ARM: LPAE: MMU setup for the 3-level page table format

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>

4 files changed, 200 insertions, 10 deletions

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index dc8c550e6cbd..1935311e17fc 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 307a4def8d3a..2d8ff3ad86d3 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 000000000000..8de0f1dd1549
--- /dev/null
+++ b/arch/arm/mm/proc-v7-3level.S
@@ -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
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index ed1a4d115331..7efa2a721d5d 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
@@ -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.