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Subject[PATCH v8 09/16] ARM: LPAE: MMU setup for the 3-level page table format
Date
This patch adds the MMU initialisation for the LPAE page table format.
The swapper_pg_dir size with LPAE is 5 rather than 4 pages. A new
proc-v7-3level.S file contains the TTB initialisation, context switch
and PTE setting code with the LPAE. The TTBRx split is based on the
PAGE_OFFSET with TTBR1 used for the kernel mappings. The 36-bit mappings
(supersections) and a few other memory types in mmu.c are conditionally
compiled.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
arch/arm/kernel/head.S | 43 ++++++++++++-
arch/arm/mm/mmu.c | 30 +++++++++
arch/arm/mm/proc-macros.S | 5 +-
arch/arm/mm/proc-v7-3level.S | 149 ++++++++++++++++++++++++++++++++++++++++++
arch/arm/mm/proc-v7.S | 23 +++++--
5 files changed, 239 insertions(+), 11 deletions(-)
create mode 100644 arch/arm/mm/proc-v7-3level.S
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 6ee994c..efa8bdb 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -39,8 +39,14 @@
#error KERNEL_RAM_VADDR must start at 0xXXXX8000
#endif

+#ifdef CONFIG_ARM_LPAE
+ /* LPAE requires an additional page for the PGD */
+#define PG_DIR_SIZE 0x5000
+#define PMD_ORDER 3
+#else
#define PG_DIR_SIZE 0x4000
#define PMD_ORDER 2
+#endif

.globl swapper_pg_dir
.equ swapper_pg_dir, KERNEL_RAM_VADDR - PG_DIR_SIZE
@@ -164,6 +170,25 @@ __create_page_tables:
teq r0, r6
bne 1b

+#ifdef CONFIG_ARM_LPAE
+ /*
+ * Build the PGD table (first level) to point to the PMD table. A PGD
+ * entry is 64-bit wide.
+ */
+ mov r0, r4
+ add r3, r4, #0x1000 @ first PMD table address
+ orr r3, r3, #3 @ PGD block type
+ mov r6, #4 @ PTRS_PER_PGD
+ mov r7, #1 << (55 - 32) @ L_PGD_SWAPPER
+1: str r3, [r0], #4 @ set bottom PGD entry bits
+ str r7, [r0], #4 @ set top PGD entry bits
+ add r3, r3, #0x1000 @ next PMD table
+ subs r6, r6, #1
+ bne 1b
+
+ add r4, r4, #0x1000 @ point to the PMD tables
+#endif
+
ldr r7, [r10, #PROCINFO_MM_MMUFLAGS] @ mm_mmuflags

/*
@@ -219,8 +244,8 @@ __create_page_tables:
#endif

/*
- * Then map boot params address in r2 or
- * the first 1MB of ram if boot params address is not specified.
+ * Then map boot params address in r2 or the first 1MB (2MB with LPAE)
+ * of ram if boot params address is not specified.
*/
mov r0, r2, lsr #SECTION_SHIFT
movs r0, r0, lsl #SECTION_SHIFT
@@ -251,7 +276,13 @@ __create_page_tables:
mov r3, r7, lsr #SECTION_SHIFT
ldr r7, [r10, #PROCINFO_IO_MMUFLAGS] @ io_mmuflags
orr r3, r7, r3, lsl #SECTION_SHIFT
+#ifdef CONFIG_ARM_LPAE
+ mov r7, #1 << (54 - 32) @ XN
+#endif
1: str r3, [r0], #4
+#ifdef CONFIG_ARM_LPAE
+ str r7, [r0], #4
+#endif
add r3, r3, #1 << SECTION_SHIFT
cmp r0, r6
blo 1b
@@ -283,6 +314,9 @@ __create_page_tables:
str r3, [r0]
#endif
#endif
+#ifdef CONFIG_ARM_LPAE
+ sub r4, r4, #0x1000 @ point to the PGD table
+#endif
mov pc, lr
ENDPROC(__create_page_tables)
.ltorg
@@ -374,12 +408,17 @@ __enable_mmu:
#ifdef CONFIG_CPU_ICACHE_DISABLE
bic r0, r0, #CR_I
#endif
+#ifdef CONFIG_ARM_LPAE
+ mov r5, #0
+ mcrr p15, 0, r4, r5, c2 @ load TTBR0
+#else
mov r5, #(domain_val(DOMAIN_USER, DOMAIN_MANAGER) | \
domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \
domain_val(DOMAIN_TABLE, DOMAIN_MANAGER) | \
domain_val(DOMAIN_IO, DOMAIN_CLIENT))
mcr p15, 0, r5, c3, c0, 0 @ load domain access register
mcr p15, 0, r4, c2, c0, 0 @ load page table pointer
+#endif
b __turn_mmu_on
ENDPROC(__enable_mmu)

