On 8/22/2012 3:23 PM, Russell King - ARM Linux wrote:
On Wed, Aug 22, 2012 at 12:16:08PM +0530, Trilok Soni wrote:
Thanks for the patch, but how about just checking pmd_none on such
addresses and since there won't be any mapping created for such gaps? We
need to check if this is fine for all, since I remember that Nico
added these functions for the OMAP boot issue I guess.
A better solution would be as below - this requires no changes to the
existing ioremap code, we just mark these differently.
diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h
index 2e8a1ef..87fa3f2 100644
--- a/arch/arm/mm/mm.h
+++ b/arch/arm/mm/mm.h
@@ -55,6 +55,9 @@ extern void __flush_dcache_page(struct address_space *mapping, struct page *page
/* permanent static mappings from iotable_init() */
#define VM_ARM_STATIC_MAPPING 0x40000000
+/* empty mapping */
+#define VM_ARM_EMPTY_MAPPING 0x20000000
+
/* mapping type (attributes) for permanent static mappings */
#define VM_ARM_MTYPE(mt) ((mt)<< 20)
#define VM_ARM_MTYPE_MASK (0x1f<< 20)
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index cf4528d..da90ef1 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -813,7 +813,7 @@ static void __init pmd_empty_section_gap(unsigned long addr)
vm = early_alloc_aligned(sizeof(*vm), __alignof__(*vm));
vm->addr = (void *)addr;
vm->size = SECTION_SIZE;
- vm->flags = VM_IOREMAP | VM_ARM_STATIC_MAPPING;
+ vm->flags = VM_IOREMAP | VM_ARM_EMPTY_MAPPING;
vm->caller = pmd_empty_section_gap;
vm_area_add_early(vm);
}
@@ -826,7 +826,7 @@ static void __init fill_pmd_gaps(void)
/* we're still single threaded hence no lock needed here */
for (vm = vmlist; vm; vm = vm->next) {
- if (!(vm->flags& VM_ARM_STATIC_MAPPING))
+ if (!(vm->flags& (VM_ARM_STATIC_MAPPING | VM_ARM_EMPTY_MAPPING))
continue;
addr = (unsigned long)vm->addr;
if (addr< next)
Tested on MSM platform
Tested-by: Murali Nalajala <mnalajal@xxxxxxxxxxxxxx>
Thanks,
Murali N
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