]> err.no Git - linux-2.6/blobdiff - drivers/infiniband/hw/ipath/ipath_eeprom.c
IB/ipath: Future proof eeprom checksum code (contents reading)
[linux-2.6] / drivers / infiniband / hw / ipath / ipath_eeprom.c
index 26daac9d8b636be8edf711470793718a81798f0e..bcfa3ccb555f988cfba9e719602f130767356001 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2006 QLogic, Inc. All rights reserved.
+ * Copyright (c) 2006, 2007 QLogic Corporation. All rights reserved.
  * Copyright (c) 2003, 2004, 2005, 2006 PathScale, Inc. All rights reserved.
  *
  * This software is available to you under a choice of one of two
@@ -367,8 +367,8 @@ bail:
  * @len: number of bytes to receive
  */
 
-int ipath_eeprom_read(struct ipath_devdata *dd, u8 eeprom_offset,
-                     void *buffer, int len)
+static int ipath_eeprom_internal_read(struct ipath_devdata *dd,
+                                       u8 eeprom_offset, void *buffer, int len)
 {
        /* compiler complains unless initialized */
        u8 single_byte = 0;
@@ -418,6 +418,7 @@ bail:
        return ret;
 }
 
+
 /**
  * ipath_eeprom_write - writes data to the eeprom via I2C
  * @dd: the infinipath device
@@ -425,8 +426,8 @@ bail:
  * @buffer: data to write
  * @len: number of bytes to write
  */
-int ipath_eeprom_write(struct ipath_devdata *dd, u8 eeprom_offset,
-                      const void *buffer, int len)
+static int ipath_eeprom_internal_write(struct ipath_devdata *dd, u8 eeprom_offset,
+                                      const void *buffer, int len)
 {
        u8 single_byte;
        int sub_len;
@@ -500,6 +501,38 @@ bail:
        return ret;
 }
 
+/*
+ * The public entry-points ipath_eeprom_read() and ipath_eeprom_write()
+ * are now just wrappers around the internal functions.
+ */
+int ipath_eeprom_read(struct ipath_devdata *dd, u8 eeprom_offset,
+                       void *buff, int len)
+{
+       int ret;
+
+       ret = down_interruptible(&dd->ipath_eep_sem);
+       if (!ret) {
+               ret = ipath_eeprom_internal_read(dd, eeprom_offset, buff, len);
+               up(&dd->ipath_eep_sem);
+       }
+
+       return ret;
+}
+
+int ipath_eeprom_write(struct ipath_devdata *dd, u8 eeprom_offset,
+                       const void *buff, int len)
+{
+       int ret;
+
+       ret = down_interruptible(&dd->ipath_eep_sem);
+       if (!ret) {
+               ret = ipath_eeprom_internal_write(dd, eeprom_offset, buff, len);
+               up(&dd->ipath_eep_sem);
+       }
+
+       return ret;
+}
+
 static u8 flash_csum(struct ipath_flash *ifp, int adjust)
 {
        u8 *ip = (u8 *) ifp;
@@ -527,7 +560,7 @@ void ipath_get_eeprom_info(struct ipath_devdata *dd)
        void *buf;
        struct ipath_flash *ifp;
        __be64 guid;
-       int len;
+       int len, eep_stat;
        u8 csum, *bguid;
        int t = dd->ipath_unit;
        struct ipath_devdata *dd0 = ipath_lookup(0);
@@ -563,7 +596,11 @@ void ipath_get_eeprom_info(struct ipath_devdata *dd)
                goto bail;
        }
 
-       len = offsetof(struct ipath_flash, if_future);
+       /*
+        * read full flash, not just currently used part, since it may have
+        * been written with a newer definition
+        * */
+       len = sizeof(struct ipath_flash);
        buf = vmalloc(len);
        if (!buf) {
                ipath_dev_err(dd, "Couldn't allocate memory to read %u "
@@ -571,7 +608,11 @@ void ipath_get_eeprom_info(struct ipath_devdata *dd)
                goto bail;
        }
 
