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 <tob...@waldekranz.com>
---
drivers/block/blkmap.c | 106 +++++++++++++++++++++++++++++++++++++++++
include/blkmap.h | 4 ++
2 files changed, 110 insertions(+)
diff --git a/drivers/block/blkmap.c b/drivers/block/blkmap.c
index a6ba07404c..c8c2dcac11 100644
--- a/drivers/block/blkmap.c
+++ b/drivers/block/blkmap.c
@@ -12,6 +12,7 @@
#include <dm/lists.h>
#include <dm/root.h>
#include <malloc.h>
+#include <mapmem.h>
#include <part.h>
struct blkmap;
@@ -93,6 +94,111 @@ static int blkmap_add(struct blkmap *bm, struct
blkmap_slice *new)
return 0;
}
+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->dev);
+ 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->dev);
+ 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(int devnum, lbaint_t blknr, lbaint_t blkcnt, void *addr,
+ bool remapped)
+{
+ struct blkmap_mem *bmm;
+ struct blkmap *bm;
+ int err;
+
+ bm = blkmap_from_devnum(devnum);
+ if (!bm)
+ return -ENODEV;
+
+ 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_add(bm, &bmm->slice);
+ if (err)
+ free(bmm);
+
+ return err;
+}
+
+int blkmap_map_mem(int devnum, lbaint_t blknr, lbaint_t blkcnt, void *addr)
+{
+ return __blkmap_map_mem(devnum, blknr, blkcnt, addr, false);
+}
+
+int blkmap_map_pmem(int devnum, lbaint_t blknr, lbaint_t blkcnt,
+ phys_addr_t paddr)
+{
+ struct blk_desc *bd;
+ struct blkmap *bm;
+ void *addr;
+ int err;
+
+ bm = blkmap_from_devnum(devnum);
+ if (!bm)
+ return -ENODEV;
+
+ bd = dev_get_uclass_plat(bm->dev);
+
+ addr = map_sysmem(paddr, blkcnt << bd->log2blksz);
+ if (!addr)
+ return -ENOMEM;
+
+ err = __blkmap_map_mem(devnum, blknr, blkcnt, addr, true);
+ if (err)
+ unmap_sysmem(addr);
+
+ return err;
+}
+
static struct udevice *blkmap_root(void)
{
static struct udevice *dev;
diff --git a/include/blkmap.h b/include/blkmap.h
index 37c0c31c3f..a93611ff62 100644
--- a/include/blkmap.h
+++ b/include/blkmap.h
@@ -9,6 +9,10 @@
#include <stdbool.h>
+int blkmap_map_mem(int devnum, lbaint_t blknr, lbaint_t blkcnt, void *addr);
+int blkmap_map_pmem(int devnum, lbaint_t blknr, lbaint_t blkcnt,
+ phys_addr_t paddr);
+
int blkmap_create(int devnum);
int blkmap_destroy(int devnum);
--
2.34.1
