blk: blkmap: Add memory mapping support
Allow a slice of RAM to be mapped to a blkmap. This means that RAM can
now be accessed as if it was a block device, meaning that existing
filesystem drivers can now be used to access ramdisks.
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/block/blkmap.c b/drivers/block/blkmap.c
index acfc002..6d6eed8 100644
--- a/drivers/block/blkmap.c
+++ b/drivers/block/blkmap.c
@@ -130,6 +130,111 @@
return 0;
}
+/**
+ * struct blkmap_mem - Memory mapping
+ *
+ * @slice: Common map data
+ * @addr: Target memory region of this mapping
+ * @remapped: True if @addr is backed by a physical to virtual memory
+ * mapping that must be torn down at the end of this mapping's
+ * lifetime.
+ */
+struct blkmap_mem {
+ struct blkmap_slice slice;
+ void *addr;
+ bool remapped;
+};
+
+static ulong blkmap_mem_read(struct blkmap *bm, struct blkmap_slice *bms,
+ lbaint_t blknr, lbaint_t blkcnt, void *buffer)
+{
+ struct blkmap_mem *bmm = container_of(bms, struct blkmap_mem, slice);
+ struct blk_desc *bd = dev_get_uclass_plat(bm->blk);
+ char *src;
+
+ src = bmm->addr + (blknr << bd->log2blksz);
+ memcpy(buffer, src, blkcnt << bd->log2blksz);
+ return blkcnt;
+}
+
+static ulong blkmap_mem_write(struct blkmap *bm, struct blkmap_slice *bms,
+ lbaint_t blknr, lbaint_t blkcnt,
+ const void *buffer)
+{
+ struct blkmap_mem *bmm = container_of(bms, struct blkmap_mem, slice);
+ struct blk_desc *bd = dev_get_uclass_plat(bm->blk);
+ char *dst;
+
+ dst = bmm->addr + (blknr << bd->log2blksz);
+ memcpy(dst, buffer, blkcnt << bd->log2blksz);
+ return blkcnt;
+}
+
+static void blkmap_mem_destroy(struct blkmap *bm, struct blkmap_slice *bms)
+{
+ struct blkmap_mem *bmm = container_of(bms, struct blkmap_mem, slice);
+
+ if (bmm->remapped)
+ unmap_sysmem(bmm->addr);
+}
+
+int __blkmap_map_mem(struct udevice *dev, lbaint_t blknr, lbaint_t blkcnt,
+ void *addr, bool remapped)
+{
+ struct blkmap *bm = dev_get_plat(dev);
+ struct blkmap_mem *bmm;
+ int err;
+
+ bmm = malloc(sizeof(*bmm));
+ if (!bmm)
+ return -ENOMEM;
+
+ *bmm = (struct blkmap_mem) {
+ .slice = {
+ .blknr = blknr,
+ .blkcnt = blkcnt,
+
+ .read = blkmap_mem_read,
+ .write = blkmap_mem_write,
+ .destroy = blkmap_mem_destroy,
+ },
+
+ .addr = addr,
+ .remapped = remapped,
+ };
+
+ err = blkmap_slice_add(bm, &bmm->slice);
+ if (err)
+ free(bmm);
+
+ return err;
+}
+
+int blkmap_map_mem(struct udevice *dev, lbaint_t blknr, lbaint_t blkcnt,
+ void *addr)
+{
+ return __blkmap_map_mem(dev, blknr, blkcnt, addr, false);
+}
+
+int blkmap_map_pmem(struct udevice *dev, lbaint_t blknr, lbaint_t blkcnt,
+ phys_addr_t paddr)
+{
+ struct blkmap *bm = dev_get_plat(dev);
+ struct blk_desc *bd = dev_get_uclass_plat(bm->blk);
+ void *addr;
+ int err;
+
+ addr = map_sysmem(paddr, blkcnt << bd->log2blksz);
+ if (!addr)
+ return -ENOMEM;
+
+ err = __blkmap_map_mem(dev, blknr, blkcnt, addr, true);
+ if (err)
+ unmap_sysmem(addr);
+
+ return err;
+}
+
static ulong blkmap_blk_read_slice(struct blkmap *bm, struct blkmap_slice *bms,
lbaint_t blknr, lbaint_t blkcnt,
void *buffer)