Re: [PATCH 4/8] blk: blkmap: Add memory mapping support

Hi Tobias,

On Wed, 1 Feb 2023 at 11:10, Tobias Waldekranz tobias@waldekranz.com wrote:

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);
  

Comments again.

int blkmap_create(int devnum); int blkmap_destroy(int devnum);

-- 2.34.1

Other than that and the devnum stuff, LGTM

Regards, Simon