sparc64: use the generic get_user_pages_fast code (7b9afb86) · Commits · 戴 / test

arch/sparc/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -28,6 +28,7 @@ config SPARC
		select RTC_DRV_M48T59
		select RTC_SYSTOHC
		select HAVE_ARCH_JUMP_LABEL if SPARC64
		select HAVE_GENERIC_GUP if SPARC64
		select GENERIC_IRQ_SHOW
		select ARCH_WANT_IPC_PARSE_VERSION
		select GENERIC_PCI_IOMAP

arch/sparc/include/asm/pgtable_64.h

+18 −0

Original line number	Diff line number	Diff line
		@@ -1100,6 +1100,24 @@ static inline unsigned long untagged_addr(unsigned long start)
		}
		#define untagged_addr untagged_addr

		static inline bool pte_access_permitted(pte_t pte, bool write)
		{
		u64 prot;

		if (tlb_type == hypervisor) {
		prot = _PAGE_PRESENT_4V \| _PAGE_P_4V;
		if (write)
		prot \|= _PAGE_WRITE_4V;
		} else {
		prot = _PAGE_PRESENT_4U \| _PAGE_P_4U;
		if (write)
		prot \|= _PAGE_WRITE_4U;
		}

		return (pte_val(pte) & (prot \| _PAGE_SPECIAL)) == prot;
		}
		#define pte_access_permitted pte_access_permitted

		#include <asm/tlbflush.h>
		#include <asm-generic/pgtable.h>

arch/sparc/mm/Makefile

+1 −1

Original line number	Diff line number	Diff line
		@@ -5,7 +5,7 @@
		asflags-y := -ansi
		ccflags-y := -Werror

		obj-$(CONFIG_SPARC64) += ultra.o tlb.o tsb.o gup.o
		obj-$(CONFIG_SPARC64) += ultra.o tlb.o tsb.o
		obj-y += fault_$(BITS).o
		obj-y += init_$(BITS).o
		obj-$(CONFIG_SPARC32) += extable.o srmmu.o iommu.o io-unit.o

arch/sparc/mm/gup.c

deleted100644 → 0

+0 −340

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0
		/*
		* Lockless get_user_pages_fast for sparc, cribbed from powerpc
		*
		* Copyright (C) 2008 Nick Piggin
		* Copyright (C) 2008 Novell Inc.
		*/

		#include <linux/sched.h>
		#include <linux/mm.h>
		#include <linux/vmstat.h>
		#include <linux/pagemap.h>
		#include <linux/rwsem.h>
		#include <asm/pgtable.h>
		#include <asm/adi.h>

		/*
		* The performance critical leaf functions are made noinline otherwise gcc
		* inlines everything into a single function which results in too much
		* register pressure.
		*/
		static noinline int gup_pte_range(pmd_t pmd, unsigned long addr,
		unsigned long end, int write, struct page *pages, int nr)
		{
		unsigned long mask, result;
		pte_t *ptep;

		if (tlb_type == hypervisor) {
		result = _PAGE_PRESENT_4V\|_PAGE_P_4V;
		if (write)
		result \|= _PAGE_WRITE_4V;
		} else {
		result = _PAGE_PRESENT_4U\|_PAGE_P_4U;
		if (write)
		result \|= _PAGE_WRITE_4U;
		}
		mask = result \| _PAGE_SPECIAL;

		ptep = pte_offset_kernel(&pmd, addr);
		do {
		struct page page, head;
		pte_t pte = *ptep;

		if ((pte_val(pte) & mask) != result)
		return 0;
		VM_BUG_ON(!pfn_valid(pte_pfn(pte)));

