2 files changed, 19 insertions, 14 deletions

diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt
index a96e85397eb7..2233e3d5e5f3 100644
--- a/Documentation/powerpc/booting-without-of.txt
+++ b/Documentation/powerpc/booting-without-of.txt
@@ -851,12 +851,18 @@ address which can extend beyond that limit.
         /cpus/PowerPC,970FX@0
         /cpus/PowerPC,970FX@1
       (unit addresses do not require leading zeroes)
-    - d-cache-line-size : one cell, L1 data cache line size in bytes
-    - i-cache-line-size : one cell, L1 instruction cache line size in
+    - d-cache-block-size : one cell, L1 data cache block size in bytes (*)
+    - i-cache-block-size : one cell, L1 instruction cache block size in
       bytes
     - d-cache-size : one cell, size of L1 data cache in bytes
     - i-cache-size : one cell, size of L1 instruction cache in bytes
 
+(*) The cache "block" size is the size on which the cache management
+instructions operate. Historically, this document used the cache
+"line" size here which is incorrect. The kernel will prefer the cache
+block size and will fallback to cache line size for backward
+compatibility.
+
   Recommended properties:
 
     - timebase-frequency : a cell indicating the frequency of the
@@ -870,6 +876,10 @@ address which can extend beyond that limit.
       for the above, the common code doesn't use that property, but
       you are welcome to re-use the pSeries or Maple one. A future
       kernel version might provide a common function for this.
+    - d-cache-line-size : one cell, L1 data cache line size in bytes
+      if different from the block size
+    - i-cache-line-size : one cell, L1 instruction cache line size in
+      bytes if different from the block size
 
   You are welcome to add any property you find relevant to your board,
   like some information about the mechanism used to soft-reset the
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index ede77dbbd4df..3b1529c103ef 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -291,23 +291,16 @@ static void __init initialize_cache_info(void)
                 if ( num_cpus == 1 ) {
                         const u32 *sizep, *lsizep;
                         u32 size, lsize;
-                        const char *dc, *ic;
-
-                        /* Then read cache informations */
-                        if (machine_is(powermac)) {
-                                dc = "d-cache-block-size";
-                                ic = "i-cache-block-size";
-                        } else {
-                                dc = "d-cache-line-size";
-                                ic = "i-cache-line-size";
-                        }
 
                         size = 0;
                         lsize = cur_cpu_spec->dcache_bsize;
                         sizep = of_get_property(np, "d-cache-size", NULL);
                         if (sizep != NULL)
                                 size = *sizep;
-                        lsizep = of_get_property(np, dc, NULL);
+                        lsizep = of_get_property(np, "d-cache-block-size", NULL);
+                        /* fallback if block size missing */
+                        if (lsizep == NULL)
+                                lsizep = of_get_property(np, "d-cache-line-size", NULL);
                         if (lsizep != NULL)
                                 lsize = *lsizep;
                         if (sizep == 0 || lsizep == 0)
@@ -324,7 +317,9 @@ static void __init initialize_cache_info(void)
                         sizep = of_get_property(np, "i-cache-size", NULL);
                         if (sizep != NULL)
                                 size = *sizep;
-                        lsizep = of_get_property(np, ic, NULL);
+                        lsizep = of_get_property(np, "i-cache-block-size", NULL);
+                        if (lsizep == NULL)
+                                lsizep = of_get_property(np, "i-cache-line-size", NULL);
                         if (lsizep != NULL)
                                 lsize = *lsizep;
                         if (sizep == 0 || lsizep == 0)