Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux

[mirror_ubuntu-artful-kernel.git] / drivers / md / dm-switch.c

diff --git a/drivers/md/dm-switch.c b/drivers/md/dm-switch.c
index 09a688b3d48ca1445e136544321a54b112b280e1..50fca469cafd92b3dac8c4455391cf24419de7ac 100644 (file)
--- a/drivers/md/dm-switch.c
+++ b/drivers/md/dm-switch.c
@@ -137,13 +137,23 @@ static void switch_get_position(struct switch_ctx *sctx, unsigned long region_nr
        *bit *= sctx->region_table_entry_bits;
 }
 
+static unsigned switch_region_table_read(struct switch_ctx *sctx, unsigned long region_nr)
+{
+       unsigned long region_index;
+       unsigned bit;
+
+       switch_get_position(sctx, region_nr, &region_index, &bit);
+
+       return (ACCESS_ONCE(sctx->region_table[region_index]) >> bit) &
+               ((1 << sctx->region_table_entry_bits) - 1);
+}
+
 /*
  * Find which path to use at given offset.
  */
 static unsigned switch_get_path_nr(struct switch_ctx *sctx, sector_t offset)
 {
-       unsigned long region_index;
-       unsigned bit, path_nr;
+       unsigned path_nr;
        sector_t p;
 
        p = offset;
@@ -152,9 +162,7 @@ static unsigned switch_get_path_nr(struct switch_ctx *sctx, sector_t offset)
        else
                sector_div(p, sctx->region_size);
 
-       switch_get_position(sctx, p, &region_index, &bit);
-       path_nr = (ACCESS_ONCE(sctx->region_table[region_index]) >> bit) &
-              ((1 << sctx->region_table_entry_bits) - 1);
+       path_nr = switch_region_table_read(sctx, p);
 
        /* This can only happen if the processor uses non-atomic stores. */
        if (unlikely(path_nr >= sctx->nr_paths))
@@ -363,7 +371,7 @@ static __always_inline unsigned long parse_hex(const char **string)
 }
 
 static int process_set_region_mappings(struct switch_ctx *sctx,
-                            unsigned argc, char **argv)
+                                      unsigned argc, char **argv)
 {
        unsigned i;
        unsigned long region_index = 0;
@@ -372,6 +380,51 @@ static int process_set_region_mappings(struct switch_ctx *sctx,
                unsigned long path_nr;
                const char *string = argv[i];
 
+               if ((*string & 0xdf) == 'R') {
+                       unsigned long cycle_length, num_write;
+
+                       string++;
+                       if (unlikely(*string == ',')) {
+                               DMWARN("invalid set_region_mappings argument: '%s'", argv[i]);
+                               return -EINVAL;
+                       }
+                       cycle_length = parse_hex(&string);
+                       if (unlikely(*string != ',')) {
+                               DMWARN("invalid set_region_mappings argument: '%s'", argv[i]);
+                               return -EINVAL;
+                       }
+                       string++;
+                       if (unlikely(!*string)) {
+                               DMWARN("invalid set_region_mappings argument: '%s'", argv[i]);
+                               return -EINVAL;
+                       }
+                       num_write = parse_hex(&string);
+                       if (unlikely(*string)) {
+                               DMWARN("invalid set_region_mappings argument: '%s'", argv[i]);
+                               return -EINVAL;
+                       }
+
+                       if (unlikely(!cycle_length) || unlikely(cycle_length - 1 > region_index)) {
+                               DMWARN("invalid set_region_mappings cycle length: %lu > %lu",
+                                      cycle_length - 1, region_index);
+                               return -EINVAL;
+                       }
+                       if (unlikely(region_index + num_write < region_index) ||
+                           unlikely(region_index + num_write >= sctx->nr_regions)) {
+                               DMWARN("invalid set_region_mappings region number: %lu + %lu >= %lu",
+                                      region_index, num_write, sctx->nr_regions);
+                               return -EINVAL;
+                       }
+
+                       while (num_write--) {
+                               region_index++;
+                               path_nr = switch_region_table_read(sctx, region_index - cycle_length);
+                               switch_region_table_write(sctx, region_index, path_nr);
+                       }
+
+                       continue;
+               }
+
                if (*string == ':')
                        region_index++;
                else {
@@ -500,7 +553,7 @@ static int switch_iterate_devices(struct dm_target *ti,
 
 static struct target_type switch_target = {
        .name = "switch",
-       .version = {1, 0, 0},
+       .version = {1, 1, 0},
        .module = THIS_MODULE,
        .ctr = switch_ctr,
        .dtr = switch_dtr,