From: Arnd Bergmann <arnd@arndb.de> To: "David S. Miller" <davem@davemloft.net> Cc: linux-arm-kernel@lists.infradead.org, Arnd Bergmann <arnd@arndb.de>, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/9] net: davinci_cpdma: use dma_addr_t for DMA address Date: Wed, 27 Jan 2016 15:04:51 +0100 [thread overview] Message-ID: <1453903507-3427225-2-git-send-email-arnd@arndb.de> (raw) In-Reply-To: <1453903507-3427225-1-git-send-email-arnd@arndb.de> The davinci_cpdma mixes up physical addresses as seen from the CPU and DMA addresses as seen from a DMA master, since it can operate on both normal memory or an on-chip buffer. If dma_addr_t is different from phys_addr_t, this means we get a compile-time warning about the type mismatch: ethernet/ti/davinci_cpdma.c: In function 'cpdma_desc_pool_create': ethernet/ti/davinci_cpdma.c:182:48: error: passing argument 3 of 'dma_alloc_coherent' from incompatible pointer type [-Werror=incompatible-pointer-types] pool->cpumap = dma_alloc_coherent(dev, size, &pool->phys, In file included from ethernet/ti/davinci_cpdma.c:21:0: dma-mapping.h:398:21: note: expected 'dma_addr_t * {aka long long unsigned int *}' but argument is of type 'phys_addr_t * {aka unsigned int *}' static inline void *dma_alloc_coherent(struct device *dev, size_t size, This slightly restructures the code so the address we use for mapping RAM into a DMA address is always a dma_addr_t, avoiding the warning. The code is correct even if both types are 32-bit because the DMA master in this device only supports 32-bit addressing anyway, independent of the types that are used. We still assign this value to pool->phys, and that is wrong if the driver is ever used with an IOMMU, but that value appears to be never used, so there is no problem really. I've added a couple of comments about where we do things that are slightly violating the API. Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- drivers/net/ethernet/ti/davinci_cpdma.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c b/drivers/net/ethernet/ti/davinci_cpdma.c index 657b65bf5cac..18bf3a8fdc50 100644 --- a/drivers/net/ethernet/ti/davinci_cpdma.c +++ b/drivers/net/ethernet/ti/davinci_cpdma.c @@ -82,7 +82,7 @@ struct cpdma_desc { struct cpdma_desc_pool { phys_addr_t phys; - u32 hw_addr; + dma_addr_t hw_addr; void __iomem *iomap; /* ioremap map */ void *cpumap; /* dma_alloc map */ int desc_size, mem_size; @@ -152,7 +152,7 @@ struct cpdma_chan { * abstract out these details */ static struct cpdma_desc_pool * -cpdma_desc_pool_create(struct device *dev, u32 phys, u32 hw_addr, +cpdma_desc_pool_create(struct device *dev, u32 phys, dma_addr_t hw_addr, int size, int align) { int bitmap_size; @@ -176,13 +176,13 @@ cpdma_desc_pool_create(struct device *dev, u32 phys, u32 hw_addr, if (phys) { pool->phys = phys; - pool->iomap = ioremap(phys, size); + pool->iomap = ioremap(phys, size); /* should be memremap? */ pool->hw_addr = hw_addr; } else { - pool->cpumap = dma_alloc_coherent(dev, size, &pool->phys, + pool->cpumap = dma_alloc_coherent(dev, size, &pool->hw_addr, GFP_KERNEL); - pool->iomap = pool->cpumap; - pool->hw_addr = pool->phys; + pool->iomap = (void __iomem __force *)pool->cpumap; + pool->phys = pool->hw_addr; /* assumes no IOMMU, don't use this value */ } if (pool->iomap) -- 2.7.0
WARNING: multiple messages have this Message-ID (diff)
From: arnd@arndb.de (Arnd Bergmann) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 1/9] net: davinci_cpdma: use dma_addr_t for DMA address Date: Wed, 27 Jan 2016 15:04:51 +0100 [thread overview] Message-ID: <1453903507-3427225-2-git-send-email-arnd@arndb.de> (raw) In-Reply-To: <1453903507-3427225-1-git-send-email-arnd@arndb.de> The davinci_cpdma mixes up physical addresses as seen from the CPU and DMA addresses as seen from a DMA master, since it can operate on both normal memory or an on-chip buffer. If dma_addr_t is different from phys_addr_t, this means we get a compile-time warning about the type mismatch: ethernet/ti/davinci_cpdma.c: In function 'cpdma_desc_pool_create': ethernet/ti/davinci_cpdma.c:182:48: error: passing argument 3 of 'dma_alloc_coherent' from incompatible pointer type [-Werror=incompatible-pointer-types] pool->cpumap = dma_alloc_coherent(dev, size, &pool->phys, In file included from ethernet/ti/davinci_cpdma.c:21:0: dma-mapping.h:398:21: note: expected 'dma_addr_t * {aka long long unsigned int *}' but argument is of type 'phys_addr_t * {aka unsigned int *}' static inline void *dma_alloc_coherent(struct device *dev, size_t size, This slightly restructures the code so the address we use for mapping RAM into a DMA address is always a dma_addr_t, avoiding the warning. The code is correct even if both types are 32-bit because the DMA master in this device only supports 32-bit addressing anyway, independent of the types that are used. We still assign this value to pool->phys, and that is wrong if the driver is ever used with an IOMMU, but that value appears to be never used, so there is no problem really. I've added a couple of comments about where we do things that are slightly violating the API. Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- drivers/net/ethernet/ti/davinci_cpdma.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c b/drivers/net/ethernet/ti/davinci_cpdma.c index 657b65bf5cac..18bf3a8fdc50 100644 --- a/drivers/net/ethernet/ti/davinci_cpdma.c +++ b/drivers/net/ethernet/ti/davinci_cpdma.c @@ -82,7 +82,7 @@ struct cpdma_desc { struct cpdma_desc_pool { phys_addr_t phys; - u32 hw_addr; + dma_addr_t hw_addr; void __iomem *iomap; /* ioremap map */ void *cpumap; /* dma_alloc map */ int desc_size, mem_size; @@ -152,7 +152,7 @@ struct cpdma_chan { * abstract out these details */ static struct cpdma_desc_pool * -cpdma_desc_pool_create(struct device *dev, u32 phys, u32 hw_addr, +cpdma_desc_pool_create(struct device *dev, u32 phys, dma_addr_t hw_addr, int size, int align) { int bitmap_size; @@ -176,13 +176,13 @@ cpdma_desc_pool_create(struct device *dev, u32 phys, u32 hw_addr, if (phys) { pool->phys = phys; - pool->iomap = ioremap(phys, size); + pool->iomap = ioremap(phys, size); /* should be memremap? */ pool->hw_addr = hw_addr; } else { - pool->cpumap = dma_alloc_coherent(dev, size, &pool->phys, + pool->cpumap = dma_alloc_coherent(dev, size, &pool->hw_addr, GFP_KERNEL); - pool->iomap = pool->cpumap; - pool->hw_addr = pool->phys; + pool->iomap = (void __iomem __force *)pool->cpumap; + pool->phys = pool->hw_addr; /* assumes no IOMMU, don't use this value */ } if (pool->iomap) -- 2.7.0
next prev parent reply other threads:[~2016-01-27 14:06 UTC|newest] Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-01-27 14:04 [PATCH 0/9] network driver fixes Arnd Bergmann 2016-01-27 14:04 ` Arnd Bergmann 2016-01-27 14:04 ` Arnd Bergmann [this message] 2016-01-27 14:04 ` [PATCH 1/9] net: davinci_cpdma: use dma_addr_t for DMA address Arnd Bergmann 2016-01-27 14:04 ` [PATCH 2/9] net: hp100: remove unnecessary #ifdefs Arnd Bergmann 2016-01-27 14:04 ` Arnd Bergmann 2016-01-27 14:04 ` [PATCH 3/9] net: bgmac: clarify CONFIG_BCMA dependency Arnd Bergmann 2016-01-27 14:04 ` Arnd Bergmann 2016-01-27 16:11 ` Paul Gortmaker 2016-01-27 16:11 ` Paul Gortmaker 2016-01-27 16:11 ` Paul Gortmaker 2016-01-28 8:49 ` Arnd Bergmann 2016-01-28 8:49 ` Arnd Bergmann 2016-01-27 14:04 ` [PATCH 4/9] net: moxart: use correct accessors for DMA memory Arnd Bergmann 2016-01-27 14:04 ` Arnd Bergmann 2016-01-28 12:36 ` David Laight 2016-01-28 12:36 ` David Laight 2016-01-28 16:53 ` Arnd Bergmann 2016-01-28 16:53 ` Arnd Bergmann 2016-01-28 16:58 ` Arnd Bergmann 2016-01-28 16:58 ` Arnd Bergmann 2016-01-27 14:04 ` [PATCH 5/9] net: fddi/defxx: avoid warning about uninitialized variable use Arnd Bergmann 2016-01-27 14:04 ` Arnd Bergmann 2016-01-27 15:15 ` Maciej W. Rozycki 2016-01-27 15:15 ` Maciej W. Rozycki 2016-01-27 14:04 ` [PATCH 6/9] net: vxge: avoid unused function warnings Arnd Bergmann 2016-01-27 14:04 ` Arnd Bergmann 2016-01-27 14:04 ` [PATCH 7/9] net: macb: avoid uninitialized variables Arnd Bergmann 2016-01-27 14:04 ` Arnd Bergmann 2016-01-27 15:51 ` Nicolas Ferre 2016-01-27 15:51 ` Nicolas Ferre 2016-01-27 16:04 ` Nicolas Ferre 2016-01-27 16:04 ` Nicolas Ferre 2016-01-28 16:32 ` Arnd Bergmann 2016-01-28 16:32 ` Arnd Bergmann 2016-01-28 13:27 ` Sergei Shtylyov 2016-01-28 13:27 ` Sergei Shtylyov 2016-01-27 14:04 ` [PATCH 8/9] net: nb8800: avoid uninitialized variable warning Arnd Bergmann 2016-01-27 14:04 ` Arnd Bergmann 2016-01-27 14:13 ` Måns Rullgård 2016-01-27 14:13 ` Måns Rullgård 2016-01-27 15:21 ` Arnd Bergmann 2016-01-27 15:21 ` Arnd Bergmann 2016-01-27 14:04 ` [PATCH 9/9] net: tg3: " Arnd Bergmann 2016-01-27 14:04 ` Arnd Bergmann 2016-01-29 0:14 ` [PATCH 0/9] network driver fixes David Miller 2016-01-29 0:14 ` David Miller 2016-01-29 12:56 ` Arnd Bergmann 2016-01-29 12:56 ` Arnd Bergmann
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