powerpc/mm: Drop WIMG in favour of new constants

PowerISA 3.0 introduces two pte bits with the below meaning for radix:
  00 -> Normal Memory
  01 -> Strong Access Order (SAO)
  10 -> Non idempotent I/O (Cache inhibited and guarded)
  11 -> Tolerant I/O (Cache inhibited)

We drop the existing WIMG bits in the Linux page table in favour of the
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@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Aneesh Kumar K.V 2016-04-29 23:25:38 +10:00 committed by Michael Ellerman
parent 72176dd0ad
commit 30bda41aba
9 changed files with 66 additions and 90 deletions

View File

@ -21,11 +21,9 @@
#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_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
@ -126,9 +129,6 @@
#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
@ -147,10 +147,9 @@
/*
* 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,
@ -159,7 +158,7 @@
* 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,
*
@ -200,9 +199,9 @@
/* 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)
@ -509,45 +508,26 @@ 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
@ -555,6 +535,18 @@ 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,

View File

@ -276,19 +276,24 @@ 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);
}
/*
@ -325,18 +330,6 @@ 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)

View File

@ -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(&current->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.

View File

@ -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

View File

@ -244,7 +244,7 @@ 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

View File

@ -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;
}
@ -1142,8 +1143,7 @@ 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;
@ -1297,13 +1297,13 @@ 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 */

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@ -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;
}

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@ -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;

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@ -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;