[Skiboot] [RFC PATCH 4/7] external/common: Add POWERPC code reenable building pflash for POWER
Cyril Bur
cyril.bur at au1.ibm.com
Fri Jul 17 17:01:21 AEST 2015
As per commit to create the external/common code, this commit introduces
the POWER arch compatibility flash reading code.
This commit actually should cause no functional change to pflash (it won't
be able to access the BMC flash if it ever could), however rather than
accessing the flash via the debug xscom interface it will access it though
the MTD interface provided by linux and skiboot.
Signed-off-by: Cyril Bur <cyril.bur at au1.ibm.com>
---
external/common/arch_flash_powerpc.c | 200 ++++++++++++++++++++++++++++++++
external/common/arch_flash_powerpc_io.h | 0
external/pflash/rules.mk | 5 +
3 files changed, 205 insertions(+)
create mode 100644 external/common/arch_flash_powerpc.c
create mode 100644 external/common/arch_flash_powerpc_io.h
diff --git a/external/common/arch_flash_powerpc.c b/external/common/arch_flash_powerpc.c
new file mode 100644
index 0000000..921fba4
--- /dev/null
+++ b/external/common/arch_flash_powerpc.c
@@ -0,0 +1,200 @@
+/* Copyright 2013-2015 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <limits.h>
+#include <unistd.h>
+#include <dirent.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <string.h>
+
+#include <libflash/file.h>
+
+#include "arch_flash.h"
+
+#define FDT_FLASH_PATH "/proc/device-tree/chosen/ibm,system-flash"
+#define SYSFS_MTD_PATH "/sys/class/mtd/"
+
+static int get_dev_attr(const char *dev, const char *attr_file, uint32_t *attr)
+{
+ char dev_path[PATH_MAX] = SYSFS_MTD_PATH;
+ /*
+ * Needs to be large enough to hold at most uint32_t represented as a
+ * string in hex with leading 0x
+ */
+ char attr_buf[10];
+ int fd, rc;
+
+ /*
+ * sizeof(dev_path) - (strlen(dev_path) + 1) is the remaining space in
+ * dev_path, + 1 to account for the '\0'. As strncat could write n+1 bytes
+ * to dev_path the correct calulcation for n is:
+ * (sizeof(dev_path) - (strlen(dev_path) + 1) - 1)
+ */
+ strncat(dev_path, dev, (sizeof(dev_path) - (strlen(dev_path) + 1) - 1));
+ strncat(dev_path, "/", (sizeof(dev_path) - (strlen(dev_path) + 1) - 1));
+ strncat(dev_path, attr_file, (sizeof(dev_path) - (strlen(dev_path) + 1) - 1));
+ fd = open(dev_path, O_RDONLY);
+ if (fd == -1)
+ goto out;
+
+ rc = read(fd, attr_buf, sizeof(attr_buf));
+ close(fd);
+ if (rc == -1)
+ goto out;
+
+ if (attr)
+ *attr = strtol(attr_buf, NULL, 0);
+
+ return 0;
+
+out:
+ fprintf(stderr, "Couldn't get MTD device attribute '%s' from '%s'\n", dev, attr_file);
+ return -1;
+}
+
+static int get_dev_mtd(const char *fdt_flash_path, char **r_path)
+{
+ struct dirent **namelist;
+ char fdt_node_path[PATH_MAX];
+ int count, i, rc, fd, done;
+
+ if (!fdt_flash_path)
+ return -1;
+
+ fd = open(fdt_flash_path, O_RDONLY);
+ if (fd == -1) {
+ fprintf(stderr, "Couldn't open '%s' FDT attribute to determine which flash device to use\n",
+ fdt_flash_path);
+ return -1;
+ }
+
+ rc = read(fd, fdt_node_path, sizeof(fdt_node_path));
+ close(fd);
+ if (rc == -1) {
+ fprintf(stderr, "Couldn't read flash FDT node from '%s'\n", fdt_flash_path);
+ return -1;
+ }
+
+ count = scandir(SYSFS_MTD_PATH, &namelist, NULL, alphasort);
+ if (count == -1) {
+ fprintf(stderr, "Couldn't scan '%s' for MTD devices\n", SYSFS_MTD_PATH);
+ return -1;
+ }
+
+ rc = 0;
+ done = 0;
+ for (i = 0; i < count; i++) {
+ struct dirent *dirent;
+ char dev_path[PATH_MAX] = SYSFS_MTD_PATH;
+ char fdt_node_path_tmp[PATH_MAX];
+
+ dirent = namelist[i];
+ if (dirent->d_name[0] == '.' || rc || done) {
+ free(namelist[i]);
+ continue;
+ }
+
+ strncat(dev_path, dirent->d_name, sizeof(dev_path) - strlen(dev_path) - 2);
+ strncat(dev_path, "/device/of_node", sizeof(dev_path) - strlen(dev_path) - 2);
+
+ rc = readlink(dev_path, fdt_node_path_tmp, sizeof(fdt_node_path_tmp) - 1);
+ if (rc == -1) {
+ /*
+ * This might fail because it could not exist if the system has flash
+ * devices that present as mtd but don't have corresponding FDT
+ * nodes, just continue silently.
