[PATCH] powerpc: Kill _machine and hard-coded platform numbers

This removes statically assigned platform numbers and reworks the
powerpc platform probe code to use a better mechanism.  With this,
board support files can simply declare a new machine type with a
macro, and implement a probe() function that uses the flattened
device-tree to detect if they apply for a given machine.

We now have a machine_is() macro that replaces the comparisons of
_machine with the various PLATFORM_* constants.  This commit also
changes various drivers to use the new macro instead of looking at
_machine.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 34 insertions, 17 deletions

diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 0d088784450..d66c5e77fcf 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -180,6 +180,16 @@ static unsigned long __initdata prom_tce_alloc_start;
 static unsigned long __initdata prom_tce_alloc_end;
 #endif
 
+/* Platforms codes are now obsolete in the kernel. Now only used within this
+ * file and ultimately gone too. Feel free to change them if you need, they
+ * are not shared with anything outside of this file anymore
+ */
+#define PLATFORM_PSERIES        0x0100
+#define PLATFORM_PSERIES_LPAR   0x0101
+#define PLATFORM_LPAR           0x0001
+#define PLATFORM_POWERMAC       0x0400
+#define PLATFORM_GENERIC        0x0500
+
 static int __initdata of_platform;
 
 static char __initdata prom_cmd_line[COMMAND_LINE_SIZE];
@@ -1492,7 +1502,10 @@ static int __init prom_find_machine_type(void)
         int len, i = 0;
 #ifdef CONFIG_PPC64
         phandle rtas;
+        int x;
 #endif
+
+        /* Look for a PowerMac */
         len = prom_getprop(_prom->root, "compatible",
                            compat, sizeof(compat)-1);
         if (len > 0) {
@@ -1505,28 +1518,36 @@ static int __init prom_find_machine_type(void)
                         if (strstr(p, RELOC("Power Macintosh")) ||
                             strstr(p, RELOC("MacRISC")))
                                 return PLATFORM_POWERMAC;
-#ifdef CONFIG_PPC64
-                        if (strstr(p, RELOC("Momentum,Maple")))
-                                return PLATFORM_MAPLE;
-                        if (strstr(p, RELOC("IBM,CPB")))
-                                return PLATFORM_CELL;
-#endif
                         i += sl + 1;
                 }
         }
 #ifdef CONFIG_PPC64
+        /* If not a mac, try to figure out if it's an IBM pSeries or any other
+         * PAPR compliant platform. We assume it is if :
+         *  - /device_type is "chrp" (please, do NOT use that for future
+         *    non-IBM designs !
+         *  - it has /rtas
+         */
+        len = prom_getprop(_prom->root, "model",
+                           compat, sizeof(compat)-1);
+        if (len <= 0)
+                return PLATFORM_GENERIC;
+        compat[len] = 0;
+        if (strcmp(compat, "chrp"))
+                return PLATFORM_GENERIC;
+
         /* Default to pSeries. We need to know if we are running LPAR */
         rtas = call_prom("finddevice", 1, 1, ADDR("/rtas"));
-        if (PHANDLE_VALID(rtas)) {
-                int x = prom_getproplen(rtas, "ibm,hypertas-functions");
-                if (x != PROM_ERROR) {
-                        prom_printf("Hypertas detected, assuming LPAR !\n");
-                        return PLATFORM_PSERIES_LPAR;
-                }
+        if (!PHANDLE_VALID(rtas))
+                return PLATFORM_GENERIC;
+        x = prom_getproplen(rtas, "ibm,hypertas-functions");
+        if (x != PROM_ERROR) {
+                prom_printf("Hypertas detected, assuming LPAR !\n");
+                return PLATFORM_PSERIES_LPAR;
         }
         return PLATFORM_PSERIES;
 #else
-        return PLATFORM_CHRP;
+        return PLATFORM_GENERIC;
 #endif
 }
 
@@ -2034,7 +2055,6 @@ unsigned long __init prom_init(unsigned long r3, unsigned long r4,
 {       
         struct prom_t *_prom;
         unsigned long hdr;
-        u32 getprop_rval;
         unsigned long offset = reloc_offset();
 
 #ifdef CONFIG_PPC32
@@ -2070,9 +2090,6 @@ unsigned long __init prom_init(unsigned long r3, unsigned long r4,
          * between pSeries SMP and pSeries LPAR
          */
         RELOC(of_platform) = prom_find_machine_type();
-        getprop_rval = RELOC(of_platform);
-        prom_setprop(_prom->chosen, "/chosen", "linux,platform",
-                     &getprop_rval, sizeof(getprop_rval));
 
         /* Bail if this is a kdump kernel. */
         if (PHYSICAL_START > 0)