| Message ID | 20190614144431.21760-6-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/7] arm-nommu: remove the partial DMA_ATTR_NON_CONSISTENT support | expand |
On Sun, Jun 16, 2019 at 06:08:40PM +0800, Hillf Danton wrote: > Literally, any cpu (call it cpuW) other than pcx12 and pcx1 will no longer do > dma alloc for any device with this patch applied. Yes. And that is not a chance from the previous code, where only pcx1 and pcx12 could do coherent allocations, > On the other hand, > !dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_NON_CONSISTENT) will ask > any cpu to do dma alloc, regardless of pcx1. This patch works imo unless cpuW > plays games only with devices that are dma coherent. I doubt it is true. I can't parse these two sentences. But to explains the bits mentioned here - dev_is_dma_coherent will return if a device is coherently attached vs the cpu. This will never be true for the parisc direct mapping. DMA_ATTR_NON_CONSISTENT asks for a non-coherent mapping that needs to be explicitly synced. This support now is in the dma-direct core code, and this is what the parisc specific devices used on the non-pcxl systems use, as they do not support dma coherency at all. (the story slightly changes when using an iommu, but that is irrelevant here)
On 14.06.19 16:44, Christoph Hellwig wrote: > Only call into arch_dma_alloc if we require an uncached mapping, > and remove the parisc code manually doing normal cached > DMA_ATTR_NON_CONSISTENT allocations. > > Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Helge Deller <deller@gmx.de> # parisc Boot-tested 32-bit kernel on PCX-L and PCX-W2 machines (although the patches don't cleanly apply any longer against git head). Helge > --- > arch/parisc/kernel/pci-dma.c | 48 ++++++++++-------------------------- > kernel/dma/direct.c | 4 +-- > 2 files changed, 15 insertions(+), 37 deletions(-) > > diff --git a/arch/parisc/kernel/pci-dma.c b/arch/parisc/kernel/pci-dma.c > index 239162355b58..ca35d9a76e50 100644 > --- a/arch/parisc/kernel/pci-dma.c > +++ b/arch/parisc/kernel/pci-dma.c > @@ -394,17 +394,20 @@ pcxl_dma_init(void) > > __initcall(pcxl_dma_init); > > -static void *pcxl_dma_alloc(struct device *dev, size_t size, > - dma_addr_t *dma_handle, gfp_t flag, unsigned long attrs) > +void *arch_dma_alloc(struct device *dev, size_t size, > + dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) > { > unsigned long vaddr; > unsigned long paddr; > int order; > > + if (boot_cpu_data.cpu_type != pcxl2 && boot_cpu_data.cpu_type != pcxl) > + return NULL; > + > order = get_order(size); > size = 1 << (order + PAGE_SHIFT); > vaddr = pcxl_alloc_range(size); > - paddr = __get_free_pages(flag | __GFP_ZERO, order); > + paddr = __get_free_pages(gfp | __GFP_ZERO, order); > flush_kernel_dcache_range(paddr, size); > paddr = __pa(paddr); > map_uncached_pages(vaddr, size, paddr); > @@ -421,44 +424,19 @@ static void *pcxl_dma_alloc(struct device *dev, size_t size, > return (void *)vaddr; > } > > -static void *pcx_dma_alloc(struct device *dev, size_t size, > - dma_addr_t *dma_handle, gfp_t flag, unsigned long attrs) > -{ > - void *addr; > - > - if ((attrs & DMA_ATTR_NON_CONSISTENT) == 0) > - return NULL; > - > - addr = (void *)__get_free_pages(flag | __GFP_ZERO, get_order(size)); > - if (addr) > - *dma_handle = (dma_addr_t)virt_to_phys(addr); > - > - return addr; > -} > - > -void *arch_dma_alloc(struct device *dev, size_t size, > - dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) > -{ > - > - if (boot_cpu_data.cpu_type == pcxl2 || boot_cpu_data.cpu_type == pcxl) > - return pcxl_dma_alloc(dev, size, dma_handle, gfp, attrs); > - else > - return pcx_dma_alloc(dev, size, dma_handle, gfp, attrs); > -} > - > void arch_dma_free(struct device *dev, size_t size, void *vaddr, > dma_addr_t dma_handle, unsigned long attrs) > { > int order = get_order(size); > > - if (boot_cpu_data.cpu_type == pcxl2 || boot_cpu_data.cpu_type == pcxl) { > - size = 1 << (order + PAGE_SHIFT); > - unmap_uncached_pages((unsigned long)vaddr, size); > - pcxl_free_range((unsigned long)vaddr, size); > + WARN_ON_ONCE(boot_cpu_data.cpu_type != pcxl2 && > + boot_cpu_data.cpu_type != pcxl); > > - vaddr = __va(dma_handle); > - } > - free_pages((unsigned long)vaddr, get_order(size)); > + size = 1 << (order + PAGE_SHIFT); > + unmap_uncached_pages((unsigned long)vaddr, size); > + pcxl_free_range((unsigned long)vaddr, size); > + > + free_pages((unsigned long)__va(dma_handle), order); > } > > void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr, > diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c > index c2893713bf80..fc354f4f490b 100644 > --- a/kernel/dma/direct.c > +++ b/kernel/dma/direct.c > @@ -191,7 +191,7 @@ void *dma_direct_alloc(struct device *dev, size_t size, > dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) > { > if (!IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT) && > - !dev_is_dma_coherent(dev)) > + dma_alloc_need_uncached(dev, attrs)) > return arch_dma_alloc(dev, size, dma_handle, gfp, attrs); > return dma_direct_alloc_pages(dev, size, dma_handle, gfp, attrs); > } > @@ -200,7 +200,7 @@ void dma_direct_free(struct device *dev, size_t size, > void *cpu_addr, dma_addr_t dma_addr, unsigned long attrs) > { > if (!IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT) && > - !dev_is_dma_coherent(dev)) > + dma_alloc_need_uncached(dev, attrs)) > arch_dma_free(dev, size, cpu_addr, dma_addr, attrs); > else > dma_direct_free_pages(dev, size, cpu_addr, dma_addr, attrs); >
On Tue, Jun 25, 2019 at 02:23:45PM +0200, Helge Deller wrote: > On 14.06.19 16:44, Christoph Hellwig wrote: > > Only call into arch_dma_alloc if we require an uncached mapping, > > and remove the parisc code manually doing normal cached > > DMA_ATTR_NON_CONSISTENT allocations. > > > > Signed-off-by: Christoph Hellwig <hch@lst.de> > > Acked-by: Helge Deller <deller@gmx.de> # parisc > > Boot-tested 32-bit kernel on PCX-L and PCX-W2 machines (although > the patches don't cleanly apply any longer against git head). The series was against the dma-mapping tree, which might have diverged a bit already. Thanks for testing!
