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authorJonathan Neuschäfer2018-03-28 02:25:42 +0200
committerMichael Ellerman2018-03-31 15:47:43 +0200
commit2bbf63264ab2e8cbc740c738f66984b2aafa29c5 (patch)
tree4610ddecbf8a4af5baed26bff2b2f1ebff4d0e2f /arch/powerpc
parentpowerpc/mm: Use memblock API for PPC32 page_is_ram (diff)
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powerpc/mm/32: Use page_is_ram to check for RAM
On systems where there is MMIO space between different blocks of RAM in the physical address space, __ioremap_caller did not allow mapping these MMIO areas, because they were below the end RAM and thus considered RAM as well. Use the memblock-based page_is_ram function, which returns false for such MMIO holes. v2: Keep the check for p < virt_to_phys(high_memory). On 32-bit systems with high memory (memory above physical address 4GiB), the high memory is expected to be available though ioremap. The high_memory variable marks the end of low memory; comparing against it means that only ioremap requests for low RAM will be denied. Reported by Michael Ellerman. Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/mm/pgtable_32.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
index d35d9ad3c1cd..6668ecc041ad 100644
--- a/arch/powerpc/mm/pgtable_32.c
+++ b/arch/powerpc/mm/pgtable_32.c
@@ -148,6 +148,7 @@ __ioremap_caller(phys_addr_t addr, unsigned long size, unsigned long flags,
* mem_init() sets high_memory so only do the check after that.
*/
if (slab_is_available() && (p < virt_to_phys(high_memory)) &&
+ page_is_ram(__phys_to_pfn(p)) &&
!(__allow_ioremap_reserved && memblock_is_region_reserved(p, size))) {
printk("__ioremap(): phys addr 0x%llx is RAM lr %ps\n",
(unsigned long long)p, __builtin_return_address(0));