ARM: LPAE: MMU setup for the 3-level page table format
authorCatalin Marinas <catalin.marinas@arm.com>
Tue, 22 Nov 2011 17:30:29 +0000 (17:30 +0000)
committerCatalin Marinas <catalin.marinas@arm.com>
Thu, 8 Dec 2011 10:30:39 +0000 (10:30 +0000)
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
arch/arm/mm/mmu.c
arch/arm/mm/proc-macros.S
arch/arm/mm/proc-v7-3level.S [new file with mode: 0644]
arch/arm/mm/proc-v7.S

index 54eb94aff6cd84d13e0dda6f71c61379f4449aa8..c8e797baaf55fa8ab02cb2dbfcdbffa7c1576097 100644 (file)
 #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 +276,15 @@ __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
+#else
+       orr     r3, r3, #PMD_SECT_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
@@ -282,6 +315,9 @@ __create_page_tables:
        add     r0, r4, #0xd8000000 >> (SECTION_SHIFT - PMD_ORDER)
        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)
@@ -374,12 +410,17 @@ __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)
 
index dc8c550e6cbde82ae786488dadc33d92550c1d0c..1935311e17fcafa4a1edf81ce232653a5a65c83e 100644 (file)
@@ -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
index 307a4def8d3a7d6c89d06211e53f855a7e518fea..2d8ff3ad86d3e1a2b9d9abd83a1bdd3ab42eba3a 100644 (file)
@@ -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 (file)
index 0000000..8de0f1d
--- /dev/null
@@ -0,0 +1,150 @@
+/*
+ * 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
+       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
+       ldr     \tmp, =swapper_pg_dir           @ swapper_pg_dir virtual address
+       cmp     \ttbr1, \tmp                    @ PHYS_OFFSET > PAGE_OFFSET? (branch below)
+       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)
+       /*
+        * 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.
+        */
+       bhi     9001f                           @ PHYS_OFFSET > PAGE_OFFSET?
+       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
+       /* CONFIG_VMSPLIT_1G does not need TTBR1 adjustment */
+9001:  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
index ed1a4d115331b6735a2be52e3383d9b2a9cfea1d..7efa2a721d5dd9dbc0853eab8b9c8980c47c5e17 100644 (file)
 
 #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
@@ -87,7 +91,7 @@ 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}
@@ -96,10 +100,11 @@ 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)
 
@@ -111,13 +116,15 @@ 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
@@ -291,11 +298,11 @@ __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)
-       .long   PMD_TYPE_SECT | PMD_SECT_XN | PMD_SECT_AP_WRITE | \
-               PMD_SECT_AP_READ | \io_mmuflags
+                       PMD_SECT_AF | PMD_FLAGS_UP | \mm_mmuflags)
+       .long   PMD_TYPE_SECT | PMD_SECT_AP_WRITE | \
+               PMD_SECT_AP_READ | PMD_SECT_AF | \io_mmuflags
        W(b)    \initfunc
        .long   cpu_arch_name
        .long   cpu_elf_name
@@ -308,6 +315,7 @@ __v7_setup_stack:
        .long   v7_cache_fns
 .endm
 
+#ifndef CONFIG_ARM_LPAE
        /*
         * ARM Ltd. Cortex A5 processor.
         */
@@ -327,6 +335,7 @@ __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.