diff --git a/arch/parisc/kernel/pci-dma.c b/arch/parisc/kernel/pci-dma.c index 239162355b58..ca35d9a76e50 100644 --- a/arch/parisc/kernel/pci-dma.c +++ b/arch/parisc/kernel/pci-dma.c @@ -394,17 +394,20 @@ pcxl_dma_init(void) __initcall(pcxl_dma_init); -static void *pcxl_dma_alloc(struct device *dev, size_t size, - dma_addr_t *dma_handle, gfp_t flag, unsigned long attrs) +void *arch_dma_alloc(struct device *dev, size_t size, + dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) { unsigned long vaddr; unsigned long paddr; int order; + if (boot_cpu_data.cpu_type != pcxl2 && boot_cpu_data.cpu_type != pcxl) + return NULL; + order = get_order(size); size = 1 << (order + PAGE_SHIFT); vaddr = pcxl_alloc_range(size); - paddr = __get_free_pages(flag | __GFP_ZERO, order); + paddr = __get_free_pages(gfp | __GFP_ZERO, order); flush_kernel_dcache_range(paddr, size); paddr = __pa(paddr); map_uncached_pages(vaddr, size, paddr); @@ -421,44 +424,19 @@ static void *pcxl_dma_alloc(struct device *dev, size_t size, return (void *)vaddr; } -static void *pcx_dma_alloc(struct device *dev, size_t size, - dma_addr_t *dma_handle, gfp_t flag, unsigned long attrs) -{ - void *addr; - - if ((attrs & DMA_ATTR_NON_CONSISTENT) == 0) - return NULL; - - addr = (void *)__get_free_pages(flag | __GFP_ZERO, get_order(size)); - if (addr) - *dma_handle = (dma_addr_t)virt_to_phys(addr); - - return addr; -} - -void *arch_dma_alloc(struct device *dev, size_t size, - dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) -{ - - if (boot_cpu_data.cpu_type == pcxl2 || boot_cpu_data.cpu_type == pcxl) - return pcxl_dma_alloc(dev, size, dma_handle, gfp, attrs); - else - return pcx_dma_alloc(dev, size, dma_handle, gfp, attrs); -} - void arch_dma_free(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle, unsigned long attrs) { int order = get_order(size); - if (boot_cpu_data.cpu_type == pcxl2 || boot_cpu_data.cpu_type == pcxl) { - size = 1 << (order + PAGE_SHIFT); - unmap_uncached_pages((unsigned long)vaddr, size); - pcxl_free_range((unsigned long)vaddr, size); + WARN_ON_ONCE(boot_cpu_data.cpu_type != pcxl2 && + boot_cpu_data.cpu_type != pcxl); - vaddr = __va(dma_handle); - } - free_pages((unsigned long)vaddr, get_order(size)); + size = 1 << (order + PAGE_SHIFT); + unmap_uncached_pages((unsigned long)vaddr, size); + pcxl_free_range((unsigned long)vaddr, size); + + free_pages((unsigned long)__va(dma_handle), order); } void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr, diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index c2893713bf80..fc354f4f490b 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -191,7 +191,7 @@ void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) { if (!IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT) && - !dev_is_dma_coherent(dev)) + dma_alloc_need_uncached(dev, attrs)) return arch_dma_alloc(dev, size, dma_handle, gfp, attrs); return dma_direct_alloc_pages(dev, size, dma_handle, gfp, attrs); } @@ -200,7 +200,7 @@ void dma_direct_free(struct device *dev, size_t size, void *cpu_addr, dma_addr_t dma_addr, unsigned long attrs) { if (!IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT) && - !dev_is_dma_coherent(dev)) + dma_alloc_need_uncached(dev, attrs)) arch_dma_free(dev, size, cpu_addr, dma_addr, attrs); else dma_direct_free_pages(dev, size, cpu_addr, dma_addr, attrs);
Only call into arch_dma_alloc if we require an uncached mapping, and remove the parisc code manually doing normal cached DMA_ATTR_NON_CONSISTENT allocations. Signed-off-by: Christoph Hellwig <hch@lst.de> --- arch/parisc/kernel/pci-dma.c | 48 ++++++++++-------------------------- kernel/dma/direct.c | 4 +-- 2 files changed, 15 insertions(+), 37 deletions(-)