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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/char/ipmi/ipmi_bt_sm.c
downloadvexpress-lsk-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/char/ipmi/ipmi_bt_sm.c')
-rw-r--r--drivers/char/ipmi/ipmi_bt_sm.c513
1 files changed, 513 insertions, 0 deletions
diff --git a/drivers/char/ipmi/ipmi_bt_sm.c b/drivers/char/ipmi/ipmi_bt_sm.c
new file mode 100644
index 00000000000..225b330115b
--- /dev/null
+++ b/drivers/char/ipmi/ipmi_bt_sm.c
@@ -0,0 +1,513 @@
+/*
+ * ipmi_bt_sm.c
+ *
+ * The state machine for an Open IPMI BT sub-driver under ipmi_si.c, part
+ * of the driver architecture at http://sourceforge.net/project/openipmi
+ *
+ * Author: Rocky Craig <first.last@hp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
+ * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
+ * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * 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.,
+ * 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include <linux/kernel.h> /* For printk. */
+#include <linux/string.h>
+#include <linux/ipmi_msgdefs.h> /* for completion codes */
+#include "ipmi_si_sm.h"
+
+#define IPMI_BT_VERSION "v33"
+
+static int bt_debug = 0x00; /* Production value 0, see following flags */
+
+#define BT_DEBUG_ENABLE 1
+#define BT_DEBUG_MSG 2
+#define BT_DEBUG_STATES 4
+
+/* Typical "Get BT Capabilities" values are 2-3 retries, 5-10 seconds,
+ and 64 byte buffers. However, one HP implementation wants 255 bytes of
+ buffer (with a documented message of 160 bytes) so go for the max.
+ Since the Open IPMI architecture is single-message oriented at this
+ stage, the queue depth of BT is of no concern. */
+
+#define BT_NORMAL_TIMEOUT 2000000 /* seconds in microseconds */
+#define BT_RETRY_LIMIT 2
+#define BT_RESET_DELAY 6000000 /* 6 seconds after warm reset */
+
+enum bt_states {
+ BT_STATE_IDLE,
+ BT_STATE_XACTION_START,
+ BT_STATE_WRITE_BYTES,
+ BT_STATE_WRITE_END,
+ BT_STATE_WRITE_CONSUME,
+ BT_STATE_B2H_WAIT,
+ BT_STATE_READ_END,
+ BT_STATE_RESET1, /* These must come last */
+ BT_STATE_RESET2,
+ BT_STATE_RESET3,
+ BT_STATE_RESTART,
+ BT_STATE_HOSED
+};
+
+struct si_sm_data {
+ enum bt_states state;
+ enum bt_states last_state; /* assist printing and resets */
+ unsigned char seq; /* BT sequence number */
+ struct si_sm_io *io;
+ unsigned char write_data[IPMI_MAX_MSG_LENGTH];
+ int write_count;
+ unsigned char read_data[IPMI_MAX_MSG_LENGTH];
+ int read_count;
+ int truncated;
+ long timeout;
+ unsigned int error_retries; /* end of "common" fields */
+ int nonzero_status; /* hung BMCs stay all 0 */
+};
+
+#define BT_CLR_WR_PTR 0x01 /* See IPMI 1.5 table 11.6.4 */
+#define BT_CLR_RD_PTR 0x02
+#define BT_H2B_ATN 0x04
+#define BT_B2H_ATN 0x08
+#define BT_SMS_ATN 0x10
+#define BT_OEM0 0x20
+#define BT_H_BUSY 0x40
+#define BT_B_BUSY 0x80
+
+/* Some bits are toggled on each write: write once to set it, once
+ more to clear it; writing a zero does nothing. To absolutely
+ clear it, check its state and write if set. This avoids the "get
+ current then use as mask" scheme to modify one bit. Note that the
+ variable "bt" is hardcoded into these macros. */
+
+#define BT_STATUS bt->io->inputb(bt->io, 0)
+#define BT_CONTROL(x) bt->io->outputb(bt->io, 0, x)
+
+#define BMC2HOST bt->io->inputb(bt->io, 1)
+#define HOST2BMC(x) bt->io->outputb(bt->io, 1, x)
+
+#define BT_INTMASK_R bt->io->inputb(bt->io, 2)
+#define BT_INTMASK_W(x) bt->io->outputb(bt->io, 2, x)
+
+/* Convenience routines for debugging. These are not multi-open safe!
