At present, the cxlflash driver only supports hardware with two FC ports. The
code was initially designed with this assumption and is dependent on having
two FC ports - adding more ports will break logic within the driver.
To mitigate this issue, remove the existing port assumptions and transition
the code to support more than two ports. As a side effect, clarify the
interpretation of the DK_CXLFLASH_ALL_PORTS_ACTIVE flag.
Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The usage of prints within the cxlflash driver is inconsistent. This
hinders debug and makes the driver source and log output appear sloppy.
The following cleanups help unify the prints within cxlflash:
- move all prints to dev-* where possible
- transition all hex prints to lowercase
- standardize variable prints in debug output
- derive pointers in a consistent manner
- change int to bool where appropriate
- remove superfluous data from prints and print statements that do not
make sense
Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
During test, the following crash was observed:
[34538.981505] Faulting instruction address: 0xd000000007c9c870
cpu 0x9: Vector: 300 (Data Access) at [c0000007f1e8f590]
pc: d000000007c9c870: cxlflash_restore_luntable+0x70/0x1d0 [cxlflash]
lr: d000000007c9c84c: cxlflash_restore_luntable+0x4c/0x1d0 [cxlflash]
sp: c0000007f1e8f810
msr: 9000000100009033
dar: c00000171d637438
dsisr: 40000000
current = 0xc0000007f1e43f90
paca = 0xc000000007b25100 softe: 0 irq_happened: 0x01
pid = 493, comm = eehd
enter ? for help
[c0000007f1e8f8a0] d000000007c940b0 init_afu+0xd60/0x1200 [cxlflash]
[c0000007f1e8f9a0] d000000007c945a8 cxlflash_pci_slot_reset+0x58/0xe0 [cxlflash]
[c0000007f1e8fa20] d00000000715f790 cxl_pci_slot_reset+0x230/0x340 [cxl]
[c0000007f1e8fae0] c000000000040dd4 eeh_report_reset+0x144/0x180
[c0000007f1e8fb20] c00000000003f708 eeh_pe_dev_traverse+0x98/0x170
[c0000007f1e8fbb0] c000000000041618 eeh_handle_normal_event+0x328/0x410
[c0000007f1e8fc30] c000000000041db8 eeh_handle_event+0x178/0x330
[c0000007f1e8fce0] c000000000042118 eeh_event_handler+0x1a8/0x1b0
[c0000007f1e8fd80] c00000000011420c kthread+0xec/0x100
[c0000007f1e8fe30] c00000000000a47c ret_from_kernel_thread+0x5c/0xe0
When superpipe mode is disabled for a LUN, the references for the
local lun are deleted but the LUN is still identified as being present
in the LUN table. This mismatched state can result in the above crash
when the LUN table is restored during an error recovery operation.
To fix this issue, the local LUN information structure is updated to
reflect the LUN is no longer in the LUN table once all references to
the LUN are gone.
Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The port selection mask of a LUN can be corrupted when the manage LUN
ioctl (DK_CXLFLASH_MANAGE_LUN) is issued more than once for any device.
This mask indicates to the AFU which port[s] can be used for a data
transfer to/from a particular LUN. The mask is critical to ensuring the
correct behavior when using the virtual LUN function of this adapter.
When the mask is configured for both ports, an I/O may be sent to either
port as the AFU assumes that each port has access to the same physical
device (specified by LUN ID in the port LUN table).
In a situation where the mask becomes incorrectly configured to reflect
access to both ports when in fact there is only access through a single
port, an I/O can be targeted to the wrong physical device. This can lead
to data corruption among other ill effects (e.g. security leaks).
The cause for this corruption is the assumption that the ioctl will only
be called a second time for a LUN when it is being configured for access
via a second port. A boolean 'newly_created' variable is used to
differentiate between a LUN that was created (and subsequently configured
for single port access) and one that is destined for access across both
ports. While initially set to 'true', this sticky boolean is toggled to
the 'false' state during a lookup on any next ioctl performed on a device
with a matching WWN/WWID. The code fails to realize that the match could
in fact be the same device calling in again. From here, an assumption is
made that any LUN with 'newly_created' set to 'false' is configured for
access over both ports and the port selection mask is set to reflect this.
Any future attempts to use this LUN for hosting a virtual LUN will result
in the port LUN table being incorrectly programmed.
As a remedy, the 'newly_created' concept was removed entirely and replaced
with code that always constructs the port selection mask based upon the
SCSI channel of the LUN being accessed. The bits remain sticky, therefore
allowing for a device to be accessed over both ports when that is in fact
the correct physical configuration.
Also included in this commit are a few minor related changes to enhance
the fix and provide better debug information for port selection mask and
port LUN table bugs in the future. These include renaming refresh_local()
to lookup_local(), tracing the WWN/WWID as a big-endian entity, and
tracing the port selection mask, SCSI channel, and LUN ID each time the
port LUN table is programmed.
Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Acked-by: Manoj Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
If two concurrent MANAGE_LUN ioctls are issued with the same
WWID parameter, it would result in an incorrect value of port_sel.
This is because port_sel is modified without any locks being
held. If the first caller stalls after the return from
find_and_create_lun(), the value of port_sel will be set
incorrectly to indicate a single port, though in this case
it should have been set to both ports.
To fix, use the global mutex to serialize the lookup of the
WWID and the subsequent modification of port_sel.
Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
Add support for physical LUN segmentation (virtual LUNs) to device
driver supporting the IBM CXL Flash adapter. This patch allows user
space applications to virtually segment a physical LUN into N virtual
LUNs, taking advantage of the translation features provided by this
adapter.
Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
Reviewed-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
Add superpipe supporting infrastructure to device driver for the IBM CXL
Flash adapter. This patch allows userspace applications to take advantage
of the accelerated I/O features that this adapter provides and bypass the
traditional filesystem stack.
Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
Reviewed-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
