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um: add support for folded p4d page tables 

The UML port uses 4 and 5 level fixups to support higher level page
table directories in the generic VM code.

Implement primitives necessary for the 4th level folding, add walks of
p4d level where appropriate and drop usage of __ARCH_USE_5LEVEL_HACK.

Link: http://lkml.kernel.org/r/1572938135-31886-13-git-send-email-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Anatoly Pugachev <matorola@gmail.com>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Peter Rosin <peda@axentia.se>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rolf Eike Beer <eike-kernel@sf-tec.de>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Sam Creasey <sammy@sammy.net>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Mike Rapoport 2019-12-04 16:54:28 -08:00 committed by Linus Torvalds
parent 4e65e76f1e
commit e19f97ed67
8 changed files with 78 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/um/include/asm/pgtable-2level.h
View File

@ -8,7 +8,6 @@
#ifndef __UM_PGTABLE_2LEVEL_H
#define __UM_PGTABLE_2LEVEL_H
#define __ARCH_USE_5LEVEL_HACK
#include <asm-generic/pgtable-nopmd.h>
/* PGDIR_SHIFT determines what a third-level page table entry can map */

1
arch/um/include/asm/pgtable-3level.h
View File

@ -7,7 +7,6 @@
#ifndef __UM_PGTABLE_3LEVEL_H
#define __UM_PGTABLE_3LEVEL_H
#define __ARCH_USE_5LEVEL_HACK
#include <asm-generic/pgtable-nopud.h>
/* PGDIR_SHIFT determines what a third-level page table entry can map */

3
arch/um/include/asm/pgtable.h
View File

@ -106,6 +106,9 @@ extern unsigned long end_iomem;
#define pud_newpage(x) (pud_val(x) & _PAGE_NEWPAGE)
#define pud_mkuptodate(x) (pud_val(x) &= ~_PAGE_NEWPAGE)
#define p4d_newpage(x) (p4d_val(x) & _PAGE_NEWPAGE)
#define p4d_mkuptodate(x) (p4d_val(x) &= ~_PAGE_NEWPAGE)
#define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK)
#define pte_page(x) pfn_to_page(pte_pfn(x))

8
arch/um/kernel/mem.c
View File

@ -96,6 +96,7 @@ static void __init fixrange_init(unsigned long start, unsigned long end,
pgd_t *pgd_base)
{
pgd_t *pgd;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
int i, j;
@ -107,7 +108,8 @@ static void __init fixrange_init(unsigned long start, unsigned long end,
pgd = pgd_base + i;
for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
pud = pud_offset(pgd, vaddr);
p4d = p4d_offset(pgd, vaddr);
pud = pud_offset(p4d, vaddr);
if (pud_none(*pud))
one_md_table_init(pud);
pmd = pmd_offset(pud, vaddr);
@ -124,6 +126,7 @@ static void __init fixaddr_user_init( void)
#ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
long size = FIXADDR_USER_END - FIXADDR_USER_START;
pgd_t *pgd;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
@ -144,7 +147,8 @@ static void __init fixaddr_user_init( void)
for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE,
p += PAGE_SIZE) {
pgd = swapper_pg_dir + pgd_index(vaddr);
pud = pud_offset(pgd, vaddr);
p4d = p4d_offset(pgd, vaddr);
pud = pud_offset(p4d, vaddr);
pmd = pmd_offset(pud, vaddr);
pte = pte_offset_kernel(pmd, vaddr);
pte_set_val(*pte, p, PAGE_READONLY);

12
arch/um/kernel/skas/mmu.c
View File

@ -19,15 +19,21 @@ static int init_stub_pte(struct mm_struct *mm, unsigned long proc,
unsigned long kernel)
{
pgd_t *pgd;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
pgd = pgd_offset(mm, proc);
pud = pud_alloc(mm, pgd, proc);
if (!pud)
p4d = p4d_alloc(mm, pgd, proc);
if (!p4d)
goto out;
pud = pud_alloc(mm, p4d, proc);
if (!pud)
goto out_pud;
pmd = pmd_alloc(mm, pud, proc);
if (!pmd)
goto out_pmd;
@ -44,6 +50,8 @@ static int init_stub_pte(struct mm_struct *mm, unsigned long proc,
pmd_free(mm, pmd);
out_pmd:
pud_free(mm, pud);
out_pud:
p4d_free(mm, p4d);
out:
return -ENOMEM;
}

