[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, 2 insertions, 1 deletions

diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 8671eb634a92..396109a537cd 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -627,6 +627,7 @@ static void __init early_cmdline_parse(void)
 /* Option vector 3: processor options supported */
 #define OV3_FP                  0x80    /* floating point */
 #define OV3_VMX                 0x40    /* VMX/Altivec */
+#define OV3_DFP                 0x20    /* decimal FP */
 
 /* Option vector 5: PAPR/OF options supported */
 #define OV5_LPAR                0x80    /* logical partitioning supported */
@@ -668,7 +669,7 @@ static unsigned char ibm_architecture_vec[] = {
         /* option vector 3: processor options supported */
         3 - 2,                          /* length */
         0,                              /* don't ignore, don't halt */
-        OV3_FP | OV3_VMX,
+        OV3_FP | OV3_VMX | OV3_DFP,
 
         /* option vector 4: IBM PAPR implementation */
         2 - 2,                          /* length */