diff options
| author | Jiaxun Yang <jiaxun.yang@flygoat.com> | 2023-02-21 16:16:58 +0300 |
|---|---|---|
| committer | Thomas Bogendoerfer <tsbogend@alpha.franken.de> | 2023-03-14 19:06:16 +0300 |
| commit | 7b76ab837522fd6aa72b25d1c5460995095fedc0 (patch) | |
| tree | d1768e1ee3e73429e6b2e9b99076588aa6efb1b8 /arch/mips/include/asm/io.h | |
| parent | 162e134aedcacc9ab9d5648349ceb5409f9ec880 (diff) | |
| download | linux-7b76ab837522fd6aa72b25d1c5460995095fedc0.tar.xz | |
MIPS: Loongson64: Opt-out war_io_reorder_wmb
It is clearly stated on "Loongson 3A3000/3B3000 processor
user manual vol 2" that
"All access requests using a non-cached algorithm are executed in a
blocking order. That is, before the current read request data is
returned to the processor, all subsequent requests are blocked and issued;
All subsequent requests are blocked until the write request data has been
sent or the issued write request has not received a write reply from the
final receiver."
Which means uncached read/write is strongly ordered. So we won't need this
workaround.
This option was introduced when we add initial support for GS464E, it looks
like a misinterpretation of another section in the manual saying we need
barriers to ensure MMIO order against DMA requests.
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Diffstat (limited to 'arch/mips/include/asm/io.h')
| -rw-r--r-- | arch/mips/include/asm/io.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h index e6d5ccaa309e..cc28d207a061 100644 --- a/arch/mips/include/asm/io.h +++ b/arch/mips/include/asm/io.h @@ -210,7 +210,7 @@ void iounmap(const volatile void __iomem *addr); #define ioremap_wc(offset, size) \ ioremap_prot((offset), (size), boot_cpu_data.writecombine) -#if defined(CONFIG_CPU_CAVIUM_OCTEON) || defined(CONFIG_CPU_LOONGSON64) +#if defined(CONFIG_CPU_CAVIUM_OCTEON) #define war_io_reorder_wmb() wmb() #else #define war_io_reorder_wmb() barrier() |