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authorLennert Buytenhek <buytenh@wantstofly.org>2006-07-01 19:58:20 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2006-07-01 19:58:20 +0100
commita069c896d0d6c028581089da7a9a9037a63c2803 (patch)
tree7b82eeab31974be5e5554f696dbf4351f678e680 /arch
parentae95bfbb2b67eba5d67a0478a8715682a87e2616 (diff)
[ARM] 3705/1: add supersection support to ioremap()
Patch from Lennert Buytenhek Analogous to the previous patch that allows ioremap() to use section mappings, this patch allows ioremap() to use supersection mappings. Original patch by Deepak Saxena. Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/mm/ioremap.c66
1 files changed, 63 insertions, 3 deletions
diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c
index 6aa13d59c85..7eac87f0518 100644
--- a/arch/arm/mm/ioremap.c
+++ b/arch/arm/mm/ioremap.c
@@ -33,8 +33,8 @@
#include <asm/sizes.h>
/*
- * Used by ioremap() and iounmap() code to mark section-mapped I/O regions
- * in vm_struct->flags field.
+ * Used by ioremap() and iounmap() code to mark (super)section-mapped
+ * I/O regions in vm_struct->flags field.
*/
#define VM_ARM_SECTION_MAPPING 0x80000000
@@ -233,6 +233,54 @@ remap_area_sections(unsigned long virt, unsigned long pfn,
return 0;
}
+
+static int
+remap_area_supersections(unsigned long virt, unsigned long pfn,
+ unsigned long size, unsigned long flags)
+{
+ unsigned long prot, addr = virt, end = virt + size;
+ pgd_t *pgd;
+
+ /*
+ * Remove and free any PTE-based mapping, and
+ * sync the current kernel mapping.
+ */
+ unmap_area_sections(virt, size);
+
+ prot = PMD_TYPE_SECT | PMD_SECT_SUPER | PMD_SECT_AP_WRITE |
+ PMD_DOMAIN(DOMAIN_IO) |
+ (flags & (L_PTE_CACHEABLE | L_PTE_BUFFERABLE));
+
+ /*
+ * ARMv6 and above need XN set to prevent speculative prefetches
+ * hitting IO.
+ */
+ if (cpu_architecture() >= CPU_ARCH_ARMv6)
+ prot |= PMD_SECT_XN;
+
+ pgd = pgd_offset_k(virt);
+ do {
+ unsigned long super_pmd_val, i;
+
+ super_pmd_val = __pfn_to_phys(pfn) | prot;
+ super_pmd_val |= ((pfn >> (32 - PAGE_SHIFT)) & 0xf) << 20;
+
+ for (i = 0; i < 8; i++) {
+ pmd_t *pmd = pmd_offset(pgd, addr);
+
+ pmd[0] = __pmd(super_pmd_val);
+ pmd[1] = __pmd(super_pmd_val);
+ flush_pmd_entry(pmd);
+
+ addr += PGDIR_SIZE;
+ pgd++;
+ }
+
+ pfn += SUPERSECTION_SIZE >> PAGE_SHIFT;
+ } while (addr < end);
+
+ return 0;
+}
#endif
@@ -255,6 +303,13 @@ __ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size,
int err;
unsigned long addr;
struct vm_struct * area;
+ unsigned int cr = get_cr();
+
+ /*
+ * High mappings must be supersection aligned
+ */
+ if (pfn >= 0x100000 && (__pfn_to_phys(pfn) & ~SUPERSECTION_MASK))
+ return NULL;
area = get_vm_area(size, VM_IOREMAP);
if (!area)
@@ -262,7 +317,12 @@ __ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size,
addr = (unsigned long)area->addr;
#ifndef CONFIG_SMP
- if (!((__pfn_to_phys(pfn) | size | addr) & ~PMD_MASK)) {
+ if ((((cpu_architecture() >= CPU_ARCH_ARMv6) && (cr & CR_XP)) ||
+ cpu_is_xsc3()) &&
+ !((__pfn_to_phys(pfn) | size | addr) & ~SUPERSECTION_MASK)) {
+ area->flags |= VM_ARM_SECTION_MAPPING;
+ err = remap_area_supersections(addr, pfn, size, flags);
+ } else if (!((__pfn_to_phys(pfn) | size | addr) & ~PMD_MASK)) {
area->flags |= VM_ARM_SECTION_MAPPING;
err = remap_area_sections(addr, pfn, size, flags);
} else