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>
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 54eb94a..c8e797b 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 @@
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 @@
#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 @@
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
@@ -283,6 +316,9 @@
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 +410,17 @@
#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)