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>
23 static inline struct dma_coherent_mem *dev_get_coherent_memory(struct device *dev)  in dev_get_coherent_memory()
25 	if (dev && dev->dma_mem)  in dev_get_coherent_memory()
26 		return dev->dma_mem;  in dev_get_coherent_memory()
30 static inline dma_addr_t dma_get_device_base(struct device *dev,  in dma_get_device_base()
33 	if (mem->use_dev_dma_pfn_offset)  in dma_get_device_base()
34 		return phys_to_dma(dev, PFN_PHYS(mem->pfn_base));  in dma_get_device_base()
35 	return mem->device_base;  in dma_get_device_base()
47 		return ERR_PTR(-EINVAL);  in dma_init_coherent_memory()
51 		return ERR_PTR(-EINVAL);  in dma_init_coherent_memory()
56 	dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);  in dma_init_coherent_memory()
57 	if (!dma_mem->bitmap)  in dma_init_coherent_memory()
60 	dma_mem->virt_base = mem_base;  in dma_init_coherent_memory()
61 	dma_mem->device_base = device_addr;  in dma_init_coherent_memory()
62 	dma_mem->pfn_base = PFN_DOWN(phys_addr);  in dma_init_coherent_memory()
63 	dma_mem->size = pages;  in dma_init_coherent_memory()
64 	dma_mem->use_dev_dma_pfn_offset = use_dma_pfn_offset;  in dma_init_coherent_memory()
65 	spin_lock_init(&dma_mem->spinlock);  in dma_init_coherent_memory()
75 	return ERR_PTR(-ENOMEM);  in dma_init_coherent_memory()
83 	memunmap(mem->virt_base);  in dma_release_coherent_memory()
84 	kfree(mem->bitmap);  in dma_release_coherent_memory()
88 static int dma_assign_coherent_memory(struct device *dev,  in dma_assign_coherent_memory()
92 		return -ENODEV;  in dma_assign_coherent_memory()
94 	if (dev->dma_mem)  in dma_assign_coherent_memory()
95 		return -EBUSY;  in dma_assign_coherent_memory()
97 	dev->dma_mem = mem;  in dma_assign_coherent_memory()
103  * is asked for coherent memory for this device.  This shall only be used
104  * from platform code, usually based on the device tree description.
109  * device_addr is the DMA address the device needs to be programmed with to
116  * be declared per device.
118 int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,  in dma_declare_coherent_memory()
134 static void *__dma_alloc_from_coherent(struct device *dev,  in __dma_alloc_from_coherent()
143 	spin_lock_irqsave(&mem->spinlock, flags);  in __dma_alloc_from_coherent()
145 	if (unlikely(size > ((dma_addr_t)mem->size << PAGE_SHIFT)))  in __dma_alloc_from_coherent()
148 	pageno = bitmap_find_free_region(mem->bitmap, mem->size, order);  in __dma_alloc_from_coherent()
157 	ret = mem->virt_base + ((dma_addr_t)pageno << PAGE_SHIFT);  in __dma_alloc_from_coherent()
158 	spin_unlock_irqrestore(&mem->spinlock, flags);  in __dma_alloc_from_coherent()
162 	spin_unlock_irqrestore(&mem->spinlock, flags);  in __dma_alloc_from_coherent()
167  * dma_alloc_from_dev_coherent() - allocate memory from device coherent pool
168  * @dev:	device from which we allocate memory
174  * This function should be only called from per-arch dma_alloc_coherent()
175  * to support allocation from per-device coherent memory pools.