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index dc8c550..1935311 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -150,6 +150,7 @@ static int __init early_nowrite(char *__unused)
}
early_param("nowb", early_nowrite);

+#ifndef CONFIG_ARM_LPAE
static int __init early_ecc(char *p)
{
if (memcmp(p, "on", 2) == 0)
@@ -159,6 +160,7 @@ static int __init early_ecc(char *p)
return 0;
}
early_param("ecc", early_ecc);
+#endif

static int __init noalign_setup(char *__unused)
{
@@ -228,10 +230,12 @@ static struct mem_type mem_types[] = {
.prot_sect = PMD_TYPE_SECT | PMD_SECT_XN,
.domain = DOMAIN_KERNEL,
},
+#ifndef CONFIG_ARM_LPAE
[MT_MINICLEAN] = {
.prot_sect = PMD_TYPE_SECT | PMD_SECT_XN | PMD_SECT_MINICACHE,
.domain = DOMAIN_KERNEL,
},
+#endif
[MT_LOW_VECTORS] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
L_PTE_RDONLY,
@@ -429,6 +433,7 @@ static void __init build_mem_type_table(void)
* ARMv6 and above have extended page tables.
*/
if (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP)) {
+#ifndef CONFIG_ARM_LPAE
/*
* Mark cache clean areas and XIP ROM read only
* from SVC mode and no access from userspace.
@@ -436,6 +441,7 @@ static void __init build_mem_type_table(void)
mem_types[MT_ROM].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
mem_types[MT_MINICLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
+#endif

if (is_smp()) {
/*
@@ -474,6 +480,18 @@ static void __init build_mem_type_table(void)
mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_BUFFERABLE;
}

+#ifdef CONFIG_ARM_LPAE
+ /*
+ * Do not generate access flag faults for the kernel mappings.
+ */
+ for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
+ mem_types[i].prot_pte |= PTE_EXT_AF;
+ mem_types[i].prot_sect |= PMD_SECT_AF;
+ }
+ kern_pgprot |= PTE_EXT_AF;
+ vecs_pgprot |= PTE_EXT_AF;
+#endif
+
for (i = 0; i < 16; i++) {
unsigned long v = pgprot_val(protection_map[i]);
protection_map[i] = __pgprot(v | user_pgprot);
@@ -572,8 +590,10 @@ static void __init alloc_init_section(pud_t *pud, unsigned long addr,
if (((addr | end | phys) & ~SECTION_MASK) == 0) {
pmd_t *p = pmd;

+#ifndef CONFIG_ARM_LPAE
if (addr & SECTION_SIZE)
pmd++;
+#endif

do {
*pmd = __pmd(phys | type->prot_sect);
@@ -603,6 +623,7 @@ static void alloc_init_pud(pgd_t *pgd, unsigned long addr, unsigned long end,
} while (pud++, addr = next, addr != end);
}

+#ifndef CONFIG_ARM_LPAE
static void __init create_36bit_mapping(struct map_desc *md,
const struct mem_type *type)
{
@@ -662,6 +683,7 @@ static void __init create_36bit_mapping(struct map_desc *md,
pgd += SUPERSECTION_SIZE >> PGDIR_SHIFT;
} while (addr != end);
}
+#endif /* !CONFIG_ARM_LPAE */

/*
* Create the page directory entries and any necessary
@@ -693,6 +715,7 @@ static void __init create_mapping(struct map_desc *md)

type = &mem_types[md->type];

+#ifndef CONFIG_ARM_LPAE
/*
* Catch 36-bit addresses
*/
@@ -700,6 +723,7 @@ static void __init create_mapping(struct map_desc *md)
create_36bit_mapping(md, type);
return;
}
+#endif

addr = md->virtual & PAGE_MASK;
phys = __pfn_to_phys(md->pfn);
@@ -897,7 +921,13 @@ static inline void prepare_page_table(void)
pmd_clear(pmd_off_k(addr));
}

