Merge branch 'stable/for-linus-5.2' of git://git.kernel.org/pub/scm/linux/kernel...
authorLinus Torvalds <torvalds@linux-foundation.org>
Wed, 8 May 2019 01:45:27 +0000 (18:45 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 8 May 2019 01:45:27 +0000 (18:45 -0700)
Pull swiotlb updates from Konrad Rzeszutek Wilk:
 "Cleanups in the swiotlb code and extra debugfs knobs to help with the
  field diagnostics"

* 'stable/for-linus-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb:
  swiotlb-xen: ensure we have a single callsite for xen_dma_map_page
  swiotlb-xen: simplify the DMA sync method implementations
  swiotlb-xen: use ->map_page to implement ->map_sg
  swiotlb-xen: make instances match their method names
  swiotlb: save io_tlb_used to local variable before leaving critical section
  swiotlb: dump used and total slots when swiotlb buffer is full

drivers/xen/swiotlb-xen.c
kernel/dma/swiotlb.c

index 877baf2a94f4070a345923e05467cf9e320a8b2c..5dcb06fe9667ee91cc5f04877850bdb5a7f5a875 100644 (file)
@@ -391,13 +391,8 @@ static dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
        if (dma_capable(dev, dev_addr, size) &&
            !range_straddles_page_boundary(phys, size) &&
                !xen_arch_need_swiotlb(dev, phys, dev_addr) &&
-               (swiotlb_force != SWIOTLB_FORCE)) {
-               /* we are not interested in the dma_addr returned by
-                * xen_dma_map_page, only in the potential cache flushes executed
-                * by the function. */
-               xen_dma_map_page(dev, page, dev_addr, offset, size, dir, attrs);
-               return dev_addr;
-       }
+               swiotlb_force != SWIOTLB_FORCE)
+               goto done;
 
        /*
         * Oh well, have to allocate and map a bounce buffer.
@@ -410,19 +405,25 @@ static dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
                return DMA_MAPPING_ERROR;
 
        dev_addr = xen_phys_to_bus(map);
-       xen_dma_map_page(dev, pfn_to_page(map >> PAGE_SHIFT),
-                                       dev_addr, map & ~PAGE_MASK, size, dir, attrs);
 
        /*
         * Ensure that the address returned is DMA'ble
         */
-       if (dma_capable(dev, dev_addr, size))
-               return dev_addr;
-
-       attrs |= DMA_ATTR_SKIP_CPU_SYNC;
-       swiotlb_tbl_unmap_single(dev, map, size, dir, attrs);
+       if (unlikely(!dma_capable(dev, dev_addr, size))) {
+               swiotlb_tbl_unmap_single(dev, map, size, dir,
+                               attrs | DMA_ATTR_SKIP_CPU_SYNC);
+               return DMA_MAPPING_ERROR;
+       }
 
-       return DMA_MAPPING_ERROR;
+       page = pfn_to_page(map >> PAGE_SHIFT);
+       offset = map & ~PAGE_MASK;
+done:
+       /*
+        * we are not interested in the dma_addr returned by xen_dma_map_page,
+        * only in the potential cache flushes executed by the function.
+        */
+       xen_dma_map_page(dev, page, dev_addr, offset, size, dir, attrs);
+       return dev_addr;
 }
 
 /*
@@ -455,48 +456,28 @@ static void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
        xen_unmap_single(hwdev, dev_addr, size, dir, attrs);
 }
 
-/*
- * Make physical memory consistent for a single streaming mode DMA translation
- * after a transfer.
- *
- * If you perform a xen_swiotlb_map_page() but wish to interrogate the buffer
- * using the cpu, yet do not wish to teardown the dma mapping, you must
- * call this function before doing so.  At the next point you give the dma
- * address back to the card, you must first perform a
- * xen_swiotlb_dma_sync_for_device, and then the device again owns the buffer
- */
 static void
-xen_swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,
-                       size_t size, enum dma_data_direction dir,
-                       enum dma_sync_target target)
+xen_swiotlb_sync_single_for_cpu(struct device *dev, dma_addr_t dma_addr,
+               size_t size, enum dma_data_direction dir)
 {
-       phys_addr_t paddr = xen_bus_to_phys(dev_addr);
-
-       BUG_ON(dir == DMA_NONE);
-
-       if (target == SYNC_FOR_CPU)
-               xen_dma_sync_single_for_cpu(hwdev, dev_addr, size, dir);
+       phys_addr_t paddr = xen_bus_to_phys(dma_addr);
 
