powerpc: Fixes to get the Longtrail CHRP a bit further

Talk about buggy firmware...  the OF on the Longtrail returns 0
from the claim client service rather than -1 when the claim fails.
It also has no device_type on the /memory node and blows up if
the output buffer for package-to-path is too big.

This also fixes a bug with calling alloc_up with align == 0, where
we did _ALIGN_UP(alloc_bottom, 0) which will end up as 0.

Lastly, we now check the return value (in r3) from calling the
prom, and return -1 from call_prom if we get a negative value back.
That is supposed to indicate that the requested client service
doesn't exist.

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

1 files changed, 28 insertions, 14 deletions

diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index debe9734636e..2ad9947bd675 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -145,11 +145,11 @@ typedef u32 cell_t;
 extern void __start(unsigned long r3, unsigned long r4, unsigned long r5);
 
 #ifdef CONFIG_PPC64
-extern void enter_prom(struct prom_args *args, unsigned long entry);
+extern int enter_prom(struct prom_args *args, unsigned long entry);
 #else
-static inline void enter_prom(struct prom_args *args, unsigned long entry)
+static inline int enter_prom(struct prom_args *args, unsigned long entry)
 {
-        ((void (*)(struct prom_args *))entry)(args);
+        return ((int (*)(struct prom_args *))entry)(args);
 }
 #endif
 
@@ -241,7 +241,8 @@ static int __init call_prom(const char *service, int nargs, int nret, ...)
         for (i = 0; i < nret; i++)
                 args.args[nargs+i] = 0;
 
-        enter_prom(&args, RELOC(prom_entry));
+        if (enter_prom(&args, RELOC(prom_entry)) < 0)
+                return PROM_ERROR;
 
         return (nret > 0) ? args.args[nargs] : 0;
 }
@@ -265,7 +266,8 @@ static int __init call_prom_ret(const char *service, int nargs, int nret,
         for (i = 0; i < nret; i++)
                 rets[nargs+i] = 0;
 
-        enter_prom(&args, RELOC(prom_entry));
+        if (enter_prom(&args, RELOC(prom_entry)) < 0)
+                return PROM_ERROR;
 
         if (rets != NULL)
                 for (i = 1; i < nret; ++i)
@@ -670,9 +672,11 @@ static void __init prom_send_capabilities(void)
  */
 static unsigned long __init alloc_up(unsigned long size, unsigned long align)
 {
-        unsigned long base = _ALIGN_UP(RELOC(alloc_bottom), align);
+        unsigned long base = RELOC(alloc_bottom);
         unsigned long addr = 0;
 
+        if (align)
+                base = _ALIGN_UP(base, align);
         prom_debug("alloc_up(%x, %x)\n", size, align);
         if (RELOC(ram_top) == 0)
                 prom_panic("alloc_up() called with mem not initialized\n");
@@ -686,7 +690,7 @@ static unsigned long __init alloc_up(unsigned long size, unsigned long align)
             base = _ALIGN_UP(base + 0x100000, align)) {
                 prom_debug("    trying: 0x%x\n\r", base);
                 addr = (unsigned long)prom_claim(base, size, 0);
-                if (addr != PROM_ERROR)
+                if (addr != PROM_ERROR && addr != 0)
                         break;
                 addr = 0;
                 if (align == 0)
@@ -746,7 +750,7 @@ static unsigned long __init alloc_down(unsigned long size, unsigned long align,
              base = _ALIGN_DOWN(base - 0x100000, align))  {
                 prom_debug("    trying: 0x%x\n\r", base);
                 addr = (unsigned long)prom_claim(base, size, 0);
-                if (addr != PROM_ERROR)
+                if (addr != PROM_ERROR && addr != 0)
                         break;
                 addr = 0;
         }
@@ -852,9 +856,16 @@ static void __init prom_init_mem(void)
                 type[0] = 0;
                 prom_getprop(node, "device_type", type, sizeof(type));
 
+                if (type[0] == 0) {
+                        /*
+                         * CHRP Longtrail machines have no device_type
+                         * on the memory node, so check the name instead...
+                         */
+                        prom_getprop(node, "name", type, sizeof(type));
+                }
                 if (strcmp(type, RELOC("memory")))
                         continue;
-        
+
                 plen = prom_getprop(node, "reg", RELOC(regbuf), sizeof(regbuf));
                 if (plen > sizeof(regbuf)) {
                         prom_printf("memory node too large for buffer !\n");
@@ -1632,18 +1643,21 @@ static void __init scan_dt_build_struct(phandle node, unsigned long *mem_start,
         unsigned long soff;
         unsigned char *valp;
         static char pname[MAX_PROPERTY_NAME];
-        int l;
+        int l, room;
 
         dt_push_token(OF_DT_BEGIN_NODE, mem_start, mem_end);
 
         /* get the node's full name */
         namep = (char *)*mem_start;
-        l = call_prom("package-to-path", 3, 1, node,
-                      namep, *mem_end - *mem_start);
+        room = *mem_end - *mem_start;
+        if (room > 255)
+                room = 255;
+        l = call_prom("package-to-path", 3, 1, node, namep, room);
         if (l >= 0) {
                 /* Didn't fit?  Get more room. */
-                if ((l+1) > (*mem_end - *mem_start)) {
-                        namep = make_room(mem_start, mem_end, l+1, 1);
+                if (l >= room) {
+                        if (l >= *mem_end - *mem_start)
+                                namep = make_room(mem_start, mem_end, l+1, 1);
                         call_prom("package-to-path", 3, 1, node, namep, l);
                 }
                 namep[l] = '\0';