+#ifdef CONFIG_ARM_LPAE
+/* the first page is reserved for pgd */
+#define SWAPPER_PG_DIR_SIZE (PAGE_SIZE + \
+ PTRS_PER_PGD * PTRS_PER_PMD * sizeof(pmd_t))
+#else
#define SWAPPER_PG_DIR_SIZE (PTRS_PER_PGD * sizeof(pgd_t))
+#endif

/*
* Reserve the special regions of memory
diff --git a/arch/arm/mm/proc-macros.S b/arch/arm/mm/proc-macros.S
index 307a4de..2d8ff3a 100644
--- a/arch/arm/mm/proc-macros.S
+++ b/arch/arm/mm/proc-macros.S
@@ -91,8 +91,9 @@
#if L_PTE_SHARED != PTE_EXT_SHARED
#error PTE shared bit mismatch
#endif
-#if (L_PTE_XN+L_PTE_USER+L_PTE_RDONLY+L_PTE_DIRTY+L_PTE_YOUNG+\
- L_PTE_FILE+L_PTE_PRESENT) > L_PTE_SHARED
+#if !defined (CONFIG_ARM_LPAE) && \
+ (L_PTE_XN+L_PTE_USER+L_PTE_RDONLY+L_PTE_DIRTY+L_PTE_YOUNG+\
+ L_PTE_FILE+L_PTE_PRESENT) > L_PTE_SHARED
#error Invalid Linux PTE bit settings
#endif
#endif /* CONFIG_MMU */
diff --git a/arch/arm/mm/proc-v7-3level.S b/arch/arm/mm/proc-v7-3level.S
new file mode 100644
index 0000000..e2ec6db
--- /dev/null
+++ b/arch/arm/mm/proc-v7-3level.S
@@ -0,0 +1,149 @@
+/*
+ * 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)
+
+/*
+ * 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
+ ldr r1, [r1, #MM_CONTEXT_ID] @ get mm->context.id
+ mov r2, #0
+ and r3, r1, #0xff
+ mov r3, r3, lsl #(48 - 32) @ ASID
+ mcrr p15, 0, r0, r3, c2 @ set TTB 0
+ isb
+#endif
+ mov pc, lr
+ENDPROC(cpu_v7_switch_mm)
+
+/*
+ * 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 r2, #L_PTE_PRESENT
+ beq 1f
+ tst r3, #1 << (55 - 32) @ L_PTE_DIRTY
+ orreq r2, #L_PTE_RDONLY
+1: strd r2, r3, [r0]
+ 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
+ mrc p15, 0, \tmp, c2, c0, 2 @ TTB control register
+ orr \tmp, \tmp, #TTB_EAE
+ ALT_SMP(orr \tmp, \tmp, #TTB_FLAGS_SMP)
+ ALT_SMP(orr \tmp, \tmp, #TTB_FLAGS_SMP << 16)
+ ALT_UP(orr \tmp, \tmp, #TTB_FLAGS_UP)
+ ALT_UP(orr \tmp, \tmp, #TTB_FLAGS_UP << 16)
+#if PHYS_OFFSET <= PAGE_OFFSET
+ /*
+ * TTBR0/TTBR1 split (PAGE_OFFSET):
+ * 0x40000000: T0SZ = 2, T1SZ = 0 (not used)
+ * 0x80000000: T0SZ = 0, T1SZ = 1
+ * 0xc0000000: T0SZ = 0, T1SZ = 2
+ *
+ * Only use this feature if PHYS_OFFSET <= PAGE_OFFSET, otherwise
+ * booting secondary CPUs would end up using TTBR1 for the identity
+ * mapping set up in TTBR0.
+ */
+ orr \tmp, \tmp, #(((PAGE_OFFSET >> 30) - 1) << 16) @ TTBCR.T1SZ
+#if defined CONFIG_VMSPLIT_2G
+ /* PAGE_OFFSET == 0x80000000, T1SZ == 1 */
+ add \ttbr1, \ttbr1, #1 << 4 @ skip two L1 entries
+#elif defined CONFIG_VMSPLIT_3G
+ /* PAGE_OFFSET == 0xc0000000, T1SZ == 2 */
+ add \ttbr1, \ttbr1, #4096 * (1 + 3) @ only L2 used, skip pgd+3*pmd
+#endif
+#endif /* PHYS_OFFSET <= PAGE_OFFSET */
+ mcr p15, 0, \tmp, c2, c0, 2 @ TTB control register
+ mcrr p15, 1, \ttbr1, \zero, c2 @ load TTBR1
+ .endm
+
+ __CPUINIT
+
+ /*
+ * 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
+
+ .previous
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 8debdba..468b8b5 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -19,7 +19,11 @@

