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MIPS: make CPU_HAS_LOAD_STORE_LR opt-out

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CPU_HAS_LOAD_STORE_LR was introduced in 932afdeec1 ("MIPS: Add Kconfig
variable for CPUs with unaligned load/store instructions") to make code
in kernel/unaligned.c and lib/mem{cpy,set}.S more intuitive and give a
possibility to easily add new CPUs without these instruction sets in
future.

Hovewer, this variant is not optimal for mainly two reasons:
* For now, we have 20+ CPUs with such instructions and only two (MIPS R6)
  without. It will obviously be more effective and straightforward to
  have an option for these two rather than for the rest.
* You can easily miss the fact that you need to select this option when
  adding a new CPU, while all processors lacking these sets are
  well-known, so the probability of missing something is way much lower.

We can address both points by turning CPU_HAS_LOAD_STORE_LR into opt-out
CPU_NO_LOAD_STORE_LR. This also makes MIPS root Kconfig more clear and
understandable.

Signed-off-by: Alexander Lobakin <alobakin@dlink.ru>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Microchip Linux Driver Support <UNGLinuxDriver@microchip.com>
Cc: Will Deacon <will@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Allison Randal <allison@lohutok.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
This commit is contained in:
Alexander Lobakin
2020-01-22 13:58:50 +03:00
committed by Paul Burton
parent 7de86604bb
commit 18d84e2e55
4 changed files with 40 additions and 60 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
arch/mips/lib/memset.S
View File

@@ -115,7 +115,7 @@
#endif
.set reorder
#ifdef CONFIG_CPU_HAS_LOAD_STORE_LR
#ifndef CONFIG_CPU_NO_LOAD_STORE_LR
R10KCBARRIER(0(ra))
#ifdef __MIPSEB__
EX(LONG_S_L, a1, (a0), .Lfirst_fixup\@) /* make word/dword aligned */
@@ -125,7 +125,7 @@
PTR_SUBU a0, t0 /* long align ptr */
PTR_ADDU a2, t0 /* correct size */
#else /* !CONFIG_CPU_HAS_LOAD_STORE_LR */
#else /* CONFIG_CPU_NO_LOAD_STORE_LR */
#define STORE_BYTE(N) \
EX(sb, a1, N(a0), .Lbyte_fixup\@); \
.set noreorder; \
@@ -150,7 +150,7 @@
ori a0, STORMASK
xori a0, STORMASK
PTR_ADDIU a0, STORSIZE
#endif /* !CONFIG_CPU_HAS_LOAD_STORE_LR */
#endif /* CONFIG_CPU_NO_LOAD_STORE_LR */
1: ori t1, a2, 0x3f /* # of full blocks */
xori t1, 0x3f
andi t0, a2, 0x40-STORSIZE
@@ -185,7 +185,7 @@
.set noreorder
beqz a2, 1f
#ifdef CONFIG_CPU_HAS_LOAD_STORE_LR
#ifndef CONFIG_CPU_NO_LOAD_STORE_LR
PTR_ADDU a0, a2 /* What's left */
.set reorder
R10KCBARRIER(0(ra))
@@ -194,7 +194,7 @@
#else
EX(LONG_S_L, a1, -1(a0), .Llast_fixup\@)
#endif
#else
#else /* CONFIG_CPU_NO_LOAD_STORE_LR */
PTR_SUBU t0, $0, a2
.set reorder
move a2, zero /* No remaining longs */
@@ -211,7 +211,7 @@
EX(sb, a1, 6(a0), .Lbyte_fixup\@)
#endif
0:
#endif
#endif /* CONFIG_CPU_NO_LOAD_STORE_LR */
1: move a2, zero
jr ra
@@ -234,7 +234,7 @@
.hidden __memset
.endif
#ifndef CONFIG_CPU_HAS_LOAD_STORE_LR
#ifdef CONFIG_CPU_NO_LOAD_STORE_LR
.Lbyte_fixup\@:
/*
* unset_bytes = (#bytes - (#unaligned bytes)) - (-#unaligned bytes remaining + 1) + 1
@@ -243,7 +243,7 @@
PTR_SUBU a2, t0
PTR_ADDIU a2, 1
jr ra
#endif /* !CONFIG_CPU_HAS_LOAD_STORE_LR */
#endif /* CONFIG_CPU_NO_LOAD_STORE_LR */
.Lfirst_fixup\@:
/* unset_bytes already in a2 */