Add a framework for IOMMUs.

ok patrick@

diff --git a/sys/dev/ofw/ofw_misc.c b/sys/dev/ofw/ofw_misc.c
index b3019b8..32f239e 100644 (file)
--- a/sys/dev/ofw/ofw_misc.c
+++ b/sys/dev/ofw/ofw_misc.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: ofw_misc.c,v 1.27 2020/11/30 17:57:36 kettenis Exp $  */
+/*     $OpenBSD: ofw_misc.c,v 1.28 2021/02/25 22:14:54 kettenis Exp $  */
 /*
  * Copyright (c) 2017 Mark Kettenis
  *
@@ -839,3 +839,95 @@ mii_byphandle(uint32_t phandle)
 
        return mii_bynode(node);
 }
+
+/* IOMMU support */
+
+LIST_HEAD(, iommu_device) iommu_devices =
+       LIST_HEAD_INITIALIZER(iommu_devices);
+
+void
+iommu_device_register(struct iommu_device *id)
+{
+       id->id_phandle = OF_getpropint(id->id_node, "phandle", 0);
+       if (id->id_phandle == 0)
+               return;
+
+       LIST_INSERT_HEAD(&iommu_devices, id, id_list);
+}
+
+bus_dma_tag_t
+iommu_device_do_map(uint32_t phandle, uint32_t *cells, bus_dma_tag_t dmat)
+{
+       struct iommu_device *id;
+
+       if (phandle == 0)
+               return dmat;
+
+       LIST_FOREACH(id, &iommu_devices, id_list) {
+               if (id->id_phandle == phandle)
+                       return id->id_map(id->id_cookie, cells, dmat);
+       }
+
+       return dmat;
+}
+
+bus_dma_tag_t
+iommu_device_map_pci(int node, uint32_t rid, bus_dma_tag_t dmat)
+{
+       uint64_t sid_base, sid = 0;
+       uint32_t phandle = 0;
+       uint32_t *cell;
+       uint32_t *map;
+       uint32_t mask, rid_base;
+       uint32_t scells[2];
+       int i, len, length, icells, ncells;
+
+       len = OF_getproplen(node, "iommu-map");
+       if (len <= 0)
+               return dmat;
+
+       map = malloc(len, M_TEMP, M_WAITOK);
+       OF_getpropintarray(node, "iommu-map", map, len);
+
+       mask = OF_getpropint(node, "msi-map-mask", 0xffff);
+       rid = rid & mask;
+
+       cell = map;
+       ncells = len / sizeof(uint32_t);
+       while (ncells > 1) {
+               node = OF_getnodebyphandle(cell[1]);
+               if (node == 0)
+                       goto out;
+
+               icells = OF_getpropint(node, "#iommu-cells", 1);
+               if (ncells < icells + 3)
+                       goto out;
+
+               /* We support 64-bit stream IDs. */
+               KASSERT(icells >= 1 && icells <= 2);
+
+               rid_base = cell[0];
+               length = cell[2 + icells];
+               sid_base = cell[2];
+               for (i = 1; i < icells; i++) {
+                       sid_base <<= 32;
+                       sid_base |= cell[2 + i];
+               }
+               if (rid >= rid_base && rid < rid_base + length) {
+                       sid = sid_base + (rid - rid_base);
+                       phandle = cell[1];
+                       break;
+               }
+
+               cell += (3 + icells);
+               ncells -= (3 + icells);
+       }
+
+out:
+       free(map, M_TEMP, len);
+
+       /* Map stream ID back into cells. */
+       scells[0] = sid >> 32;
+       scells[1] = sid & 0xffffffff;
+       return iommu_device_do_map(phandle, scells, dmat);
+}

diff --git a/sys/dev/ofw/ofw_misc.h b/sys/dev/ofw/ofw_misc.h
index 48ad8e8..a0cc4cb 100644 (file)
--- a/sys/dev/ofw/ofw_misc.h
+++ b/sys/dev/ofw/ofw_misc.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: ofw_misc.h,v 1.17 2020/11/30 17:57:36 kettenis Exp $  */
+/*     $OpenBSD: ofw_misc.h,v 1.18 2021/02/25 22:14:54 kettenis Exp $  */
 /*
  * Copyright (c) 2017 Mark Kettenis
  *
@@ -233,4 +233,18 @@ void       mii_register(struct mii_bus *);
 struct mii_bus *mii_bynode(int);
 struct mii_bus *mii_byphandle(uint32_t);
 
+/* IOMMU support */
+
+struct iommu_device {
+       int     id_node;
+       void    *id_cookie;
+       bus_dma_tag_t (*id_map)(void *, uint32_t *, bus_dma_tag_t);
+
+       LIST_ENTRY(iommu_device) id_list;
+       uint32_t id_phandle;
+};
+
+void   iommu_device_register(struct iommu_device *);
+bus_dma_tag_t iommu_device_map_pci(int, uint32_t, bus_dma_tag_t);
+
 #endif /* _DEV_OFW_MISC_H_ */