efi: Use correct type for struct efi_memory_map::phys_map

We have been getting away with using a void* for the physical
address of the UEFI memory map, since, even on 32-bit platforms
with 64-bit physical addresses, no truncation takes place if the
memory map has been allocated by the firmware (which only uses
1:1 virtually addressable memory), which is usually the case.

However, commit:

  0f96a99dab36 ("efi: Add "efi_fake_mem" boot option")

adds code that clones and modifies the UEFI memory map, and the
clone may live above 4 GB on 32-bit platforms.

This means our use of void* for struct efi_memory_map::phys_map has
graduated from 'incorrect but working' to 'incorrect and
broken', and we need to fix it.

So redefine struct efi_memory_map::phys_map as phys_addr_t, and
get rid of a bunch of casts that are now unneeded.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: izumi.taku@jp.fujitsu.com
Cc: kamezawa.hiroyu@jp.fujitsu.com
Cc: linux-efi@vger.kernel.org
Cc: matt.fleming@intel.com
Link: http://lkml.kernel.org/r/1445593697-1342-1-git-send-email-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

4 files changed, 9 insertions, 9 deletions

diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
index 4b7df346e388..61eb1d17586a 100644
--- a/arch/arm64/kernel/efi.c
+++ b/arch/arm64/kernel/efi.c
@@ -208,7 +208,7 @@ void __init efi_init(void)
 
         memblock_reserve(params.mmap & PAGE_MASK,
                          PAGE_ALIGN(params.mmap_size + (params.mmap & ~PAGE_MASK)));
-        memmap.phys_map = (void *)params.mmap;
+        memmap.phys_map = params.mmap;
         memmap.map = early_memremap(params.mmap, params.mmap_size);
         memmap.map_end = memmap.map + params.mmap_size;
         memmap.desc_size = params.desc_size;
@@ -282,7 +282,7 @@ static int __init arm64_enable_runtime_services(void)
         pr_info("Remapping and enabling EFI services.\n");
 
         mapsize = memmap.map_end - memmap.map;
-        memmap.map = (__force void *)ioremap_cache((phys_addr_t)memmap.phys_map,
+        memmap.map = (__force void *)ioremap_cache(memmap.phys_map,
                                                    mapsize);
         if (!memmap.map) {
                 pr_err("Failed to remap EFI memory map\n");
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 3e1d09e885c0..ad285404ea7f 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -194,7 +194,7 @@ static void __init do_add_efi_memmap(void)
 int __init efi_memblock_x86_reserve_range(void)
 {
         struct efi_info *e = &boot_params.efi_info;
-        unsigned long pmap;
+        phys_addr_t pmap;
 
         if (efi_enabled(EFI_PARAVIRT))
                 return 0;
@@ -209,7 +209,7 @@ int __init efi_memblock_x86_reserve_range(void)
 #else
         pmap = (e->efi_memmap | ((__u64)e->efi_memmap_hi << 32));
 #endif
-        memmap.phys_map         = (void *)pmap;
+        memmap.phys_map         = pmap;
         memmap.nr_map           = e->efi_memmap_size /
                                   e->efi_memdesc_size;
         memmap.desc_size        = e->efi_memdesc_size;
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 31fc864eb037..027ca212179f 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -254,7 +254,7 @@ subsys_initcall(efisubsys_init);
 int __init efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
 {
         struct efi_memory_map *map = efi.memmap;
-        void *p, *e;
+        phys_addr_t p, e;
 
         if (!efi_enabled(EFI_MEMMAP)) {
                 pr_err_once("EFI_MEMMAP is not enabled.\n");
@@ -286,10 +286,10 @@ int __init efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
                  * So just always get our own virtual map on the CPU.
                  *
                  */
-                md = early_memremap((phys_addr_t)p, sizeof (*md));
+                md = early_memremap(p, sizeof (*md));
                 if (!md) {
-                        pr_err_once("early_memremap(%p, %zu) failed.\n",
-                                    p, sizeof (*md));
+                        pr_err_once("early_memremap(%pa, %zu) failed.\n",
+                                    &p, sizeof (*md));
                         return -ENOMEM;
                 }
 
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 4d01c1033fce..569b5a866bb1 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -680,7 +680,7 @@ typedef struct {
 } efi_system_table_t;
 
 struct efi_memory_map {
-        void *phys_map;
+        phys_addr_t phys_map;
         void *map;
         void *map_end;
         int nr_map;