-       if (ipath_eeprom_read(dd, 0, buf, len)) {
+       down(&dd->ipath_eep_sem);
+       eep_stat = ipath_eeprom_internal_read(dd, 0, buf, len);
+       up(&dd->ipath_eep_sem);
+
+       if (eep_stat) {
                ipath_dev_err(dd, "Failed reading GUID from eeprom\n");
                goto done;
        }
@@ -646,8 +687,194 @@ void ipath_get_eeprom_info(struct ipath_devdata *dd)
        ipath_cdbg(VERBOSE, "Initted GUID to %llx from eeprom\n",
                   (unsigned long long) be64_to_cpu(dd->ipath_guid));
 
+       memcpy(&dd->ipath_eep_st_errs, &ifp->if_errcntp, IPATH_EEP_LOG_CNT);
+       /*
+        * Power-on (actually "active") hours are kept as little-endian value
+        * in EEPROM, but as seconds in a (possibly as small as 24-bit)
+        * atomic_t while running.
+        */
+       atomic_set(&dd->ipath_active_time, 0);
+       dd->ipath_eep_hrs = ifp->if_powerhour[0] | (ifp->if_powerhour[1] << 8);
+
 done:
        vfree(buf);
 
 bail:;
 }
+
+/**
+ * ipath_update_eeprom_log - copy active-time and error counters to eeprom
+ * @dd: the infinipath device
+ *
+ * Although the time is kept as seconds in the ipath_devdata struct, it is
+ * rounded to hours for re-write, as we have only 16 bits in EEPROM.
+ * First-cut code reads whole (expected) struct ipath_flash, modifies,
+ * re-writes. Future direction: read/write only what we need, assuming
+ * that the EEPROM had to have been "good enough" for driver init, and
+ * if not, we aren't making it worse.
+ *
+ */
+
+int ipath_update_eeprom_log(struct ipath_devdata *dd)
+{
+       void *buf;
+       struct ipath_flash *ifp;
+       int len, hi_water;
+       uint32_t new_time, new_hrs;
+       u8 csum;
+       int ret, idx;
+       unsigned long flags;
+
+       /* first, check if we actually need to do anything. */
+       ret = 0;
+       for (idx = 0; idx < IPATH_EEP_LOG_CNT; ++idx) {
+               if (dd->ipath_eep_st_new_errs[idx]) {
+                       ret = 1;
+                       break;
+               }
+       }
+       new_time = atomic_read(&dd->ipath_active_time);
+
+       if (ret == 0 && new_time < 3600)
+               return 0;
+
+       /*
+        * The quick-check above determined that there is something worthy
+        * of logging, so get current contents and do a more detailed idea.
+        * read full flash, not just currently used part, since it may have
+        * been written with a newer definition
+        */
+       len = sizeof(struct ipath_flash);
+       buf = vmalloc(len);
+       ret = 1;
+       if (!buf) {
+               ipath_dev_err(dd, "Couldn't allocate memory to read %u "
+                               "bytes from eeprom for logging\n", len);
+               goto bail;
+       }
+
+       /* Grab semaphore and read current EEPROM. If we get an
+        * error, let go, but if not, keep it until we finish write.
+        */
+       ret = down_interruptible(&dd->ipath_eep_sem);
+       if (ret) {
+               ipath_dev_err(dd, "Unable to acquire EEPROM for logging\n");
+               goto free_bail;
+       }
+       ret = ipath_eeprom_internal_read(dd, 0, buf, len);
+       if (ret) {
+               up(&dd->ipath_eep_sem);
+               ipath_dev_err(dd, "Unable read EEPROM for logging\n");
+               goto free_bail;
+       }
+       ifp = (struct ipath_flash *)buf;
+
+       csum = flash_csum(ifp, 0);
+       if (csum != ifp->if_csum) {
+               up(&dd->ipath_eep_sem);
+               ipath_dev_err(dd, "EEPROM cks err (0x%02X, S/B 0x%02X)\n",
+                               csum, ifp->if_csum);
+               ret = 1;
+               goto free_bail;
+       }
+       hi_water = 0;
+       spin_lock_irqsave(&dd->ipath_eep_st_lock, flags);
+       for (idx = 0; idx < IPATH_EEP_LOG_CNT; ++idx) {
+               int new_val = dd->ipath_eep_st_new_errs[idx];
+               if (new_val) {
+                       /*
+                        * If we have seen any errors, add to EEPROM values
