linux/arch/arm/mm/proc-v7-3level.S
Jianguo Wu 86f40622af ARM: 8037/1: mm: support big-endian page tables
When enable LPAE and big-endian in a hisilicon board, while specify
mem=384M mem=512M@7680M, will get bad page state:

Freeing unused kernel memory: 180K (c0466000 - c0493000)
BUG: Bad page state in process init  pfn:fa442
page:c7749840 count:0 mapcount:-1 mapping:  (null) index:0x0
page flags: 0x40000400(reserved)
Modules linked in:
CPU: 0 PID: 1 Comm: init Not tainted 3.10.27+ #66
[<c000f5f0>] (unwind_backtrace+0x0/0x11c) from [<c000cbc4>] (show_stack+0x10/0x14)
[<c000cbc4>] (show_stack+0x10/0x14) from [<c009e448>] (bad_page+0xd4/0x104)
[<c009e448>] (bad_page+0xd4/0x104) from [<c009e520>] (free_pages_prepare+0xa8/0x14c)
[<c009e520>] (free_pages_prepare+0xa8/0x14c) from [<c009f8ec>] (free_hot_cold_page+0x18/0xf0)
[<c009f8ec>] (free_hot_cold_page+0x18/0xf0) from [<c00b5444>] (handle_pte_fault+0xcf4/0xdc8)
[<c00b5444>] (handle_pte_fault+0xcf4/0xdc8) from [<c00b6458>] (handle_mm_fault+0xf4/0x120)
[<c00b6458>] (handle_mm_fault+0xf4/0x120) from [<c0013754>] (do_page_fault+0xfc/0x354)
[<c0013754>] (do_page_fault+0xfc/0x354) from [<c0008400>] (do_DataAbort+0x2c/0x90)
[<c0008400>] (do_DataAbort+0x2c/0x90) from [<c0008fb4>] (__dabt_usr+0x34/0x40)

The bad pfn:fa442 is not system memory(mem=384M mem=512M@7680M), after debugging,
I find in page fault handler, will get wrong pfn from pte just after set pte,
as follow:
do_anonymous_page()
{
	...
	set_pte_at(mm, address, page_table, entry);

	//debug code
	pfn = pte_pfn(entry);
	pr_info("pfn:0x%lx, pte:0x%llxn", pfn, pte_val(entry));

	//read out the pte just set
	new_pte = pte_offset_map(pmd, address);
	new_pfn = pte_pfn(*new_pte);
	pr_info("new pfn:0x%lx, new pte:0x%llxn", pfn, pte_val(entry));
	...
}

pfn:   0x1fa4f5,     pte:0xc00001fa4f575f
new_pfn:0xfa4f5, new_pte:0xc00000fa4f5f5f	//new pfn/pte is wrong.

The bug is happened in cpu_v7_set_pte_ext(ptep, pte):
An LPAE PTE is a 64bit quantity, passed to cpu_v7_set_pte_ext in the r2 and r3 registers.
On an LE kernel, r2 contains the LSB of the PTE, and r3 the MSB.
On a BE kernel, the assignment is reversed.

Unfortunately, the current code always assumes the LE case,
leading to corruption of the PTE when clearing/setting bits.

This patch fixes this issue much like it has been done already in the
cpu_v7_switch_mm case.

