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sparc64: use the generic get_user_pages_fast code

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The sparc64 code is mostly equivalent to the generic one, minus various
bugfixes and two arch overrides that this patch adds to pgtable.h.

Link: http://lkml.kernel.org/r/20190625143715.1689-10-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Cc: David Miller <davem@davemloft.net>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Christoph Hellwig 2019-07-11 20:57:11 -07:00 committed by Linus Torvalds
parent 5875509d2f
commit 7b9afb86b6
4 changed files with 20 additions and 341 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/sparc/Kconfig
View File

@ -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

18
arch/sparc/include/asm/pgtable_64.h
View File

@ -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>

2
arch/sparc/mm/Makefile
View File

@ -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

340
arch/sparc/mm/gup.c
View File

@ -1,340 +0,0 @@
// 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;
}
}