[POWERPC] Distinguish POWER6 partition modes and tell userspace

This adds code to look at the properties firmware puts in the device
tree to determine what compatibility mode the partition is in on
POWER6 machines, and set the ELF aux vector AT_HWCAP and AT_PLATFORM
entries appropriately.

Specifically, we look at the cpu-version property in the cpu node(s).
If that contains a "logical" PVR value (of the form 0x0f00000x), we
call identify_cpu again with this PVR value.  A value of 0x0f000001
indicates the partition is in POWER5+ compatibility mode, and a value
of 0x0f000002 indicates "POWER6 architected" mode, with various
extensions disabled.  We also look for various other properties:
ibm,dfp, ibm,purr and ibm,spurr.

Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 37 insertions, 6 deletions

diff --git a/arch/powerpc/kernel/cputable.c b/arch/powerpc/kernel/cputable.c
index 992121b2d261..911ac442f44a 100644
--- a/arch/powerpc/kernel/cputable.c
+++ b/arch/powerpc/kernel/cputable.c
@@ -277,10 +277,45 @@ static struct cpu_spec cpu_specs[] = {
                 .oprofile_mmcra_sipr    = MMCRA_SIPR,
                 .platform               = "power5+",
         },
+        {       /* POWER6 in P5+ mode; 2.04-compliant processor */
+                .pvr_mask               = 0xffffffff,
+                .pvr_value              = 0x0f000001,
+                .cpu_name               = "POWER5+",
+                .cpu_features           = CPU_FTRS_POWER5,
+                .cpu_user_features      = COMMON_USER_POWER5_PLUS,
+                .icache_bsize           = 128,
+                .dcache_bsize           = 128,
+                .num_pmcs               = 6,
+                .oprofile_cpu_type      = "ppc64/power6",
+                .oprofile_type          = PPC_OPROFILE_POWER4,
+                .oprofile_mmcra_sihv    = POWER6_MMCRA_SIHV,
+                .oprofile_mmcra_sipr    = POWER6_MMCRA_SIPR,
+                .oprofile_mmcra_clear   = POWER6_MMCRA_THRM |
+                        POWER6_MMCRA_OTHER,
+                .platform               = "power5+",
+        },
         {       /* Power6 */
                 .pvr_mask               = 0xffff0000,
                 .pvr_value              = 0x003e0000,
-                .cpu_name               = "POWER6",
+                .cpu_name               = "POWER6 (raw)",
+                .cpu_features           = CPU_FTRS_POWER6,
+                .cpu_user_features      = COMMON_USER_POWER6 |
+                        PPC_FEATURE_POWER6_EXT,
+                .icache_bsize           = 128,
+                .dcache_bsize           = 128,
+                .num_pmcs               = 6,
+                .oprofile_cpu_type      = "ppc64/power6",
+                .oprofile_type          = PPC_OPROFILE_POWER4,
+                .oprofile_mmcra_sihv    = POWER6_MMCRA_SIHV,
+                .oprofile_mmcra_sipr    = POWER6_MMCRA_SIPR,
+                .oprofile_mmcra_clear   = POWER6_MMCRA_THRM |
+                        POWER6_MMCRA_OTHER,
+                .platform               = "power6x",
+        },
+        {       /* 2.05-compliant processor, i.e. Power6 "architected" mode */
+                .pvr_mask               = 0xffffffff,
+                .pvr_value              = 0x0f000002,
+                .cpu_name               = "POWER6 (architected)",
                 .cpu_features           = CPU_FTRS_POWER6,
                 .cpu_user_features      = COMMON_USER_POWER6,
                 .icache_bsize           = 128,
@@ -1173,19 +1208,15 @@ static struct cpu_spec cpu_specs[] = {
 #endif /* CONFIG_PPC32 */
 };
 
-struct cpu_spec *identify_cpu(unsigned long offset)
+struct cpu_spec *identify_cpu(unsigned long offset, unsigned int pvr)
 {
         struct cpu_spec *s = cpu_specs;
         struct cpu_spec **cur = &cur_cpu_spec;
-        unsigned int pvr = mfspr(SPRN_PVR);
         int i;
 
         s = PTRRELOC(s);
         cur = PTRRELOC(cur);
 
-        if (*cur != NULL)
-                return PTRRELOC(*cur);
-
         for (i = 0; i < ARRAY_SIZE(cpu_specs); i++,s++)
                 if ((pvr & s->pvr_mask) == s->pvr_value) {
                         *cur = cpu_specs + i;