Merge tag 'fixes-2021-07-09' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock

Pull memblock fix from Mike Rapoport:
 "This is a fix for the rework of ARM's pfn_valid() implementation
  merged during this merge window.

  Don't abuse pfn_valid() to check if pfn is in RAM

  The semantics of pfn_valid() is to check presence of the memory map
  for a PFN and not whether a PFN is in RAM. The memory map may be
  present for a hole in the physical memory and if such hole corresponds
  to an MMIO range, __arm_ioremap_pfn_caller() will produce a WARN() and
  fail.

  Use memblock_is_map_memory() instead of pfn_valid() to check if a PFN
  is in RAM or not"

* tag 'fixes-2021-07-09' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
  arm: ioremap: don't abuse pfn_valid() to check if pfn is in RAM

1 files changed, 3 insertions, 1 deletions

diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c
index 000e8210000b..80fb5a4a5c05 100644
--- a/arch/arm/mm/ioremap.c
+++ b/arch/arm/mm/ioremap.c
@@ -27,6 +27,7 @@
 #include <linux/vmalloc.h>
 #include <linux/io.h>
 #include <linux/sizes.h>
+#include <linux/memblock.h>
 
 #include <asm/cp15.h>
 #include <asm/cputype.h>
@@ -284,7 +285,8 @@ static void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn,
 	 * Don't allow RAM to be mapped with mismatched attributes - this
 	 * causes problems with ARMv6+
 	 */
-	if (WARN_ON(pfn_valid(pfn) && mtype != MT_MEMORY_RW))
+	if (WARN_ON(memblock_is_map_memory(PFN_PHYS(pfn)) &&
+		    mtype != MT_MEMORY_RW))
 		return NULL;
 
 	area = get_vm_area_caller(size, VM_IOREMAP, caller);