		/* The hugepage case is simplified on sparc64 because
		* we encode the sub-page pfn offsets into the
		* hugepage PTEs. We could optimize this in the future
		* use page_cache_add_speculative() for the hugepage case.
		*/
		page = pte_page(pte);
		head = compound_head(page);
		if (!page_cache_get_speculative(head))
		return 0;
		if (unlikely(pte_val(pte) != pte_val(*ptep))) {
		put_page(head);
		return 0;
		}

		pages[*nr] = page;
		(*nr)++;
		} while (ptep++, addr += PAGE_SIZE, addr != end);

		return 1;
		}

		static int gup_huge_pmd(pmd_t *pmdp, pmd_t pmd, unsigned long addr,
		unsigned long end, int write, struct page **pages,
		int *nr)
		{
		struct page head, page;
		int refs;

		if (!(pmd_val(pmd) & _PAGE_VALID))
		return 0;

		if (write && !pmd_write(pmd))
		return 0;

		refs = 0;
		page = pmd_page(pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
		head = compound_head(page);
		do {
		VM_BUG_ON(compound_head(page) != head);
		pages[*nr] = page;
		(*nr)++;
		page++;
		refs++;
		} while (addr += PAGE_SIZE, addr != end);

		if (!page_cache_add_speculative(head, refs)) {
		*nr -= refs;
		return 0;
		}

		if (unlikely(pmd_val(pmd) != pmd_val(*pmdp))) {
		*nr -= refs;
		while (refs--)
		put_page(head);
		return 0;
		}

		return 1;
		}

		static int gup_huge_pud(pud_t *pudp, pud_t pud, unsigned long addr,
		unsigned long end, int write, struct page **pages,
		int *nr)
		{
		struct page head, page;
		int refs;

		if (!(pud_val(pud) & _PAGE_VALID))
		return 0;

		if (write && !pud_write(pud))
		return 0;

		refs = 0;
		page = pud_page(pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
		head = compound_head(page);
		do {
		VM_BUG_ON(compound_head(page) != head);
		pages[*nr] = page;
		(*nr)++;
		page++;
		refs++;
		} while (addr += PAGE_SIZE, addr != end);

		if (!page_cache_add_speculative(head, refs)) {
		*nr -= refs;
		return 0;
		}

		if (unlikely(pud_val(pud) != pud_val(*pudp))) {
		*nr -= refs;
		while (refs--)
		put_page(head);
		return 0;
		}

		return 1;
		}

		static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end,
		int write, struct page *pages, int nr)
		{
		unsigned long next;
		pmd_t *pmdp;

		pmdp = pmd_offset(&pud, addr);
		do {
		pmd_t pmd = *pmdp;

		next = pmd_addr_end(addr, end);
		if (pmd_none(pmd))
		return 0;
		if (unlikely(pmd_large(pmd))) {
		if (!gup_huge_pmd(pmdp, pmd, addr, next,
		write, pages, nr))
		return 0;
		} else if (!gup_pte_range(pmd, addr, next, write,
		pages, nr))
		return 0;
		} while (pmdp++, addr = next, addr != end);

		return 1;
		}

		static int gup_pud_range(pgd_t pgd, unsigned long addr, unsigned long end,
		int write, struct page *pages, int nr)
		{
		unsigned long next;
		pud_t *pudp;

		pudp = pud_offset(&pgd, addr);
		do {
		pud_t pud = *pudp;

		next = pud_addr_end(addr, end);
		if (pud_none(pud))
		return 0;
		if (unlikely(pud_large(pud))) {
		if (!gup_huge_pud(pudp, pud, addr, next,
		write, pages, nr))
		return 0;
		} else if (!gup_pmd_range(pud, addr, next, write, pages, nr))
		return 0;
		} while (pudp++, addr = next, addr != end);

		return 1;
		}

		/*
		* Note a difference with get_user_pages_fast: this always returns the
		* number of pages pinned, 0 if no pages were pinned.
		*/
		int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
		struct page **pages)
		{
		struct mm_struct *mm = current->mm;
		unsigned long addr, len, end;
		unsigned long next, flags;
		pgd_t *pgdp;
		int nr = 0;

		#ifdef CONFIG_SPARC64
		if (adi_capable()) {
		long addr = start;

