lkml.org 
[lkml]   [2020]   [Mar]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v9 11/18] arm64: kexec: arm64_relocate_new_kernel clean-ups
Date
Remove excessive empty lines from arm64_relocate_new_kernel.
Also, use comments on the same lines with instructions where
appropriate.

Change ENDPROC to END it never returns.

copy_page(dest, src, tmps...)
Increments dest and src by PAGE_SIZE, so no need to store dest
prior to calling copy_page and increment it after. Also, src is not
used after a copy, not need to copy either.

Call raw_dcache_line_size() only when relocation is actually going to
happen.

Since '.align 3' is intended to align globals at the end of the file,
move it there.

Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
---
arch/arm64/kernel/relocate_kernel.S | 50 +++++++----------------------
1 file changed, 11 insertions(+), 39 deletions(-)

diff --git a/arch/arm64/kernel/relocate_kernel.S b/arch/arm64/kernel/relocate_kernel.S
index c1d7db71a726..e9c974ea4717 100644
--- a/arch/arm64/kernel/relocate_kernel.S
+++ b/arch/arm64/kernel/relocate_kernel.S
@@ -8,7 +8,6 @@

#include <linux/kexec.h>
#include <linux/linkage.h>
-
#include <asm/assembler.h>
#include <asm/kexec.h>
#include <asm/page.h>
@@ -17,25 +16,21 @@
/*
* arm64_relocate_new_kernel - Put a 2nd stage image in place and boot it.
*
- * The memory that the old kernel occupies may be overwritten when coping the
+ * The memory that the old kernel occupies may be overwritten when copying the
* new image to its final location. To assure that the
* arm64_relocate_new_kernel routine which does that copy is not overwritten,
* all code and data needed by arm64_relocate_new_kernel must be between the
* symbols arm64_relocate_new_kernel and arm64_relocate_new_kernel_end. The
* machine_kexec() routine will copy arm64_relocate_new_kernel to the kexec
- * control_code_page, a special page which has been set up to be preserved
- * during the copy operation.
+ * safe memory that has been set up to be preserved during the copy operation.
*/
ENTRY(arm64_relocate_new_kernel)
-
/* Setup the list loop variables. */
mov x18, x2 /* x18 = dtb address */
mov x17, x1 /* x17 = kimage_start */
mov x16, x0 /* x16 = kimage_head */
- raw_dcache_line_size x15, x0 /* x15 = dcache line size */
mov x14, xzr /* x14 = entry ptr */
mov x13, xzr /* x13 = copy dest */
-
/* Clear the sctlr_el2 flags. */
mrs x0, CurrentEL
cmp x0, #CurrentEL_EL2
@@ -46,14 +41,11 @@ ENTRY(arm64_relocate_new_kernel)
pre_disable_mmu_workaround
msr sctlr_el2, x0
isb
-1:
-
- /* Check if the new image needs relocation. */
+1: /* Check if the new image needs relocation. */
tbnz x16, IND_DONE_BIT, .Ldone
-
+ raw_dcache_line_size x15, x1 /* x15 = dcache line size */
.Lloop:
and x12, x16, PAGE_MASK /* x12 = addr */
-
/* Test the entry flags. */
.Ltest_source:
tbz x16, IND_SOURCE_BIT, .Ltest_indirection
@@ -69,34 +61,18 @@ ENTRY(arm64_relocate_new_kernel)
b.lo 2b
dsb sy

- mov x20, x13
- mov x21, x12
- copy_page x20, x21, x0, x1, x2, x3, x4, x5, x6, x7
-
- /* dest += PAGE_SIZE */
- add x13, x13, PAGE_SIZE
+ copy_page x13, x12, x0, x1, x2, x3, x4, x5, x6, x7
b .Lnext
-
.Ltest_indirection:
tbz x16, IND_INDIRECTION_BIT, .Ltest_destination
-
- /* ptr = addr */
- mov x14, x12
+ mov x14, x12 /* ptr = addr */
b .Lnext
-
.Ltest_destination:
tbz x16, IND_DESTINATION_BIT, .Lnext
-
- /* dest = addr */
- mov x13, x12
-
+ mov x13, x12 /* dest = addr */
.Lnext:
- /* entry = *ptr++ */
- ldr x16, [x14], #8
-
- /* while (!(entry & DONE)) */
- tbz x16, IND_DONE_BIT, .Lloop
-
+ ldr x16, [x14], #8 /* entry = *ptr++ */
+ tbz x16, IND_DONE_BIT, .Lloop /* while (!(entry & DONE)) */
.Ldone:
/* wait for writes from copy_page to finish */
dsb nsh
@@ -110,16 +86,12 @@ ENTRY(arm64_relocate_new_kernel)
mov x2, xzr
mov x3, xzr
br x17
-
-ENDPROC(arm64_relocate_new_kernel)
-
.ltorg
-
-.align 3 /* To keep the 64-bit values below naturally aligned. */
+END(arm64_relocate_new_kernel)

.Lcopy_end:
.org KEXEC_CONTROL_PAGE_SIZE
-
+.align 3 /* To keep the 64-bit values below naturally aligned. */
/*
* arm64_relocate_new_kernel_size - Number of bytes to copy to the
* control_code_page.
--
2.17.1
\
 
 \ /
  Last update: 2020-03-26 04:25    [W:0.072 / U:8.436 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site