+ */
+ free(namelist[i]);
+ /* Should still try the next dir so reset rc */
+ rc = 0;
+ continue;
+ }
+ fdt_node_path_tmp[rc] = '\0';
+
+ if (strstr(fdt_node_path_tmp, fdt_node_path)) {
+ uint32_t flags, size;
+
+ /*
+ * size and flags could perhaps have be gotten another way but this
+ * method is super unlikely to fail so it will do.
+ */
+
+ /* Check to see if device is writeable */
+ rc = get_dev_attr(dirent->d_name, "flags", &flags);
+ if (rc) {
+ free(namelist[i]);
+ continue;
+ }
+
+ /* Get the size of the mtd device while we're at it */
+ rc = get_dev_attr(dirent->d_name, "size", &size);
+ if (rc) {
+ free(namelist[i]);
+ continue;
+ }
+
+ strcpy(dev_path, "/dev/");
+ strncat(dev_path, dirent->d_name, sizeof(dev_path) - strlen(dev_path) - 2);
+ *r_path = strdup(dev_path);
+ done = 1;
+ }
+ free(namelist[i]);
+ }
+ free(namelist);
+
+ if (!done)
+ fprintf(stderr, "Couldn't find '%s' corresponding MTD\n", fdt_flash_path);
+
+ /* explicit negative value so as to not return a libflash code */
+ return done ? rc : -1;
+}
+
+static struct blocklevel_device *arch_init_blocklevel(const char *file)
+{
+ int rc;
+ struct blocklevel_device *new_bl = NULL;
+ char *real_file;
+
+ if (!file) {
+ rc = get_dev_mtd(FDT_FLASH_PATH, &real_file);
+ if (rc)
+ return NULL;
+ }
+
+ file_init_path(file ? file : real_file, NULL, &new_bl);
+ return new_bl;
+}
+
+int arch_flash_init(struct blocklevel_device **r_bl, const char *file)
+{
+ struct blocklevel_device *new_bl;
+
+ new_bl = arch_init_blocklevel(file);
+ if (!new_bl)
+ return -1;
+
+ *r_bl = new_bl;
+ return 0;
+}
+
+void arch_flash_close(struct blocklevel_device *bl, const char *file)
+{
+ file_exit_close(bl);
+}
diff --git a/external/common/arch_flash_powerpc_io.h b/external/common/arch_flash_powerpc_io.h
new file mode 100644
index 0000000..e69de29
diff --git a/external/pflash/rules.mk b/external/pflash/rules.mk
index 4ad381c..7098131 100644
--- a/external/pflash/rules.mk
+++ b/external/pflash/rules.mk
@@ -4,8 +4,13 @@ ifeq ($(ARCH),ARCH_ARM)
arch = arm
ARCH_OBJS = common/arch_flash_common.o common/arch_flash_arm.o ast-sf-ctrl.o
else
+ifeq ($(ARCH),ARCH_POWERPC)
+arch = powerpc
+ARCH_OBJS = common/arch_flash_common.o common/arch_flash_powerpc.o
+else
$(error Unsupported architecture $(ARCH))
endif
+endif
.DEFAULT_GOAL := all
--
2.4.6
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