| Message ID | 1414085246-16160-3-git-send-email-stefano.stabellini@eu.citrix.com |
|---|---|
| State | New |
| Headers | show |
On Thu, 2014-10-23 at 18:27 +0100, Stefano Stabellini wrote: > Introduce a utility function to check whether a device is dma coherent. > The current implementation is suboptimal. Let's rework it later in > common arch/arm code. > > Use it to figure out whether we need to issue cache maintenance > operations instead of checking on the existence of a particular dma_ops > function for the device. > > Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> As well as refactoring this also changes the nature of the test, making it tighter AFAICT. Perhaps it is the same because you happen to know that arm_coherent_dma_ops is the only possible one which doesn't set the hooks you were checking before. Either way this should be mentioned in the commit log. With that done: Acked-by: Ian Campbell <ian.campbell@citrix.com> > > --- > > Changes in v5: > - introduce xen_is_dma_coherent as a xen specific function; > - call xen_is_dma_coherent instead of is_dma_coherent. > --- > arch/arm/include/asm/xen/page-coherent.h | 5 +++++ > arch/arm/xen/mm32.c | 6 +++--- > 2 files changed, 8 insertions(+), 3 deletions(-) > > diff --git a/arch/arm/include/asm/xen/page-coherent.h b/arch/arm/include/asm/xen/page-coherent.h > index e8275ea..6f0f882 100644 > --- a/arch/arm/include/asm/xen/page-coherent.h > +++ b/arch/arm/include/asm/xen/page-coherent.h > @@ -5,6 +5,11 @@ > #include <linux/dma-attrs.h> > #include <linux/dma-mapping.h> > > +static inline bool xen_is_dma_coherent(struct device *dev) > +{ > + return (__generic_dma_ops(dev) == &arm_coherent_dma_ops); > +} > + > static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size, > dma_addr_t *dma_handle, gfp_t flags, > struct dma_attrs *attrs) > diff --git a/arch/arm/xen/mm32.c b/arch/arm/xen/mm32.c > index 6153d61..6c0224e 100644 > --- a/arch/arm/xen/mm32.c > +++ b/arch/arm/xen/mm32.c > @@ -76,7 +76,7 @@ void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle, > struct dma_attrs *attrs) > > { > - if (!__generic_dma_ops(hwdev)->unmap_page) > + if (xen_is_dma_coherent(hwdev)) > return; > if (dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) > return; > @@ -87,7 +87,7 @@ void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle, > void xen_dma_sync_single_for_cpu(struct device *hwdev, > dma_addr_t handle, size_t size, enum dma_data_direction dir) > { > - if (!__generic_dma_ops(hwdev)->sync_single_for_cpu) > + if (xen_is_dma_coherent(hwdev)) > return; > __xen_dma_page_dev_to_cpu(hwdev, handle, size, dir); > } > @@ -95,7 +95,7 @@ void xen_dma_sync_single_for_cpu(struct device *hwdev, > void xen_dma_sync_single_for_device(struct device *hwdev, > dma_addr_t handle, size_t size, enum dma_data_direction dir) > { > - if (!__generic_dma_ops(hwdev)->sync_single_for_device) > + if (xen_is_dma_coherent(hwdev)) > return; > __xen_dma_page_cpu_to_dev(hwdev, handle, size, dir); > } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
diff --git a/arch/arm/include/asm/xen/page-coherent.h b/arch/arm/include/asm/xen/page-coherent.h index e8275ea..6f0f882 100644 --- a/arch/arm/include/asm/xen/page-coherent.h +++ b/arch/arm/include/asm/xen/page-coherent.h @@ -5,6 +5,11 @@ #include <linux/dma-attrs.h> #include <linux/dma-mapping.h> +static inline bool xen_is_dma_coherent(struct device *dev) +{ + return (__generic_dma_ops(dev) == &arm_coherent_dma_ops); +} + static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size, dma_addr_t *dma_handle, gfp_t flags, struct dma_attrs *attrs) diff --git a/arch/arm/xen/mm32.c b/arch/arm/xen/mm32.c index 6153d61..6c0224e 100644 --- a/arch/arm/xen/mm32.c +++ b/arch/arm/xen/mm32.c @@ -76,7 +76,7 @@ void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle, struct dma_attrs *attrs) { - if (!__generic_dma_ops(hwdev)->unmap_page) + if (xen_is_dma_coherent(hwdev)) return; if (dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) return; @@ -87,7 +87,7 @@ void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle, void xen_dma_sync_single_for_cpu(struct device *hwdev, dma_addr_t handle, size_t size, enum dma_data_direction dir) { - if (!__generic_dma_ops(hwdev)->sync_single_for_cpu) + if (xen_is_dma_coherent(hwdev)) return; __xen_dma_page_dev_to_cpu(hwdev, handle, size, dir); } @@ -95,7 +95,7 @@ void xen_dma_sync_single_for_cpu(struct device *hwdev, void xen_dma_sync_single_for_device(struct device *hwdev, dma_addr_t handle, size_t size, enum dma_data_direction dir) { - if (!__generic_dma_ops(hwdev)->sync_single_for_device) + if (xen_is_dma_coherent(hwdev)) return; __xen_dma_page_cpu_to_dev(hwdev, handle, size, dir); }
Introduce a utility function to check whether a device is dma coherent. The current implementation is suboptimal. Let's rework it later in common arch/arm code. Use it to figure out whether we need to issue cache maintenance operations instead of checking on the existence of a particular dma_ops function for the device. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> --- Changes in v5: - introduce xen_is_dma_coherent as a xen specific function; - call xen_is_dma_coherent instead of is_dma_coherent. --- arch/arm/include/asm/xen/page-coherent.h | 5 +++++ arch/arm/xen/mm32.c | 6 +++--- 2 files changed, 8 insertions(+), 3 deletions(-)