[PATCH 10/65] powerpc/mm: Drop WIMG in favour of new constants
Aneesh Kumar K.V
aneesh.kumar at linux.vnet.ibm.com
Sun Mar 27 19:23:18 AEDT 2016
PowerISA 3.0 introduce two pte bits with the below meaning w.r.t Radix
00 -> Normal Memory
01 -> Strong Access Order
10 -> Non idempotent I/O (Cache inhibited and guarded)
11 -> Tolerant I/O (Cache inhibited)
We drop the existing WIMG bits in linux page table in favour of above
constants. We loose _PAGE_WRITETHRU with this conversion. We only use
writethru via pgprot_cached_wthru() which is used by fbdev/controlfb.c
which is Apple control display and also PPC32.
With respect to _PAGE_COHERENCE, we have been marking hpte
always coherent for some time now. htab_convert_pte_flags always added
HPTE_R_M.
NOTE: KVM changes need closer review.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
---
arch/powerpc/include/asm/book3s/64/hash.h | 72 ++++++++++++++-----------------
arch/powerpc/include/asm/kvm_book3s_64.h | 27 +++++-------
arch/powerpc/kvm/book3s_64_mmu_hv.c | 11 +++--
arch/powerpc/kvm/book3s_hv_rm_mmu.c | 12 +++---
arch/powerpc/mm/hash64_64k.c | 2 +-
arch/powerpc/mm/hash_utils_64.c | 18 ++++----
arch/powerpc/mm/pgtable.c | 8 ++--
arch/powerpc/mm/pgtable_64.c | 4 --
arch/powerpc/platforms/pseries/lpar.c | 4 --
9 files changed, 67 insertions(+), 91 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h
index 2a80981f1b0b..fd2d0ebfc49c 100644
--- a/arch/powerpc/include/asm/book3s/64/hash.h
+++ b/arch/powerpc/include/asm/book3s/64/hash.h
@@ -20,12 +20,10 @@
#define _PAGE_READ 0x00004 /* read access allowed */
#define _PAGE_RW (_PAGE_READ | _PAGE_WRITE)
#define _PAGE_RWX (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC)
-#define _PAGE_PRIVILEGED 0x00008 /* kernel access only */
-#define _PAGE_GUARDED 0x00010 /* G: guarded (side-effect) page */
-/* M (memory coherence) is always set in the HPTE, so we don't need it here */
-#define _PAGE_COHERENT 0x0
-#define _PAGE_NO_CACHE 0x00020 /* I: cache inhibit */
-#define _PAGE_WRITETHRU 0x00040 /* W: cache write-through */
+#define _PAGE_PRIVILEGED 0x00008 /* kernel access only */
+#define _PAGE_SAO 0x00010 /* Strong access order */
+#define _PAGE_NON_IDEMPOTENT 0x00020 /* non idempotent memory */
+#define _PAGE_TOLERANT 0x00030 /* tolerant memory, cache inhibited */
#define _PAGE_DIRTY 0x00080 /* C: page changed */
#define _PAGE_ACCESSED 0x00100 /* R: page referenced */
#define _PAGE_SPECIAL 0x00400 /* software: special page */
@@ -43,7 +41,12 @@
#define _PAGE_HASHPTE (1ul << 61) /* PTE has associated HPTE */
#define _PAGE_PTE (1ul << 62) /* distinguishes PTEs from pointers */
#define _PAGE_PRESENT (1ul << 63) /* pte contains a translation */
-
+/*
+ * Drivers request for cache inhibited pte mapping using _PAGE_NO_CACHE
+ * Instead of fixing all of them, add an alternate define which
+ * maps CI pte mapping.
+ */
+#define _PAGE_NO_CACHE _PAGE_TOLERANT
/*
* We need to differentiate between explicit huge page and THP huge
* page, since THP huge page also need to track real subpage details
@@ -122,9 +125,6 @@
#define _PAGE_KERNEL_RWX (_PAGE_PRIVILEGED | _PAGE_DIRTY | \
_PAGE_RW | _PAGE_EXEC)
-/* Strong Access Ordering */
-#define _PAGE_SAO (_PAGE_WRITETHRU | _PAGE_NO_CACHE | _PAGE_COHERENT)
-
/* No page size encoding in the linux PTE */
#define _PAGE_PSIZE 0
@@ -150,10 +150,9 @@
/*
* Mask of bits returned by pte_pgprot()
*/
-#define PAGE_PROT_BITS (_PAGE_GUARDED | _PAGE_COHERENT | _PAGE_NO_CACHE | \
- _PAGE_WRITETHRU | _PAGE_4K_PFN | \
- _PAGE_PRIVILEGED | _PAGE_ACCESSED | _PAGE_READ |\
- _PAGE_WRITE | _PAGE_DIRTY | _PAGE_EXEC | \
+#define PAGE_PROT_BITS (_PAGE_SAO | _PAGE_NON_IDEMPOTENT | _PAGE_TOLERANT | \
+ _PAGE_4K_PFN | _PAGE_PRIVILEGED | _PAGE_ACCESSED | \
+ _PAGE_READ | _PAGE_WRITE | _PAGE_DIRTY | _PAGE_EXEC | \
_PAGE_SOFT_DIRTY)
/*
* We define 2 sets of base prot bits, one for basic pages (ie,
@@ -162,7 +161,7 @@
* the processor might need it for DMA coherency.
