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>
This commit is contained in:
Kleber Sacilotto de Souza 2014-06-04 10:57:50 -03:00 committed by Greg Kroah-Hartman
parent fc51768ba2
commit c1f732ad76
4 changed files with 125 additions and 0 deletions

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@ -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

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@ -760,6 +760,89 @@ static u64 genwqe_fir_checking(struct genwqe_dev *cd)
return IO_ILLEGAL_VALUE;
}
/**
* 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
*
@ -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();
}

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@ -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,
};

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@ -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,
};