[PATCH V2 2/3] powerpc: Add support for swiotlb on 32-bit
Becky Bruce
beckyb at kernel.crashing.org
Thu May 28 05:05:08 EST 2009
On May 22, 2009, at 6:11 AM, Ian Campbell wrote:
>
>
> BTW do you need swiotlb_bus_to_virt to be __weak or is the fact that
> it
> is implemented in terms of swiotlb_bus_to_phys sufficient?
The default one in swiotlb calls phys_to_virt on the result of
swiotlb_bus_to_phys, which only works on lowmem.
>
>
> I have an appointment all afternoon and it's a bank holiday on Monday
> but here is my WIP patch as an example of what I'm thinking. Obviously
> some cleanups are still very much required:
> * The Xen specific stuff in arch/x86/include/asm/dma-mapping.h
> clearly needs to be properly abstracted away (I just stuck it
> there for testing).
> * swiotlb_phys_to_bus and swiotlb_bus_to_phys need to move to
> arch/*/include/asm/dma-mapping.h instead of being __weak
> * Maybe swiotlb_bus_to_virt can become static again.
> * Need to finish auditing the handful of non-swiotlb users of
> is_buffer_dma_capable.
> * It might be possible to implement swiolb_dma_mapping_error
> and/or swiotlb_dma_supported in terms of dma_map_range.
> * Minor detail: it doesn't actually work at the moment ;-)
Minor detail :)
I'm in the same boat- been offline most of the week and will continue
to be offline (I'm sneaking in an hour here to read emails!!!!) until
sometime next week. I'm in the middle of a big lab construction and
move project. I'll take a look as soon as I can - thanks!
-Becky
>
>
> Ian.
>
> diff --git a/arch/ia64/include/asm/dma-mapping.h b/arch/ia64/include/
> asm/dma-mapping.h
> index 36c0009..026667f 100644
> --- a/arch/ia64/include/asm/dma-mapping.h
> +++ b/arch/ia64/include/asm/dma-mapping.h
> @@ -174,4 +174,12 @@ dma_cache_sync (struct device *dev, void
> *vaddr, size_t size,
>
> #define dma_is_consistent(d, h) (1) /* all we do is coherent
> memory... */
>
> +static inline dma_addr_t dma_map_range(struct device *dev, u64 mask,
> + phys_addr_t addr, size_t size)
> +{
> + if (addr + size <= mask)
> + return addr;
> + return 0;
> +}
> +
> #endif /* _ASM_IA64_DMA_MAPPING_H */
> diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/
> asm/dma-mapping.h
> index 916cbb6..b2813ab 100644
> --- a/arch/x86/include/asm/dma-mapping.h
> +++ b/arch/x86/include/asm/dma-mapping.h
> @@ -309,4 +309,20 @@ static inline void dma_free_coherent(struct
> device *dev, size_t size,
> ops->free_coherent(dev, size, vaddr, bus);
> }
>
> +static inline dma_addr_t dma_map_range(struct device *dev, u64 mask,
> + phys_addr_t addr, size_t size)
> +{
> + dma_addr_t dma_addr;
> +#ifdef CONFIG_XEN
> + extern int xen_range_needs_mapping(phys_addr_t paddr, size_t size);
> + if (xen_pv_domain() && xen_range_needs_mapping(addr, size))
> + return 0;
> +#endif
> +
> + dma_addr = swiotlb_phys_to_bus(dev, addr);
> + if (dma_addr + size <= mask)
> + return 0;
> + return dma_addr;
> +}
> +
> #endif
> diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
> index 2fffc22..c2b4196 100644
> --- a/arch/x86/kernel/pci-dma.c
> +++ b/arch/x86/kernel/pci-dma.c
> @@ -145,8 +145,8 @@ again:
> if (!page)
> return NULL;
>
> - addr = page_to_phys(page);
> - if (!is_buffer_dma_capable(dma_mask, addr, size)) {
> + addr = dma_map_range(dev, dma_mask, page_to_phys(page), size);
> + if (!(addr == 0)) {
> __free_pages(page, get_order(size));
>
> if (dma_mask < DMA_BIT_MASK(32) && !(flag & GFP_DMA)) {
> diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-
> gart_64.c
> index 1e8920d..6a55770 100644
> --- a/arch/x86/kernel/pci-gart_64.c
> +++ b/arch/x86/kernel/pci-gart_64.c
> @@ -191,13 +191,13 @@ static inline int
> need_iommu(struct device *dev, unsigned long addr, size_t size)
> {
> return force_iommu ||
> - !is_buffer_dma_capable(*dev->dma_mask, addr, size);
> + dma_map_range(dev, *dev->dma_mask, addr, size) == 0;
> }
>
> static inline int
> nonforced_iommu(struct device *dev, unsigned long addr, size_t size)
> {
> - return !is_buffer_dma_capable(*dev->dma_mask, addr, size);
> + return dma_map_range(dev, *dev->dma_mask, addr, size) == 0;
> }
>
> /* Map a single continuous physical area into the IOMMU.
