At boot time, UEFI runtime support needs to call into the UEFI firmware
to switch to a virtual address map. This call must be made with UEFI
memory regions identity mapped. The exisitng early boot code creates
an identity map of kernel text/data but this is not sufficient for UEFI.
This patch adds a create_id_mapping() function which reuses the core
code of create_mapping() used to create the kernel RAM mappings.
Signed-off-by: Mark Salter <msal...@redhat.com>
CC: Catalin Marinas <catalin.mari...@arm.com>
CC: Will Deacon <will.dea...@arm.com>
CC: linux-arm-ker...@lists.infradead.org
---
arch/arm64/include/asm/mmu.h | 1 +
arch/arm64/mm/mmu.c | 34 ++++++++++++++++++++++++----------
2 files changed, 25 insertions(+), 10 deletions(-)
diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h
index f600d40..9ad4dd4 100644
--- a/arch/arm64/include/asm/mmu.h
+++ b/arch/arm64/include/asm/mmu.h
@@ -28,5 +28,6 @@ extern void paging_init(void);
extern void setup_mm_for_reboot(void);
extern void __iomem *early_io_map(phys_addr_t phys, unsigned long virt);
extern void init_mem_pgprot(void);
+extern void create_id_mapping(phys_addr_t addr, phys_addr_t size);
#endif
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 7b345e3..ccfca44 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -228,22 +228,14 @@ static void __init alloc_init_pud(pgd_t *pgd, unsigned
long addr,
* Create the page directory entries and any necessary page tables for the
* mapping specified by 'md'.
*/
-static void __init create_mapping(phys_addr_t phys, unsigned long virt,
- phys_addr_t size)
+static void __init __create_mapping(pgd_t *pgd, phys_addr_t phys,
+ unsigned long virt, phys_addr_t size)
{
unsigned long addr, length, end, next;
- pgd_t *pgd;
-
- if (virt < VMALLOC_START) {
- pr_warning("BUG: not creating mapping for 0x%016llx at 0x%016lx
- outside kernel range\n",
- phys, virt);
- return;
- }
addr = virt & PAGE_MASK;
length = PAGE_ALIGN(size + (virt & ~PAGE_MASK));
- pgd = pgd_offset_k(addr);
end = addr + length;
do {
next = pgd_addr_end(addr, end);
@@ -252,6 +244,28 @@ static void __init create_mapping(phys_addr_t phys,
unsigned long virt,
} while (pgd++, addr = next, addr != end);
}
+static void __init create_mapping(phys_addr_t phys, unsigned long virt,
+ phys_addr_t size)
+{
+ if (virt < VMALLOC_START) {
+ pr_warn("BUG: not creating mapping for 0x%016llx at 0x%016lx -
outside kernel range\n",
+ phys, virt);
+ return;
+ }
+ __create_mapping(pgd_offset_k(virt & PAGE_MASK), phys, virt, size);
+}
+
+void __init create_id_mapping(phys_addr_t addr, phys_addr_t size)
+{
+ pgd_t *pgd = &idmap_pg_dir[pgd_index(addr)];
+
+ if (pgd >= &idmap_pg_dir[ARRAY_SIZE(idmap_pg_dir)]) {
+ pr_warn("BUG: not creating id mapping for 0x%016llx\n", addr);
+ return;
+ }
+ __create_mapping(pgd, addr, addr, size);
+}
+
static void __init map_mem(void)
{
struct memblock_region *reg;
--
1.8.3.1
--
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