UPSTREAM: arm64: introduce KIMAGE_VADDR as the virtual base of the kernel region

This introduces the preprocessor symbol KIMAGE_VADDR which will serve as
the symbolic virtual base of the kernel region, i.e., the kernel's virtual
offset will be KIMAGE_VADDR + TEXT_OFFSET. For now, we define it as being
equal to PAGE_OFFSET, but in the future, it will be moved below it once
we move the kernel virtual mapping out of the linear mapping.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Bug: 30369029
Patchset: kaslr-arm64-4.4

(cherry picked from commit ab893fb9f1b17f02139bce547bb4b69e96b9ae16)
Signed-off-by: Jeff Vander Stoep <jeffv@google.com>
Change-Id: I31427bd2b948a22bb8ce1d22109682fc66efb98d

diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index c65aad7b13dc5032d5694b34f6824e1666c31122..aebc739f5a11d3fe3cf04657c21f09b0125a836d 100644 (file)
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -51,7 +51,8 @@
 #define VA_BITS                        (CONFIG_ARM64_VA_BITS)
 #define VA_START               (UL(0xffffffffffffffff) << VA_BITS)
 #define PAGE_OFFSET            (UL(0xffffffffffffffff) << (VA_BITS - 1))
-#define MODULES_END            (PAGE_OFFSET)
+#define KIMAGE_VADDR           (PAGE_OFFSET)
+#define MODULES_END            (KIMAGE_VADDR)
 #define MODULES_VADDR          (MODULES_END - SZ_64M)
 #define PCI_IO_END             (MODULES_VADDR - SZ_2M)
 #define PCI_IO_START           (PCI_IO_END - PCI_IO_SIZE)
@@ -75,8 +76,13 @@
  * private definitions which should NOT be used outside memory.h
  * files.  Use virt_to_phys/phys_to_virt/__pa/__va instead.
  */
-#define __virt_to_phys(x)      (((phys_addr_t)(x) - PAGE_OFFSET + PHYS_OFFSET))
+#define __virt_to_phys(x) ({                                           \
+       phys_addr_t __x = (phys_addr_t)(x);                             \
+       __x >= PAGE_OFFSET ? (__x - PAGE_OFFSET + PHYS_OFFSET) :        \
+                            (__x - KIMAGE_VADDR + PHYS_OFFSET); })
+
 #define __phys_to_virt(x)      ((unsigned long)((x) - PHYS_OFFSET + PAGE_OFFSET))
+#define __phys_to_kimg(x)      ((unsigned long)((x) - PHYS_OFFSET + KIMAGE_VADDR))
 
 /*
  * Convert a page to/from a physical address

diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 53b9f9f128c2a418686f405b2b2a0072545dcff3..04d38a058b19e064adadc0d83042bc6f81a6e771 100644 (file)
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -389,7 +389,7 @@ __create_page_tables:
         * Map the kernel image (starting with PHYS_OFFSET).
         */
        mov     x0, x26                         // swapper_pg_dir
-       mov     x5, #PAGE_OFFSET
+       ldr     x5, =KIMAGE_VADDR
        create_pgd_entry x0, x5, x3, x6
        ldr     x6, =KERNEL_END                 // __va(KERNEL_END)
        mov     x3, x24                         // phys offset

diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index 763e5aab57529011795d24c9ab82f8b765376249..7703feba23d6f7f2e75149d654e1b1137868c542 100644 (file)
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -89,7 +89,7 @@ SECTIONS
                *(.discard.*)
        }
 
-       . = PAGE_OFFSET + TEXT_OFFSET;
+       . = KIMAGE_VADDR + TEXT_OFFSET;
 
        .head.text : {
                _text = .;
@@ -188,4 +188,4 @@ ASSERT(__idmap_text_end - (__idmap_text_start & ~(SZ_4K - 1)) <= SZ_4K,
 /*
  * If padding is applied before .head.text, virt<->phys conversions will fail.
  */
-ASSERT(_text == (PAGE_OFFSET + TEXT_OFFSET), "HEAD is misaligned")
+ASSERT(_text == (KIMAGE_VADDR + TEXT_OFFSET), "HEAD is misaligned")