+                        * We need to saturate at 0xFF (255) and we also
+                        * would need to adjust the checksum if we were
+                        * trying to minimize EEPROM traffic
+                        * Note that we add to actual current count in EEPROM,
+                        * in case it was altered while we were running.
+                        */
+                       new_val += ifp->if_errcntp[idx];
+                       if (new_val > 0xFF)
+                               new_val = 0xFF;
+                       if (ifp->if_errcntp[idx] != new_val) {
+                               ifp->if_errcntp[idx] = new_val;
+                               hi_water = offsetof(struct ipath_flash,
+                                               if_errcntp) + idx;
+                       }
+                       /*
+                        * update our shadow (used to minimize EEPROM
+                        * traffic), to match what we are about to write.
+                        */
+                       dd->ipath_eep_st_errs[idx] = new_val;
+                       dd->ipath_eep_st_new_errs[idx] = 0;
+               }
+       }
+       /*
+        * now update active-time. We would like to round to the nearest hour
+        * but unless atomic_t are sure to be proper signed ints we cannot,
+        * because we need to account for what we "transfer" to EEPROM and
+        * if we log an hour at 31 minutes, then we would need to set
+        * active_time to -29 to accurately count the _next_ hour.
+        */
+       if (new_time > 3600) {
+               new_hrs = new_time / 3600;
+               atomic_sub((new_hrs * 3600), &dd->ipath_active_time);
+               new_hrs += dd->ipath_eep_hrs;
+               if (new_hrs > 0xFFFF)
+                       new_hrs = 0xFFFF;
+               dd->ipath_eep_hrs = new_hrs;
+               if ((new_hrs & 0xFF) != ifp->if_powerhour[0]) {
+                       ifp->if_powerhour[0] = new_hrs & 0xFF;
+                       hi_water = offsetof(struct ipath_flash, if_powerhour);
+               }
+               if ((new_hrs >> 8) != ifp->if_powerhour[1]) {
+                       ifp->if_powerhour[1] = new_hrs >> 8;
+                       hi_water = offsetof(struct ipath_flash, if_powerhour)
+                                       + 1;
+               }
+       }
+       /*
+        * There is a tiny possibility that we could somehow fail to write
+        * the EEPROM after updating our shadows, but problems from holding
+        * the spinlock too long are a much bigger issue.
+        */
+       spin_unlock_irqrestore(&dd->ipath_eep_st_lock, flags);
+       if (hi_water) {
+               /* we made some change to the data, uopdate cksum and write */
+               csum = flash_csum(ifp, 1);
+               ret = ipath_eeprom_internal_write(dd, 0, buf, hi_water + 1);
+       }
+       up(&dd->ipath_eep_sem);
+       if (ret)
+               ipath_dev_err(dd, "Failed updating EEPROM\n");
+
+free_bail:
+       vfree(buf);
+bail:
+       return ret;
+
+}
+
+/**
+ * ipath_inc_eeprom_err - increment one of the four error counters
+ * that are logged to EEPROM.
+ * @dd: the infinipath device
+ * @eidx: 0..3, the counter to increment
+ * @incr: how much to add
+ *
+ * Each counter is 8-bits, and saturates at 255 (0xFF). They
+ * are copied to the EEPROM (aka flash) whenever ipath_update_eeprom_log()
+ * is called, but it can only be called in a context that allows sleep.
+ * This function can be called even at interrupt level.
+ */
+
+void ipath_inc_eeprom_err(struct ipath_devdata *dd, u32 eidx, u32 incr)
+{
+       uint new_val;
+       unsigned long flags;
+
+       spin_lock_irqsave(&dd->ipath_eep_st_lock, flags);
+       new_val = dd->ipath_eep_st_new_errs[eidx] + incr;
+       if (new_val > 255)
+               new_val = 255;
+       dd->ipath_eep_st_new_errs[eidx] = new_val;
+       spin_unlock_irqrestore(&dd->ipath_eep_st_lock, flags);
+       return;
+}