Re: [PATCH v6 04/19] powerpc: mm: Add p?d_large() definitions

From: Christophe Leroy
Date: Tue Mar 26 2019 - 12:58:18 EST




Le 26/03/2019 Ã 17:26, Steven Price a ÃcritÂ:
walk_page_range() is going to be allowed to walk page tables other than
those of user space. For this it needs to know when it has reached a
'leaf' entry in the page tables. This information is provided by the
p?d_large() functions/macros.

For powerpc pmd_large() was already implemented, so hoist it out of the
CONFIG_TRANSPARENT_HUGEPAGE condition and implement the other levels.

Also since we now have a pmd_large always implemented we can drop the
pmd_is_leaf() function.

Wouldn't it be better to drop the pmd_is_leaf() in a second patch ?

Christophe


CC: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
CC: Paul Mackerras <paulus@xxxxxxxxx>
CC: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
CC: linuxppc-dev@xxxxxxxxxxxxxxxx
CC: kvm-ppc@xxxxxxxxxxxxxxx
Signed-off-by: Steven Price <steven.price@xxxxxxx>
---
arch/powerpc/include/asm/book3s/64/pgtable.h | 30 ++++++++++++++------
arch/powerpc/kvm/book3s_64_mmu_radix.c | 12 ++------
2 files changed, 24 insertions(+), 18 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 581f91be9dd4..f6d1ac8b832e 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -897,6 +897,12 @@ static inline int pud_present(pud_t pud)
return !!(pud_raw(pud) & cpu_to_be64(_PAGE_PRESENT));
}
+#define pud_large pud_large
+static inline int pud_large(pud_t pud)
+{
+ return !!(pud_raw(pud) & cpu_to_be64(_PAGE_PTE));
+}
+
extern struct page *pud_page(pud_t pud);
extern struct page *pmd_page(pmd_t pmd);
static inline pte_t pud_pte(pud_t pud)
@@ -940,6 +946,12 @@ static inline int pgd_present(pgd_t pgd)
return !!(pgd_raw(pgd) & cpu_to_be64(_PAGE_PRESENT));
}
+#define pgd_large pgd_large
+static inline int pgd_large(pgd_t pgd)
+{
+ return !!(pgd_raw(pgd) & cpu_to_be64(_PAGE_PTE));
+}
+
static inline pte_t pgd_pte(pgd_t pgd)
{
return __pte_raw(pgd_raw(pgd));
@@ -1093,6 +1105,15 @@ static inline bool pmd_access_permitted(pmd_t pmd, bool write)
return pte_access_permitted(pmd_pte(pmd), write);
}
+#define pmd_large pmd_large
+/*
+ * returns true for pmd migration entries, THP, devmap, hugetlb
+ */
+static inline int pmd_large(pmd_t pmd)
+{
+ return !!(pmd_raw(pmd) & cpu_to_be64(_PAGE_PTE));
+}
+
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
extern pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot);
extern pmd_t mk_pmd(struct page *page, pgprot_t pgprot);
@@ -1119,15 +1140,6 @@ pmd_hugepage_update(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp,
return hash__pmd_hugepage_update(mm, addr, pmdp, clr, set);
}
-/*
- * returns true for pmd migration entries, THP, devmap, hugetlb
- * But compile time dependent on THP config
- */
-static inline int pmd_large(pmd_t pmd)
-{
- return !!(pmd_raw(pmd) & cpu_to_be64(_PAGE_PTE));
-}
-
static inline pmd_t pmd_mknotpresent(pmd_t pmd)
{
return __pmd(pmd_val(pmd) & ~_PAGE_PRESENT);
diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
index f55ef071883f..1b57b4e3f819 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -363,12 +363,6 @@ static void kvmppc_pte_free(pte_t *ptep)
kmem_cache_free(kvm_pte_cache, ptep);
}
-/* Like pmd_huge() and pmd_large(), but works regardless of config options */
-static inline int pmd_is_leaf(pmd_t pmd)
-{
- return !!(pmd_val(pmd) & _PAGE_PTE);
-}
-
static pmd_t *kvmppc_pmd_alloc(void)
{
return kmem_cache_alloc(kvm_pmd_cache, GFP_KERNEL);
@@ -460,7 +454,7 @@ static void kvmppc_unmap_free_pmd(struct kvm *kvm, pmd_t *pmd, bool full,
for (im = 0; im < PTRS_PER_PMD; ++im, ++p) {
if (!pmd_present(*p))
continue;
- if (pmd_is_leaf(*p)) {
+ if (pmd_large(*p)) {
if (full) {
pmd_clear(p);
} else {
@@ -593,7 +587,7 @@ int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
else if (level <= 1)
new_pmd = kvmppc_pmd_alloc();
- if (level == 0 && !(pmd && pmd_present(*pmd) && !pmd_is_leaf(*pmd)))
+ if (level == 0 && !(pmd && pmd_present(*pmd) && !pmd_large(*pmd)))
new_ptep = kvmppc_pte_alloc();
/* Check if we might have been invalidated; let the guest retry if so */
@@ -662,7 +656,7 @@ int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
new_pmd = NULL;
}
pmd = pmd_offset(pud, gpa);
- if (pmd_is_leaf(*pmd)) {
+ if (pmd_large(*pmd)) {
unsigned long lgpa = gpa & PMD_MASK;
/* Check if we raced and someone else has set the same thing */