Re: [PATCH -next 4/4] riscv: mm: add THP support on 64-bit
From: Palmer Dabbelt
Date: Wed May 26 2021 - 01:54:12 EST
On Tue, 25 May 2021 05:14:45 PDT (-0700), geert@xxxxxxxxxxxxxx wrote:
Hi Nanyong,
On Fri, Apr 30, 2021 at 9:58 AM Nanyong Sun <sunnanyong@xxxxxxxxxx> wrote:
Bring Transparent HugePage support to riscv. A
transparent huge page is always represented as a pmd.
Signed-off-by: Nanyong Sun <sunnanyong@xxxxxxxxxx>
Thanks for your patch, which is now commit e88b333142e4aba7 ("riscv:
mm: add THP support on 64-bit") in riscv/for-next.
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -438,6 +459,141 @@ static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
return ptep_test_and_clear_young(vma, address, ptep);
}
+/*
+ * THP functions
+ */
+static inline pmd_t pte_pmd(pte_t pte)
+{
+ return __pmd(pte_val(pte));
+}
+
+static inline pmd_t pmd_mkhuge(pmd_t pmd)
+{
+ return pmd;
+}
+
+static inline pmd_t pmd_mkinvalid(pmd_t pmd)
+{
+ return __pmd(pmd_val(pmd) & ~(_PAGE_PRESENT|_PAGE_PROT_NONE));
+}
+
+#define __pmd_to_phys(pmd) (pmd_val(pmd) >> _PAGE_PFN_SHIFT << PAGE_SHIFT)
+
+static inline unsigned long pmd_pfn(pmd_t pmd)s
+{
+ return ((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT);
+}
+
+static inline pmd_t mk_pmd(struct page *page, pgprot_t prot)
+{
+ return pfn_pmd(page_to_pfn(page), prot);
+}
+
+static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
+{
+ return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
+}
+
+#define pmd_write pmd_write
+static inline int pmd_write(pmd_t pmd)
+{
+ return pte_write(pmd_pte(pmd));
+}
+
+static inline int pmd_dirty(pmd_t pmd)
+{
+ return pte_dirty(pmd_pte(pmd));
+}
+
+static inline int pmd_young(pmd_t pmd)
+{
+ return pte_young(pmd_pte(pmd));
+}
+
+static inline pmd_t pmd_mkold(pmd_t pmd)
+{
+ return pte_pmd(pte_mkold(pmd_pte(pmd)));
+}
+
+static inline pmd_t pmd_mkyoung(pmd_t pmd)
+{
+ return pte_pmd(pte_mkyoung(pmd_pte(pmd)));
+}
+
+static inline pmd_t pmd_mkwrite(pmd_t pmd)
+{
+ return pte_pmd(pte_mkwrite(pmd_pte(pmd)));
+}
+
+static inline pmd_t pmd_wrprotect(pmd_t pmd)
+{
+ return pte_pmd(pte_wrprotect(pmd_pte(pmd)));
+}
+
+static inline pmd_t pmd_mkclean(pmd_t pmd)
+{
+ return pte_pmd(pte_mkclean(pmd_pte(pmd)));
+}
+
+static inline pmd_t pmd_mkdirty(pmd_t pmd)
+{
+ return pte_pmd(pte_mkdirty(pmd_pte(pmd)));
+}
+
+static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
+ pmd_t *pmdp, pmd_t pmd)
+{
+ return set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd));
+}
This conflicts with the existing definition recently added in commit
756a8896b6166bba ("riscv: mremap speedup - enable HAVE_MOVE_PUD and
HAVE_MOVE_PMD"):
arch/riscv/include/asm/pgtable.h:579:20: error: redefinition of ‘set_pmd_at’
579 | static inline void set_pmd_at(struct mm_struct *mm,
unsigned long addr,
| ^~~~~~~~~~
arch/riscv/include/asm/pgtable.h:420:20: note: previous definition
of ‘set_pmd_at’ was here
420 | static inline void set_pmd_at(struct mm_struct *mm,
unsigned long addr,
| ^~~~~~~~~~
Sorry about that. I was trying to re-arrange for-next to keep patch
sets on branches to avoid the rebasing like we had last time, but that
makes merges like this more of a headache and just makes the whole thing
a bit clunky.
I've fixed this up, along with just making the history linear again.
Thanks!
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static inline int pmd_trans_huge(pmd_t pmd)
+{
+ return pmd_leaf(pmd);
+}
+
+#define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
+static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
+ unsigned long address, pmd_t *pmdp,
+ pmd_t entry, int dirty)
+{
+ return ptep_set_access_flags(vma, address, (pte_t *)pmdp, pmd_pte(entry), dirty);
+}
+
+#define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
+static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
+ unsigned long address, pmd_t *pmdp)
+{
+ return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
+}
+
+#define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
+static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
+ unsigned long address, pmd_t *pmdp)
+{
+ return pte_pmd(ptep_get_and_clear(mm, address, (pte_t *)pmdp));
+}
+
+#define __HAVE_ARCH_PMDP_SET_WRPROTECT
+static inline void pmdp_set_wrprotect(struct mm_struct *mm,
+ unsigned long address, pmd_t *pmdp)
+{
+ ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
+}
+
+#define pmdp_establish pmdp_establish
+static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
+ unsigned long address, pmd_t *pmdp, pmd_t pmd)
+{
+ return __pmd(atomic_long_xchg((atomic_long_t *)pmdp, pmd_val(pmd)));
+}
+
+#define __HAVE_ARCH_FLUSH_PMD_TLB_RANGE
+void flush_pmd_tlb_range(struct vm_area_struct *vma, unsigned long start,
+ unsigned long end);
+
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
/*
* Encode and decode a swap entry
*
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds