_bolted_realmode(void);
> >
> > extern void slb_vmalloc_update(void);
> > extern void slb_set_size(u16 size);
> > diff --git a/arch/powerpc/kernel/mce_power.c
> > b/arch/powerpc/kernel/mce_power.c index d6756af6ec78..50f7b9817246
> > 100644 --- a/arch/powerpc/kernel/mce_power.c
> > +++ b/arch/powerpc/kernel/mce_power.c
> > @@ -62,11 +62,8 @@ static unsigned long addr_to_pfn(struct pt_regs
> > *regs, unsigned long addr) #ifdef CONFIG_PPC_BOOK3S_64
> > static void flush_and_reload_slb(void)
> > {
> > - struct slb_shadow *slb;
> > - unsigned long i, n;
> > -
> > /* Invalidate all SLBs */
> > - asm volatile("slbmte %0,%0; slbia" : : "r" (0));
> > + slb_flush_all_realmode();
> >
> > #ifdef CONFIG_KVM_BOOK3S_HANDLER
> > /*
> > @@ -76,22 +73,10 @@ static void flush_and_reload_slb(void)
> > if (get_paca()->kvm_hstate.in_guest)
> > return;
> > #endif
> > -
> > - /* For host kernel, reload the SLBs from shadow SLB buffer.
> > */
> > - slb = get_slb_shadow();
> > - if (!slb)
> > + if (early_radix_enabled())
> > return;
>
> And we lose the check that the shadow slb exists. Is !slb equivalent to
> early_radix_enabled()
Yeah pretty close to.
>
> >
> > - n = min_t(u32, be32_to_cpu(slb->persistent), SLB_MIN_SIZE);
> > -
> > - /* Load up the SLB entries from shadow SLB */
> > - for (i = 0; i < n; i++) {
> > - unsigned long rb =
> > be64_to_cpu(slb->save_area[i].esid);
> > - unsigned long rs =
> > be64_to_cpu(slb->save_area[i].vsid); -
> > - rb = (rb & ~0xFFFul) | i;
> > - asm volatile("slbmte %0,%1" : : "r" (rs), "r" (rb));
> > - }
> > + slb_restore_bolted_realmode();
> > }
> > #endif
> >
> > diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
> > index cb796724a6fc..136db8652577 100644
> > --- a/arch/powerpc/mm/slb.c
> > +++ b/arch/powerpc/mm/slb.c
> > @@ -90,6 +90,44 @@ static inline void create_shadowed_slbe(unsigned
> > long ea, int ssize, : "memory" );
> > }
> >
> > +/*
> > + * Insert bolted entries into SLB (which may not be empty).
> > + */
> > +void __slb_restore_bolted_realmode(void)
> > +{
> > + struct slb_shadow *p = get_slb_shadow();
> > + enum slb_index index;
>
> or can we get here at some point when shadow slb is not populated?
We shouldn't because we won't turn the MMU on so we shouldn't get SLB
MCEs... But I don't think that's guaranteed anywhere, so yeah wouldn't
hurt to add that check back in.
I'll send out another revision.
Thanks,
Nick
Re: [PATCH 1/2] powerpc/64s: move machine check SLB flushing to mm/slb.c
On Fri, 3 Aug 2018 14:13:49 +1000
Nicholas Piggin wrote:
> The machine check code that flushes and restores bolted segments in
> real mode belongs in mm/slb.c. This will be used by pseries machine
> check and idle code.
