[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>

1 files changed, 47 insertions, 13 deletions

diff --git a/arch/arm/mm/mm-armv.c b/arch/arm/mm/mm-armv.c
index 64db10e806b3..61bc2fa0511e 100644
--- 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) {