*/
#define _PAGE_BASE_NC (_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_PSIZE)
-#define _PAGE_BASE (_PAGE_BASE_NC | _PAGE_COHERENT)
+#define _PAGE_BASE (_PAGE_BASE_NC)
/* Permission masks used to generate the __P and __S table,
*
@@ -203,9 +202,9 @@
/* Permission masks used for kernel mappings */
#define PAGE_KERNEL __pgprot(_PAGE_BASE | _PAGE_KERNEL_RW)
#define PAGE_KERNEL_NC __pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | \
- _PAGE_NO_CACHE)
+ _PAGE_TOLERANT)
#define PAGE_KERNEL_NCG __pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | \
- _PAGE_NO_CACHE | _PAGE_GUARDED)
+ _PAGE_NON_IDEMPOTENT)
#define PAGE_KERNEL_X __pgprot(_PAGE_BASE | _PAGE_KERNEL_RWX)
#define PAGE_KERNEL_RO __pgprot(_PAGE_BASE | _PAGE_KERNEL_RO)
#define PAGE_KERNEL_ROX __pgprot(_PAGE_BASE | _PAGE_KERNEL_ROX)
@@ -512,45 +511,26 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
*ptep = pte;
}
-/*
- * Macro to mark a page protection value as "uncacheable".
- */
-
-#define _PAGE_CACHE_CTL (_PAGE_COHERENT | _PAGE_GUARDED | _PAGE_NO_CACHE | \
- _PAGE_WRITETHRU)
+#define _PAGE_CACHE_CTL (_PAGE_NON_IDEMPOTENT | _PAGE_TOLERANT)
#define pgprot_noncached pgprot_noncached
static inline pgprot_t pgprot_noncached(pgprot_t prot)
{
return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) |
- _PAGE_NO_CACHE | _PAGE_GUARDED);
+ _PAGE_NON_IDEMPOTENT);
}
#define pgprot_noncached_wc pgprot_noncached_wc
static inline pgprot_t pgprot_noncached_wc(pgprot_t prot)
{
return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) |
- _PAGE_NO_CACHE);
+ _PAGE_TOLERANT);
}
#define pgprot_cached pgprot_cached
static inline pgprot_t pgprot_cached(pgprot_t prot)
{
- return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) |
- _PAGE_COHERENT);
-}
-
-#define pgprot_cached_wthru pgprot_cached_wthru
-static inline pgprot_t pgprot_cached_wthru(pgprot_t prot)
-{
- return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) |
- _PAGE_COHERENT | _PAGE_WRITETHRU);
-}
-
-#define pgprot_cached_noncoherent pgprot_cached_noncoherent
-static inline pgprot_t pgprot_cached_noncoherent(pgprot_t prot)
-{
- return __pgprot(pgprot_val(prot) & ~_PAGE_CACHE_CTL);
+ return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL));
}
#define pgprot_writecombine pgprot_writecombine
@@ -558,6 +538,18 @@ static inline pgprot_t pgprot_writecombine(pgprot_t prot)
{
return pgprot_noncached_wc(prot);
}
+/*
+ * check a pte mapping have cache inhibited property
+ */
+static inline bool pte_ci(pte_t pte)
+{
+ unsigned long pte_v = pte_val(pte);
+
+ if (((pte_v & _PAGE_CACHE_CTL) == _PAGE_TOLERANT) ||
+ ((pte_v & _PAGE_CACHE_CTL) == _PAGE_NON_IDEMPOTENT))
+ return true;
+ return false;
+}
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
extern void hpte_do_hugepage_flush(struct mm_struct *mm, unsigned long addr,
diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index f9a7a89a3e4f..ebdaf576cf26 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -278,19 +278,24 @@ static inline unsigned long hpte_make_readonly(unsigned long ptel)
return ptel;
}
-static inline int hpte_cache_flags_ok(unsigned long ptel, unsigned long io_type)
+static inline bool hpte_cache_flags_ok(unsigned long hptel, bool is_ci)
{
- unsigned int wimg = ptel & HPTE_R_WIMG;
+ unsigned int wimg = hptel & HPTE_R_WIMG;
/* Handle SAO */
if (wimg == (HPTE_R_W | HPTE_R_I | HPTE_R_M) &&
cpu_has_feature(CPU_FTR_ARCH_206))
wimg = HPTE_R_M;
- if (!io_type)
+ if (!is_ci)
return wimg == HPTE_R_M;
-
- return (wimg & (HPTE_R_W | HPTE_R_I)) == io_type;
+ /*
+ * if host is mapped cache inhibited, make sure hptel also have
+ * cache inhibited.
