GenWQE: Add sysfs interface for bitstream reload

This patch adds an interface on sysfs for userspace to request a card
bitstream reload. It sets the appropriate register and try to perform a
fundamental reset on the PCIe slot for the card to reload the bitstream
from the chosen partition.

Signed-off-by: Kleber Sacilotto de Souza <klebers@linux.vnet.ibm.com>
Acked-by: Frank Haverkamp <haver@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/Documentation/ABI/testing/sysfs-driver-genwqe b/Documentation/ABI/testing/sysfs-driver-genwqe
index 1870737..64ac6d5 100644 (file)
--- a/Documentation/ABI/testing/sysfs-driver-genwqe
+++ b/Documentation/ABI/testing/sysfs-driver-genwqe
@@ -25,6 +25,15 @@ Date:           Oct 2013
 Contact:        haver@linux.vnet.ibm.com
 Description:    Interface to set the next bitstream to be used.
 
+What:           /sys/class/genwqe/genwqe<n>_card/reload_bitstream
+Date:           May 2014
+Contact:        klebers@linux.vnet.ibm.com
+Description:    Interface to trigger a PCIe card reset to reload the bitstream.
+                  sudo sh -c 'echo 1 > \
+                    /sys/class/genwqe/genwqe0_card/reload_bitstream'
+                If successfully, the card will come back with the bitstream set
+                on 'next_bitstream'.
+
 What:           /sys/class/genwqe/genwqe<n>_card/tempsens
 Date:           Oct 2013
 Contact:        haver@linux.vnet.ibm.com

diff --git a/drivers/misc/genwqe/card_base.c b/drivers/misc/genwqe/card_base.c
index 74d51c9..e6cc3e1 100644 (file)
--- a/drivers/misc/genwqe/card_base.c
+++ b/drivers/misc/genwqe/card_base.c
@@ -761,6 +761,89 @@ static u64 genwqe_fir_checking(struct genwqe_dev *cd)
 }
 
 /**
+ * genwqe_pci_fundamental_reset() - trigger a PCIe fundamental reset on the slot
+ *
+ * Note: pci_set_pcie_reset_state() is not implemented on all archs, so this
+ * reset method will not work in all cases.
+ *
+ * Return: 0 on success or error code from pci_set_pcie_reset_state()
+ */
+static int genwqe_pci_fundamental_reset(struct pci_dev *pci_dev)
+{
+       int rc;
+
+       /*
+        * lock pci config space access from userspace,
+        * save state and issue PCIe fundamental reset
+        */
+       pci_cfg_access_lock(pci_dev);
+       pci_save_state(pci_dev);
+       rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset);
+       if (!rc) {
+               /* keep PCIe reset asserted for 250ms */
+               msleep(250);
+               pci_set_pcie_reset_state(pci_dev, pcie_deassert_reset);
+               /* Wait for 2s to reload flash and train the link */
+               msleep(2000);
+       }
+       pci_restore_state(pci_dev);
+       pci_cfg_access_unlock(pci_dev);
+       return rc;
+}
+
+/*
+ * genwqe_reload_bistream() - reload card bitstream
+ *
+ * Set the appropriate register and call fundamental reset to reaload the card
+ * bitstream.
+ *
+ * Return: 0 on success, error code otherwise
+ */
+static int genwqe_reload_bistream(struct genwqe_dev *cd)
+{
+       struct pci_dev *pci_dev = cd->pci_dev;
+       int rc;
+
+       dev_info(&pci_dev->dev,
+                "[%s] resetting card for bitstream reload\n",
+                __func__);
+
+       genwqe_stop(cd);
+
+       /*
+        * Cause a CPLD reprogram with the 'next_bitstream'
+        * partition on PCIe hot or fundamental reset
+        */
+       __genwqe_writeq(cd, IO_SLC_CFGREG_SOFTRESET,
+                       (cd->softreset & 0xcull) | 0x70ull);
+
+       rc = genwqe_pci_fundamental_reset(pci_dev);
+       if (rc) {
+               /*
+                * A fundamental reset failure can be caused
+                * by lack of support on the arch, so we just
+                * log the error and try to start the card
+                * again.
+                */
+               dev_err(&pci_dev->dev,
+                       "[%s] err: failed to reset card for bitstream reload\n",
+                       __func__);
+       }
+
+       rc = genwqe_start(cd);
+       if (rc) {
+               dev_err(&pci_dev->dev,
+                       "[%s] err: cannot start card services! (err=%d)\n",
+                       __func__, rc);
+               return rc;
+       }
+       dev_info(&pci_dev->dev,
+                "[%s] card reloaded\n", __func__);
+       return 0;
+}
+
+
+/**
  * genwqe_health_thread() - Health checking thread
  *
  * This thread is only started for the PF of the card.
@@ -846,6 +929,13 @@ static int genwqe_health_thread(void *data)
                        }
                }
 
+               if (cd->card_state == GENWQE_CARD_RELOAD_BITSTREAM) {
+                       /* Userspace requested card bitstream reload */
+                       rc = genwqe_reload_bistream(cd);
+                       if (rc)
+                               goto fatal_error;
+               }
+
                cd->last_gfir = gfir;
                cond_resched();
        }

diff --git a/drivers/misc/genwqe/card_sysfs.c b/drivers/misc/genwqe/card_sysfs.c
index a72a992..7232e40 100644 (file)
--- a/drivers/misc/genwqe/card_sysfs.c
+++ b/drivers/misc/genwqe/card_sysfs.c
@@ -223,6 +223,30 @@ static ssize_t next_bitstream_store(struct device *dev,
 }
 static DEVICE_ATTR_RW(next_bitstream);
 
+static ssize_t reload_bitstream_store(struct device *dev,
+                               struct device_attribute *attr,
+                               const char *buf, size_t count)
+{
+       int reload;
+       struct genwqe_dev *cd = dev_get_drvdata(dev);
+
+       if (kstrtoint(buf, 0, &reload) < 0)
+               return -EINVAL;
+
+       if (reload == 0x1) {
+               if (cd->card_state == GENWQE_CARD_UNUSED ||
+                   cd->card_state == GENWQE_CARD_USED)
+                       cd->card_state = GENWQE_CARD_RELOAD_BITSTREAM;
+               else
+                       return -EIO;
+       } else {
+               return -EINVAL;
+       }
+
+       return count;
+}
+static DEVICE_ATTR_WO(reload_bitstream);
+
 /*
  * Create device_attribute structures / params: name, mode, show, store
  * additional flag if valid in VF
@@ -239,6 +263,7 @@ static struct attribute *genwqe_attributes[] = {
        &dev_attr_status.attr,
        &dev_attr_freerunning_timer.attr,
        &dev_attr_queue_working_time.attr,
+       &dev_attr_reload_bitstream.attr,
        NULL,
 };
 

diff --git a/include/uapi/linux/genwqe/genwqe_card.h b/include/uapi/linux/genwqe/genwqe_card.h
index 795e957..4fc065f 100644 (file)
--- a/include/uapi/linux/genwqe/genwqe_card.h
+++ b/include/uapi/linux/genwqe/genwqe_card.h
@@ -328,6 +328,7 @@ enum genwqe_card_state {
        GENWQE_CARD_UNUSED = 0,
        GENWQE_CARD_USED = 1,
        GENWQE_CARD_FATAL_ERROR = 2,
+       GENWQE_CARD_RELOAD_BITSTREAM = 3,
        GENWQE_CARD_STATE_MAX,
 };