-       /* NOTE: We use dev_addr here, not paddr! */
-       if (is_xen_swiotlb_buffer(dev_addr))
-               swiotlb_tbl_sync_single(hwdev, paddr, size, dir, target);
+       xen_dma_sync_single_for_cpu(dev, dma_addr, size, dir);
 
-       if (target == SYNC_FOR_DEVICE)
-               xen_dma_sync_single_for_device(hwdev, dev_addr, size, dir);
+       if (is_xen_swiotlb_buffer(dma_addr))
+               swiotlb_tbl_sync_single(dev, paddr, size, dir, SYNC_FOR_CPU);
 }
 
-void
-xen_swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
-                               size_t size, enum dma_data_direction dir)
+static void
+xen_swiotlb_sync_single_for_device(struct device *dev, dma_addr_t dma_addr,
+               size_t size, enum dma_data_direction dir)
 {
-       xen_swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_CPU);
-}
+       phys_addr_t paddr = xen_bus_to_phys(dma_addr);
 
-void
-xen_swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr,
-                                  size_t size, enum dma_data_direction dir)
-{
-       xen_swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE);
+       if (is_xen_swiotlb_buffer(dma_addr))
+               swiotlb_tbl_sync_single(dev, paddr, size, dir, SYNC_FOR_DEVICE);
+
+       xen_dma_sync_single_for_device(dev, dma_addr, size, dir);
 }
 
 /*
@@ -504,9 +485,8 @@ xen_swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr,
  * concerning calls here are the same as for swiotlb_unmap_page() above.
  */
 static void
-xen_swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
-                          int nelems, enum dma_data_direction dir,
-                          unsigned long attrs)
+xen_swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
+               enum dma_data_direction dir, unsigned long attrs)
 {
        struct scatterlist *sg;
        int i;
@@ -518,26 +498,9 @@ xen_swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
 
 }
 
-/*
- * Map a set of buffers described by scatterlist in streaming mode for DMA.
- * This is the scatter-gather version of the above xen_swiotlb_map_page
- * interface.  Here the scatter gather list elements are each tagged with the
- * appropriate dma address and length.  They are obtained via
- * sg_dma_{address,length}(SG).
- *
- * NOTE: An implementation may be able to use a smaller number of
- *       DMA address/length pairs than there are SG table elements.
- *       (for example via virtual mapping capabilities)
- *       The routine returns the number of addr/length pairs actually
- *       used, at most nents.
- *
- * Device ownership issues as mentioned above for xen_swiotlb_map_page are the
- * same here.
- */
 static int
-xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
-                        int nelems, enum dma_data_direction dir,
-                        unsigned long attrs)
+xen_swiotlb_map_sg(struct device *dev, struct scatterlist *sgl, int nelems,
+               enum dma_data_direction dir, unsigned long attrs)
 {
        struct scatterlist *sg;
        int i;
@@ -545,85 +508,44 @@ xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
        BUG_ON(dir == DMA_NONE);
 
        for_each_sg(sgl, sg, nelems, i) {
-               phys_addr_t paddr = sg_phys(sg);
-               dma_addr_t dev_addr = xen_phys_to_bus(paddr);
-
-               if (swiotlb_force == SWIOTLB_FORCE ||
-                   xen_arch_need_swiotlb(hwdev, paddr, dev_addr) ||
-                   !dma_capable(hwdev, dev_addr, sg->length) ||
-                   range_straddles_page_boundary(paddr, sg->length)) {
-                       phys_addr_t map = swiotlb_tbl_map_single(hwdev,
-                                                                start_dma_addr,
-                                                                sg_phys(sg),
-                                                                sg->length,
-                                                                dir, attrs);
-                       if (map == DMA_MAPPING_ERROR) {
-                               dev_warn(hwdev, "swiotlb buffer is full\n");
-                               /* Don't panic here, we expect map_sg users
-                                  to do proper error handling. */
-                               attrs |= DMA_ATTR_SKIP_CPU_SYNC;
-                               xen_swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir,
-                                                          attrs);
-                               sg_dma_len(sgl) = 0;
-                               return 0;
-                       }
-                       dev_addr = xen_phys_to_bus(map);
-                       xen_dma_map_page(hwdev, pfn_to_page(map >> PAGE_SHIFT),
-                                               dev_addr,
-                                               map & ~PAGE_MASK,
-                                               sg->length,
-                                               dir,
-                                               attrs);
-                       sg->dma_address = dev_addr;
-               } else {
-                       /* we are not interested in the dma_addr returned by
-                        * xen_dma_map_page, only in the potential cache flushes executed
-                        * by the function. */
-                       xen_dma_map_page(hwdev, pfn_to_page(paddr >> PAGE_SHIFT),
-                                               dev_addr,
-                                               paddr & ~PAGE_MASK,
-                                               sg->length,
-                                               dir,
-                                               attrs);
-                       sg->dma_address = dev_addr;
-               }
+               sg->dma_address = xen_swiotlb_map_page(dev, sg_page(sg),
+                               sg->offset, sg->length, dir, attrs);
+               if (sg->dma_address == DMA_MAPPING_ERROR)
+                       goto out_unmap;
                sg_dma_len(sg) = sg->length;
        }
+
        return nelems;
+out_unmap:
+       xen_swiotlb_unmap_sg(dev, sgl, i, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC);
+       sg_dma_len(sgl) = 0;
+       return 0;
 }
 