+ Note the macros have hardcoded variables in them. */
+
+static char *state2txt(unsigned char state)
+{
+ switch (state) {
+ case BT_STATE_IDLE: return("IDLE");
+ case BT_STATE_XACTION_START: return("XACTION");
+ case BT_STATE_WRITE_BYTES: return("WR_BYTES");
+ case BT_STATE_WRITE_END: return("WR_END");
+ case BT_STATE_WRITE_CONSUME: return("WR_CONSUME");
+ case BT_STATE_B2H_WAIT: return("B2H_WAIT");
+ case BT_STATE_READ_END: return("RD_END");
+ case BT_STATE_RESET1: return("RESET1");
+ case BT_STATE_RESET2: return("RESET2");
+ case BT_STATE_RESET3: return("RESET3");
+ case BT_STATE_RESTART: return("RESTART");
+ case BT_STATE_HOSED: return("HOSED");
+ }
+ return("BAD STATE");
+}
+#define STATE2TXT state2txt(bt->state)
+
+static char *status2txt(unsigned char status, char *buf)
+{
+ strcpy(buf, "[ ");
+ if (status & BT_B_BUSY) strcat(buf, "B_BUSY ");
+ if (status & BT_H_BUSY) strcat(buf, "H_BUSY ");
+ if (status & BT_OEM0) strcat(buf, "OEM0 ");
+ if (status & BT_SMS_ATN) strcat(buf, "SMS ");
+ if (status & BT_B2H_ATN) strcat(buf, "B2H ");
+ if (status & BT_H2B_ATN) strcat(buf, "H2B ");
+ strcat(buf, "]");
+ return buf;
+}
+#define STATUS2TXT(buf) status2txt(status, buf)
+
+/* This will be called from within this module on a hosed condition */
+#define FIRST_SEQ 0
+static unsigned int bt_init_data(struct si_sm_data *bt, struct si_sm_io *io)
+{
+ bt->state = BT_STATE_IDLE;
+ bt->last_state = BT_STATE_IDLE;
+ bt->seq = FIRST_SEQ;
+ bt->io = io;
+ bt->write_count = 0;
+ bt->read_count = 0;
+ bt->error_retries = 0;
+ bt->nonzero_status = 0;
+ bt->truncated = 0;
+ bt->timeout = BT_NORMAL_TIMEOUT;
+ return 3; /* We claim 3 bytes of space; ought to check SPMI table */
+}
+
+static int bt_start_transaction(struct si_sm_data *bt,
+ unsigned char *data,
+ unsigned int size)
+{
+ unsigned int i;
+
+ if ((size < 2) || (size > IPMI_MAX_MSG_LENGTH)) return -1;
+
+ if ((bt->state != BT_STATE_IDLE) && (bt->state != BT_STATE_HOSED))
+ return -2;
+
+ if (bt_debug & BT_DEBUG_MSG) {
+ printk(KERN_WARNING "+++++++++++++++++++++++++++++++++++++\n");
+ printk(KERN_WARNING "BT: write seq=0x%02X:", bt->seq);
+ for (i = 0; i < size; i ++) printk (" %02x", data[i]);
+ printk("\n");
+ }
+ bt->write_data[0] = size + 1; /* all data plus seq byte */
+ bt->write_data[1] = *data; /* NetFn/LUN */
+ bt->write_data[2] = bt->seq;
+ memcpy(bt->write_data + 3, data + 1, size - 1);
+ bt->write_count = size + 2;
+
+ bt->error_retries = 0;
+ bt->nonzero_status = 0;
+ bt->read_count = 0;
+ bt->truncated = 0;
+ bt->state = BT_STATE_XACTION_START;
+ bt->last_state = BT_STATE_IDLE;
+ bt->timeout = BT_NORMAL_TIMEOUT;
+ return 0;
+}
+
+/* After the upper state machine has been told SI_SM_TRANSACTION_COMPLETE
+ it calls this. Strip out the length and seq bytes. */
+
+static int bt_get_result(struct si_sm_data *bt,
+ unsigned char *data,
+ unsigned int length)
+{
+ int i, msg_len;
+
+ msg_len = bt->read_count - 2; /* account for length & seq */
+ /* Always NetFn, Cmd, cCode */
+ if (msg_len < 3 || msg_len > IPMI_MAX_MSG_LENGTH) {
