*/
#include <linux/dma-mapping.h>
-#include <linux/dma-debug.h>
-#include <linux/export.h>
#include <asm/cache.h>
#include <asm/cacheflush.h>
-/*
- * Helpers for Coherent DMA API.
- */
-void *dma_alloc_noncoherent(struct device *dev, size_t size,
- dma_addr_t *dma_handle, gfp_t gfp)
-{
- void *paddr;
-
- /* This is linear addr (0x8000_0000 based) */
- paddr = alloc_pages_exact(size, gfp);
- if (!paddr)
- return NULL;
-
- /* This is bus address, platform dependent */
- *dma_handle = (dma_addr_t)paddr;
-
- return paddr;
-}
-EXPORT_SYMBOL(dma_alloc_noncoherent);
-
-void dma_free_noncoherent(struct device *dev, size_t size, void *vaddr,
- dma_addr_t dma_handle)
-{
- free_pages_exact((void *)dma_handle, size);
-}
-EXPORT_SYMBOL(dma_free_noncoherent);
-void *dma_alloc_coherent(struct device *dev, size_t size,
- dma_addr_t *dma_handle, gfp_t gfp)
+static void *arc_dma_alloc(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, gfp_t gfp, struct dma_attrs *attrs)
{
- void *paddr, *kvaddr;
+ unsigned long order = get_order(size);
+ struct page *page;
+ phys_addr_t paddr;
+ void *kvaddr;
+ int need_coh = 1, need_kvaddr = 0;
+
+ page = alloc_pages(gfp, order);
+ if (!page)
+ return NULL;
/*
* IOC relies on all data (even coherent DMA data) being in cache
* Thus allocate normal cached memory
*
* The gains with IOC are two pronged:
- * -For streaming data, elides needs for cache maintenance, saving
+ * -For streaming data, elides need for cache maintenance, saving
* cycles in flush code, and bus bandwidth as all the lines of a
* buffer need to be flushed out to memory
* -For coherent data, Read/Write to buffers terminate early in cache
* (vs. always going to memory - thus are faster)
*/
- if (is_isa_arcv2() && ioc_exists)
- return dma_alloc_noncoherent(dev, size, dma_handle, gfp);
+ if ((is_isa_arcv2() && ioc_exists) ||
+ dma_get_attr(DMA_ATTR_NON_CONSISTENT, attrs))
+ need_coh = 0;
+
+ /*
+ * - A coherent buffer needs MMU mapping to enforce non-cachability
+ * - A highmem page needs a virtual handle (hence MMU mapping)
+ * independent of cachability
+ */
+ if (PageHighMem(page) || need_coh)
+ need_kvaddr = 1;
/* This is linear addr (0x8000_0000 based) */
- paddr = alloc_pages_exact(size, gfp);
- if (!paddr)
- return NULL;
+ paddr = page_to_phys(page);
- /* This is kernel Virtual address (0x7000_0000 based) */
- kvaddr = ioremap_nocache((unsigned long)paddr, size);
- if (kvaddr == NULL)
- return NULL;
+ *dma_handle = plat_phys_to_dma(dev, paddr);
- /* This is bus address, platform dependent */
- *dma_handle = (dma_addr_t)paddr;
+ /* This is kernel Virtual address (0x7000_0000 based) */
+ if (need_kvaddr) {
+ kvaddr = ioremap_nocache(paddr, size);
+ if (kvaddr == NULL) {
+ __free_pages(page, order);
+ return NULL;
+ }
+ } else {
+ kvaddr = (void *)(u32)paddr;
+ }
/*
* Evict any existing L1 and/or L2 lines for the backing page
* Currently flush_cache_vmap nukes the L1 cache completely which
* will be optimized as a separate commit
*/
- dma_cache_wback_inv((unsigned long)paddr, size);
+ if (need_coh)
+ dma_cache_wback_inv(paddr, size);
return kvaddr;
}
-EXPORT_SYMBOL(dma_alloc_coherent);
-void dma_free_coherent(struct device *dev, size_t size, void *kvaddr,
- dma_addr_t dma_handle)
+static void arc_dma_free(struct device *dev, size_t size, void *vaddr,
+ dma_addr_t dma_handle, struct dma_attrs *attrs)
{
- if (is_isa_arcv2() && ioc_exists)
- return dma_free_noncoherent(dev, size, kvaddr, dma_handle);
+ struct page *page = virt_to_page(dma_handle);
+ int is_non_coh = 1;
+
+ is_non_coh = dma_get_attr(DMA_ATTR_NON_CONSISTENT, attrs) ||
+ (is_isa_arcv2() && ioc_exists);
- iounmap((void __force __iomem *)kvaddr);
+ if (PageHighMem(page) || !is_non_coh)
+ iounmap((void __force __iomem *)vaddr);
- free_pages_exact((void *)dma_handle, size);
+ __free_pages(page, get_order(size));
}
-EXPORT_SYMBOL(dma_free_coherent);
/*
- * Helper for streaming DMA...
