path: root/include/asm-generic/early_ioremap.h
diff options
authorMark Salter <msalter@redhat.com>2015-09-08 15:03:01 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-09-08 15:35:28 -0700
commit6b0f68e32ea8749ff7d4a66cd5761e915e48e59d (patch)
tree6d9ca9d3b45bd0a9dc76929ed946f9cc7e4f7f3c /include/asm-generic/early_ioremap.h
parente6590740ceb83fd014fae7d571fe5a5d5886b7c8 (diff)
mm: add utility for early copy from unmapped ram
When booting an arm64 kernel w/initrd using UEFI/grub, use of mem= will likely cut off part or all of the initrd. This leaves it outside the kernel linear map which leads to failure when unpacking. The x86 code has a similar need to relocate an initrd outside of mapped memory in some cases. The current x86 code uses early_memremap() to copy the original initrd from unmapped to mapped RAM. This patchset creates a generic copy_from_early_mem() utility based on that x86 code and has arm64 and x86 share it in their respective initrd relocation code. This patch (of 3): In some early boot circumstances, it may be necessary to copy from RAM outside the kernel linear mapping to mapped RAM. The need to relocate an initrd is one example in the x86 code. This patch creates a helper function based on current x86 code. Signed-off-by: Mark Salter <msalter@redhat.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/asm-generic/early_ioremap.h')
1 files changed, 6 insertions, 0 deletions
diff --git a/include/asm-generic/early_ioremap.h b/include/asm-generic/early_ioremap.h
index a5de55c04fb2..e539f27ec51b 100644
--- a/include/asm-generic/early_ioremap.h
+++ b/include/asm-generic/early_ioremap.h
@@ -33,6 +33,12 @@ extern void early_ioremap_setup(void);
extern void early_ioremap_reset(void);
+ * Early copy from unmapped memory to kernel mapped memory.
+ */
+extern void copy_from_early_mem(void *dest, phys_addr_t src,
+ unsigned long size);
static inline void early_ioremap_init(void) { }
static inline void early_ioremap_setup(void) { }

Privacy Policy