+ */
+ if (wimg & HPTE_R_W) /* FIXME!! is this ok for all guest. ? */
+ return false;
+ return !!(wimg & HPTE_R_I);
}
/*
@@ -333,18 +338,6 @@ static inline pte_t kvmppc_read_update_linux_pte(pte_t *ptep, int writing)
return new_pte;
}
-
-/* Return HPTE cache control bits corresponding to Linux pte bits */
-static inline unsigned long hpte_cache_bits(unsigned long pte_val)
-{
-#if _PAGE_NO_CACHE == HPTE_R_I && _PAGE_WRITETHRU == HPTE_R_W
- return pte_val & (HPTE_R_W | HPTE_R_I);
-#else
- return ((pte_val & _PAGE_NO_CACHE) ? HPTE_R_I : 0) +
- ((pte_val & _PAGE_WRITETHRU) ? HPTE_R_W : 0);
-#endif
-}
-
static inline bool hpte_read_permission(unsigned long pp, unsigned long key)
{
if (key)
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index c7b78d8336b2..05f09ae82587 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -447,7 +447,7 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
struct revmap_entry *rev;
struct page *page, *pages[1];
long index, ret, npages;
- unsigned long is_io;
+ bool is_ci;
unsigned int writing, write_ok;
struct vm_area_struct *vma;
unsigned long rcbits;
@@ -503,7 +503,7 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
smp_rmb();
ret = -EFAULT;
- is_io = 0;
+ is_ci = false;
pfn = 0;
page = NULL;
pte_size = PAGE_SIZE;
@@ -521,7 +521,7 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
pfn = vma->vm_pgoff +
((hva - vma->vm_start) >> PAGE_SHIFT);
pte_size = psize;
- is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot));
+ is_ci = pte_ci(__pte((pgprot_val(vma->vm_page_prot))));
write_ok = vma->vm_flags & VM_WRITE;
}
up_read(¤t->mm->mmap_sem);
@@ -558,10 +558,9 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
goto out_put;
/* Check WIMG vs. the actual page we're accessing */
- if (!hpte_cache_flags_ok(r, is_io)) {
- if (is_io)
+ if (!hpte_cache_flags_ok(r, is_ci)) {
+ if (is_ci)
goto out_put;
-
/*
* Allow guest to map emulated device memory as
* uncacheable, but actually make it cacheable.
diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
index 4cb8db05f3e5..99b4e9d5dd23 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -175,7 +175,7 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags,
unsigned long g_ptel;
struct kvm_memory_slot *memslot;
unsigned hpage_shift;
- unsigned long is_io;
+ bool is_ci;
unsigned long *rmap;
pte_t *ptep;
unsigned int writing;
@@ -199,7 +199,7 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags,
gfn = gpa >> PAGE_SHIFT;
memslot = __gfn_to_memslot(kvm_memslots_raw(kvm), gfn);
pa = 0;
- is_io = ~0ul;
+ is_ci = false;
rmap = NULL;
if (!(memslot && !(memslot->flags & KVM_MEMSLOT_INVALID))) {
/* Emulated MMIO - mark this with key=31 */
@@ -250,7 +250,7 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags,
if (writing && !pte_write(pte))
/* make the actual HPTE be read-only */
ptel = hpte_make_readonly(ptel);
- is_io = hpte_cache_bits(pte_val(pte));
+ is_ci = pte_ci(pte);
pa = pte_pfn(pte) << PAGE_SHIFT;
pa |= hva & (host_pte_size - 1);
pa |= gpa & ~PAGE_MASK;
@@ -267,9 +267,9 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags,
else
pteh |= HPTE_V_ABSENT;
- /* Check WIMG */
- if (is_io != ~0ul && !hpte_cache_flags_ok(ptel, is_io)) {
- if (is_io)
+ /*If we had host pte mapping then Check WIMG */
+ if (ptep && !hpte_cache_flags_ok(ptel, is_ci)) {
+ if (is_ci)
return H_PARAMETER;
/*
* Allow guest to map emulated device memory as
diff --git a/arch/powerpc/mm/hash64_64k.c b/arch/powerpc/mm/hash64_64k.c
index f33b410d6c8a..419562b0e9c8 100644
--- a/arch/powerpc/mm/hash64_64k.c
+++ b/arch/powerpc/mm/hash64_64k.c
@@ -248,7 +248,7 @@ int __hash_page_64K(unsigned long ea, unsigned long access,
* If so, bail out and refault as a 4k page
*/
if (!mmu_has_feature(MMU_FTR_CI_LARGE_PAGE) &&