>
> Signed-off-by: Nicholas Piggin
> ---
> arch/powerpc/include/asm/book3s/64/mmu-hash.h | 3 ++
> arch/powerpc/kernel/mce_power.c | 21 ++
> arch/powerpc/mm/slb.c | 38
> +++ 3 files changed, 44 insertions(+), 18 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/book3s/64/mmu-hash.h
> b/arch/powerpc/include/asm/book3s/64/mmu-hash.h index
> 2f74bdc805e0..d4e398185b3a 100644 ---
> a/arch/powerpc/include/asm/book3s/64/mmu-hash.h +++
> b/arch/powerpc/include/asm/book3s/64/mmu-hash.h @@ -497,6 +497,9 @@
> extern void hpte_init_native(void);
> extern void slb_initialize(void);
> extern void slb_flush_and_rebolt(void);
> +extern void slb_flush_all_realmode(void);
> +extern void __slb_restore_bolted_realmode(void);
> +extern void slb_restore_bolted_realmode(void);
>
> extern void slb_vmalloc_update(void);
> extern void slb_set_size(u16 size);
> diff --git a/arch/powerpc/kernel/mce_power.c
> b/arch/powerpc/kernel/mce_power.c index d6756af6ec78..50f7b9817246
> 100644 --- a/arch/powerpc/kernel/mce_power.c
> +++ b/arch/powerpc/kernel/mce_power.c
> @@ -62,11 +62,8 @@ static unsigned long addr_to_pfn(struct pt_regs
> *regs, unsigned long addr) #ifdef CONFIG_PPC_BOOK3S_64
> static void flush_and_reload_slb(void)
> {
> - struct slb_shadow *slb;
> - unsigned long i, n;
> -
> /* Invalidate all SLBs */
> - asm volatile("slbmte %0,%0; slbia" : : "r" (0));
> + slb_flush_all_realmode();
>
> #ifdef CONFIG_KVM_BOOK3S_HANDLER
> /*
> @@ -76,22 +73,10 @@ static void flush_and_reload_slb(void)
> if (get_paca()->kvm_hstate.in_guest)
> return;
> #endif
> -
> - /* For host kernel, reload the SLBs from shadow SLB buffer.
> */
> - slb = get_slb_shadow();
> - if (!slb)
> + if (early_radix_enabled())
> return;
And we lose the check that the shadow slb exists. Is !slb equivalent to
early_radix_enabled()
>
> - n = min_t(u32, be32_to_cpu(slb->persistent), SLB_MIN_SIZE);
> -
> - /* Load up the SLB entries from shadow SLB */
> - for (i = 0; i < n; i++) {
> - unsigned long rb =
> be64_to_cpu(slb->save_area[i].esid);
> - unsigned long rs =
> be64_to_cpu(slb->save_area[i].vsid); -
> - rb = (rb & ~0xFFFul) | i;
> - asm volatile("slbmte %0,%1" : : "r" (rs), "r" (rb));
> - }
> + slb_restore_bolted_realmode();
> }
> #endif
>
> diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
> index cb796724a6fc..136db8652577 100644
> --- a/arch/powerpc/mm/slb.c
> +++ b/arch/powerpc/mm/slb.c
> @@ -90,6 +90,44 @@ static inline void create_shadowed_slbe(unsigned
> long ea, int ssize, : "memory" );
> }
>
> +/*
> + * Insert bolted entries into SLB (which may not be empty).
> + */
> +void __slb_restore_bolted_realmode(void)
> +{
> + struct slb_shadow *p = get_slb_shadow();
> + enum slb_index index;
or can we get here at some point when shadow slb is not populated?
Thanks
Michal
> +
> + /* No isync needed because realmode. */
> + for (index = 0; index < SLB_NUM_BOLTED; index++) {
> + asm volatile("slbmte %0,%1" :
> + : "r" (be64_to_cpu(p->save_area[index].vsid)),
> +"r" (be64_to_cpu(p->save_area[index].esid)));
> + }
> +}
> +
> +/*
> + * Insert bolted entries into an empty SLB.
> + * This is not the same as rebolt because the bolted segments
> + * (e.g., kstack) are not changed (rebolted).
> + */
> +void slb_restore_bolted_realmode(void)
> +{
> + __slb_restore_bolted_realmode();
> + get_paca()->slb_cache_ptr = 0;
> +}
> +
> +/*
> + * This flushes all SLB entries including 0, so it must be realmode.
> + */
> +void slb_flush_all_realmode(void)
> +{
> + /*
> + * This flushes all SLB entries including 0, so it must be
> realmode.
