sh: Support for L2 cache on newer SH-4A CPUs.

This implements preliminary support for the L2 caches found
on newer SH-4A CPUs.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 46 insertions, 1 deletions

diff --git a/arch/sh/kernel/cpu/sh4/probe.c b/arch/sh/kernel/cpu/sh4/probe.c
index 0e65aa6ddc..bee00cac0b 100644
--- a/arch/sh/kernel/cpu/sh4/probe.c
+++ b/arch/sh/kernel/cpu/sh4/probe.c
@@ -29,7 +29,7 @@ int __init detect_cpu_and_cache_system(void)
                 [9] = (1 << 16)
         };
 
-        pvr = (ctrl_inl(CCN_PVR) >> 8) & 0xffff;
+        pvr = (ctrl_inl(CCN_PVR) >> 8) & 0xffffff;
         prr = (ctrl_inl(CCN_PRR) >> 4) & 0xff;
         cvr = (ctrl_inl(CCN_CVR));
 
@@ -54,6 +54,26 @@ int __init detect_cpu_and_cache_system(void)
         cpu_data->dcache.linesz         = L1_CACHE_BYTES;
 
         /*
+         * Setup some generic flags we can probe
+         * (L2 and DSP detection only work on SH-4A)
+         */
+        if (((pvr >> 16) & 0xff) == 0x10) {
+                if ((cvr & 0x02000000) == 0)
+                        cpu_data->flags |= CPU_HAS_L2_CACHE;
+                if ((cvr & 0x10000000) == 0)
+                        cpu_data->flags |= CPU_HAS_DSP;
+
+                cpu_data->flags |= CPU_HAS_LLSC;
+        }
+
+        /* FPU detection works for everyone */
+        if ((cvr & 0x20000000) == 1)
+                cpu_data->flags |= CPU_HAS_FPU;
+
+        /* Mask off the upper chip ID */
+        pvr &= 0xffff;
+
+        /*
          * Probe the underlying processor version/revision and
          * adjust cpu_data setup accordingly.
          */
@@ -181,5 +201,30 @@ int __init detect_cpu_and_cache_system(void)
         cpu_data->dcache.way_size = cpu_data->dcache.sets *
                                     cpu_data->dcache.linesz;
 
+        /*
+         * Setup the L2 cache desc
+         *
+         * SH-4A's have an optional PIPT L2.
+         */
+        if (cpu_data->flags & CPU_HAS_L2_CACHE) {
+                /*
+                 * Size calculation is much more sensible
+                 * than it is for the L1.
+                 *
+                 * Sizes are 128KB, 258KB, 512KB, and 1MB.
+                 */
+                size = (cvr & 0xf) << 17;
+
+                BUG_ON(!size);
+
+                cpu_data->scache.way_incr       = (1 << 16);
+                cpu_data->scache.entry_shift    = 5;
+                cpu_data->scache.entry_mask     = 0xffe0;
+                cpu_data->scache.ways           = 4;
+                cpu_data->scache.linesz         = L1_CACHE_BYTES;
+                cpu_data->scache.sets           = size /
+                        (cpu_data->scache.linesz * cpu_data->scache.ways);
+        }
+
         return 0;
 }