| Message ID | 20161025153658.4815.84254.stgit@ahduyck-blue-test.jf.intel.com |
|---|---|
| State | Awaiting Upstream |
| Delegated to: | Jeff Kirsher |
| Headers | show |
On Tue, Oct 25, 2016 at 11:36:58AM -0400, Alexander Duyck wrote: > The mapping function should always return DMA_ERROR_CODE when a mapping has > failed as this is what the DMA API expects when a DMA error has occurred. > The current function for mapping a page in Xen was returning either > DMA_ERROR_CODE or 0 depending on where it failed. > > On x86 DMA_ERROR_CODE is 0, but on other architectures such as ARM it is > ~0. We need to make sure we return the same error value if either the > mapping failed or the device is not capable of accessing the mapping. > > If we are returning DMA_ERROR_CODE as our error value we can drop the > function for checking the error code as the default is to compare the > return value against DMA_ERROR_CODE if no function is defined. > > Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> I am pretty sure I gave an Ack. Any particular reason from dropping it (if so, please add a comment under the --- of the reason). Thanks. > Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> > --- > arch/arm/xen/mm.c | 1 - > arch/x86/xen/pci-swiotlb-xen.c | 1 - > drivers/xen/swiotlb-xen.c | 18 ++++++------------ > include/xen/swiotlb-xen.h | 3 --- > 4 files changed, 6 insertions(+), 17 deletions(-) > > diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c > index d062f08..bd62d94 100644 > --- a/arch/arm/xen/mm.c > +++ b/arch/arm/xen/mm.c > @@ -186,7 +186,6 @@ void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order) > EXPORT_SYMBOL(xen_dma_ops); > > static struct dma_map_ops xen_swiotlb_dma_ops = { > - .mapping_error = xen_swiotlb_dma_mapping_error, > .alloc = xen_swiotlb_alloc_coherent, > .free = xen_swiotlb_free_coherent, > .sync_single_for_cpu = xen_swiotlb_sync_single_for_cpu, > diff --git a/arch/x86/xen/pci-swiotlb-xen.c b/arch/x86/xen/pci-swiotlb-xen.c > index 0e98e5d..a9fafb5 100644 > --- a/arch/x86/xen/pci-swiotlb-xen.c > +++ b/arch/x86/xen/pci-swiotlb-xen.c > @@ -19,7 +19,6 @@ > int xen_swiotlb __read_mostly; > > static struct dma_map_ops xen_swiotlb_dma_ops = { > - .mapping_error = xen_swiotlb_dma_mapping_error, > .alloc = xen_swiotlb_alloc_coherent, > .free = xen_swiotlb_free_coherent, > .sync_single_for_cpu = xen_swiotlb_sync_single_for_cpu, > diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c > index 87e6035..b8014bf 100644 > --- a/drivers/xen/swiotlb-xen.c > +++ b/drivers/xen/swiotlb-xen.c > @@ -416,11 +416,12 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page, > /* > * Ensure that the address returned is DMA'ble > */ > - if (!dma_capable(dev, dev_addr, size)) { > - swiotlb_tbl_unmap_single(dev, map, size, dir); > - dev_addr = 0; > - } > - return dev_addr; > + if (dma_capable(dev, dev_addr, size)) > + return dev_addr; > + > + swiotlb_tbl_unmap_single(dev, map, size, dir); > + > + return DMA_ERROR_CODE; > } > EXPORT_SYMBOL_GPL(xen_swiotlb_map_page); > > @@ -648,13 +649,6 @@ void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, > } > EXPORT_SYMBOL_GPL(xen_swiotlb_sync_sg_for_device); > > -int > -xen_swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr) > -{ > - return !dma_addr; > -} > -EXPORT_SYMBOL_GPL(xen_swiotlb_dma_mapping_error); > - > /* > * Return whether the given device DMA address mask can be supported > * properly. For example, if your device can only drive the low 24-bits > diff --git a/include/xen/swiotlb-xen.h b/include/xen/swiotlb-xen.h > index 7c35e27..a0083be 100644 > --- a/include/xen/swiotlb-xen.h > +++ b/include/xen/swiotlb-xen.h > @@ -51,9 +51,6 @@ extern void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, > int nelems, enum dma_data_direction dir); > > extern int > -xen_swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr); > - > -extern int > xen_swiotlb_dma_supported(struct device *hwdev, u64 mask); > > extern int >
diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c index d062f08..bd62d94 100644 --- a/arch/arm/xen/mm.c +++ b/arch/arm/xen/mm.c @@ -186,7 +186,6 @@ void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order) EXPORT_SYMBOL(xen_dma_ops); static struct dma_map_ops xen_swiotlb_dma_ops = { - .mapping_error = xen_swiotlb_dma_mapping_error, .alloc = xen_swiotlb_alloc_coherent, .free = xen_swiotlb_free_coherent, .sync_single_for_cpu = xen_swiotlb_sync_single_for_cpu, diff --git a/arch/x86/xen/pci-swiotlb-xen.c b/arch/x86/xen/pci-swiotlb-xen.c index 0e98e5d..a9fafb5 100644 --- a/arch/x86/xen/pci-swiotlb-xen.c +++ b/arch/x86/xen/pci-swiotlb-xen.c @@ -19,7 +19,6 @@ int xen_swiotlb __read_mostly; static struct dma_map_ops xen_swiotlb_dma_ops = { - .mapping_error = xen_swiotlb_dma_mapping_error, .alloc = xen_swiotlb_alloc_coherent, .free = xen_swiotlb_free_coherent, .sync_single_for_cpu = xen_swiotlb_sync_single_for_cpu, diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 87e6035..b8014bf 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -416,11 +416,12 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page, /* * Ensure that the address returned is DMA'ble */ - if (!dma_capable(dev, dev_addr, size)) { - swiotlb_tbl_unmap_single(dev, map, size, dir); - dev_addr = 0; - } - return dev_addr; + if (dma_capable(dev, dev_addr, size)) + return dev_addr; + + swiotlb_tbl_unmap_single(dev, map, size, dir); + + return DMA_ERROR_CODE; } EXPORT_SYMBOL_GPL(xen_swiotlb_map_page); @@ -648,13 +649,6 @@ void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, } EXPORT_SYMBOL_GPL(xen_swiotlb_sync_sg_for_device); -int -xen_swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr) -{ - return !dma_addr; -} -EXPORT_SYMBOL_GPL(xen_swiotlb_dma_mapping_error); - /* * Return whether the given device DMA address mask can be supported * properly. For example, if your device can only drive the low 24-bits diff --git a/include/xen/swiotlb-xen.h b/include/xen/swiotlb-xen.h index 7c35e27..a0083be 100644 --- a/include/xen/swiotlb-xen.h +++ b/include/xen/swiotlb-xen.h @@ -51,9 +51,6 @@ extern void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, int nelems, enum dma_data_direction dir); extern int -xen_swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr); - -extern int xen_swiotlb_dma_supported(struct device *hwdev, u64 mask); extern int
The mapping function should always return DMA_ERROR_CODE when a mapping has failed as this is what the DMA API expects when a DMA error has occurred. The current function for mapping a page in Xen was returning either DMA_ERROR_CODE or 0 depending on where it failed. On x86 DMA_ERROR_CODE is 0, but on other architectures such as ARM it is ~0. We need to make sure we return the same error value if either the mapping failed or the device is not capable of accessing the mapping. If we are returning DMA_ERROR_CODE as our error value we can drop the function for checking the error code as the default is to compare the return value against DMA_ERROR_CODE if no function is defined. Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> --- arch/arm/xen/mm.c | 1 - arch/x86/xen/pci-swiotlb-xen.c | 1 - drivers/xen/swiotlb-xen.c | 18 ++++++------------ include/xen/swiotlb-xen.h | 3 --- 4 files changed, 6 insertions(+), 17 deletions(-)