imsm: detect option-rom capabilities

The option-rom advertises its capabilities in a data structure located in
the platform ROM region 0xc0000-0xf0000.  Attempt to detect the option-rom
and limit array creation to the platform's capabilities.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 178 insertions, 0 deletions

diff --git a/platform-intel.c b/platform-intel.c
new file mode 100644
index 0000000..6cd5830
--- /dev/null
+++ b/platform-intel.c
@@ -0,0 +1,178 @@
+/*
+ * Intel(R) Matrix Storage Manager hardware and firmware support routines
+ *
+ * Copyright (C) 2008 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#include "mdadm.h"
+#include "platform-intel.h"
+#include "probe_roms.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+void free_sys_dev(struct sys_dev **list)
+{
+	while (*list) {
+		struct sys_dev *next = (*list)->next;
+
+		if ((*list)->path)
+			free((*list)->path);
+		free(*list);
+		*list = next;
+	}
+}
+
+struct sys_dev *find_driver_devices(const char *bus, const char *driver)
+{
+	/* search sysfs for devices driven by 'driver' */
+	char path[256];
+	char link[256];
+	char *c;
+	DIR *driver_dir;
+	struct dirent *de;
+	struct sys_dev *head = NULL;
+	struct sys_dev *list = NULL;
+
+	sprintf(path, "/sys/bus/%s/drivers/%s", bus, driver);
+	driver_dir = opendir(path);
+	if (!driver_dir)
+		return NULL;
+	for (de = readdir(driver_dir); de; de = readdir(driver_dir)) {
+		/* is 'de' a device? check that the 'subsystem' link exists and
+		 * that its target matches 'bus'
+		 */
+		sprintf(path, "/sys/bus/%s/drivers/%s/%s/subsystem",
+			bus, driver, de->d_name);
+		if (readlink(path, link, sizeof(link)) < 0)
+			continue;
+		c = strrchr(link, '/');
+		if (!c)
+			continue;
+		if (strncmp(bus, c+1, strlen(bus)) != 0)
+			continue;
+
+		/* start / add list entry */
+		if (!head) {
+			head = malloc(sizeof(*head));
+			list = head;
+		} else {
+			list->next = malloc(sizeof(*head));
+			list = list->next;
+		}
+
+		if (!list) {
+			free_sys_dev(&head);
+			break;
+		}
+
+		/* generate canonical path name for the device */
+		sprintf(path, "/sys/bus/%s/drivers/%s/%s",
+			bus, driver, de->d_name);
+		list->path = canonicalize_file_name(path);
+		list->next = NULL;
+	}
+
+	return head;
+}
+
+__u16 devpath_to_vendor(const char *dev_path)
+{
+	char path[strlen(dev_path) + strlen("/vendor") + 1];
+	char vendor[7];
+	int fd;
+	__u16 id = 0xffff;
+	int n;
+
+	sprintf(path, "%s/vendor", dev_path);
+
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
+		return 0xffff;
+
+	n = read(fd, vendor, sizeof(vendor));
+	if (n == sizeof(vendor)) {
+		vendor[n - 1] = '\0';
+		id = strtoul(vendor, NULL, 16);
+	}
+	close(fd);
+
+	return id;
+}
+
+static int platform_has_intel_ahci(void)
+{
+	struct sys_dev *devices = find_driver_devices("pci", "ahci");
+	struct sys_dev *dev;
+	int ret = 0;
+
+	for (dev = devices; dev; dev = dev->next)
+		if (devpath_to_vendor(dev->path) == 0x8086) {
+			ret = 1;
+			break;
+		}
+
+	free_sys_dev(&devices);
+
+	return ret;
+}
+
+
+static struct imsm_orom imsm_orom;
+static int scan(const void *start, const void *end)
+{
+	int offset;
+	const struct imsm_orom *imsm_mem;
+	int len = (end - start);
+
+	for (offset = 0; offset < len; offset += 4) {
+		imsm_mem = start + offset;
+		if (memcmp(imsm_mem->signature, "$VER", 4) == 0) {
+			imsm_orom = *imsm_mem;
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+const struct imsm_orom *find_imsm_orom(void)
+{
+	static int populated = 0;
+
+	/* it's static data so we only need to read it once */
+	if (populated)
+		return &imsm_orom;
+
+	if (!platform_has_intel_ahci())
+		return NULL;
+
+	/* scan option-rom memory looking for an imsm signature */
+	if (probe_roms_init() != 0)
+		return NULL;
+	probe_roms();
+	populated = scan_adapter_roms(scan);
+	probe_roms_exit();
+
+	if (populated)
+		return &imsm_orom;
+	return NULL;
+}