ppc/powerpc: workarounds for old Open Firmware versions

This adds code to work around some problems with old versions of
Open Firmware, such as on the early powermacs (7500 etc.) and the
"Longtrail" CHRP machine.  On these machines we have to claim
the physical and virtual address ranges explicitly when claiming
memory and then set up a V->P mapping.

The Longtrail has more problems: setprop doesn't work, and we have
to set an "allow-reclaim" variable to 0 in order to get claim on
physical memory ranges to fail if the memory is already claimed.

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

1 files changed, 77 insertions, 20 deletions

diff --git a/arch/ppc/boot/of1275/claim.c b/arch/ppc/boot/of1275/claim.c
index 13169a5..1ed3aee 100644
--- a/arch/ppc/boot/of1275/claim.c
+++ b/arch/ppc/boot/of1275/claim.c
@@ -9,27 +9,84 @@
  */
 
 #include "of1275.h"
+#include "nonstdio.h"
 
-void *
-claim(unsigned int virt, unsigned int size, unsigned int align)
+/*
+ * Older OF's require that when claiming a specific range of addresses,
+ * we claim the physical space in the /memory node and the virtual
+ * space in the chosen mmu node, and then do a map operation to
+ * map virtual to physical.
+ */
+static int need_map = -1;
+static ihandle chosen_mmu;
+static phandle memory;
+
+/* returns true if s2 is a prefix of s1 */
+static int string_match(const char *s1, const char *s2)
+{
+	for (; *s2; ++s2)
+		if (*s1++ != *s2)
+			return 0;
+	return 1;
+}
+
+static int check_of_version(void)
+{
+	phandle oprom, chosen;
+	char version[64];
+
+	oprom = finddevice("/openprom");
+	if (oprom == OF_INVALID_HANDLE)
+		return 0;
+	if (getprop(oprom, "model", version, sizeof(version)) <= 0)
+		return 0;
+	version[sizeof(version)-1] = 0;
+	printf("OF version = '%s'\n", version);
+	if (!string_match(version, "Open Firmware, 1.")
+	    && !string_match(version, "FirmWorks,3."))
+		return 0;
+	chosen = finddevice("/chosen");
+	if (chosen == OF_INVALID_HANDLE) {
+		chosen = finddevice("/chosen@0");
+		if (chosen == OF_INVALID_HANDLE) {
+			printf("no chosen\n");
+			return 0;
+		}
+	}
+	if (getprop(chosen, "mmu", &chosen_mmu, sizeof(chosen_mmu)) <= 0) {
+		printf("no mmu\n");
+		return 0;
+	}
+	memory = (ihandle) call_prom("open", 1, 1, "/memory");
+	if (memory == OF_INVALID_HANDLE) {
+		memory = (ihandle) call_prom("open", 1, 1, "/memory@0");
+		if (memory == OF_INVALID_HANDLE) {
+			printf("no memory node\n");
+			return 0;
+		}
+	}
+	printf("old OF detected\n");
+	return 1;
+}
+
+void *claim(unsigned int virt, unsigned int size, unsigned int align)
 {
-    struct prom_args {
-	char *service;
-	int nargs;
-	int nret;
-	unsigned int virt;
-	unsigned int size;
-	unsigned int align;
-	void *ret;
-    } args;
+	int ret;
+	unsigned int result;
 
-    args.service = "claim";
-    args.nargs = 3;
-    args.nret = 1;
-    args.virt = virt;
-    args.size = size;
-    args.align = align;
-    args.ret = (void *) 0;
-    (*of_prom_entry)(&args);
-    return args.ret;
+	if (need_map < 0)
+		need_map = check_of_version();
+	if (align || !need_map)
+		return (void *) call_prom("claim", 3, 1, virt, size, align);
+	
+	ret = call_prom_ret("call-method", 5, 2, &result, "claim", memory,
+			    align, size, virt);
+	if (ret != 0 || result == -1)
+		return (void *) -1;
+	ret = call_prom_ret("call-method", 5, 2, &result, "claim", chosen_mmu,
+			    align, size, virt);
+	/* 0x12 == coherent + read/write */
+	ret = call_prom("call-method", 6, 1, "map", chosen_mmu,
+			0x12, size, virt, virt);
+	return virt;
 }