From: Stephen M. Cameron <scameron@xxxxxxxxxxxxxxxxxx>
This attribute, requested by Redhat, allows kexec-tools to know
whether the controller can honor the reset_devices kernel parameter
and actually reset the controller. For kdump to work properly it
is necessary that the reset_devices parameter be honored. This
attribute enables kexec-tools to warn the user if they attempt to
designate a non-resettable controller as the dump device.
Signed-off-by: Stephen M. Cameron <scameron@xxxxxxxxxxxxxxxxxx>
---
Documentation/scsi/hpsa.txt | 12 ++++++++++++
drivers/scsi/hpsa.c | 41 +++++++++++++++++++++++++++++++++++++++++
2 files changed, 53 insertions(+), 0 deletions(-)
diff --git a/Documentation/scsi/hpsa.txt b/Documentation/scsi/hpsa.txt
index dca6583..8b418b3 100644
--- a/Documentation/scsi/hpsa.txt
+++ b/Documentation/scsi/hpsa.txt
@@ -39,6 +39,7 @@ HPSA specific entries in /sys
/sys/class/scsi_host/host*/rescan
/sys/class/scsi_host/host*/firmware_revision
+ /sys/class/scsi_host/host*/resettable
the host "rescan" attribute is a write only attribute. Writing to this
attribute will cause the driver to scan for new, changed, or removed devices
@@ -55,6 +56,17 @@ HPSA specific entries in /sys
root@host:/sys/class/scsi_host/host4# cat firmware_revision
7.14
+ The "resettable" read-only attribute indicates whether a particular
+ controller is able to honor the "reset_devices" kernel parameter. If the
+ device is resettable, this file will contain a "1", otherwise, a "0". This
+ parameter is used by kdump, for example, to reset the controller at driver
+ load time to eliminate any outstanding commands on the controller and get the
+ controller into a known state so that the kdump initiated i/o will work right
+ and not be disrupted in any way by stale commands or other stale state
+ remaining on the controller from the previous kernel. This attribute enables
+ kexec tools to warn the user if they attempt to designate a device which is
+ unable to honor the reset_devices kernel parameter as a dump device.
+
HPSA specific disk attributes:
------------------------------
diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index dcabef4..415ad4f 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -273,6 +273,44 @@ static ssize_t host_show_transport_mode(struct device *dev,
"performant" : "simple");
}
+/* List of controllers which cannot be reset on kexec with reset_devices */
+static u32 unresettable_controller[] = {
+ 0x324a103C, /* Smart Array P712m */
+ 0x324b103C, /* SmartArray P711m */
+ 0x3223103C, /* Smart Array P800 */
+ 0x3234103C, /* Smart Array P400 */
+ 0x3235103C, /* Smart Array P400i */
+ 0x3211103C, /* Smart Array E200i */
+ 0x3212103C, /* Smart Array E200 */
+ 0x3213103C, /* Smart Array E200i */
+ 0x3214103C, /* Smart Array E200i */
+ 0x3215103C, /* Smart Array E200i */
+ 0x3237103C, /* Smart Array E500 */
+ 0x323D103C, /* Smart Array P700m */
+ 0x409C0E11, /* Smart Array 6400 */
+ 0x409D0E11, /* Smart Array 6400 EM */
+};
+
+static int ctlr_is_resettable(struct ctlr_info *h)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(unresettable_controller); i++)
+ if (unresettable_controller[i] == h->board_id)
+ return 0;
+ return 1;
+}
+
+static ssize_t host_show_resettable(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct ctlr_info *h;
+ struct Scsi_Host *shost = class_to_shost(dev);
+
+ h = shost_to_hba(shost);
+ return snprintf(buf, 20, "%d\n", ctlr_is_resettable(h));
+}
+
static inline int is_logical_dev_addr_mode(unsigned char scsi3addr[])
{
return (scsi3addr[3] & 0xC0) == 0x40;
@@ -379,6 +417,8 @@ static DEVICE_ATTR(commands_outstanding, S_IRUGO,
host_show_commands_outstanding, NULL);
static DEVICE_ATTR(transport_mode, S_IRUGO,
host_show_transport_mode, NULL);
+static DEVICE_ATTR(resettable, S_IRUGO,
+ host_show_resettable, NULL);
static struct device_attribute *hpsa_sdev_attrs[] = {
&dev_attr_raid_level,
@@ -392,6 +432,7 @@ static struct device_attribute *hpsa_shost_attrs[] = {
&dev_attr_firmware_revision,
&dev_attr_commands_outstanding,
&dev_attr_transport_mode,
+ &dev_attr_resettable,
NULL,
};
--
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