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-rw-r--r--arch/powerpc/boot/oflib.c219
1 files changed, 219 insertions, 0 deletions
diff --git a/arch/powerpc/boot/oflib.c b/arch/powerpc/boot/oflib.c
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+++ b/arch/powerpc/boot/oflib.c
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+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) Paul Mackerras 1997.
+ */
+#include <stddef.h>
+#include "types.h"
+#include "elf.h"
+#include "string.h"
+#include "stdio.h"
+#include "page.h"
+#include "ops.h"
+
+#include "of.h"
+
+typedef u32 prom_arg_t;
+
+/* The following structure is used to communicate with open firmware.
+ * All arguments in and out are in big endian format. */
+struct prom_args {
+ __be32 service; /* Address of service name string. */
+ __be32 nargs; /* Number of input arguments. */
+ __be32 nret; /* Number of output arguments. */
+ __be32 args[10]; /* Input/output arguments. */
+};
+
+#ifdef __powerpc64__
+extern int prom(void *);
+#else
+static int (*prom) (void *);
+#endif
+
+void of_init(void *promptr)
+{
+#ifndef __powerpc64__
+ prom = (int (*)(void *))promptr;
+#endif
+}
+
+#define ADDR(x) (u32)(unsigned long)(x)
+
+int of_call_prom(const char *service, int nargs, int nret, ...)
+{
+ int i;
+ struct prom_args args;
+ va_list list;
+
+ args.service = cpu_to_be32(ADDR(service));
+ args.nargs = cpu_to_be32(nargs);
+ args.nret = cpu_to_be32(nret);
+
+ va_start(list, nret);
+ for (i = 0; i < nargs; i++)
+ args.args[i] = cpu_to_be32(va_arg(list, prom_arg_t));
+ va_end(list);
+
+ for (i = 0; i < nret; i++)
+ args.args[nargs+i] = 0;
+
+ if (prom(&args) < 0)
+ return PROM_ERROR;
+
+ return (nret > 0) ? be32_to_cpu(args.args[nargs]) : 0;
+}
+
+static int of_call_prom_ret(const char *service, int nargs, int nret,
+ prom_arg_t *rets, ...)
+{
+ int i;
+ struct prom_args args;
+ va_list list;
+
+ args.service = cpu_to_be32(ADDR(service));
+ args.nargs = cpu_to_be32(nargs);
+ args.nret = cpu_to_be32(nret);
+
+ va_start(list, rets);
+ for (i = 0; i < nargs; i++)
+ args.args[i] = cpu_to_be32(va_arg(list, prom_arg_t));
+ va_end(list);
+
+ for (i = 0; i < nret; i++)
+ args.args[nargs+i] = 0;
+
+ if (prom(&args) < 0)
+ return PROM_ERROR;
+
+ if (rets != NULL)
+ for (i = 1; i < nret; ++i)
+ rets[i-1] = be32_to_cpu(args.args[nargs+i]);
+
+ return (nret > 0) ? be32_to_cpu(args.args[nargs]) : 0;
+}
+
+/* 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;
+}
+
+/*
+ * 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 ihandle memory;
+
+static int check_of_version(void)
+{
+ phandle oprom, chosen;
+ char version[64];
+
+ oprom = of_finddevice("/openprom");
+ if (oprom == (phandle) -1)
+ return 0;
+ if (of_getprop(oprom, "model", version, sizeof(version)) <= 0)
+ return 0;
+ version[sizeof(version)-1] = 0;
+ printf("OF version = '%s'\r\n", version);
+ if (!string_match(version, "Open Firmware, 1.")
+ && !string_match(version, "FirmWorks,3."))
+ return 0;
+ chosen = of_finddevice("/chosen");
+ if (chosen == (phandle) -1) {
+ chosen = of_finddevice("/chosen@0");
+ if (chosen == (phandle) -1) {
+ printf("no chosen\n");
+ return 0;
+ }
+ }
+ if (of_getprop(chosen, "mmu", &chosen_mmu, sizeof(chosen_mmu)) <= 0) {
+ printf("no mmu\n");
+ return 0;
+ }
+ memory = of_call_prom("open", 1, 1, "/memory");
+ if (memory == PROM_ERROR) {
+ memory = of_call_prom("open", 1, 1, "/memory@0");
+ if (memory == PROM_ERROR) {
+ printf("no memory node\n");
+ return 0;
+ }
+ }
+ printf("old OF detected\r\n");
+ return 1;
+}
+
+unsigned int of_claim(unsigned long virt, unsigned long size,
+ unsigned long align)
+{
+ int ret;
+ prom_arg_t result;
+
+ if (need_map < 0)
+ need_map = check_of_version();
+ if (align || !need_map)
+ return of_call_prom("claim", 3, 1, virt, size, align);
+
+ ret = of_call_prom_ret("call-method", 5, 2, &result, "claim", memory,
+ align, size, virt);
+ if (ret != 0 || result == -1)
+ return -1;
+ ret = of_call_prom_ret("call-method", 5, 2, &result, "claim", chosen_mmu,
+ align, size, virt);
+ /* 0x12 == coherent + read/write */
+ ret = of_call_prom("call-method", 6, 1, "map", chosen_mmu,
+ 0x12, size, virt, virt);
+ return virt;
+}
+
+void *of_vmlinux_alloc(unsigned long size)
+{
+ unsigned long start = (unsigned long)_start, end = (unsigned long)_end;
+ unsigned long addr;
+ void *p;
+
+ /* With some older POWER4 firmware we need to claim the area the kernel
+ * will reside in. Newer firmwares don't need this so we just ignore
+ * the return value.
+ */
+ addr = (unsigned long) of_claim(start, end - start, 0);
+ printf("Trying to claim from 0x%lx to 0x%lx (0x%lx) got %lx\r\n",
+ start, end, end - start, addr);
+
+ p = malloc(size);
+ if (!p)
+ fatal("Can't allocate memory for kernel image!\n\r");
+
+ return p;
+}
+
+void of_exit(void)
+{
+ of_call_prom("exit", 0, 0);
+}
+
+/*
+ * OF device tree routines
+ */
+void *of_finddevice(const char *name)
+{
+ return (void *) (unsigned long) of_call_prom("finddevice", 1, 1, name);
+}
+
+int of_getprop(const void *phandle, const char *name, void *buf,
+ const int buflen)
+{
+ return of_call_prom("getprop", 4, 1, phandle, name, buf, buflen);
+}
+
+int of_setprop(const void *phandle, const char *name, const void *buf,
+ const int buflen)
+{
+ return of_call_prom("setprop", 4, 1, phandle, name, buf, buflen);
+}