> diff --git a/arch/x86/kernel/pci-nommu.c b/arch/x86/kernel/pci-nommu.c
> index 71d412a..712ce59 100644
> --- a/arch/x86/kernel/pci-nommu.c
> +++ b/arch/x86/kernel/pci-nommu.c
> @@ -12,13 +12,13 @@
> #include <asm/dma.h>
>
> static int
> -check_addr(char *name, struct device *hwdev, dma_addr_t bus, size_t
> size)
> +check_addr(char *name, struct device *hwdev, phys_addr_t phys,
> size_t size)
> {
> - if (hwdev && !is_buffer_dma_capable(*hwdev->dma_mask, bus, size)) {
> + if (hwdev && dma_map_range(hwdev, *hwdev->dma_mask, phys, size) ==
> 0) {
> if (*hwdev->dma_mask >= DMA_BIT_MASK(32))
> printk(KERN_ERR
> "nommu_%s: overflow %Lx+%zu of device mask %Lx\n",
> - name, (long long)bus, size,
> + name, (long long)phys, size,
> (long long)*hwdev->dma_mask);
> return 0;
> }
> @@ -30,12 +30,12 @@ static dma_addr_t nommu_map_page(struct device
> *dev, struct page *page,
> enum dma_data_direction dir,
> struct dma_attrs *attrs)
> {
> - dma_addr_t bus = page_to_phys(page) + offset;
> + phys_addr_t phys = page_to_phys(page) + offset;
> WARN_ON(size == 0);
> - if (!check_addr("map_single", dev, bus, size))
> + if (!check_addr("map_single", dev, phys, size))
> return bad_dma_address;
> flush_write_buffers();
> - return bus;
> + return phys;
> }
>
> /* Map a set of buffers described by scatterlist in streaming
> diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
> index 8083b6a..85dafa1 100644
> --- a/include/linux/dma-mapping.h
> +++ b/include/linux/dma-mapping.h
> @@ -96,11 +96,6 @@ static inline int is_device_dma_capable(struct
> device *dev)
> return dev->dma_mask != NULL && *dev->dma_mask != DMA_MASK_NONE;
> }
>
> -static inline int is_buffer_dma_capable(u64 mask, dma_addr_t addr,
> size_t size)
> -{
> - return addr + size <= mask;
> -}
> -
> #ifdef CONFIG_HAS_DMA
> #include <asm/dma-mapping.h>
> #else
> diff --git a/lib/swiotlb.c b/lib/swiotlb.c
> index cec5f62..4fd5185 100644
> --- a/lib/swiotlb.c
> +++ b/lib/swiotlb.c
> @@ -147,17 +147,6 @@ void * __weak swiotlb_bus_to_virt(struct device
> *hwdev, dma_addr_t address)
> return phys_to_virt(swiotlb_bus_to_phys(hwdev, address));
> }
>
> -int __weak swiotlb_arch_address_needs_mapping(struct device *hwdev,
> - dma_addr_t addr, size_t size)
> -{
> - return !is_buffer_dma_capable(dma_get_mask(hwdev), addr, size);
> -}
> -
> -int __weak swiotlb_arch_range_needs_mapping(phys_addr_t paddr,
> size_t size)
> -{
> - return 0;
> -}
> -
> static void swiotlb_print_info(unsigned long bytes)
> {
> phys_addr_t pstart, pend;
> @@ -318,17 +307,6 @@ cleanup1:
> return -ENOMEM;
> }
>
> -static inline int
> -address_needs_mapping(struct device *hwdev, dma_addr_t addr, size_t
> size)
> -{
> - return swiotlb_arch_address_needs_mapping(hwdev, addr, size);
> -}
> -
> -static inline int range_needs_mapping(phys_addr_t paddr, size_t size)
> -{
> - return swiotlb_force || swiotlb_arch_range_needs_mapping(paddr,
> size);
> -}
> -
> static int is_swiotlb_buffer(char *addr)
> {
> return addr >= io_tlb_start && addr < io_tlb_end;
> @@ -555,18 +533,17 @@ void *
> swiotlb_alloc_coherent(struct device *hwdev, size_t size,
> dma_addr_t *dma_handle, gfp_t flags)
> {
> - dma_addr_t dev_addr;
> + phys_addr_t phys;
> void *ret;
> int order = get_order(size);
> u64 dma_mask = DMA_BIT_MASK(32);
> + dma_addr_t dma_addr;
>
> if (hwdev && hwdev->coherent_dma_mask)
> dma_mask = hwdev->coherent_dma_mask;
>
> ret = (void *)__get_free_pages(flags, order);
> - if (ret &&
> - !is_buffer_dma_capable(dma_mask, swiotlb_virt_to_bus(hwdev,
> ret),
> - size)) {
> + if (ret && dma_map_range(hwdev, dma_mask, virt_to_phys(ret), size)
> == 0) {
> /*
> * The allocated memory isn't reachable by the device.
