From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: [PATCH 04/21] microblaze: dma-mapping: skip extra DMA flushes Date: Mon, 27 Mar 2023 14:13:00 +0200 Message-ID: <20230327121317.4081816-5-arnd@kernel.org> References: <20230327121317.4081816-1-arnd@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1679919272; bh=ZhYG8JNUwjljPv9OKiF3eMGP7VJHxmj1d7o6guSf4No=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PBdwMSfV6WhGkWO4GD6yfcHOXcUpefrDC/+txqBn1K1TXjh6vtxTQLHjgNJ0FEkt0 8kEYArEe0oN6TTz55A/ouqhYMm5G10akCJmXzW/muCfT8GBSGN5Uni+3VEARUH4Auc H3B65ricYeSXsGj53UrQTCcr95NZtYK/45G5qbsvcFbKhYxNglRYB3Jv/RHrFzHtks DVdr6HivllSdF2l5dgd1hATA9JZvKqwXHc1koDjA6e60zts4nydXjlN/RqoC6otSSa Tq0Qb2MNzDbHG7RwE+Edr/TKARawLeFdDNo+IyVrlawBJzvWe5xP0tuqDo6AiiQKTk Trtj2/d6VSosQ== In-Reply-To: <20230327121317.4081816-1-arnd@kernel.org> List-ID: Content-Type: text/plain; charset="us-ascii" To: linux-kernel@vger.kernel.org Cc: Arnd Bergmann , Vineet Gupta , Russell King , Neil Armstrong , Linus Walleij , Catalin Marinas , Will Deacon , Guo Ren , Brian Cain , Geert Uytterhoeven , Michal Simek , Thomas Bogendoerfer , Dinh Nguyen , Stafford Horne , Helge Deller , Michael Ellerman , Christophe Leroy , Paul Walmsley , Palmer Dabbelt , Rich Felker , John From: Arnd Bergmann The microblaze dma_sync_* implementation uses the same function for both _for_cpu() and _for_device(), which is inconsistent with other architectures and slightly more expensive. Split it up into separate functions and skip the parts that are not needed: - on dma_sync_*_for_cpu(..., DMA_TO_DEVICE), skip the second writeback, which does nothing. - on dma_sync_*_for_cpu(..., DMA_BIDIRECTIONAL), only invalidate the cache to clear out cache lines that got loaded speculatively, but skip the extraneous writeback. Signed-off-by: Arnd Bergmann --- arch/microblaze/kernel/dma.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/arch/microblaze/kernel/dma.c b/arch/microblaze/kernel/dma.c index 04d091ade417..b4c4e45fd45e 100644 --- a/arch/microblaze/kernel/dma.c +++ b/arch/microblaze/kernel/dma.c @@ -14,8 +14,8 @@ #include #include -static void __dma_sync(phys_addr_t paddr, size_t size, - enum dma_data_direction direction) +void arch_sync_dma_for_device(phys_addr_t paddr, size_t size, + enum dma_data_direction dir) { switch (direction) { case DMA_TO_DEVICE: @@ -30,14 +30,16 @@ static void __dma_sync(phys_addr_t paddr, size_t size, } } -void arch_sync_dma_for_device(phys_addr_t paddr, size_t size, - enum dma_data_direction dir) -{ - __dma_sync(paddr, size, dir); -} - void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size, enum dma_data_direction dir) { - __dma_sync(paddr, size, dir); -} + switch (direction) { + case DMA_TO_DEVICE: + break; + case DMA_BIDIRECTIONAL: + case DMA_FROM_DEVICE: + invalidate_dcache_range(paddr, paddr + size); + break; + default: + BUG(); + }} -- 2.39.2