#include "proc-macros.S"

+#ifdef CONFIG_ARM_LPAE
+#include "proc-v7-3level.S"
+#else
#include "proc-v7-2level.S"
+#endif

ENTRY(cpu_v7_proc_init)
mov pc, lr
@@ -85,7 +89,7 @@ ENDPROC(cpu_v7_dcache_clean_area)

/* Suspend/resume support: derived from arch/arm/mach-s5pv210/sleep.S */
.globl cpu_v7_suspend_size
-.equ cpu_v7_suspend_size, 4 * 7
+.equ cpu_v7_suspend_size, 4 * 8
#ifdef CONFIG_ARM_CPU_SUSPEND
ENTRY(cpu_v7_do_suspend)
stmfd sp!, {r4 - r10, lr}
@@ -94,10 +98,11 @@ ENTRY(cpu_v7_do_suspend)
stmia r0!, {r4 - r5}
mrc p15, 0, r6, c3, c0, 0 @ Domain ID
mrc p15, 0, r7, c2, c0, 1 @ TTB 1
+ mrc p15, 0, r11, c2, c0, 2 @ TTB control register
mrc p15, 0, r8, c1, c0, 0 @ Control register
mrc p15, 0, r9, c1, c0, 1 @ Auxiliary control register
mrc p15, 0, r10, c1, c0, 2 @ Co-processor access control
- stmia r0, {r6 - r10}
+ stmia r0, {r6 - r11}
ldmfd sp!, {r4 - r10, pc}
ENDPROC(cpu_v7_do_suspend)

@@ -109,13 +114,15 @@ ENTRY(cpu_v7_do_resume)
ldmia r0!, {r4 - r5}
mcr p15, 0, r4, c13, c0, 0 @ FCSE/PID
mcr p15, 0, r5, c13, c0, 3 @ User r/o thread ID
- ldmia r0, {r6 - r10}
+ ldmia r0, {r6 - r11}
mcr p15, 0, r6, c3, c0, 0 @ Domain ID
+#ifndef CONFIG_ARM_LPAE
ALT_SMP(orr r1, r1, #TTB_FLAGS_SMP)
ALT_UP(orr r1, r1, #TTB_FLAGS_UP)
+#endif
mcr p15, 0, r1, c2, c0, 0 @ TTB 0
mcr p15, 0, r7, c2, c0, 1 @ TTB 1
- mcr p15, 0, ip, c2, c0, 2 @ TTB control register
+ mcr p15, 0, r11, c2, c0, 2 @ TTB control register
mrc p15, 0, r4, c1, c0, 1 @ Read Auxiliary control register
teq r4, r9 @ Is it already set?
mcrne p15, 0, r9, c1, c0, 1 @ No, so write it
@@ -289,11 +296,11 @@ __v7_setup_stack:
*/
.macro __v7_proc initfunc, mm_mmuflags = 0, io_mmuflags = 0, hwcaps = 0
ALT_SMP(.long PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_AP_READ | \
- PMD_FLAGS_SMP | \mm_mmuflags)
+ PMD_SECT_AF | PMD_FLAGS_SMP | \mm_mmuflags)
ALT_UP(.long PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_AP_READ | \
- PMD_FLAGS_UP | \mm_mmuflags)
+ PMD_SECT_AF | PMD_FLAGS_UP | \mm_mmuflags)
.long PMD_TYPE_SECT | PMD_SECT_XN | PMD_SECT_AP_WRITE | \
- PMD_SECT_AP_READ | \io_mmuflags
+ PMD_SECT_AP_READ | PMD_SECT_AF | \io_mmuflags
W(b) \initfunc
.long cpu_arch_name
.long cpu_elf_name
@@ -306,6 +313,7 @@ __v7_setup_stack:
.long v7_cache_fns
.endm

+#ifndef CONFIG_ARM_LPAE
/*
* ARM Ltd. Cortex A5 processor.
*/
@@ -325,6 +333,7 @@ __v7_ca9mp_proc_info:
.long 0xff0ffff0
__v7_proc __v7_ca9mp_setup
.size __v7_ca9mp_proc_info, . - __v7_ca9mp_proc_info
+#endif /* CONFIG_ARM_LPAE */

/*
* ARM Ltd. Cortex A15 processor.


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