7
arch/um/kernel/skas/uaccess.c
View File

@ -17,6 +17,7 @@
pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr)
{
pgd_t *pgd;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
@ -27,7 +28,11 @@ pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr)
if (!pgd_present(*pgd))
return NULL;
pud = pud_offset(pgd, addr);
p4d = p4d_offset(pgd, addr);
if (!p4d_present(*p4d))
return NULL;
pud = pud_offset(p4d, addr);
if (!pud_present(*pud))
return NULL;

56
arch/um/kernel/tlb.c
View File

@ -277,7 +277,7 @@ static inline int update_pmd_range(pud_t *pud, unsigned long addr,
return ret;
}
static inline int update_pud_range(pgd_t *pgd, unsigned long addr,
static inline int update_pud_range(p4d_t *p4d, unsigned long addr,
unsigned long end,
struct host_vm_change *hvc)
{
@ -285,7 +285,7 @@ static inline int update_pud_range(pgd_t *pgd, unsigned long addr,
unsigned long next;
int ret = 0;
pud = pud_offset(pgd, addr);
pud = pud_offset(p4d, addr);
do {
next = pud_addr_end(addr, end);
if (!pud_present(*pud)) {
@ -299,6 +299,28 @@ static inline int update_pud_range(pgd_t *pgd, unsigned long addr,
return ret;
}
static inline int update_p4d_range(pgd_t *pgd, unsigned long addr,
unsigned long end,
struct host_vm_change *hvc)
{
p4d_t *p4d;
unsigned long next;
int ret = 0;
p4d = p4d_offset(pgd, addr);
do {
next = p4d_addr_end(addr, end);
if (!p4d_present(*p4d)) {
if (hvc->force || p4d_newpage(*p4d)) {
ret = add_munmap(addr, next - addr, hvc);
p4d_mkuptodate(*p4d);
}
} else
ret = update_pud_range(p4d, addr, next, hvc);
} while (p4d++, addr = next, ((addr < end) && !ret));
return ret;
}
void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
unsigned long end_addr, int force)
{
@ -316,8 +338,8 @@ void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
ret = add_munmap(addr, next - addr, &hvc);
pgd_mkuptodate(*pgd);
}
}
else ret = update_pud_range(pgd, addr, next, &hvc);
} else
ret = update_p4d_range(pgd, addr, next, &hvc);
} while (pgd++, addr = next, ((addr < end_addr) && !ret));
if (!ret)
@ -338,6 +360,7 @@ static int flush_tlb_kernel_range_common(unsigned long start, unsigned long end)
{
struct mm_struct *mm;
pgd_t *pgd;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
@ -364,7 +387,23 @@ static int flush_tlb_kernel_range_common(unsigned long start, unsigned long end)
continue;
}
pud = pud_offset(pgd, addr);
p4d = p4d_offset(pgd, addr);
if (!p4d_present(*p4d)) {
last = ADD_ROUND(addr, P4D_SIZE);
if (last > end)
last = end;
if (p4d_newpage(*p4d)) {
updated = 1;
err = add_munmap(addr, last - addr, &hvc);
if (err < 0)
panic("munmap failed, errno = %d\n",
-err);
}
addr = last;
continue;
}
pud = pud_offset(p4d, addr);
if (!pud_present(*pud)) {
last = ADD_ROUND(addr, PUD_SIZE);
if (last > end)
@ -424,6 +463,7 @@ static int flush_tlb_kernel_range_common(unsigned long start, unsigned long end)
void flush_tlb_page(struct vm_area_struct *vma, unsigned long address)
{
pgd_t *pgd;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
@ -437,7 +477,11 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned long address)
if (!pgd_present(*pgd))
goto kill;
pud = pud_offset(pgd, address);
p4d = p4d_offset(pgd, address);
if (!p4d_present(*p4d))
goto kill;
pud = pud_offset(p4d, address);
if (!pud_present(*pud))
goto kill;

4
arch/um/kernel/trap.c
View File

@ -28,6 +28,7 @@ int handle_page_fault(unsigned long address, unsigned long ip,
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
pgd_t *pgd;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
@ -104,7 +105,8 @@ int handle_page_fault(unsigned long address, unsigned long ip,
}
pgd = pgd_offset(mm, address);
pud = pud_offset(pgd, address);
p4d = p4d_offset(pgd, address);
pud = pud_offset(p4d, address);
pmd = pmd_offset(pud, address);
pte = pte_offset_kernel(pmd, address);
} while (!pte_present(*pte));