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 	if (dev && dev->dma_mem)  in dev_get_coherent_memory()
26 		return dev->dma_mem;  in dev_get_coherent_memory()
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()
73 	pr_err("Reserved memory: failed to init DMA memory pool at %pa, size %zd MiB\n",  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()
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
109  * device_addr is the DMA address the device needs to be programmed with to
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()
153 	 * Memory was found in the coherent area.  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
170  * @dma_handle:	This will be filled with the correct dma handle
174  * This function should be only called from per-arch dma_alloc_coherent()
175  * to support allocation from per-device coherent memory pools.
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
214  * This checks whether the memory was allocated from the per-device
215  * coherent memory pool and if so, releases that memory.
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
257  * This checks whether the memory was allocated from the per-device
258  * coherent memory pool and if so, maps that memory to the provided vma.
260  * Returns 1 if @vaddr belongs to the device coherent pool and the caller
312 	pr_info("DMA: default coherent area is set\n");  in dma_init_global_coherent()
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()
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()
373 		     "Reserved memory: region for default DMA coherent area is redefined\n");  in rmem_dma_setup()
378 	rmem->ops = &rmem_dma_ops;  in rmem_dma_setup()
379 	pr_info("Reserved memory: created DMA memory pool at %pa, size %ld MiB\n",  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);