From: Xianting TIan <xianting.tian@linux.alibaba.com> To: Jisheng Zhang <jszhang3@mail.ustc.edu.cn> Cc: paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, guoren@kernel.org, arnd@arndb.de Subject: Re: [PATCH] riscv: add ARCH_DMA_MINALIGN support Date: Mon, 9 Aug 2021 09:55:43 +0800 [thread overview] Message-ID: <6a189d9d-b35d-3a15-5bfa-172c50e60c8c@linux.alibaba.com> (raw) In-Reply-To: <20210809003044.6692ddce@xhacker> 在 2021/8/9 上午12:30, Jisheng Zhang 写道: > On Sat, 7 Aug 2021 22:55:37 +0800 > Xianting Tian <xianting.tian@linux.alibaba.com> wrote: > >> Introduce ARCH_DMA_MINALIGN to riscv arch. >> >> Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com> >> --- >> arch/riscv/include/asm/cache.h | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/arch/riscv/include/asm/cache.h b/arch/riscv/include/asm/cache.h >> index 9b58b1045..2945bbe2b 100644 >> --- a/arch/riscv/include/asm/cache.h >> +++ b/arch/riscv/include/asm/cache.h >> @@ -11,6 +11,8 @@ >> >> #define L1_CACHE_BYTES (1 << L1_CACHE_SHIFT) >> >> +#define ARCH_DMA_MINALIGN L1_CACHE_BYTES > It's not a good idea to blindly set this for all riscv. For "coherent" > platforms, this is not necessary and will waste memory. > thanks for the reply, So riscv is the "coherent" platform? I submit this patch as I got a fix suggestion of another patch to use ARCH_DMA_MINALIGN, but riscv doesn't define it. https://lkml.org/lkml/2021/8/6/723 <https://lkml.org/lkml/2021/8/6/723> Considering the portability of the code, in my opinion, it is better to define it for riscv if it is not "coherent" platform. >> + >> /* >> * RISC-V requires the stack pointer to be 16-byte aligned, so ensure that >> * the flat loader aligns it accordingly.
WARNING: multiple messages have this Message-ID (diff)
From: Xianting TIan <xianting.tian@linux.alibaba.com> To: Jisheng Zhang <jszhang3@mail.ustc.edu.cn> Cc: paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, guoren@kernel.org, arnd@arndb.de Subject: Re: [PATCH] riscv: add ARCH_DMA_MINALIGN support Date: Mon, 9 Aug 2021 09:55:43 +0800 [thread overview] Message-ID: <6a189d9d-b35d-3a15-5bfa-172c50e60c8c@linux.alibaba.com> (raw) In-Reply-To: <20210809003044.6692ddce@xhacker> 在 2021/8/9 上午12:30, Jisheng Zhang 写道: > On Sat, 7 Aug 2021 22:55:37 +0800 > Xianting Tian <xianting.tian@linux.alibaba.com> wrote: > >> Introduce ARCH_DMA_MINALIGN to riscv arch. >> >> Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com> >> --- >> arch/riscv/include/asm/cache.h | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/arch/riscv/include/asm/cache.h b/arch/riscv/include/asm/cache.h >> index 9b58b1045..2945bbe2b 100644 >> --- a/arch/riscv/include/asm/cache.h >> +++ b/arch/riscv/include/asm/cache.h >> @@ -11,6 +11,8 @@ >> >> #define L1_CACHE_BYTES (1 << L1_CACHE_SHIFT) >> >> +#define ARCH_DMA_MINALIGN L1_CACHE_BYTES > It's not a good idea to blindly set this for all riscv. For "coherent" > platforms, this is not necessary and will waste memory. > thanks for the reply, So riscv is the "coherent" platform? I submit this patch as I got a fix suggestion of another patch to use ARCH_DMA_MINALIGN, but riscv doesn't define it. https://lkml.org/lkml/2021/8/6/723 <https://lkml.org/lkml/2021/8/6/723> Considering the portability of the code, in my opinion, it is better to define it for riscv if it is not "coherent" platform. >> + >> /* >> * RISC-V requires the stack pointer to be 16-byte aligned, so ensure that >> * the flat loader aligns it accordingly. _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv
next prev parent reply other threads:[~2021-08-09 1:55 UTC|newest] Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-08-07 14:55 [PATCH] riscv: add ARCH_DMA_MINALIGN support Xianting Tian 2021-08-07 14:55 ` Xianting Tian 2021-08-08 16:30 ` Jisheng Zhang 2021-08-08 16:30 ` Jisheng Zhang 2021-08-09 1:55 ` Xianting TIan [this message] 2021-08-09 1:55 ` Xianting TIan 2021-08-10 1:30 ` Guo Ren 2021-08-10 1:30 ` Guo Ren 2021-08-09 6:20 ` Xianting TIan 2021-08-09 6:20 ` Xianting TIan 2021-08-09 7:49 ` Arnd Bergmann 2021-08-09 7:49 ` Arnd Bergmann 2021-08-09 9:00 ` Xianting TIan 2021-08-09 9:00 ` Xianting TIan 2021-08-09 19:19 ` Atish Patra 2021-08-09 19:19 ` Atish Patra
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