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authorMichael Ellerman <mpe@ellerman.id.au>2017-08-23 22:20:10 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2017-08-23 22:20:10 +1000
commit15c659ff9d5b367c886166a9854a89b72c524a68 (patch)
treed33acaf62889bf6304f6109dd69923a17ab938be /arch/powerpc/include
parent516fa8d0e19d854253460ea7692551e836e7e2b5 (diff)
parent1a92a80ad386a1a6e3b36d576d52a1a456394b70 (diff)
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Merge branch 'fixes' into next
There's a non-trivial dependency between some commits we want to put in next and the KVM prefetch work around that went into fixes. So merge fixes into next.
Diffstat (limited to 'arch/powerpc/include')
-rw-r--r--arch/powerpc/include/asm/book3s/64/mmu.h15
-rw-r--r--arch/powerpc/include/asm/book3s/64/pgtable.h10
-rw-r--r--arch/powerpc/include/asm/mmu_context.h36
-rw-r--r--arch/powerpc/include/asm/pgtable-be-types.h1
-rw-r--r--arch/powerpc/include/asm/pgtable-types.h1
5 files changed, 53 insertions, 10 deletions
diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h b/arch/powerpc/include/asm/book3s/64/mmu.h
index cbf1945f4338..1a220cdff923 100644
--- a/arch/powerpc/include/asm/book3s/64/mmu.h
+++ b/arch/powerpc/include/asm/book3s/64/mmu.h
@@ -59,13 +59,14 @@ extern struct patb_entry *partition_tb;
#define PRTS_MASK 0x1f /* process table size field */
#define PRTB_MASK 0x0ffffffffffff000UL
-/*
- * Limit process table to PAGE_SIZE table. This
- * also limit the max pid we can support.
- * MAX_USER_CONTEXT * 16 bytes of space.
- */
-#define PRTB_SIZE_SHIFT (CONTEXT_BITS + 4)
-#define PRTB_ENTRIES (1ul << CONTEXT_BITS)
+/* Number of supported PID bits */
+extern unsigned int mmu_pid_bits;
+
+/* Base PID to allocate from */
+extern unsigned int mmu_base_pid;
+
+#define PRTB_SIZE_SHIFT (mmu_pid_bits + 4)
+#define PRTB_ENTRIES (1ul << mmu_pid_bits)
/*
* Power9 currently only support 64K partition table size.
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index a43c60aa1c2c..b9aff515b4de 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -614,9 +614,17 @@ static inline pte_t pte_mkdevmap(pte_t pte)
return __pte(pte_val(pte) | _PAGE_SPECIAL|_PAGE_DEVMAP);
}
+/*
+ * This is potentially called with a pmd as the argument, in which case it's not
+ * safe to check _PAGE_DEVMAP unless we also confirm that _PAGE_PTE is set.
+ * That's because the bit we use for _PAGE_DEVMAP is not reserved for software
+ * use in page directory entries (ie. non-ptes).
+ */
static inline int pte_devmap(pte_t pte)
{
- return !!(pte_raw(pte) & cpu_to_be64(_PAGE_DEVMAP));
+ u64 mask = cpu_to_be64(_PAGE_DEVMAP | _PAGE_PTE);
+
+ return (pte_raw(pte) & mask) == mask;
}
static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
index eb749c86dca5..2ab328f0159e 100644
--- a/arch/powerpc/include/asm/mmu_context.h
+++ b/arch/powerpc/include/asm/mmu_context.h
@@ -45,7 +45,7 @@ extern void set_context(unsigned long id, pgd_t *pgd);
#ifdef CONFIG_PPC_BOOK3S_64
extern void radix__switch_mmu_context(struct mm_struct *prev,
- struct mm_struct *next);
+ struct mm_struct *next);
static inline void switch_mmu_context(struct mm_struct *prev,
struct mm_struct *next,
struct task_struct *tsk)
@@ -67,6 +67,12 @@ extern void __destroy_context(unsigned long context_id);
extern void mmu_context_init(void);
#endif
+#if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_RADIX_MMU)
+extern void radix_kvm_prefetch_workaround(struct mm_struct *mm);
+#else
+static inline void radix_kvm_prefetch_workaround(struct mm_struct *mm) { }
+#endif
+
extern void switch_cop(struct mm_struct *next);
extern int use_cop(unsigned long acop, struct mm_struct *mm);
extern void drop_cop(unsigned long acop, struct mm_struct *mm);
@@ -79,10 +85,32 @@ static inline void switch_mm_irqs_off(struct mm_struct *prev,
struct mm_struct *next,
struct task_struct *tsk)
{
+ bool new_on_cpu = false;
+
/* Mark this context has been used on the new CPU */
- if (!cpumask_test_cpu(smp_processor_id(), mm_cpumask(next)))
+ if (!cpumask_test_cpu(smp_processor_id(), mm_cpumask(next))) {
cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
+ /*
+ * This full barrier orders the store to the cpumask above vs
+ * a subsequent operation which allows this CPU to begin loading
+ * translations for next.
+ *
+ * When using the radix MMU that operation is the load of the
+ * MMU context id, which is then moved to SPRN_PID.
+ *
+ * For the hash MMU it is either the first load from slb_cache
+ * in switch_slb(), and/or the store of paca->mm_ctx_id in
+ * copy_mm_to_paca().
+ *
+ * On the read side the barrier is in pte_xchg(), which orders
+ * the store to the PTE vs the load of mm_cpumask.
+ */
+ smp_mb();
+
+ new_on_cpu = true;
+ }
+
/* 32-bit keeps track of the current PGDIR in the thread struct */
#ifdef CONFIG_PPC32
tsk->thread.pgdir = next->pgd;
@@ -103,6 +131,10 @@ static inline void switch_mm_irqs_off(struct mm_struct *prev,
if (cpu_has_feature(CPU_FTR_ALTIVEC))
asm volatile ("dssall");
#endif /* CONFIG_ALTIVEC */
+
+ if (new_on_cpu)
+ radix_kvm_prefetch_workaround(next);
+
/*
* The actual HW switching method differs between the various
* sub architectures. Out of line for now
diff --git a/arch/powerpc/include/asm/pgtable-be-types.h b/arch/powerpc/include/asm/pgtable-be-types.h
index 9c0f5db5cf46..67e7e3d990f4 100644
--- a/arch/powerpc/include/asm/pgtable-be-types.h
+++ b/arch/powerpc/include/asm/pgtable-be-types.h
@@ -87,6 +87,7 @@ static inline bool pte_xchg(pte_t *ptep, pte_t old, pte_t new)
unsigned long *p = (unsigned long *)ptep;
__be64 prev;
+ /* See comment in switch_mm_irqs_off() */
prev = (__force __be64)__cmpxchg_u64(p, (__force unsigned long)pte_raw(old),
(__force unsigned long)pte_raw(new));
diff --git a/arch/powerpc/include/asm/pgtable-types.h b/arch/powerpc/include/asm/pgtable-types.h
index 8bd3b13fe2fb..369a164b545c 100644
--- a/arch/powerpc/include/asm/pgtable-types.h
+++ b/arch/powerpc/include/asm/pgtable-types.h
@@ -62,6 +62,7 @@ static inline bool pte_xchg(pte_t *ptep, pte_t old, pte_t new)
{
unsigned long *p = (unsigned long *)ptep;
+ /* See comment in switch_mm_irqs_off() */
return pte_val(old) == __cmpxchg_u64(p, pte_val(old), pte_val(new));
}
#endif