> + */
> + asm volatile("slbmte %0,%0; slbia" : : "r" (0));
> +}
> +
> static void __slb_flush_and_rebolt(void)
> {
> /* If you change this make sure you change SLB_NUM_BOLTED
[PATCH 1/2] powerpc/64s: move machine check SLB flushing to mm/slb.c
The machine check code that flushes and restores bolted segments in
real mode belongs in mm/slb.c. This will be used by pseries machine
check and idle code.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/include/asm/book3s/64/mmu-hash.h | 3 ++
arch/powerpc/kernel/mce_power.c | 21 ++
arch/powerpc/mm/slb.c | 38 +++
3 files changed, 44 insertions(+), 18 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/mmu-hash.h
b/arch/powerpc/include/asm/book3s/64/mmu-hash.h
index 2f74bdc805e0..d4e398185b3a 100644
--- a/arch/powerpc/include/asm/book3s/64/mmu-hash.h
+++ b/arch/powerpc/include/asm/book3s/64/mmu-hash.h
@@ -497,6 +497,9 @@ extern void hpte_init_native(void);
extern void slb_initialize(void);
extern void slb_flush_and_rebolt(void);
+extern void slb_flush_all_realmode(void);
+extern void __slb_restore_bolted_realmode(void);
+extern void slb_restore_bolted_realmode(void);
extern void slb_vmalloc_update(void);
extern void slb_set_size(u16 size);
diff --git a/arch/powerpc/kernel/mce_power.c b/arch/powerpc/kernel/mce_power.c
index d6756af6ec78..50f7b9817246 100644
--- a/arch/powerpc/kernel/mce_power.c
+++ b/arch/powerpc/kernel/mce_power.c
@@ -62,11 +62,8 @@ static unsigned long addr_to_pfn(struct pt_regs *regs,
unsigned long addr)
#ifdef CONFIG_PPC_BOOK3S_64
static void flush_and_reload_slb(void)
{
- struct slb_shadow *slb;
- unsigned long i, n;
-
/* Invalidate all SLBs */
- asm volatile("slbmte %0,%0; slbia" : : "r" (0));
+ slb_flush_all_realmode();
#ifdef CONFIG_KVM_BOOK3S_HANDLER
/*
@@ -76,22 +73,10 @@ static void flush_and_reload_slb(void)
if (get_paca()->kvm_hstate.in_guest)
return;
#endif
-
- /* For host kernel, reload the SLBs from shadow SLB buffer. */
- slb = get_slb_shadow();
- if (!slb)
+ if (early_radix_enabled())
return;
- n = min_t(u32, be32_to_cpu(slb->persistent), SLB_MIN_SIZE);
-
- /* Load up the SLB entries from shadow SLB */
- for (i = 0; i < n; i++) {
- unsigned long rb = be64_to_cpu(slb->save_area[i].esid);
- unsigned long rs = be64_to_cpu(slb->save_area[i].vsid);
-
- rb = (rb & ~0xFFFul) | i;
- asm volatile("slbmte %0,%1" : : "r" (rs), "r" (rb));
- }
+ slb_restore_bolted_realmode();
}
#endif
diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
index cb796724a6fc..136db8652577 100644
--- a/arch/powerpc/mm/slb.c
+++ b/arch/powerpc/mm/slb.c
@@ -90,6 +90,44 @@ static inline void create_shadowed_slbe(unsigned long ea,
int ssize,
: "memory" );
}
+/*
+ * Insert bolted entries into SLB (which may not be empty).
+ */
+void __slb_restore_bolted_realmode(void)
+{
+ struct slb_shadow *p = get_slb_shadow();
+ enum slb_index index;
+
+/* No isync needed because realmode. */
+ for (index = 0; index < SLB_NUM_BOLTED; index++) {
+ asm volatile("slbmte %0,%1" :
+: "r" (be64_to_cpu(p->save_area[index].vsid)),
+ "r" (be64_to_cpu(p->save_area[index].esid)));
+ }
+}
+
+/*
+ * Insert bolted entries into an empty SLB.
+ * This is not the same as rebolt because the bolted segments
+ * (e.g., kstack) are not changed (rebolted).
+ */
+void slb_restore_bolted_realmode(void)
+{
+ __slb_restore_bolted_realmode();
+ get_paca()->slb_cache_ptr = 0;
+}
+
+/*
+ * This flushes all SLB entries including 0, so it must be realmode.
+ */
+void slb_flush_all_realmode(void)
+{
+ /*
+* This flushes all SLB entries including 0, so it must be realmode.
+*/
+ asm volatile("slbmte %0,%0; slbia" : : "r" (0));
+}
+
static void __slb_flush_and_rebolt(void)
{
/* If you change this make sure you change SLB_NUM_BOLTED
--
2.17.0
