1 // SPDX-License-Identifier: GPL-2.0
3  * Coherent per-device memory handling.
10 #include <linux/dma-direct.h>
11 #include <linux/dma-map-ops.h>
25 static inline struct dma_coherent_mem *dev_get_coherent_memory(struct device *dev)  in dev_get_coherent_memory()
27 	if (dev && dev->dma_mem)  in dev_get_coherent_memory()
28 		return dev->dma_mem;  in dev_get_coherent_memory()
32 static inline dma_addr_t dma_get_device_base(struct device *dev,  in dma_get_device_base()
35 	if (mem->use_dev_dma_pfn_offset)  in dma_get_device_base()
36 		return phys_to_dma(dev, PFN_PHYS(mem->pfn_base));  in dma_get_device_base()
37 	return mem->device_base;  in dma_get_device_base()
51 		ret = -EINVAL;  in dma_init_coherent_memory()
57 		ret = -EINVAL;  in dma_init_coherent_memory()
62 		ret = -ENOMEM;  in dma_init_coherent_memory()
65 	dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);  in dma_init_coherent_memory()
66 	if (!dma_mem->bitmap) {  in dma_init_coherent_memory()
67 		ret = -ENOMEM;  in dma_init_coherent_memory()
71 	dma_mem->virt_base = mem_base;  in dma_init_coherent_memory()
72 	dma_mem->device_base = device_addr;  in dma_init_coherent_memory()
73 	dma_mem->pfn_base = PFN_DOWN(phys_addr);  in dma_init_coherent_memory()
74 	dma_mem->size = pages;  in dma_init_coherent_memory()
75 	spin_lock_init(&dma_mem->spinlock);  in dma_init_coherent_memory()
92 	memunmap(mem->virt_base);  in dma_release_coherent_memory()
93 	kfree(mem->bitmap);  in dma_release_coherent_memory()
97 static int dma_assign_coherent_memory(struct device *dev,  in dma_assign_coherent_memory()
101 		return -ENODEV;  in dma_assign_coherent_memory()
103 	if (dev->dma_mem)  in dma_assign_coherent_memory()
104 		return -EBUSY;  in dma_assign_coherent_memory()
106 	dev->dma_mem = mem;  in dma_assign_coherent_memory()
112  * is asked for coherent memory for this device.  This shall only be used
113  * from platform code, usually based on the device tree description.
118  * device_addr is the DMA address the device needs to be programmed with to
125  * be declared per device.
127 int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,  in dma_declare_coherent_memory()
143 static void *__dma_alloc_from_coherent(struct device *dev,  in __dma_alloc_from_coherent()
152 	spin_lock_irqsave(&mem->spinlock, flags);  in __dma_alloc_from_coherent()
154 	if (unlikely(size > ((dma_addr_t)mem->size << PAGE_SHIFT)))  in __dma_alloc_from_coherent()
157 	pageno = bitmap_find_free_region(mem->bitmap, mem->size, order);  in __dma_alloc_from_coherent()
166 	ret = mem->virt_base + ((dma_addr_t)pageno << PAGE_SHIFT);  in __dma_alloc_from_coherent()
167 	spin_unlock_irqrestore(&mem->spinlock, flags);  in __dma_alloc_from_coherent()
171 	spin_unlock_irqrestore(&mem->spinlock, flags);  in __dma_alloc_from_coherent()
176  * dma_alloc_from_dev_coherent() - allocate memory from device coherent pool
177  * @dev:	device from which we allocate memory
183  * This function should be only called from per-arch dma_alloc_coherent()
184  * to support allocation from per-device coherent memory pools.
