[ARM] 3705/1: add supersection support to ioremap()
authorLennert Buytenhek <buytenh@wantstofly.org>
Sat, 1 Jul 2006 18:58:20 +0000 (19:58 +0100)
committerRussell King <rmk+kernel@arm.linux.org.uk>
Sat, 1 Jul 2006 18:58:20 +0000 (19:58 +0100)
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>
arch/arm/mm/ioremap.c
include/asm-arm/memory.h

index 6aa13d59c85872d650dcd19d00e965c23eb9c748..7eac87f05180682ea45f3db06c0bdfe59e7739f1 100644 (file)
@@ -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
index 176a4fb04989a63aa461fe624cbe902d8892ca73..91d536c215d79fc700b5c79f0dfb185bc6003eba 100644 (file)
@@ -69,9 +69,9 @@
 #define XIP_VIRT_ADDR(physaddr)  (MODULE_START + ((physaddr) & 0x000fffff))
 
 /*
- * Allow 2MB-aligned ioremap pages
+ * Allow 16MB-aligned ioremap pages
  */
-#define IOREMAP_MAX_ORDER      21
+#define IOREMAP_MAX_ORDER      24
 
 #else /* CONFIG_MMU */