Commit Graph

7 Commits

Author SHA1 Message Date
Matthew R. Ochs 0a27ae5147 cxlflash: Fix to avoid CXL services during EEH
During an EEH freeze event, certain CXL services should not be
called until after the hardware reset has taken place. Doing so
can result in unnecessary failures and possibly cause other ill
effects by triggering hardware accesses. This translates to a
requirement to quiesce all threads that may potentially use CXL
runtime service during this window. In particular, multiple ioctls
make use of the CXL services when acting on contexts on behalf of
the user. Thus, it is essential to 'drain' running ioctls _before_
proceeding with handling the EEH freeze event.

Create the ability to drain ioctls by wrapping the ioctl handler
call in a read semaphore and then implementing a small routine that
obtains the write semaphore, effectively creating a wait point for
all currently executing ioctls.

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: Daniel Axtens <dja@axtens.net>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30 17:02:40 +09:00
Matthew R. Ochs e568e23f3c cxlflash: Fix to avoid sizeof(bool)
Using sizeof(bool) is considered poor form for various reasons and
sparse warns us of that. Correct by changing type from bool to u8.

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: Daniel Axtens <dja@axtens.net>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30 17:01:49 +09:00
Matthew R. Ochs 22fe1ae80f cxlflash: Fix potential oops following LUN removal
When a LUN is removed, the sdev that is associated with the LUN
remains intact until its reference count drops to 0. In order
to prevent an sdev from being removed while a context is still
associated with it, obtain an additional reference per-context
for each LUN attached to the context.

This resolves a potential Oops in the release handler when a
dealing with a LUN that has already been removed.

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>
2015-10-30 17:00:52 +09:00
Manoj Kumar 471a5a60aa cxlflash: Fix read capacity timeout
The timeout value for read capacity is too small. Certain devices
may take longer to respond and thus the command may prematurely
timeout. Additionally the literal used for the timeout is stale.

Update the timeout to 30 seconds (matches the value used in sd.c)
and rework the timeout literal to a more appropriate description.

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>
2015-10-30 16:58:09 +09:00
Manoj Kumar 3ebf203093 cxlflash: Replace magic numbers with literals
Magic numbers are not meaningful and can create confusion. As a
remedy, replace them with descriptive literals.

Replace 512 with literal MAX_SECTOR_UNIT.
Replace 5 with literal CMD_RETRIES.

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: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30 16:57:55 +09:00
Matthew R. Ochs 2cb79266d6 cxlflash: Virtual LUN support
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>
2015-08-26 18:05:39 -07:00
Matthew R. Ochs 65be2c79ac cxlflash: Superpipe support
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>
2015-08-26 18:04:37 -07:00