> */
> @@ -585,19 +562,20 @@ swiotlb_alloc_coherent(struct device *hwdev,
> size_t size,
> }
>
> memset(ret, 0, size);
> - dev_addr = swiotlb_virt_to_bus(hwdev, ret);
> + phys = virt_to_phys(ret);
>
> /* Confirm address can be DMA'd by device */
> - if (!is_buffer_dma_capable(dma_mask, dev_addr, size)) {
> - printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n",
> + dma_addr = dma_map_range(hwdev, dma_mask, phys, size);
> + if (dma_addr == 0) {
> + printk("hwdev DMA mask = 0x%016Lx, physical addr = 0x%016Lx\n",
> (unsigned long long)dma_mask,
> - (unsigned long long)dev_addr);
> + (unsigned long long)phys);
>
> /* DMA_TO_DEVICE to avoid memcpy in unmap_single */
> do_unmap_single(hwdev, ret, size, DMA_TO_DEVICE);
> return NULL;
> }
> - *dma_handle = dev_addr;
> + *dma_handle = dma_addr;
> return ret;
> }
> EXPORT_SYMBOL(swiotlb_alloc_coherent);
> @@ -649,7 +627,7 @@ dma_addr_t swiotlb_map_page(struct device *dev,
> struct page *page,
> struct dma_attrs *attrs)
> {
> phys_addr_t phys = page_to_phys(page) + offset;
> - dma_addr_t dev_addr = swiotlb_phys_to_bus(dev, phys);
> + dma_addr_t dma_addr;
> void *map;
>
> BUG_ON(dir == DMA_NONE);
> @@ -658,9 +636,9 @@ dma_addr_t swiotlb_map_page(struct device *dev,
> struct page *page,
> * we can safely return the device addr and not worry about bounce
> * buffering it.
> */
> - if (!address_needs_mapping(dev, dev_addr, size) &&
> - !range_needs_mapping(phys, size))
> - return dev_addr;
> + dma_addr = dma_map_range(dev, dma_get_mask(dev), phys, size);
> + if (dma_addr && !swiotlb_force)
> + return dma_addr;
>
> /*
> * Oh well, have to allocate and map a bounce buffer.
> @@ -671,15 +649,14 @@ dma_addr_t swiotlb_map_page(struct device
> *dev, struct page *page,
> map = io_tlb_overflow_buffer;
> }
>
> - dev_addr = swiotlb_virt_to_bus(dev, map);
> -
> /*
> * Ensure that the address returned is DMA'ble
> */
> - if (address_needs_mapping(dev, dev_addr, size))
> + dma_addr = dma_map_range(dev, dma_get_mask(dev),
> virt_to_phys(map), size);
> + if (dma_addr == 0)
> panic("map_single: bounce buffer is not DMA'ble");
>
> - return dev_addr;
> + return dma_addr;
> }
> EXPORT_SYMBOL_GPL(swiotlb_map_page);
>
> @@ -820,10 +797,8 @@ swiotlb_map_sg_attrs(struct device *hwdev,
> struct scatterlist *sgl, int nelems,
>
> for_each_sg(sgl, sg, nelems, i) {
> phys_addr_t paddr = sg_phys(sg);
> - dma_addr_t dev_addr = swiotlb_phys_to_bus(hwdev, paddr);
> -
> - if (range_needs_mapping(paddr, sg->length) ||
> - address_needs_mapping(hwdev, dev_addr, sg->length)) {
> + dma_addr_t dma_addr = dma_map_range(hwdev, dma_get_mask(hwdev),
> paddr, sg->length);
> + if (dma_addr == 0 || swiotlb_force) {
> void *map = map_single(hwdev, sg_phys(sg),
> sg->length, dir);
> if (!map) {
> @@ -835,9 +810,9 @@ swiotlb_map_sg_attrs(struct device *hwdev,
> struct scatterlist *sgl, int nelems,
> sgl[0].dma_length = 0;
> return 0;
> }
> - sg->dma_address = swiotlb_virt_to_bus(hwdev, map);
> - } else
> - sg->dma_address = dev_addr;
> + dma_addr = dma_map_range(hwdev, dma_get_mask(hwdev),
> virt_to_phys(map), sg->length);
> + }
> + sg->dma_address = dma_addr;
> sg->dma_length = sg->length;
> }
> return nelems;
>
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