+ printk(KERN_WARNING "BT results: bad msg_len = %d\n", msg_len);
+ data[0] = bt->write_data[1] | 0x4; /* Kludge a response */
+ data[1] = bt->write_data[3];
+ data[2] = IPMI_ERR_UNSPECIFIED;
+ msg_len = 3;
+ } else {
+ data[0] = bt->read_data[1];
+ data[1] = bt->read_data[3];
+ if (length < msg_len) bt->truncated = 1;
+ if (bt->truncated) { /* can be set in read_all_bytes() */
+ data[2] = IPMI_ERR_MSG_TRUNCATED;
+ msg_len = 3;
+ } else memcpy(data + 2, bt->read_data + 4, msg_len - 2);
+
+ if (bt_debug & BT_DEBUG_MSG) {
+ printk (KERN_WARNING "BT: res (raw)");
+ for (i = 0; i < msg_len; i++) printk(" %02x", data[i]);
+ printk ("\n");
+ }
+ }
+ bt->read_count = 0; /* paranoia */
+ return msg_len;
+}
+
+/* This bit's functionality is optional */
+#define BT_BMC_HWRST 0x80
+
+static void reset_flags(struct si_sm_data *bt)
+{
+ if (BT_STATUS & BT_H_BUSY) BT_CONTROL(BT_H_BUSY);
+ if (BT_STATUS & BT_B_BUSY) BT_CONTROL(BT_B_BUSY);
+ BT_CONTROL(BT_CLR_WR_PTR);
+ BT_CONTROL(BT_SMS_ATN);
+ BT_INTMASK_W(BT_BMC_HWRST);
+#ifdef DEVELOPMENT_ONLY_NOT_FOR_PRODUCTION
+ if (BT_STATUS & BT_B2H_ATN) {
+ int i;
+ BT_CONTROL(BT_H_BUSY);
+ BT_CONTROL(BT_B2H_ATN);
+ BT_CONTROL(BT_CLR_RD_PTR);
+ for (i = 0; i < IPMI_MAX_MSG_LENGTH + 2; i++) BMC2HOST;
+ BT_CONTROL(BT_H_BUSY);
+ }
+#endif
+}
+
+static inline void write_all_bytes(struct si_sm_data *bt)
+{
+ int i;
+
+ if (bt_debug & BT_DEBUG_MSG) {
+ printk(KERN_WARNING "BT: write %d bytes seq=0x%02X",
+ bt->write_count, bt->seq);
+ for (i = 0; i < bt->write_count; i++)
+ printk (" %02x", bt->write_data[i]);
+ printk ("\n");
+ }
+ for (i = 0; i < bt->write_count; i++) HOST2BMC(bt->write_data[i]);
+}
+
+static inline int read_all_bytes(struct si_sm_data *bt)
+{
+ unsigned char i;
+
+ bt->read_data[0] = BMC2HOST;
+ bt->read_count = bt->read_data[0];
+ if (bt_debug & BT_DEBUG_MSG)
+ printk(KERN_WARNING "BT: read %d bytes:", bt->read_count);
+
+ /* minimum: length, NetFn, Seq, Cmd, cCode == 5 total, or 4 more
+ following the length byte. */
+ if (bt->read_count < 4 || bt->read_count >= IPMI_MAX_MSG_LENGTH) {
+ if (bt_debug & BT_DEBUG_MSG)
+ printk("bad length %d\n", bt->read_count);
+ bt->truncated = 1;
+ return 1; /* let next XACTION START clean it up */
+ }
+ for (i = 1; i <= bt->read_count; i++) bt->read_data[i] = BMC2HOST;
+ bt->read_count++; /* account for the length byte */
+
+ if (bt_debug & BT_DEBUG_MSG) {
+ for (i = 0; i < bt->read_count; i++)
+ printk (" %02x", bt->read_data[i]);
+ printk ("\n");
+ }
+ if (bt->seq != bt->write_data[2]) /* idiot check */
+ printk(KERN_WARNING "BT: internal error: sequence mismatch\n");
+
+ /* per the spec, the (NetFn, Seq, Cmd) tuples should match */
+ if ((bt->read_data[3] == bt->write_data[3]) && /* Cmd */
+ (bt->read_data[2] == bt->write_data[2]) && /* Sequence */
+ ((bt->read_data[1] & 0xF8) == (bt->write_data[1] & 0xF8)))
+ return 1;
+
+ if (bt_debug & BT_DEBUG_MSG) printk(KERN_WARNING "BT: bad packet: "
+ "want 0x(%02X, %02X, %02X) got (%02X, %02X, %02X)\n",
+ bt->write_data[1], bt->write_data[2], bt->write_data[3],
+ bt->read_data[1], bt->read_data[2], bt->read_data[3]);