-/*
- * Make physical memory consistent for a set of streaming mode DMA translations
- * after a transfer.
- *
- * The same as swiotlb_sync_single_* but for a scatter-gather list, same rules
- * and usage.
- */
 static void
-xen_swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl,
-                   int nelems, enum dma_data_direction dir,
-                   enum dma_sync_target target)
+xen_swiotlb_sync_sg_for_cpu(struct device *dev, struct scatterlist *sgl,
+                           int nelems, enum dma_data_direction dir)
 {
        struct scatterlist *sg;
        int i;
 
-       for_each_sg(sgl, sg, nelems, i)
-               xen_swiotlb_sync_single(hwdev, sg->dma_address,
-                                       sg_dma_len(sg), dir, target);
-}
-
-static void
-xen_swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg,
-                           int nelems, enum dma_data_direction dir)
-{
-       xen_swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_CPU);
+       for_each_sg(sgl, sg, nelems, i) {
+               xen_swiotlb_sync_single_for_cpu(dev, sg->dma_address,
+                               sg->length, dir);
+       }
 }
 
 static void
-xen_swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
+xen_swiotlb_sync_sg_for_device(struct device *dev, struct scatterlist *sgl,
                               int nelems, enum dma_data_direction dir)
 {
-       xen_swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE);
+       struct scatterlist *sg;
+       int i;
+
+       for_each_sg(sgl, sg, nelems, i) {
+               xen_swiotlb_sync_single_for_device(dev, sg->dma_address,
+                               sg->length, dir);
+       }
 }
 
 /*
@@ -690,8 +612,8 @@ const struct dma_map_ops xen_swiotlb_dma_ops = {
        .sync_single_for_device = xen_swiotlb_sync_single_for_device,
        .sync_sg_for_cpu = xen_swiotlb_sync_sg_for_cpu,
        .sync_sg_for_device = xen_swiotlb_sync_sg_for_device,
-       .map_sg = xen_swiotlb_map_sg_attrs,
-       .unmap_sg = xen_swiotlb_unmap_sg_attrs,
+       .map_sg = xen_swiotlb_map_sg,
+       .unmap_sg = xen_swiotlb_unmap_sg,
        .map_page = xen_swiotlb_map_page,
        .unmap_page = xen_swiotlb_unmap_page,
        .dma_supported = xen_swiotlb_dma_supported,
index 53012db1e53c6915ee29b0bcd7e543def476232b..6f7619c1f8774985dfb4b669b6c83ff2186fdeaa 100644 (file)
@@ -452,6 +452,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
        unsigned long mask;
        unsigned long offset_slots;
        unsigned long max_slots;
+       unsigned long tmp_io_tlb_used;
 
        if (no_iotlb_memory)
                panic("Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer");
@@ -538,9 +539,12 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
        } while (index != wrap);
 
 not_found:
+       tmp_io_tlb_used = io_tlb_used;
+
        spin_unlock_irqrestore(&io_tlb_lock, flags);
        if (!(attrs & DMA_ATTR_NO_WARN) && printk_ratelimit())
-               dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes)\n", size);
+               dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes), total %lu (slots), used %lu (slots)\n",
+                        size, io_tlb_nslabs, tmp_io_tlb_used);
        return DMA_MAPPING_ERROR;
 found:
        io_tlb_used += nslots;