1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2021 Mark Kettenis <kettenis@openbsd.org>
4 */
5
6 #include <common.h>
7 #include <dm.h>
8 #include <iommu.h>
9 #include <lmb.h>
10 #include <asm/io.h>
11 #include <linux/sizes.h>
12
13 #define IOMMU_PAGE_SIZE SZ_4K
14
15 struct sandbox_iommu_priv {
16 struct lmb lmb;
17 };
18
sandbox_iommu_map(struct udevice * dev,void * addr,size_t size)19 static dma_addr_t sandbox_iommu_map(struct udevice *dev, void *addr,
20 size_t size)
21 {
22 struct sandbox_iommu_priv *priv = dev_get_priv(dev);
23 phys_addr_t paddr, dva;
24 phys_size_t psize, off;
25
26 paddr = ALIGN_DOWN(virt_to_phys(addr), IOMMU_PAGE_SIZE);
27 off = virt_to_phys(addr) - paddr;
28 psize = ALIGN(size + off, IOMMU_PAGE_SIZE);
29
30 dva = lmb_alloc(&priv->lmb, psize, IOMMU_PAGE_SIZE);
31
32 return dva + off;
33 }
34
sandbox_iommu_unmap(struct udevice * dev,dma_addr_t addr,size_t size)35 static void sandbox_iommu_unmap(struct udevice *dev, dma_addr_t addr,
36 size_t size)
37 {
38 struct sandbox_iommu_priv *priv = dev_get_priv(dev);
39 phys_addr_t dva;
40 phys_size_t psize;
41
42 dva = ALIGN_DOWN(addr, IOMMU_PAGE_SIZE);
43 psize = size + (addr - dva);
44 psize = ALIGN(psize, IOMMU_PAGE_SIZE);
45
46 lmb_free(&priv->lmb, dva, psize);
47 }
48
49 static struct iommu_ops sandbox_iommu_ops = {
50 .map = sandbox_iommu_map,
51 .unmap = sandbox_iommu_unmap,
52 };
53
sandbox_iommu_probe(struct udevice * dev)54 static int sandbox_iommu_probe(struct udevice *dev)
55 {
56 struct sandbox_iommu_priv *priv = dev_get_priv(dev);
57
58 lmb_init(&priv->lmb);
59 lmb_add(&priv->lmb, 0x89abc000, SZ_16K);
60
61 return 0;
62 }
63
64 static const struct udevice_id sandbox_iommu_ids[] = {
65 { .compatible = "sandbox,iommu" },
66 { /* sentinel */ }
67 };
68
69 U_BOOT_DRIVER(sandbox_iommu) = {
70 .name = "sandbox_iommu",
71 .id = UCLASS_IOMMU,
72 .of_match = sandbox_iommu_ids,
73 .priv_auto = sizeof(struct sandbox_iommu_priv),
74 .ops = &sandbox_iommu_ops,
75 .probe = sandbox_iommu_probe,
76 };
77