On Sat, Sep 19, 2020 at 03:47:31PM +0800, Huang Pei wrote: Ping? > MIPS page fault path take 3 exceptions (1 TLB Miss + 2 TLB Invalid), but > the second TLB Invalid exception is just triggered by __update_tlb from > do_page_fault writing tlb without _PAGE_VALID set. With this patch, it > only take 1 TLB Miss + 1 TLB Invalid exceptions > > This version removes pte_sw_mkyoung without polluting MM code and makes > page fault delay of MIPS on par with other architecture and covers both > no-RIXI and RIXI MIPS CPUS > > [1]: https://lkml.kernel.org/lkml/1591416169-26666-1-git-send-email > -maobibo@xxxxxxxxxxx/ > --- > V3: > - reformat with whitespace cleaned up following Thomas's advice > V2: > - remove unused asm-generic definition of pte_sw_mkyoung following Mao's > advice > --- > Co-developed-by: Huang Pei <huangpei@xxxxxxxxxxx> > Signed-off-by: Huang Pei <huangpei@xxxxxxxxxxx> > Co-developed-by: Bibo Mao <maobibo@xxxxxxxxxx> > --- > arch/mips/include/asm/pgtable.h | 10 ++++------ > arch/mips/mm/cache.c | 25 +++++++++++++------------ > include/linux/pgtable.h | 8 -------- > mm/memory.c | 3 --- > 4 files changed, 17 insertions(+), 29 deletions(-) > > diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h > index dd7a0f552cac..931fb35730f0 100644 > --- a/arch/mips/include/asm/pgtable.h > +++ b/arch/mips/include/asm/pgtable.h > @@ -27,11 +27,11 @@ struct vm_area_struct; > > #define PAGE_NONE __pgprot(_PAGE_PRESENT | _PAGE_NO_READ | \ > _page_cachable_default) > -#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_WRITE | \ > - _page_cachable_default) > +#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_WRITE | \ > + __READABLE | _page_cachable_default) > #define PAGE_COPY __pgprot(_PAGE_PRESENT | _PAGE_NO_EXEC | \ > - _page_cachable_default) > -#define PAGE_READONLY __pgprot(_PAGE_PRESENT | \ > + __READABLE | _page_cachable_default) > +#define PAGE_READONLY __pgprot(_PAGE_PRESENT | __READABLE | \ > _page_cachable_default) > #define PAGE_KERNEL __pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \ > _PAGE_GLOBAL | _page_cachable_default) > @@ -414,8 +414,6 @@ static inline pte_t pte_mkyoung(pte_t pte) > return pte; > } > > -#define pte_sw_mkyoung pte_mkyoung > - > #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT > static inline int pte_huge(pte_t pte) { return pte_val(pte) & _PAGE_HUGE; } > > diff --git a/arch/mips/mm/cache.c b/arch/mips/mm/cache.c > index 3e81ba000096..ed75f2871aad 100644 > --- a/arch/mips/mm/cache.c > +++ b/arch/mips/mm/cache.c > @@ -159,22 +159,23 @@ static inline void setup_protection_map(void) > { > if (cpu_has_rixi) { > protection_map[0] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ); > - protection_map[1] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC); > + protection_map[1] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE); > protection_map[2] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ); > - protection_map[3] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC); > - protection_map[4] = __pgprot(_page_cachable_default | _PAGE_PRESENT); > - protection_map[5] = __pgprot(_page_cachable_default | _PAGE_PRESENT); > - protection_map[6] = __pgprot(_page_cachable_default | _PAGE_PRESENT); > - protection_map[7] = __pgprot(_page_cachable_default | _PAGE_PRESENT); > + protection_map[3] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE); > + protection_map[4] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE); > + protection_map[5] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE); > + protection_map[6] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE); > + protection_map[7] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE); > > protection_map[8] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ); > - protection_map[9] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC); > + protection_map[9] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE); > protection_map[10] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE | _PAGE_NO_READ); > - protection_map[11] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE); > - protection_map[12] = __pgprot(_page_cachable_default | _PAGE_PRESENT); > - protection_map[13] = __pgprot(_page_cachable_default | _PAGE_PRESENT); > - protection_map[14] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_WRITE); > - protection_map[15] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_WRITE); > + protection_map[11] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE | __READABLE); > + protection_map[12] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE); > + protection_map[13] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE); > + protection_map[14] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE); > + protection_map[15] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE); > + > > } else { > protection_map[0] = PAGE_NONE; > diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h > index e8cbc2e795d5..ef9c5fa8673e 100644 > --- a/include/linux/pgtable.h > +++ b/include/linux/pgtable.h > @@ -377,14 +377,6 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres > * To be differentiate with macro pte_mkyoung, this macro is used on platforms > * where software maintains page access bit. > */ > -#ifndef pte_sw_mkyoung > -static inline pte_t pte_sw_mkyoung(pte_t pte) > -{ > - return pte; > -} > -#define pte_sw_mkyoung pte_sw_mkyoung > -#endif > - > #ifndef pte_savedwrite > #define pte_savedwrite pte_write > #endif > diff --git a/mm/memory.c b/mm/memory.c > index 602f4283122f..5100ab5bcf77 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -2705,7 +2705,6 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf) > } > flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte)); > entry = mk_pte(new_page, vma->vm_page_prot); > - entry = pte_sw_mkyoung(entry); > entry = maybe_mkwrite(pte_mkdirty(entry), vma); > /* > * Clear the pte entry and flush it first, before updating the > @@ -3386,7 +3385,6 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf) > __SetPageUptodate(page); > > entry = mk_pte(page, vma->vm_page_prot); > - entry = pte_sw_mkyoung(entry); > if (vma->vm_flags & VM_WRITE) > entry = pte_mkwrite(pte_mkdirty(entry)); > > @@ -3661,7 +3659,6 @@ vm_fault_t alloc_set_pte(struct vm_fault *vmf, struct page *page) > > flush_icache_page(vma, page); > entry = mk_pte(page, vma->vm_page_prot); > - entry = pte_sw_mkyoung(entry); > if (write) > entry = maybe_mkwrite(pte_mkdirty(entry), vma); > /* copy-on-write page */ > -- > 2.17.1 >