180 int dma_alloc_from_dev_coherent(struct device *dev, ssize_t size,  in dma_alloc_from_dev_coherent()
195 	if (mem && vaddr >= mem->virt_base && vaddr <  in __dma_release_from_coherent()
196 		   (mem->virt_base + ((dma_addr_t)mem->size << PAGE_SHIFT))) {  in __dma_release_from_coherent()
197 		int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;  in __dma_release_from_coherent()
200 		spin_lock_irqsave(&mem->spinlock, flags);  in __dma_release_from_coherent()
201 		bitmap_release_region(mem->bitmap, page, order);  in __dma_release_from_coherent()
202 		spin_unlock_irqrestore(&mem->spinlock, flags);  in __dma_release_from_coherent()
209  * dma_release_from_dev_coherent() - free memory to device coherent memory pool
210  * @dev:	device from which the memory was allocated
214  * This checks whether the memory was allocated from the per-device
220 int dma_release_from_dev_coherent(struct device *dev, int order, void *vaddr)  in dma_release_from_dev_coherent()
230 	if (mem && vaddr >= mem->virt_base && vaddr + size <=  in __dma_mmap_from_coherent()
231 		   (mem->virt_base + ((dma_addr_t)mem->size << PAGE_SHIFT))) {  in __dma_mmap_from_coherent()
232 		unsigned long off = vma->vm_pgoff;  in __dma_mmap_from_coherent()
233 		int start = (vaddr - mem->virt_base) >> PAGE_SHIFT;  in __dma_mmap_from_coherent()
237 		*ret = -ENXIO;  in __dma_mmap_from_coherent()
238 		if (off < count && user_count <= count - off) {  in __dma_mmap_from_coherent()
239 			unsigned long pfn = mem->pfn_base + start + off;  in __dma_mmap_from_coherent()
240 			*ret = remap_pfn_range(vma, vma->vm_start, pfn,  in __dma_mmap_from_coherent()
242 					       vma->vm_page_prot);  in __dma_mmap_from_coherent()
250  * dma_mmap_from_dev_coherent() - mmap memory from the device coherent pool
251  * @dev:	device from which the memory was allocated
257  * This checks whether the memory was allocated from the per-device
260  * Returns 1 if @vaddr belongs to the device coherent pool and the caller
264 int dma_mmap_from_dev_coherent(struct device *dev, struct vm_area_struct *vma,  in dma_mmap_from_dev_coherent()
275 void *dma_alloc_from_global_coherent(struct device *dev, ssize_t size,  in dma_alloc_from_global_coherent()
318  * Support for reserved memory regions defined in device tree
329 static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev)  in rmem_dma_device_init()
331 	if (!rmem->priv) {  in rmem_dma_device_init()
334 		mem = dma_init_coherent_memory(rmem->base, rmem->base,  in rmem_dma_device_init()
335 					       rmem->size, true);  in rmem_dma_device_init()
338 		rmem->priv = mem;  in rmem_dma_device_init()
340 	dma_assign_coherent_memory(dev, rmem->priv);  in rmem_dma_device_init()
345 				    struct device *dev)  in rmem_dma_device_release()
348 		dev->dma_mem = NULL;  in rmem_dma_device_release()
358 	unsigned long node = rmem->fdt_node;  in rmem_dma_setup()
361 		return -EINVAL;  in rmem_dma_setup()
364 	if (!of_get_flat_dt_prop(node, "no-map", NULL)) {  in rmem_dma_setup()
365 		pr_err("Reserved memory: regions without no-map are not yet supported\n");  in rmem_dma_setup()
366 		return -EINVAL;  in rmem_dma_setup()
371 	if (of_get_flat_dt_prop(node, "linux,dma-default", NULL)) {  in rmem_dma_setup()
378 	rmem->ops = &rmem_dma_ops;  in rmem_dma_setup()
380 		&rmem->base, (unsigned long)rmem->size / SZ_1M);  in rmem_dma_setup()
388 		return -ENOMEM;  in dma_init_reserved_memory()
389 	return dma_init_global_coherent(dma_reserved_default_memory->base,  in dma_init_reserved_memory()
390 					dma_reserved_default_memory->size);  in dma_init_reserved_memory()
395 RESERVEDMEM_OF_DECLARE(dma, "shared-dma-pool", rmem_dma_setup);