CC stable <stable@vger.kernel.org>

Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-04-25 12:06:59 +01:00

162 lines
4.6 KiB
ArmAsm

/*
* arch/arm/mm/proc-v7-3level.S
*
* Copyright (C) 2001 Deep Blue Solutions Ltd.
* Copyright (C) 2011 ARM Ltd.
* Author: Catalin Marinas <catalin.marinas@arm.com>
* based on arch/arm/mm/proc-v7-2level.S
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#define TTB_IRGN_NC (0 << 8)
#define TTB_IRGN_WBWA (1 << 8)
#define TTB_IRGN_WT (2 << 8)
#define TTB_IRGN_WB (3 << 8)
#define TTB_RGN_NC (0 << 10)
#define TTB_RGN_OC_WBWA (1 << 10)
#define TTB_RGN_OC_WT (2 << 10)
#define TTB_RGN_OC_WB (3 << 10)
#define TTB_S (3 << 12)
#define TTB_EAE (1 << 31)
/* PTWs cacheable, inner WB not shareable, outer WB not shareable */
#define TTB_FLAGS_UP (TTB_IRGN_WB|TTB_RGN_OC_WB)
#define PMD_FLAGS_UP (PMD_SECT_WB)
/* PTWs cacheable, inner WBWA shareable, outer WBWA not shareable */
#define TTB_FLAGS_SMP (TTB_IRGN_WBWA|TTB_S|TTB_RGN_OC_WBWA)
#define PMD_FLAGS_SMP (PMD_SECT_WBWA|PMD_SECT_S)
#ifndef __ARMEB__
# define rpgdl r0
# define rpgdh r1
#else
# define rpgdl r1
# define rpgdh r0
#endif
/*
* cpu_v7_switch_mm(pgd_phys, tsk)
*
* Set the translation table base pointer to be pgd_phys (physical address of
* the new TTB).
*/
ENTRY(cpu_v7_switch_mm)
#ifdef CONFIG_MMU
mmid r2, r2
asid r2, r2
orr rpgdh, rpgdh, r2, lsl #(48 - 32) @ upper 32-bits of pgd
mcrr p15, 0, rpgdl, rpgdh, c2 @ set TTB 0
isb
#endif
mov pc, lr
ENDPROC(cpu_v7_switch_mm)
#ifdef __ARMEB__
#define rl r3
#define rh r2
#else
#define rl r2
#define rh r3
#endif
/*
* cpu_v7_set_pte_ext(ptep, pte)
*
* Set a level 2 translation table entry.
* - ptep - pointer to level 3 translation table entry
* - pte - PTE value to store (64-bit in r2 and r3)
*/
ENTRY(cpu_v7_set_pte_ext)
#ifdef CONFIG_MMU
tst rl, #L_PTE_VALID
beq 1f
tst rh, #1 << (57 - 32) @ L_PTE_NONE
bicne rl, #L_PTE_VALID
bne 1f
tst rh, #1 << (55 - 32) @ L_PTE_DIRTY
orreq rl, #L_PTE_RDONLY
1: strd r2, r3, [r0]
ALT_SMP(W(nop))
ALT_UP (mcr p15, 0, r0, c7, c10, 1) @ flush_pte
#endif
mov pc, lr
ENDPROC(cpu_v7_set_pte_ext)
/*
* Memory region attributes for LPAE (defined in pgtable-3level.h):
*
* n = AttrIndx[2:0]
*
* n MAIR
* UNCACHED 000 00000000
* BUFFERABLE 001 01000100
* DEV_WC 001 01000100
* WRITETHROUGH 010 10101010
* WRITEBACK 011 11101110
* DEV_CACHED 011 11101110
* DEV_SHARED 100 00000100
* DEV_NONSHARED 100 00000100
* unused 101
* unused 110
* WRITEALLOC 111 11111111
*/
.equ PRRR, 0xeeaa4400 @ MAIR0
.equ NMRR, 0xff000004 @ MAIR1
/*
* Macro for setting up the TTBRx and TTBCR registers.
* - \ttbr1 updated.
*/
.macro v7_ttb_setup, zero, ttbr0, ttbr1, tmp
ldr \tmp, =swapper_pg_dir @ swapper_pg_dir virtual address
mov \tmp, \tmp, lsr #ARCH_PGD_SHIFT
cmp \ttbr1, \tmp @ PHYS_OFFSET > PAGE_OFFSET?
mrc p15, 0, \tmp, c2, c0, 2 @ TTB control register
orr \tmp, \tmp, #TTB_EAE
ALT_SMP(orr \tmp, \tmp, #TTB_FLAGS_SMP)
ALT_UP(orr \tmp, \tmp, #TTB_FLAGS_UP)
ALT_SMP(orr \tmp, \tmp, #TTB_FLAGS_SMP << 16)
ALT_UP(orr \tmp, \tmp, #TTB_FLAGS_UP << 16)
/*
* Only use split TTBRs if PHYS_OFFSET <= PAGE_OFFSET (cmp above),
* otherwise booting secondary CPUs would end up using TTBR1 for the
* identity mapping set up in TTBR0.
*/
orrls \tmp, \tmp, #TTBR1_SIZE @ TTBCR.T1SZ
mcr p15, 0, \tmp, c2, c0, 2 @ TTBCR
mov \tmp, \ttbr1, lsr #(32 - ARCH_PGD_SHIFT) @ upper bits
mov \ttbr1, \ttbr1, lsl #ARCH_PGD_SHIFT @ lower bits
addls \ttbr1, \ttbr1, #TTBR1_OFFSET
mcrr p15, 1, \ttbr1, \zero, c2 @ load TTBR1
mov \tmp, \ttbr0, lsr #(32 - ARCH_PGD_SHIFT) @ upper bits
mov \ttbr0, \ttbr0, lsl #ARCH_PGD_SHIFT @ lower bits
mcrr p15, 0, \ttbr0, \zero, c2 @ load TTBR0
mcrr p15, 1, \ttbr1, \zero, c2 @ load TTBR1
mcrr p15, 0, \ttbr0, \zero, c2 @ load TTBR0
.endm
/*
* AT
* TFR EV X F IHD LR S
* .EEE ..EE PUI. .TAT 4RVI ZWRS BLDP WCAM
* rxxx rrxx xxx0 0101 xxxx xxxx x111 xxxx < forced
* 11 0 110 1 0011 1100 .111 1101 < we want
*/
.align 2
.type v7_crval, #object
v7_crval:
crval clear=0x0120c302, mmuset=0x30c23c7d, ucset=0x00c01c7c