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authorCyril Chemparathy <cyril@ti.com>2012-07-21 23:55:04 +0400
committerWill Deacon <will.deacon@arm.com>2013-05-30 19:02:15 +0400
commit4756dcbfd37819a8359d3c69a22be2ee41666d0f (patch)
treea9c172f6940e607b9c0c9a3bd7393bf0cc03e940 /arch/arm/kernel
parenta7fbc0d62a4d46e642af889e7288fede5078bc46 (diff)
downloadlinux-4756dcbfd37819a8359d3c69a22be2ee41666d0f.tar.xz
ARM: LPAE: accomodate >32-bit addresses for page table base
This patch redefines the early boot time use of the R4 register to steal a few low order bits (ARCH_PGD_SHIFT bits) on LPAE systems. This allows for up to 38-bit physical addresses. Signed-off-by: Cyril Chemparathy <cyril@ti.com> Signed-off-by: Vitaly Andrianov <vitalya@ti.com> Acked-by: Nicolas Pitre <nico@linaro.org> Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Subash Patel <subash.rp@samsung.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r--arch/arm/kernel/head.S10
-rw-r--r--arch/arm/kernel/smp.c11
2 files changed, 13 insertions, 8 deletions
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 8bac553fe213..45e8935cae4e 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -156,7 +156,7 @@ ENDPROC(stext)
*
* Returns:
* r0, r3, r5-r7 corrupted
- * r4 = physical page table address
+ * r4 = page table (see ARCH_PGD_SHIFT in asm/memory.h)
*/
__create_page_tables:
pgtbl r4, r8 @ page table address
@@ -331,6 +331,7 @@ __create_page_tables:
#endif
#ifdef CONFIG_ARM_LPAE
sub r4, r4, #0x1000 @ point to the PGD table
+ mov r4, r4, lsr #ARCH_PGD_SHIFT
#endif
mov pc, lr
ENDPROC(__create_page_tables)
@@ -408,7 +409,7 @@ __secondary_data:
* r0 = cp#15 control register
* r1 = machine ID
* r2 = atags or dtb pointer
- * r4 = page table pointer
+ * r4 = page table (see ARCH_PGD_SHIFT in asm/memory.h)
* r9 = processor ID
* r13 = *virtual* address to jump to upon completion
*/
@@ -427,10 +428,7 @@ __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
+#ifndef CONFIG_ARM_LPAE
mov r5, #(domain_val(DOMAIN_USER, DOMAIN_MANAGER) | \
domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \
domain_val(DOMAIN_TABLE, DOMAIN_MANAGER) | \
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 550d63cef68e..217b755aadd4 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -78,6 +78,13 @@ void __init smp_set_ops(struct smp_operations *ops)
smp_ops = *ops;
};
+static unsigned long get_arch_pgd(pgd_t *pgd)
+{
+ phys_addr_t pgdir = virt_to_phys(pgd);
+ BUG_ON(pgdir & ARCH_PGD_MASK);
+ return pgdir >> ARCH_PGD_SHIFT;
+}
+
int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *idle)
{
int ret;
@@ -87,8 +94,8 @@ int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *idle)
* its stack and the page tables.
*/
secondary_data.stack = task_stack_page(idle) + THREAD_START_SP;
- secondary_data.pgdir = virt_to_phys(idmap_pgd);
- secondary_data.swapper_pg_dir = virt_to_phys(swapper_pg_dir);
+ secondary_data.pgdir = get_arch_pgd(idmap_pgd);
+ secondary_data.swapper_pg_dir = get_arch_pgd(swapper_pg_dir);
__cpuc_flush_dcache_area(&secondary_data, sizeof(secondary_data));
outer_clean_range(__pa(&secondary_data), __pa(&secondary_data + 1));