- unlikely(old_pte & _PAGE_NO_CACHE))
+ unlikely(pte_ci(pte)))
return 0;
/*
* Try to lock the PTE, add ACCESSED and DIRTY if it was
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 59d4600bacd5..e924690a5a0e 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -192,12 +192,13 @@ unsigned long htab_convert_pte_flags(unsigned long pteflags)
/*
* Add in WIG bits
*/
- if (pteflags & _PAGE_WRITETHRU)
- rflags |= HPTE_R_W;
- if (pteflags & _PAGE_NO_CACHE)
+
+ if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_TOLERANT)
rflags |= HPTE_R_I;
- if (pteflags & _PAGE_GUARDED)
- rflags |= HPTE_R_G;
+ if ((pteflags & _PAGE_CACHE_CTL ) == _PAGE_NON_IDEMPOTENT)
+ rflags |= (HPTE_R_I | HPTE_R_G);
+ if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_SAO)
+ rflags |= (HPTE_R_I | HPTE_R_W);
return rflags;
}
@@ -1138,8 +1139,7 @@ int hash_page_mm(struct mm_struct *mm, unsigned long ea,
/* If this PTE is non-cacheable and we have restrictions on
* using non cacheable large pages, then we switch to 4k
*/
- if (mmu_ci_restrictions && psize == MMU_PAGE_64K &&
- (pte_val(*ptep) & _PAGE_NO_CACHE)) {
+ if (mmu_ci_restrictions && psize == MMU_PAGE_64K && pte_ci(*ptep)) {
if (user_region) {
demote_segment_4k(mm, ea);
psize = MMU_PAGE_4K;
@@ -1293,13 +1293,13 @@ void hash_preload(struct mm_struct *mm, unsigned long ea,
WARN_ON(hugepage_shift);
#ifdef CONFIG_PPC_64K_PAGES
- /* If either _PAGE_4K_PFN or _PAGE_NO_CACHE is set (and we are on
+ /* If either _PAGE_4K_PFN or cache inhibited is set (and we are on
* a 64K kernel), then we don't preload, hash_page() will take
* care of it once we actually try to access the page.
* That way we don't have to duplicate all of the logic for segment
* page size demotion here
*/
- if (pte_val(*ptep) & (_PAGE_4K_PFN | _PAGE_NO_CACHE))
+ if ((pte_val(*ptep) & _PAGE_4K_PFN) || pte_ci(*ptep))
goto out_exit;
#endif /* CONFIG_PPC_64K_PAGES */
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index a34884beaa47..115a0a19d5a2 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -38,16 +38,16 @@ static inline int is_exec_fault(void)
/* We only try to do i/d cache coherency on stuff that looks like
* reasonably "normal" PTEs. We currently require a PTE to be present
- * and we avoid _PAGE_SPECIAL and _PAGE_NO_CACHE. We also only do that
+ * and we avoid _PAGE_SPECIAL and cache inhibited pte. We also only do that
* on userspace PTEs
*/
static inline int pte_looks_normal(pte_t pte)
{
#if defined(CONFIG_PPC_BOOK3S_64)
- if ((pte_val(pte) &
- (_PAGE_PRESENT | _PAGE_SPECIAL | _PAGE_NO_CACHE)) ==
- _PAGE_PRESENT) {
+ if ((pte_val(pte) & (_PAGE_PRESENT | _PAGE_SPECIAL)) == _PAGE_PRESENT) {
+ if (pte_ci(pte))
+ return 0;
if (pte_user(pte))
return 1;
}
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index 6f1b7064f822..db924c54f370 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -167,10 +167,6 @@ void __iomem * __ioremap_at(phys_addr_t pa, void *ea, unsigned long size,
if ((flags & _PAGE_PRESENT) == 0)
flags |= pgprot_val(PAGE_KERNEL);
- /* Non-cacheable page cannot be coherent */
- if (flags & _PAGE_NO_CACHE)
- flags &= ~_PAGE_COHERENT;
-
/* We don't support the 4K PFN hack with ioremap */
if (flags & _PAGE_4K_PFN)
return NULL;
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index 2415a0d31f8f..0d4608990702 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -152,10 +152,6 @@ static long pSeries_lpar_hpte_insert(unsigned long hpte_group,
/* Exact = 0 */
flags = 0;
- /* Make pHyp happy */
- if ((rflags & _PAGE_NO_CACHE) && !(rflags & _PAGE_WRITETHRU))
- hpte_r &= ~HPTE_R_M;
-
if (firmware_has_feature(FW_FEATURE_XCMO) && !(hpte_r & HPTE_R_N))
flags |= H_COALESCE_CAND;
--
2.5.0
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