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| author | Helge Deller <deller@gmx.de> | 2022-09-29 00:31:20 +0300 |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2022-10-11 13:01:24 +0300 |
| commit | b148766e2b8b7b61c9aef53aefedae33f637a1e7 (patch) | |
| tree | 0d469cca1896e632990fe5e35db5008f365ae32c /arch/parisc/include | |
| parent | 4fe89d07dcc2804c8b562f6c7896a45643d34b2f (diff) | |
| download | linux-b148766e2b8b7b61c9aef53aefedae33f637a1e7.tar.xz | |
parisc: Reduce kernel size by packing alternative tables
The values stored in the length and condition fields of the alternative
tables fit into 16 bits, so we can save 4 bytes per alternative table
entry.
Since a typical 32-bit kernel has more than 3000 entries this
saves > 12k of storage on disc.
bloat-o-meter shows a reduction of -0.01% by this change:
Total: Before=10196505, After=10195529, chg -0.01%
$ ls -la vmlinux vmlinux.before
-rwxr-xr-x 14437324 vmlinux
-rwxr-xr-x 14449512 vmlinux.before
Signed-off-by: Helge Deller <deller@gmx.de>
Diffstat (limited to 'arch/parisc/include')
| -rw-r--r-- | arch/parisc/include/asm/alternative.h | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/arch/parisc/include/asm/alternative.h b/arch/parisc/include/asm/alternative.h index 0ec54f43d6d2..1ed45fd085d3 100644 --- a/arch/parisc/include/asm/alternative.h +++ b/arch/parisc/include/asm/alternative.h @@ -22,10 +22,10 @@ struct alt_instr { s32 orig_offset; /* offset to original instructions */ - s32 len; /* end of original instructions */ - u32 cond; /* see ALT_COND_XXX */ + s16 len; /* end of original instructions */ + u16 cond; /* see ALT_COND_XXX */ u32 replacement; /* replacement instruction or code */ -}; +} __packed; void set_kernel_text_rw(int enable_read_write); void apply_alternatives_all(void); @@ -35,8 +35,9 @@ void apply_alternatives(struct alt_instr *start, struct alt_instr *end, /* Alternative SMP implementation. */ #define ALTERNATIVE(cond, replacement) "!0:" \ ".section .altinstructions, \"aw\" !" \ - ".word (0b-4-.), 1, " __stringify(cond) "," \ - __stringify(replacement) " !" \ + ".word (0b-4-.) !" \ + ".hword 1, " __stringify(cond) " !" \ + ".word " __stringify(replacement) " !" \ ".previous" #else @@ -44,15 +45,17 @@ void apply_alternatives(struct alt_instr *start, struct alt_instr *end, /* to replace one single instructions by a new instruction */ #define ALTERNATIVE(from, to, cond, replacement)\ .section .altinstructions, "aw" ! \ - .word (from - .), (to - from)/4 ! \ - .word cond, replacement ! \ + .word (from - .) ! \ + .hword (to - from)/4, cond ! \ + .word replacement ! \ .previous /* to replace multiple instructions by new code */ #define ALTERNATIVE_CODE(from, num_instructions, cond, new_instr_ptr)\ .section .altinstructions, "aw" ! \ - .word (from - .), -num_instructions ! \ - .word cond, (new_instr_ptr - .) ! \ + .word (from - .) ! \ + .hword -num_instructions, cond ! \ + .word (new_instr_ptr - .) ! \ .previous #endif /* __ASSEMBLY__ */ |