Re: [PATCH 1/2] powerpc/64s: move machine check SLB flushing to mm/slb.c
From: Michal Suchánek <hidden>
Date: 2018-08-08 20:22:56
On Fri, 3 Aug 2018 14:13:49 +1000 Nicholas Piggin [off-list ref] wrote:
quoted hunk ↗ jump to hunk
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 <npiggin@gmail.com> --- 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.hb/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.cb/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()
quoted hunk ↗ jump to hunk
- 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(); } #endifdiff --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(unsignedlong 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