Add the initialization function to create restricted DMA pools from
matching reserved-memory nodes.
Signed-off-by: Claire Chang
---
include/linux/device.h | 4 +++
include/linux/swiotlb.h | 3 +-
kernel/dma/swiotlb.c| 79 +
3 files changed, 85 insertions(+), 1 deletion(-)
diff --git a/include/linux/device.h b/include/linux/device.h
index 38a2071cf776..4987608ea4ff 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -416,6 +416,7 @@ struct dev_links_info {
* @dma_pools: Dma pools (if dma'ble device).
* @dma_mem: Internal for coherent mem override.
* @cma_area: Contiguous memory area for dma allocations
+ * @dma_io_tlb_mem: Internal for swiotlb io_tlb_mem override.
* @archdata: For arch-specific additions.
* @of_node: Associated device tree node.
* @fwnode:Associated device node supplied by platform firmware.
@@ -521,6 +522,9 @@ struct device {
#ifdef CONFIG_DMA_CMA
struct cma *cma_area; /* contiguous memory area for dma
allocations */
+#endif
+#ifdef CONFIG_DMA_RESTRICTED_POOL
+ struct io_tlb_mem *dma_io_tlb_mem;
#endif
/* arch specific additions */
struct dev_archdata archdata;
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 216854a5e513..03ad6e3b4056 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -72,7 +72,8 @@ extern enum swiotlb_force swiotlb_force;
* range check to see if the memory was in fact allocated by this
* API.
* @nslabs:The number of IO TLB blocks (in groups of 64) between @start and
- * @end. This is command line adjustable via setup_io_tlb_npages.
+ * @end. For default swiotlb, this is command line adjustable via
+ * setup_io_tlb_npages.
* @used: The number of used IO TLB block.
* @list: The free list describing the number of free entries available
* from each index.
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 858475bd6923..4ea027b75013 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -39,6 +39,13 @@
#ifdef CONFIG_DEBUG_FS
#include
#endif
+#ifdef CONFIG_DMA_RESTRICTED_POOL
+#include
+#include
+#include
+#include
+#include
+#endif
#include
#include
@@ -687,3 +694,75 @@ static int __init swiotlb_create_default_debugfs(void)
late_initcall(swiotlb_create_default_debugfs);
#endif
+
+#ifdef CONFIG_DMA_RESTRICTED_POOL
+static int rmem_swiotlb_device_init(struct reserved_mem *rmem,
+ struct device *dev)
+{
+ struct io_tlb_mem *mem = rmem->priv;
+ unsigned long nslabs = rmem->size >> IO_TLB_SHIFT;
+
+ if (dev->dma_io_tlb_mem)
+ return 0;
+
+ /* Since multiple devices can share the same pool, the private data,
+* io_tlb_mem struct, will be initialized by the first device attached
+* to it.
+*/
+ if (!mem) {
+ mem = kzalloc(struct_size(mem, slots, nslabs), GFP_KERNEL);
+ if (!mem)
+ return -ENOMEM;
+#ifdef CONFIG_ARM
+ if (!PageHighMem(pfn_to_page(PHYS_PFN(rmem->base {
+ kfree(mem);
+ return -EINVAL;
+ }
+#endif /* CONFIG_ARM */
+ swiotlb_init_io_tlb_mem(mem, rmem->base, nslabs, false);
+
+ rmem->priv = mem;
+
+#ifdef CONFIG_DEBUG_FS
+ if (!debugfs_dir)
+ debugfs_dir = debugfs_create_dir("swiotlb", NULL);
+
+ swiotlb_create_debugfs(mem, rmem->name, debugfs_dir);
+#endif /* CONFIG_DEBUG_FS */
+ }
+
+ dev->dma_io_tlb_mem = mem;
+
+ return 0;
+}
+
+static void rmem_swiotlb_device_release(struct reserved_mem *rmem,
+ struct device *dev)
+{
+ if (dev)
+ dev->dma_io_tlb_mem = NULL;
+}
+
+static const struct reserved_mem_ops rmem_swiotlb_ops = {
+ .device_init = rmem_swiotlb_device_init,
+ .device_release = rmem_swiotlb_device_release,
+};
+
+static int __init rmem_swiotlb_setup(struct reserved_mem *rmem)
+{
+ unsigned long node = rmem->fdt_node;
+
+ if (of_get_flat_dt_prop(node, "reusable", NULL) ||
+ of_get_flat_dt_prop(node, "linux,cma-default", NULL) ||
+ of_get_flat_dt_prop(node, "linux,dma-default", NULL) ||
+ of_get_flat_dt_prop(node, "no-map", NULL))
+ return -EINVAL;
+
+ rmem->ops = _swiotlb_ops;
+ pr_info("Reserved memory: created device swiotlb memory pool at %pa,
size %ld MiB\n",
+ >base, (unsigned long)rmem->size / SZ_1M);
+ return 0;
+}
+
+RESERVEDMEM_OF_DECLARE(dma, "restricted-dma-pool", rmem_swiotlb_setup);
+#endif /* CONFIG_DMA_RESTRICTED_POOL */
--
2.31.1.607.g51e8a6a459-goog
___
iommu mailing list