+ * streaming DMA Mapping API...
+ * CPU accesses page via normal paddr, thus needs to explicitly made
+ * consistent before each use
*/
-void __arc_dma_cache_sync(unsigned long paddr, size_t size,
- enum dma_data_direction dir)
+static void _dma_cache_sync(phys_addr_t paddr, size_t size,
+ enum dma_data_direction dir)
+{
+ switch (dir) {
+ case DMA_FROM_DEVICE:
+ dma_cache_inv(paddr, size);
+ break;
+ case DMA_TO_DEVICE:
+ dma_cache_wback(paddr, size);
+ break;
+ case DMA_BIDIRECTIONAL:
+ dma_cache_wback_inv(paddr, size);
+ break;
+ default:
+ pr_err("Invalid DMA dir [%d] for OP @ %pa[p]\n", dir, &paddr);
+ }
+}
+
+static dma_addr_t arc_dma_map_page(struct device *dev, struct page *page,
+ unsigned long offset, size_t size, enum dma_data_direction dir,
+ struct dma_attrs *attrs)
{
- __inline_dma_cache_sync(paddr, size, dir);
+ phys_addr_t paddr = page_to_phys(page) + offset;
+ _dma_cache_sync(paddr, size, dir);
+ return plat_phys_to_dma(dev, paddr);
}
-EXPORT_SYMBOL(__arc_dma_cache_sync);
+
+static int arc_dma_map_sg(struct device *dev, struct scatterlist *sg,
+ int nents, enum dma_data_direction dir, struct dma_attrs *attrs)
+{
+ struct scatterlist *s;
+ int i;
+
+ for_each_sg(sg, s, nents, i)
+ s->dma_address = dma_map_page(dev, sg_page(s), s->offset,
+ s->length, dir);
+
+ return nents;
+}
+
+static void arc_dma_sync_single_for_cpu(struct device *dev,
+ dma_addr_t dma_handle, size_t size, enum dma_data_direction dir)
+{
+ _dma_cache_sync(plat_dma_to_phys(dev, dma_handle), size, DMA_FROM_DEVICE);
+}
+
+static void arc_dma_sync_single_for_device(struct device *dev,
+ dma_addr_t dma_handle, size_t size, enum dma_data_direction dir)
+{
+ _dma_cache_sync(plat_dma_to_phys(dev, dma_handle), size, DMA_TO_DEVICE);
+}
+
+static void arc_dma_sync_sg_for_cpu(struct device *dev,
+ struct scatterlist *sglist, int nelems,
+ enum dma_data_direction dir)
+{
+ int i;
+ struct scatterlist *sg;
+
+ for_each_sg(sglist, sg, nelems, i)
+ _dma_cache_sync(sg_phys(sg), sg->length, dir);
+}
+
+static void arc_dma_sync_sg_for_device(struct device *dev,
+ struct scatterlist *sglist, int nelems,
+ enum dma_data_direction dir)
+{
+ int i;
+ struct scatterlist *sg;
+
+ for_each_sg(sglist, sg, nelems, i)
+ _dma_cache_sync(sg_phys(sg), sg->length, dir);
+}
+
+static int arc_dma_supported(struct device *dev, u64 dma_mask)
+{
+ /* Support 32 bit DMA mask exclusively */
+ return dma_mask == DMA_BIT_MASK(32);
+}
+
+struct dma_map_ops arc_dma_ops = {
+ .alloc = arc_dma_alloc,
+ .free = arc_dma_free,
+ .map_page = arc_dma_map_page,
+ .map_sg = arc_dma_map_sg,
+ .sync_single_for_device = arc_dma_sync_single_for_device,
+ .sync_single_for_cpu = arc_dma_sync_single_for_cpu,
+ .sync_sg_for_cpu = arc_dma_sync_sg_for_cpu,
+ .sync_sg_for_device = arc_dma_sync_sg_for_device,
+ .dma_supported = arc_dma_supported,
+};
+EXPORT_SYMBOL(arc_dma_ops);
projects / cascardo / linux.git / blobdiff