From patchwork Fri Nov 24 18:10:03 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robin Murphy X-Patchwork-Id: 747141 Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 3ADB819AD; Fri, 24 Nov 2023 10:10:09 -0800 (PST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2CC141007; Fri, 24 Nov 2023 10:10:55 -0800 (PST) Received: from e121345-lin.cambridge.arm.com (e121345-lin.cambridge.arm.com [10.1.196.40]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 800793F73F; Fri, 24 Nov 2023 10:10:07 -0800 (PST) From: Robin Murphy To: hch@lst.de Cc: rafael@kernel.org, lenb@kernel.org, robh+dt@kernel.org, frowand.list@gmail.com, m.szyprowski@samsung.com, james.quinlan@broadcom.com, iommu@lists.linux.dev, linux-acpi@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] dma-mapping: Don't store redundant offsets Date: Fri, 24 Nov 2023 18:10:03 +0000 Message-Id: <94e0cec15546ef2be61d90869e499e40e2a55308.1700849106.git.robin.murphy@arm.com> X-Mailer: git-send-email 2.39.2.101.g768bb238c484.dirty Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 A bus_dma_region necessarily stores both CPU and DMA base addresses for a range, so there's no need to also store the difference between them. Signed-off-by: Robin Murphy Acked-by: Rob Herring --- drivers/acpi/scan.c | 1 - drivers/of/address.c | 1 - include/linux/dma-direct.h | 19 ++++++++++++------- kernel/dma/direct.c | 1 - 4 files changed, 12 insertions(+), 10 deletions(-) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 026130b37967..c72155606550 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -1532,7 +1532,6 @@ int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map) r->cpu_start = rentry->res->start; r->dma_start = rentry->res->start - rentry->offset; r->size = resource_size(rentry->res); - r->offset = rentry->offset; r++; } } diff --git a/drivers/of/address.c b/drivers/of/address.c index b59956310f66..ae46a3605904 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -955,7 +955,6 @@ int of_dma_get_range(struct device_node *np, const struct bus_dma_region **map) r->cpu_start = range.cpu_addr; r->dma_start = range.bus_addr; r->size = range.size; - r->offset = range.cpu_addr - range.bus_addr; r++; } out: diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h index 18aade195884..3eb3589ff43e 100644 --- a/include/linux/dma-direct.h +++ b/include/linux/dma-direct.h @@ -21,7 +21,6 @@ struct bus_dma_region { phys_addr_t cpu_start; dma_addr_t dma_start; u64 size; - u64 offset; }; static inline dma_addr_t translate_phys_to_dma(struct device *dev, @@ -29,9 +28,12 @@ static inline dma_addr_t translate_phys_to_dma(struct device *dev, { const struct bus_dma_region *m; - for (m = dev->dma_range_map; m->size; m++) - if (paddr >= m->cpu_start && paddr - m->cpu_start < m->size) - return (dma_addr_t)paddr - m->offset; + for (m = dev->dma_range_map; m->size; m++) { + u64 offset = paddr - m->cpu_start; + + if (paddr >= m->cpu_start && offset < m->size) + return m->dma_start + offset; + } /* make sure dma_capable fails when no translation is available */ return DMA_MAPPING_ERROR; @@ -42,9 +44,12 @@ static inline phys_addr_t translate_dma_to_phys(struct device *dev, { const struct bus_dma_region *m; - for (m = dev->dma_range_map; m->size; m++) - if (dma_addr >= m->dma_start && dma_addr - m->dma_start < m->size) - return (phys_addr_t)dma_addr + m->offset; + for (m = dev->dma_range_map; m->size; m++) { + u64 offset = dma_addr - m->dma_start; + + if (dma_addr >= m->dma_start && offset < m->size) + return m->cpu_start + offset; + } return (phys_addr_t)-1; } diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 73c95815789a..98b2e192fd69 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -677,7 +677,6 @@ int dma_direct_set_offset(struct device *dev, phys_addr_t cpu_start, return -ENOMEM; map[0].cpu_start = cpu_start; map[0].dma_start = dma_start; - map[0].offset = offset; map[0].size = size; dev->dma_range_map = map; return 0;