+ return 0;
+}
+
+/* Modifies bt->state appropriately, need to get into the bt_event() switch */
+
+static void error_recovery(struct si_sm_data *bt, char *reason)
+{
+ unsigned char status;
+ char buf[40]; /* For getting status */
+
+ bt->timeout = BT_NORMAL_TIMEOUT; /* various places want to retry */
+
+ status = BT_STATUS;
+ printk(KERN_WARNING "BT: %s in %s %s ", reason, STATE2TXT,
+ STATUS2TXT(buf));
+
+ (bt->error_retries)++;
+ if (bt->error_retries > BT_RETRY_LIMIT) {
+ printk("retry limit (%d) exceeded\n", BT_RETRY_LIMIT);
+ bt->state = BT_STATE_HOSED;
+ if (!bt->nonzero_status)
+ printk(KERN_ERR "IPMI: BT stuck, try power cycle\n");
+ else if (bt->seq == FIRST_SEQ + BT_RETRY_LIMIT) {
+ /* most likely during insmod */
+ printk(KERN_WARNING "IPMI: BT reset (takes 5 secs)\n");
+ bt->state = BT_STATE_RESET1;
+ }
+ return;
+ }
+
+ /* Sometimes the BMC queues get in an "off-by-one" state...*/
+ if ((bt->state == BT_STATE_B2H_WAIT) && (status & BT_B2H_ATN)) {
+ printk("retry B2H_WAIT\n");
+ return;
+ }
+
+ printk("restart command\n");
+ bt->state = BT_STATE_RESTART;
+}
+
+/* Check the status and (possibly) advance the BT state machine. The
+ default return is SI_SM_CALL_WITH_DELAY. */
+
+static enum si_sm_result bt_event(struct si_sm_data *bt, long time)
+{
+ unsigned char status;
+ char buf[40]; /* For getting status */
+ int i;
+
+ status = BT_STATUS;
+ bt->nonzero_status |= status;
+
+ if ((bt_debug & BT_DEBUG_STATES) && (bt->state != bt->last_state))
+ printk(KERN_WARNING "BT: %s %s TO=%ld - %ld \n",
+ STATE2TXT,
+ STATUS2TXT(buf),
+ bt->timeout,
+ time);
+ bt->last_state = bt->state;
+
+ if (bt->state == BT_STATE_HOSED) return SI_SM_HOSED;
+
+ if (bt->state != BT_STATE_IDLE) { /* do timeout test */
+
+ /* Certain states, on error conditions, can lock up a CPU
+ because they are effectively in an infinite loop with
+ CALL_WITHOUT_DELAY (right back here with time == 0).
+ Prevent infinite lockup by ALWAYS decrementing timeout. */
+
+ /* FIXME: bt_event is sometimes called with time > BT_NORMAL_TIMEOUT
+ (noticed in ipmi_smic_sm.c January 2004) */
+
+ if ((time <= 0) || (time >= BT_NORMAL_TIMEOUT)) time = 100;
+ bt->timeout -= time;
+ if ((bt->timeout < 0) && (bt->state < BT_STATE_RESET1)) {
+ error_recovery(bt, "timed out");
+ return SI_SM_CALL_WITHOUT_DELAY;
+ }
+ }
+
+ switch (bt->state) {
+
+ case BT_STATE_IDLE: /* check for asynchronous messages */
+ if (status & BT_SMS_ATN) {
+ BT_CONTROL(BT_SMS_ATN); /* clear it */
+ return SI_SM_ATTN;
+ }
+ return SI_SM_IDLE;
+
+ case BT_STATE_XACTION_START:
+ if (status & BT_H_BUSY) {
+ BT_CONTROL(BT_H_BUSY);
+ break;
+ }
+ if (status & BT_B2H_ATN) break;
+ bt->state = BT_STATE_WRITE_BYTES;
+ return SI_SM_CALL_WITHOUT_DELAY; /* for logging */
+
+ case BT_STATE_WRITE_BYTES:
+ if (status & (BT_B_BUSY | BT_H2B_ATN)) break;
+ BT_CONTROL(BT_CLR_WR_PTR);
+ write_all_bytes(bt);
+ BT_CONTROL(BT_H2B_ATN); /* clears too fast to catch? */
+ bt->state = BT_STATE_WRITE_CONSUME;
+ return SI_SM_CALL_WITHOUT_DELAY; /* it MIGHT sail through */
+