189 int dma_alloc_from_dev_coherent(struct device *dev, ssize_t size,  in dma_alloc_from_dev_coherent()
201 void *dma_alloc_from_global_coherent(struct device *dev, ssize_t size,  in dma_alloc_from_global_coherent()
214 	if (mem && vaddr >= mem->virt_base && vaddr <  in __dma_release_from_coherent()
215 		   (mem->virt_base + ((dma_addr_t)mem->size << PAGE_SHIFT))) {  in __dma_release_from_coherent()
216 		int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;  in __dma_release_from_coherent()
219 		spin_lock_irqsave(&mem->spinlock, flags);  in __dma_release_from_coherent()
220 		bitmap_release_region(mem->bitmap, page, order);  in __dma_release_from_coherent()
221 		spin_unlock_irqrestore(&mem->spinlock, flags);  in __dma_release_from_coherent()
228  * dma_release_from_dev_coherent() - free memory to device coherent memory pool
229  * @dev:	device from which the memory was allocated
233  * This checks whether the memory was allocated from the per-device
239 int dma_release_from_dev_coherent(struct device *dev, int order, void *vaddr)  in dma_release_from_dev_coherent()
258 	if (mem && vaddr >= mem->virt_base && vaddr + size <=  in __dma_mmap_from_coherent()
259 		   (mem->virt_base + ((dma_addr_t)mem->size << PAGE_SHIFT))) {  in __dma_mmap_from_coherent()
260 		unsigned long off = vma->vm_pgoff;  in __dma_mmap_from_coherent()
261 		int start = (vaddr - mem->virt_base) >> PAGE_SHIFT;  in __dma_mmap_from_coherent()
265 		*ret = -ENXIO;  in __dma_mmap_from_coherent()
266 		if (off < count && user_count <= count - off) {  in __dma_mmap_from_coherent()
267 			unsigned long pfn = mem->pfn_base + start + off;  in __dma_mmap_from_coherent()
268 			*ret = remap_pfn_range(vma, vma->vm_start, pfn,  in __dma_mmap_from_coherent()
270 					       vma->vm_page_prot);  in __dma_mmap_from_coherent()
278  * dma_mmap_from_dev_coherent() - mmap memory from the device coherent pool
279  * @dev:	device from which the memory was allocated
285  * This checks whether the memory was allocated from the per-device
288  * Returns 1 if @vaddr belongs to the device coherent pool and the caller
292 int dma_mmap_from_dev_coherent(struct device *dev, struct vm_area_struct *vma,  in dma_mmap_from_dev_coherent()
311  * Support for reserved memory regions defined in device tree
320 static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev)  in rmem_dma_device_init()
322 	struct dma_coherent_mem *mem = rmem->priv;  in rmem_dma_device_init()
326 		ret = dma_init_coherent_memory(rmem->base, rmem->base,  in rmem_dma_device_init()
327 					       rmem->size, &mem);  in rmem_dma_device_init()
330 				&rmem->base, (unsigned long)rmem->size / SZ_1M);  in rmem_dma_device_init()
334 	mem->use_dev_dma_pfn_offset = true;  in rmem_dma_device_init()
335 	rmem->priv = mem;  in rmem_dma_device_init()
341 				    struct device *dev)  in rmem_dma_device_release()
344 		dev->dma_mem = NULL;  in rmem_dma_device_release()
354 	unsigned long node = rmem->fdt_node;  in rmem_dma_setup()
357 		return -EINVAL;  in rmem_dma_setup()
360 	if (!of_get_flat_dt_prop(node, "no-map", NULL)) {  in rmem_dma_setup()
361 		pr_err("Reserved memory: regions without no-map are not yet supported\n");  in rmem_dma_setup()
362 		return -EINVAL;  in rmem_dma_setup()
365 	if (of_get_flat_dt_prop(node, "linux,dma-default", NULL)) {  in rmem_dma_setup()
372 	rmem->ops = &rmem_dma_ops;  in rmem_dma_setup()
374 		&rmem->base, (unsigned long)rmem->size / SZ_1M);  in rmem_dma_setup()
384 		return -ENOMEM;  in dma_init_reserved_memory()
386 	ops = dma_reserved_default_memory->ops;  in dma_init_reserved_memory()
390 	 * dma_assign_coherent_memory() for "NULL" device.  in dma_init_reserved_memory()
392 	ret = ops->device_init(dma_reserved_default_memory, NULL);  in dma_init_reserved_memory()
395 		dma_coherent_default_memory = dma_reserved_default_memory->priv;  in dma_init_reserved_memory()
404 RESERVEDMEM_OF_DECLARE(dma, "shared-dma-pool", rmem_dma_setup);