[PATCH] ppc64: SMU partition recovery

This patch adds the ability to the SMU driver to recover missing
calibration partitions from the SMU chip itself. It also adds some
dynamic mecanism to /proc/device-tree so that new properties are visible
to userland.

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

1 files changed, 156 insertions, 8 deletions

diff --git a/drivers/macintosh/smu.c b/drivers/macintosh/smu.c
index a931e508feb6..a83c4acf5710 100644
--- a/drivers/macintosh/smu.c
+++ b/drivers/macintosh/smu.c
@@ -47,13 +47,13 @@
 #include <asm/uaccess.h>
 #include <asm/of_device.h>
 
-#define VERSION "0.6"
+#define VERSION "0.7"
 #define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
 
 #undef DEBUG_SMU
 
 #ifdef DEBUG_SMU
-#define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
+#define DPRINTK(fmt, args...) do { udbg_printf(KERN_DEBUG fmt , ##args); } while (0)
 #else
 #define DPRINTK(fmt, args...) do { } while (0)
 #endif
@@ -92,7 +92,7 @@ struct smu_device {
  * for now, just hard code that
  */
 static struct smu_device        *smu;
-
+static DECLARE_MUTEX(smu_part_access);
 
 /*
  * SMU driver low level stuff
@@ -113,9 +113,11 @@ static void smu_start_cmd(void)
 
         DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
                 cmd->data_len);
-        DPRINTK("SMU: data buffer: %02x %02x %02x %02x ...\n",
+        DPRINTK("SMU: data buffer: %02x %02x %02x %02x %02x %02x %02x %02x\n",
                 ((u8 *)cmd->data_buf)[0], ((u8 *)cmd->data_buf)[1],
-                ((u8 *)cmd->data_buf)[2], ((u8 *)cmd->data_buf)[3]);
+                ((u8 *)cmd->data_buf)[2], ((u8 *)cmd->data_buf)[3],
+                ((u8 *)cmd->data_buf)[4], ((u8 *)cmd->data_buf)[5],
+                ((u8 *)cmd->data_buf)[6], ((u8 *)cmd->data_buf)[7]);
 
         /* Fill the SMU command buffer */
         smu->cmd_buf->cmd = cmd->cmd;
@@ -440,7 +442,7 @@ int smu_present(void)
 EXPORT_SYMBOL(smu_present);
 
 
-int smu_init (void)
+int __init smu_init (void)
 {
         struct device_node *np;
         u32 *data;
@@ -845,16 +847,154 @@ int smu_queue_i2c(struct smu_i2c_cmd *cmd)
         return 0;
 }
 
-struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
+/*
+ * Handling of "partitions"
+ */
+
+static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
+{
+        DECLARE_COMPLETION(comp);
+        unsigned int chunk;
+        struct smu_cmd cmd;
+        int rc;
+        u8 params[8];
+
+        /* We currently use a chunk size of 0xe. We could check the
+         * SMU firmware version and use bigger sizes though
+         */
+        chunk = 0xe;
+
+        while (len) {
+                unsigned int clen = min(len, chunk);
+
+                cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
+                cmd.data_len = 7;
+                cmd.data_buf = params;
+                cmd.reply_len = chunk;
+                cmd.reply_buf = dest;
+                cmd.done = smu_done_complete;
+                cmd.misc = &comp;
+                params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
+                params[1] = 0x4;
+                *((u32 *)&params[2]) = addr;
+                params[6] = clen;
+
+                rc = smu_queue_cmd(&cmd);
+                if (rc)
+                        return rc;
+                wait_for_completion(&comp);
+                if (cmd.status != 0)
+                        return rc;
+                if (cmd.reply_len != clen) {
+                        printk(KERN_DEBUG "SMU: short read in "
+                               "smu_read_datablock, got: %d, want: %d\n",
+                               cmd.reply_len, clen);
+                        return -EIO;
+                }
+                len -= clen;
+                addr += clen;
+                dest += clen;
+        }
+        return 0;
+}
+
+static struct smu_sdbp_header *smu_create_sdb_partition(int id)
+{
+        DECLARE_COMPLETION(comp);
+        struct smu_simple_cmd cmd;
+        unsigned int addr, len, tlen;
+        struct smu_sdbp_header *hdr;
+        struct property *prop;
+
+        /* First query the partition info */
+        smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
+                         smu_done_complete, &comp,
+                         SMU_CMD_PARTITION_LATEST, id);
+        wait_for_completion(&comp);
+
+        /* Partition doesn't exist (or other error) */
+        if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
+                return NULL;
+
+        /* Fetch address and length from reply */
+        addr = *((u16 *)cmd.buffer);
+        len = cmd.buffer[3] << 2;
+        /* Calucluate total length to allocate, including the 17 bytes
+         * for "sdb-partition-XX" that we append at the end of the buffer
+         */
+        tlen = sizeof(struct property) + len + 18;
+
+        prop = kcalloc(tlen, 1, GFP_KERNEL);
+        if (prop == NULL)
+                return NULL;
+        hdr = (struct smu_sdbp_header *)(prop + 1);
+        prop->name = ((char *)prop) + tlen - 18;
+        sprintf(prop->name, "sdb-partition-%02x", id);
+        prop->length = len;
+        prop->value = (unsigned char *)hdr;
+        prop->next = NULL;
+
+        /* Read the datablock */
+        if (smu_read_datablock((u8 *)hdr, addr, len)) {
+                printk(KERN_DEBUG "SMU: datablock read failed while reading "
+                       "partition %02x !\n", id);
+                goto failure;
+        }
+
+        /* Got it, check a few things and create the property */
+        if (hdr->id != id) {
+                printk(KERN_DEBUG "SMU: Reading partition %02x and got "
+                       "%02x !\n", id, hdr->id);
+                goto failure;
+        }
+        if (prom_add_property(smu->of_node, prop)) {
+                printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
+                       "property !\n", id);
+                goto failure;
+        }
+
+        return hdr;
+ failure:
+        kfree(prop);
+        return NULL;
+}
+
+/* Note: Only allowed to return error code in pointers (using ERR_PTR)
+ * when interruptible is 1
+ */
+struct smu_sdbp_header *__smu_get_sdb_partition(int id, unsigned int *size,
+                                                int interruptible)
 {
         char pname[32];
+        struct smu_sdbp_header *part;
 
         if (!smu)
                 return NULL;
 
         sprintf(pname, "sdb-partition-%02x", id);
-        return (struct smu_sdbp_header *)get_property(smu->of_node,
+
+        if (interruptible) {
+                int rc;
+                rc = down_interruptible(&smu_part_access);
+                if (rc)
+                        return ERR_PTR(rc);
+        } else
+                down(&smu_part_access);
+
+        part = (struct smu_sdbp_header *)get_property(smu->of_node,
                                                       pname, size);
+        if (part == NULL) {
+                part = smu_create_sdb_partition(id);
+                if (part != NULL && size)
+                        *size = part->len << 2;
+        }
+        up(&smu_part_access);
+        return part;
+}
+
+struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
+{
+        return __smu_get_sdb_partition(id, size, 0);
 }
 EXPORT_SYMBOL(smu_get_sdb_partition);
 
@@ -930,6 +1070,14 @@ static ssize_t smu_write(struct file *file, const char __user *buf,
         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
                 pp->mode = smu_file_events;
                 return 0;
+        } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
+                struct smu_sdbp_header *part;
+                part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
+                if (part == NULL)
+                        return -EINVAL;
+                else if (IS_ERR(part))
+                        return PTR_ERR(part);
+                return 0;
         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
                 return -EINVAL;
         else if (pp->mode != smu_file_commands)