[PATCH 3.16 136/328] xtensa: limit offsets in __loop_cache_{all,page}

Ben Hutchings
2018-12-09T22:07:56Z

From: Max Filippov <jcmvbkbc@gmail.com>

commit be75de25251f7cf3e399ca1f584716a95510d24a upstream.

When building kernel for xtensa cores with big cache lines (e.g. 128
bytes or more) __loop_cache_all and __loop_cache_page may generate
assembly instructions with immediate fields that are too big. This
results in the following build errors:

arch/xtensa/mm/misc.S: Assembler messages:
arch/xtensa/mm/misc.S:464: Error: operand 2 of 'diwbi' has invalid value '256'
arch/xtensa/mm/misc.S:464: Error: operand 2 of 'diwbi' has invalid value '384'
arch/xtensa/kernel/head.S: Assembler messages:
arch/xtensa/kernel/head.S:172: Error: operand 2 of 'diu' has invalid value '256'
arch/xtensa/kernel/head.S:172: Error: operand 2 of 'diu' has invalid value '384'
arch/xtensa/kernel/head.S:176: Error: operand 2 of 'iiu' has invalid value '256'
arch/xtensa/kernel/head.S:176: Error: operand 2 of 'iiu' has invalid value '384'
arch/xtensa/kernel/head.S:255: Error: operand 2 of 'diwb' has invalid value '256'
arch/xtensa/kernel/head.S:255: Error: operand 2 of 'diwb' has invalid value '384'

Add parameter max_immed to these macros and use it to limit values of
immediate operands. Extract common code of these macros into the new
macro __loop_cache_unroll.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/xtensa/include/asm/cacheasm.h | 65 ++++++++++++++++++------------
1 file changed, 40 insertions(+), 25 deletions(-)

--- a/arch/xtensa/include/asm/cacheasm.h
+++ b/arch/xtensa/include/asm/cacheasm.h
@@ -31,16 +31,32 @@
*
*/

- .macro __loop_cache_all ar at insn size line_width

- movi \ar, 0
+ .macro __loop_cache_unroll ar at insn size line_width max_immed
+
+ .if (1 << (\line_width)) > (\max_immed)
+ .set _reps, 1
+ .elseif (2 << (\line_width)) > (\max_immed)
+ .set _reps, 2
+ .else
+ .set _reps, 4
+ .endif
+
+ __loopi \ar, \at, \size, (_reps << (\line_width))
+ .set _index, 0
+ .rep _reps
+ \insn \ar, _index << (\line_width)
+ .set _index, _index + 1
+ .endr
+ __endla \ar, \at, _reps << (\line_width)
+
+ .endm
+

- __loopi \ar, \at, \size, (4 << (\line_width))
- \insn \ar, 0 << (\line_width)
- \insn \ar, 1 << (\line_width)
- \insn \ar, 2 << (\line_width)
- \insn \ar, 3 << (\line_width)
- __endla \ar, \at, 4 << (\line_width)
+ .macro __loop_cache_all ar at insn size line_width max_immed
+
+ movi \ar, 0
+ __loop_cache_unroll \ar, \at, \insn, \size, \line_width, \max_immed

.endm

@@ -57,14 +73,9 @@
.endm

- .macro __loop_cache_page ar at insn line_width
+ .macro __loop_cache_page ar at insn line_width max_immed

- __loopi \ar, \at, PAGE_SIZE, 4 << (\line_width)
- \insn \ar, 0 << (\line_width)
- \insn \ar, 1 << (\line_width)
- \insn \ar, 2 << (\line_width)
- \insn \ar, 3 << (\line_width)
- __endla \ar, \at, 4 << (\line_width)
+ __loop_cache_unroll \ar, \at, \insn, PAGE_SIZE, \line_width, \max_immed

.endm

@@ -73,7 +84,8 @@

.macro ___unlock_dcache_all ar at

- __loop_cache_all \ar \at diu XCHAL_DCACHE_SIZE XCHAL_DCACHE_LINEWIDTH
+ __loop_cache_all \ar \at diu XCHAL_DCACHE_SIZE \
+ XCHAL_DCACHE_LINEWIDTH 240

.endm

@@ -83,21 +95,24 @@

.macro ___unlock_icache_all ar at

- __loop_cache_all \ar \at iiu XCHAL_ICACHE_SIZE XCHAL_ICACHE_LINEWIDTH
+ __loop_cache_all \ar \at iiu XCHAL_ICACHE_SIZE \
+ XCHAL_ICACHE_LINEWIDTH 240

.endm
#endif

.macro ___flush_invalidate_dcache_all ar at

- __loop_cache_all \ar \at diwbi XCHAL_DCACHE_SIZE XCHAL_DCACHE_LINEWIDTH
+ __loop_cache_all \ar \at diwbi XCHAL_DCACHE_SIZE \
+ XCHAL_DCACHE_LINEWIDTH 240

.endm

.macro ___flush_dcache_all ar at

- __loop_cache_all \ar \at diwb XCHAL_DCACHE_SIZE XCHAL_DCACHE_LINEWIDTH
+ __loop_cache_all \ar \at diwb XCHAL_DCACHE_SIZE \
+ XCHAL_DCACHE_LINEWIDTH 240

.endm

@@ -105,7 +120,7 @@
.macro ___invalidate_dcache_all ar at

__loop_cache_all \ar \at dii __stringify(DCACHE_WAY_SIZE) \
- XCHAL_DCACHE_LINEWIDTH
+ XCHAL_DCACHE_LINEWIDTH 1020

.endm

@@ -113,7 +128,7 @@
.macro ___invalidate_icache_all ar at

__loop_cache_all \ar \at iii __stringify(ICACHE_WAY_SIZE) \
- XCHAL_ICACHE_LINEWIDTH
+ XCHAL_ICACHE_LINEWIDTH 1020

.endm

@@ -150,27 +165,27 @@

.macro ___flush_invalidate_dcache_page ar as

- __loop_cache_page \ar \as dhwbi XCHAL_DCACHE_LINEWIDTH
+ __loop_cache_page \ar \as dhwbi XCHAL_DCACHE_LINEWIDTH 1020

.endm

.macro ___flush_dcache_page ar as

- __loop_cache_page \ar \as dhwb XCHAL_DCACHE_LINEWIDTH
+ __loop_cache_page \ar \as dhwb XCHAL_DCACHE_LINEWIDTH 1020

.endm

.macro ___invalidate_dcache_page ar as

- __loop_cache_page \ar \as dhi XCHAL_DCACHE_LINEWIDTH
+ __loop_cache_page \ar \as dhi XCHAL_DCACHE_LINEWIDTH 1020

.endm

.macro ___invalidate_icache_page ar as

- __loop_cache_page \ar \as ihi XCHAL_ICACHE_LINEWIDTH
+ __loop_cache_page \ar \as ihi XCHAL_ICACHE_LINEWIDTH 1020

.endm