		/* If userspace has passed a versioned address, kernel
		* will not find it in the VMAs since it does not store
		* the version tags in the list of VMAs. Storing version
		* tags in list of VMAs is impractical since they can be
		* changed any time from userspace without dropping into
		* kernel. Any address search in VMAs will be done with
		* non-versioned addresses. Ensure the ADI version bits
		* are dropped here by sign extending the last bit before
		* ADI bits. IOMMU does not implement version tags.
		*/
		addr = (addr << (long)adi_nbits()) >> (long)adi_nbits();
		start = addr;
		}
		#endif
		start &= PAGE_MASK;
		addr = start;
		len = (unsigned long) nr_pages << PAGE_SHIFT;
		end = start + len;

		local_irq_save(flags);
		pgdp = pgd_offset(mm, addr);
		do {
		pgd_t pgd = *pgdp;

		next = pgd_addr_end(addr, end);
		if (pgd_none(pgd))
		break;
		if (!gup_pud_range(pgd, addr, next, write, pages, &nr))
		break;
		} while (pgdp++, addr = next, addr != end);
		local_irq_restore(flags);

		return nr;
		}

		int get_user_pages_fast(unsigned long start, int nr_pages,
		unsigned int gup_flags, struct page **pages)
		{
		struct mm_struct *mm = current->mm;
		unsigned long addr, len, end;
		unsigned long next;
		pgd_t *pgdp;
		int nr = 0;

		#ifdef CONFIG_SPARC64
		if (adi_capable()) {
		long addr = start;

		/* If userspace has passed a versioned address, kernel
		* will not find it in the VMAs since it does not store
		* the version tags in the list of VMAs. Storing version
		* tags in list of VMAs is impractical since they can be
		* changed any time from userspace without dropping into
		* kernel. Any address search in VMAs will be done with
		* non-versioned addresses. Ensure the ADI version bits
		* are dropped here by sign extending the last bit before
		* ADI bits. IOMMU does not implements version tags,
		*/
		addr = (addr << (long)adi_nbits()) >> (long)adi_nbits();
		start = addr;
		}
		#endif
		start &= PAGE_MASK;
		addr = start;
		len = (unsigned long) nr_pages << PAGE_SHIFT;
		end = start + len;

		/*
		* XXX: batch / limit 'nr', to avoid large irq off latency
		* needs some instrumenting to determine the common sizes used by
		* important workloads (eg. DB2), and whether limiting the batch size
		* will decrease performance.
		*
		* It seems like we're in the clear for the moment. Direct-IO is
		* the main guy that batches up lots of get_user_pages, and even
		* they are limited to 64-at-a-time which is not so many.
		*/
		/*
		* This doesn't prevent pagetable teardown, but does prevent
		* the pagetables from being freed on sparc.
		*
		* So long as we atomically load page table pointers versus teardown,
		* we can follow the address down to the the page and take a ref on it.
		*/
		local_irq_disable();

		pgdp = pgd_offset(mm, addr);
		do {
		pgd_t pgd = *pgdp;

		next = pgd_addr_end(addr, end);
		if (pgd_none(pgd))
		goto slow;
		if (!gup_pud_range(pgd, addr, next, gup_flags & FOLL_WRITE,
		pages, &nr))
		goto slow;
		} while (pgdp++, addr = next, addr != end);

		local_irq_enable();

		VM_BUG_ON(nr != (end - start) >> PAGE_SHIFT);
		return nr;

		{
		int ret;

		slow:
		local_irq_enable();

		/* Try to get the remaining pages with get_user_pages */
		start += nr << PAGE_SHIFT;
		pages += nr;

		ret = get_user_pages_unlocked(start,
		(end - start) >> PAGE_SHIFT, pages,
		gup_flags);

		/* Have to be a bit careful with return values */
		if (nr > 0) {
		if (ret < 0)
		ret = nr;
		else
		ret += nr;
		}

		return ret;
		}
		}

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