[POWERPC] Workaround Pegasos incorrect ISA "ranges"

The Pegasos firmware doesn't create a valid "ranges" property for the
ISA bridge, thus causing translation of ISA addresses and IO ports to
fail. This fixes it, thus re-enabling proper early serial console to
work on Pegasos.

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

1 files changed, 34 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index ebd501a59abd..b6c3ac20c14c 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -2030,6 +2030,39 @@ static void __init fixup_device_tree_maple(void)
 #define fixup_device_tree_maple()
 #endif
 
+#ifdef CONFIG_PPC_CHRP
+/* Pegasos lacks the "ranges" property in the isa node */
+static void __init fixup_device_tree_chrp(void)
+{
+        phandle isa;
+        u32 isa_ranges[6];
+        char *name;
+        int rc;
+
+        name = "/pci@80000000/isa@c";
+        isa = call_prom("finddevice", 1, 1, ADDR(name));
+        if (!PHANDLE_VALID(isa))
+                return;
+
+        rc = prom_getproplen(isa, "ranges");
+        if (rc != 0 && rc != PROM_ERROR)
+                return;
+
+        prom_printf("Fixing up missing ISA range on Pegasos...\n");
+
+        isa_ranges[0] = 0x1;
+        isa_ranges[1] = 0x0;
+        isa_ranges[2] = 0x01006000;
+        isa_ranges[3] = 0x0;
+        isa_ranges[4] = 0x0;
+        isa_ranges[5] = 0x00010000;
+        prom_setprop(isa, name, "ranges",
+                        isa_ranges, sizeof(isa_ranges));
+}
+#else
+#define fixup_device_tree_chrp()
+#endif
+
 #if defined(CONFIG_PPC64) && defined(CONFIG_PPC_PMAC)
 static void __init fixup_device_tree_pmac(void)
 {
@@ -2077,6 +2110,7 @@ static void __init fixup_device_tree_pmac(void)
 static void __init fixup_device_tree(void)
 {
         fixup_device_tree_maple();
+        fixup_device_tree_chrp();
         fixup_device_tree_pmac();
 }