* Konrad Rzeszutek Wilk (konrad.wilk@xxxxxxxxxx) wrote:
> The structure contains all of the existing variables used in
> software IO TLB (swiotlb.c) collected within a structure.
>
> Additionally a name variable and a deconstructor (release) function
> variable is defined for API usages.
>
> The other set of functions: is_swiotlb_buffer, dma_capable, phys_to_bus,
> bus_to_phys, virt_to_bus, and bus_to_virt server as a method to abstract
> them out of the SWIOTLB library.
>
> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
> ---
> include/linux/swiotlb.h | 94
> +++++++++++++++++++++++++++++++++++++++++++++++
> 1 files changed, 94 insertions(+), 0 deletions(-)
>
> diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
> index febedcf..781c3aa 100644
> --- a/include/linux/swiotlb.h
> +++ b/include/linux/swiotlb.h
> @@ -24,6 +24,100 @@ extern int swiotlb_force;
>
> extern void swiotlb_init(int verbose);
>
You can move the comments to a kerneldoc section for proper
documentation.
/**
* struct swiotlb_engine - short desc...
* @name: Name of the engine...
etc
> +struct swiotlb_engine {
> +
> + /*
> + * Name of the engine (ie: "Software IO TLB")
> + */
> + const char *name;
> +
> + /*
> + * Used to do a quick range check in unmap_single and
> + * sync_single_*, to see if the memory was in fact allocated by this
> + * API.
> + */
> + char *start;
> + char *end;
Isn't this still global to swiotlb, not specific to the backend impl.?
> + /*
> + * The number of IO TLB blocks (in groups of 64) betweeen start and
> + * end. This is command line adjustable via setup_io_tlb_npages.
> + */
> + unsigned long nslabs;
Same here.
> +
> + /*
> + * When the IOMMU overflows we return a fallback buffer.
> + * This sets the size.
> + */
> + unsigned long overflow;
> +
> + void *overflow_buffer;
And here.
> + /*
> + * This is a free list describing the number of free entries available
> + * from each index
> + */
> + unsigned int *list;
> +
> + /*
> + * Current marker in the start through end location. Is incremented
> + * on each map and wraps around.
> + */
> + unsigned int index;
> +
> + /*
> + * We need to save away the original address corresponding to a mapped
> + * entry for the sync operations.
> + */
> + phys_addr_t *orig_addr;
> +
> + /*
> + * IOMMU private data.
> + */
> + void *priv;
> + /*
> + * The API call to free a SWIOTLB engine if another wants to register
> + * (or if want to turn SWIOTLB off altogether).
> + * It is imperative that this function checks for existing DMA maps
> + * and not release the IOTLB if there are out-standing maps.
> + */
> + int (*release)(struct swiotlb_engine *);
> +
> + /*
> + * Is the DMA (Bus) address within our bounce buffer (start and end).
> + */
> + int (*is_swiotlb_buffer)(struct swiotlb_engine *, dma_addr_t dev_addr,
> + phys_addr_t phys);
> +
Why is this implementation specific?
> + /*
> + * Is the DMA (Bus) address reachable by the PCI device?.
> + */
> + bool (*dma_capable)(struct device *, dma_addr_t, phys_addr_t, size_t);
This too...
> + /*
> + * Physical to bus (DMA) address translation. On
> + * most platforms this is an equivalent function.
> + */
> + dma_addr_t (*phys_to_bus)(struct device *hwdev, phys_addr_t paddr);
> +
> + /*
> + * Bus (DMA) to physical address translation. On most
> + * platforms this is an equivalant function.
> + */
> + phys_addr_t (*bus_to_phys)(struct device *hwdev, dma_addr_t baddr);
> +
> + /*
> + * Virtual to bus (DMA) address translation. On most platforms
> + * this is a call to __pa(address).
> + */
> + dma_addr_t (*virt_to_bus)(struct device *hwdev, void *address);
> +
> + /*
> + * Bus (DMA) to virtual address translation. On most platforms
> + * this is a call to __va(address).
> + */
> + void* (*bus_to_virt)(struct device *hwdev, dma_addr_t address);
> +};
> +
> extern void
> *swiotlb_alloc_coherent(struct device *hwdev, size_t size,
> dma_addr_t *dma_handle, gfp_t flags);
> --
> 1.6.2.5
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
Home