[ARM] 3017/1: Add support for 36-bit addresses to create_mapping()

Patch from Deepak Saxena

This patch adds support for 36-bit static mapped I/O. While there
are no platforms in the tree ATM that use it, it has been tested
tested on the IXP2350 NPU and I would like to get the support for
that chipset upstream one piece at a time. There are also other
Intel chipset ports in development that are waiting on this to go
upstream.

The patch replaces the print formats for physical addresses with
%016llx which will create a bit extraneous output on 32-bit systems,
but I think that is cleaner than having #ifdefs, specially since
users will only see the output in error cases.

Depends on 3016/1.

Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/mm/mm-armv.c b/arch/arm/mm/mm-armv.c
index 64db10e..61bc2fa 100644 (file)
--- a/arch/arm/mm/mm-armv.c
+++ b/arch/arm/mm/mm-armv.c
@@ -478,20 +478,20 @@ void __init create_mapping(struct map_desc *md)
        unsigned long virt, length;
        int prot_sect, prot_l1, domain;
        pgprot_t prot_pte;
-       long off;
+       unsigned long off = (u32)__pfn_to_phys(md->pfn);
 
        if (md->virtual != vectors_base() && md->virtual < TASK_SIZE) {
                printk(KERN_WARNING "BUG: not creating mapping for "
-                      "0x%08lx at 0x%08lx in user region\n",
-                      __pfn_to_phys(md->pfn), md->virtual);
+                      "0x%016llx at 0x%08lx in user region\n",
+                      __pfn_to_phys((u64)md->pfn), md->virtual);
                return;
        }
 
        if ((md->type == MT_DEVICE || md->type == MT_ROM) &&
            md->virtual >= PAGE_OFFSET && md->virtual < VMALLOC_END) {
-               printk(KERN_WARNING "BUG: mapping for 0x%08lx at 0x%08lx "
+               printk(KERN_WARNING "BUG: mapping for 0x%016llx at 0x%08lx "
                       "overlaps vmalloc space\n",
-                      __pfn_to_phys(md->pfn), md->virtual);
+                      __pfn_to_phys((u64)md->pfn), md->virtual);
        }
 
        domain    = mem_types[md->type].domain;
@@ -499,8 +499,33 @@ void __init create_mapping(struct map_desc *md)
        prot_l1   = mem_types[md->type].prot_l1 | PMD_DOMAIN(domain);
        prot_sect = mem_types[md->type].prot_sect | PMD_DOMAIN(domain);
 
+       /*
+        * Catch 36-bit addresses
+        */
+       if(md->pfn >= 0x100000) {
+               if(domain) {
+                       printk(KERN_ERR "MM: invalid domain in supersection "
+                               "mapping for 0x%016llx at 0x%08lx\n",
+                               __pfn_to_phys((u64)md->pfn), md->virtual);
+                       return;
+               }
+               if((md->virtual | md->length | __pfn_to_phys(md->pfn))
+                       & ~SUPERSECTION_MASK) {
+                       printk(KERN_ERR "MM: cannot create mapping for "
+                               "0x%016llx at 0x%08lx invalid alignment\n",
+                               __pfn_to_phys((u64)md->pfn), md->virtual);
+                       return;
+               }
+
+               /*
+                * Shift bits [35:32] of address into bits [23:20] of PMD
+                * (See ARMv6 spec).
+                */
+               off |= (((md->pfn >> (32 - PAGE_SHIFT)) & 0xF) << 20);
+       }
+
        virt   = md->virtual;
-       off    = __pfn_to_phys(md->pfn) - virt;
+       off   -= virt;
        length = md->length;
 
        if (mem_types[md->type].prot_l1 == 0 &&
@@ -525,13 +550,22 @@ void __init create_mapping(struct map_desc *md)
         *      of the actual domain assignments in use.
         */
        if (cpu_architecture() >= CPU_ARCH_ARMv6 && domain == 0) {
-               /* Align to supersection boundary */
-               while ((virt & ~SUPERSECTION_MASK || (virt + off) &
-                       ~SUPERSECTION_MASK) && length >= (PGDIR_SIZE / 2)) {
-                       alloc_init_section(virt, virt + off, prot_sect);
-
-                       virt   += (PGDIR_SIZE / 2);
-                       length -= (PGDIR_SIZE / 2);
+               /*
+                * Align to supersection boundary if !high pages.
+                * High pages have already been checked for proper
+                * alignment above and they will fail the SUPSERSECTION_MASK
+                * check because of the way the address is encoded into
+                * offset.
+                */
+               if (md->pfn <= 0x100000) {
+                       while ((virt & ~SUPERSECTION_MASK ||
+                               (virt + off) & ~SUPERSECTION_MASK) &&
+                               length >= (PGDIR_SIZE / 2)) {
+                               alloc_init_section(virt, virt + off, prot_sect);
+
+                               virt   += (PGDIR_SIZE / 2);
+                               length -= (PGDIR_SIZE / 2);
+                       }
                }
 
                while (length >= SUPERSECTION_SIZE) {