+ case BT_STATE_WRITE_CONSUME: /* BMCs usually blow right thru here */
+ if (status & (BT_H2B_ATN | BT_B_BUSY)) break;
+ bt->state = BT_STATE_B2H_WAIT;
+ /* fall through with status */
+
+ /* Stay in BT_STATE_B2H_WAIT until a packet matches. However, spinning
+ hard here, constantly reading status, seems to hold off the
+ generation of B2H_ATN so ALWAYS return CALL_WITH_DELAY. */
+
+ case BT_STATE_B2H_WAIT:
+ if (!(status & BT_B2H_ATN)) break;
+
+ /* Assume ordered, uncached writes: no need to wait */
+ if (!(status & BT_H_BUSY)) BT_CONTROL(BT_H_BUSY); /* set */
+ BT_CONTROL(BT_B2H_ATN); /* clear it, ACK to the BMC */
+ BT_CONTROL(BT_CLR_RD_PTR); /* reset the queue */
+ i = read_all_bytes(bt);
+ BT_CONTROL(BT_H_BUSY); /* clear */
+ if (!i) break; /* Try this state again */
+ bt->state = BT_STATE_READ_END;
+ return SI_SM_CALL_WITHOUT_DELAY; /* for logging */
+
+ case BT_STATE_READ_END:
+
+ /* I could wait on BT_H_BUSY to go clear for a truly clean
+ exit. However, this is already done in XACTION_START
+ and the (possible) extra loop/status/possible wait affects
+ performance. So, as long as it works, just ignore H_BUSY */
+
+#ifdef MAKE_THIS_TRUE_IF_NECESSARY
+
+ if (status & BT_H_BUSY) break;
+#endif
+ bt->seq++;
+ bt->state = BT_STATE_IDLE;
+ return SI_SM_TRANSACTION_COMPLETE;
+
+ case BT_STATE_RESET1:
+ reset_flags(bt);
+ bt->timeout = BT_RESET_DELAY;
+ bt->state = BT_STATE_RESET2;
+ break;
+
+ case BT_STATE_RESET2: /* Send a soft reset */
+ BT_CONTROL(BT_CLR_WR_PTR);
+ HOST2BMC(3); /* number of bytes following */
+ HOST2BMC(0x18); /* NetFn/LUN == Application, LUN 0 */
+ HOST2BMC(42); /* Sequence number */
+ HOST2BMC(3); /* Cmd == Soft reset */
+ BT_CONTROL(BT_H2B_ATN);
+ bt->state = BT_STATE_RESET3;
+ break;
+
+ case BT_STATE_RESET3:
+ if (bt->timeout > 0) return SI_SM_CALL_WITH_DELAY;
+ bt->state = BT_STATE_RESTART; /* printk in debug modes */
+ break;
+
+ case BT_STATE_RESTART: /* don't reset retries! */
+ bt->write_data[2] = ++bt->seq;
+ bt->read_count = 0;
+ bt->nonzero_status = 0;
+ bt->timeout = BT_NORMAL_TIMEOUT;
+ bt->state = BT_STATE_XACTION_START;
+ break;
+
+ default: /* HOSED is supposed to be caught much earlier */
+ error_recovery(bt, "internal logic error");
+ break;
+ }
+ return SI_SM_CALL_WITH_DELAY;
+}
+
+static int bt_detect(struct si_sm_data *bt)
+{
+ /* It's impossible for the BT status and interrupt registers to be
+ all 1's, (assuming a properly functioning, self-initialized BMC)
+ but that's what you get from reading a bogus address, so we
+ test that first. The calling routine uses negative logic. */
+
+ if ((BT_STATUS == 0xFF) && (BT_INTMASK_R == 0xFF)) return 1;
+ reset_flags(bt);
+ return 0;
+}
+
+static void bt_cleanup(struct si_sm_data *bt)
+{
+}
+
+static int bt_size(void)
+{
+ return sizeof(struct si_sm_data);
+}
+
+struct si_sm_handlers bt_smi_handlers =
+{
+ .version = IPMI_BT_VERSION,
+ .init_data = bt_init_data,
+ .start_transaction = bt_start_transaction,
+ .get_result = bt_get_result,
+ .event = bt_event,
+ .detect = bt_detect,
+ .cleanup = bt_cleanup,
+ .size = bt_size,
+};