linux-stable/arch/mips/include/asm/edac.h
Paul Burton 378ed6f0e3
MIPS: Avoid using .set mips0 to restore ISA
We currently have 2 commonly used methods for switching ISA within
assembly code, then restoring the original ISA.

  1) Using a pair of .set push & .set pop directives. For example:

     .set	push
     .set	mips32r2
     <some_insn>
     .set	pop

  2) Using .set mips0 to restore the ISA originally specified on the
     command line. For example:

     .set	mips32r2
     <some_insn>
     .set	mips0

Unfortunately method 2 does not work with nanoMIPS toolchains, where the
assembler rejects the .set mips0 directive like so:

     Error: cannot change ISA from nanoMIPS to mips0

In preparation for supporting nanoMIPS builds, switch all instances of
method 2 in generic non-platform-specific code to use push & pop as in
method 1 instead. The .set push & .set pop is arguably cleaner anyway,
and if nothing else it's good to consistently use one method.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21037/
Cc: linux-mips@linux-mips.org
2018-11-09 10:23:19 -08:00

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C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef ASM_EDAC_H
#define ASM_EDAC_H
#include <asm/compiler.h>
/* ECC atomic, DMA, SMP and interrupt safe scrub function */
static inline void edac_atomic_scrub(void *va, u32 size)
{
unsigned long *virt_addr = va;
unsigned long temp;
u32 i;
for (i = 0; i < size / sizeof(unsigned long); i++) {
/*
* Very carefully read and write to memory atomically
* so we are interrupt, DMA and SMP safe.
*
* Intel: asm("lock; addl $0, %0"::"m"(*virt_addr));
*/
__asm__ __volatile__ (
" .set push \n"
" .set mips2 \n"
"1: ll %0, %1 # edac_atomic_scrub \n"
" addu %0, $0 \n"
" sc %0, %1 \n"
" beqz %0, 1b \n"
" .set pop \n"
: "=&r" (temp), "=" GCC_OFF_SMALL_ASM() (*virt_addr)
: GCC_OFF_SMALL_ASM() (*virt_addr));
virt_addr++;
}
}
#endif