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 --- 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);