If MSI-X interrupt mode is used by the PCI Express port driver, too
many vectors are allocated and it is not ensured that the right
vectors will be used for the right services. Namely, the PCI Express
specification states that both PCI Express native PME and PCI Express
hotplug will always use the same MSI or MSI-X message for signalling
interrupts, which implies that the same vector will be used by both
of them. Also, the VC service does not use interrupts at all.
Moreover, is not clear which of the vectors allocated by
pci_enable_msix() in the current code will be used for PME and
hotplug and which of them will be used for AER if all of these
services are configured.
For these reasons, rework the allocation of interrupts for PCI
Express ports so that if MSI-X are enabled, the right vectors will be
used for the right purposes.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Introduce new function pci_msix_table_size() returning the size of
the MSI-X table of given PCI device or 0 if the device doesn't
support MSI-X.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The PCI Express port driver uses 'struct pcie_port_service_id' for
matching port service devices and drivers, but this structure
contains fields that duplicate information from the port device
itself (vendor, device, subvendor, subdevice) and fields that are not
used by any existing port service driver (class, class_mask,
drvier_data). Also, both existing port service drivers (AER and
PCIe HP) don't even use the vendor and device fields for device
matching. Therefore 'struct pcie_port_service_id' can be removed
altogether and the only useful members of it (port_type, service) can
be introduced directly into the port service device and port service
driver structures. That simplifies the code quite a bit and reduces
its size.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The second argument of the ->probe() callback in
struct pcie_port_service_driver is unnecessary and never used.
Remove it.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The PCI Express port driver should not attempt to register service
devices that require the ability to generate interrupts if generating
interrupts is not possible. Namely, if the port has no interrupt pin
configured and we cannot set up MSI or MSI-X for it, there is no way
it can generate interrupts and in such a case the port services that
rely on interrupts (PME, PCIe HP, AER) should not be enabled for it.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
PCI Express port driver extension, as defined by struct
pcie_port_device_ext in portdrv.h, is allocated and initialized, but
never used (it also is never freed). Extend it to hold the PCI Express
port type as well as the port interrupt mode, change its name and use it
to simplify the code in portdrv_core.c .
Additionally, remove the redundant interrupt_mode member of struct
pcie_device defined in include/linux/pcieport_if.h .
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Since creating a device node is normally an operation requiring special
privilege, Igor Zhbanov points out that it is surprising (to say the
least) that a client can, for example, create a device node on a
filesystem exported with root_squash.
So, make sure CAP_MKNOD is among the capabilities dropped when an nfsd
thread handles a request from a non-root user.
Reported-by: Igor Zhbanov <izh1979@gmail.com>
Cc: stable@kernel.org
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
* master.kernel.org:/home/rmk/linux-2.6-arm: (23 commits)
[ARM] Fix virtual to physical translation macro corner cases
[ARM] update mach-types
[ARM] 5421/1: ftrace: fix crash due to tracing of __naked functions
MX1 fix include
[ARM] 5419/1: ep93xx: fix build warnings about struct i2c_board_info
[ARM] 5418/1: restore lr before leaving mcount
ARM: OMAP: board-omap3beagle: set i2c-3 to 100kHz
ARM: OMAP: Allow I2C bus driver to be compiled as a module
ARM: OMAP: sched_clock() corrected
ARM: OMAP: Fix compile error if pm.h is included
[ARM] orion5x: pass dram mbus data to xor driver
[ARM] S3C64XX: Fix s3c64xx_setrate_clksrc
[ARM] S3C64XX: sparse warnings in arch/arm/plat-s3c64xx/irq.c
[ARM] S3C64XX: sparse warnings in arch/arm/plat-s3c64xx/s3c6400-clock.c
[ARM] S3C64XX: Fix USB host clock mux list
[ARM] S3C64XX: Fix name of USB host clock.
[ARM] S3C64XX: Rename IRQ_UHOST to IRQ_USBH
[ARM] S3C64XX: Do gpiolib configuration earlier
[ARM] S3C64XX: Staticise s3c64xx_init_irq_eint()
[ARM] SMDK6410: Declare iodesc table static
...
Stricter gfp_mask might be required for clone allocation.
For example, request-based dm may clone bio in interrupt context
so it has to use GFP_ATOMIC.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6: (31 commits)
[SCSI] qla2xxx: Update version number to 8.03.00-k4.
[SCSI] qla2xxx: Correct overwrite of pre-assigned init-control-block structure size.
[SCSI] qla2xxx: Correct truncation in return-code status checking.
[SCSI] qla2xxx: Correct vport delete bug.
[SCSI] qla2xxx: Use correct value for max vport in LOOP topology.
[SCSI] qla2xxx: Correct address range checking for option-rom updates.
[SCSI] fcoe: Change fcoe receive thread nice value from 19 (lowest priority) to -20
[SCSI] fcoe: fix handling of pending queue, prevent out of order frames (v3)
[SCSI] fcoe: Out of order tx frames was causing several check condition SCSI status
[SCSI] fcoe: fix kfree(skb)
[SCSI] fcoe: ETH_P_8021Q is already in if_ether and fcoe is not using it anyway
[SCSI] libfc: do not change the fh_rx_id of a recevied frame
[SCSI] fcoe: Correct fcoe_transports initialization vs. registration
[SCSI] fcoe: Use setup_timer() and mod_timer()
[SCSI] libfc, fcoe: Remove unnecessary cast by removing inline wrapper
[SCSI] libfc, fcoe: Cleanup function formatting and minor typos
[SCSI] libfc, fcoe: Fix kerneldoc comments
[SCSI] libfc: Cleanup libfc_function_template comments
[SCSI] libfc: check for err when recv and state is incorrect
[SCSI] libfc: rename rp to rdata in fc_disc_new_target()
...
* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
NFS: Fix the fix to Bugzilla #11061, when IPv6 isn't defined...
SUNRPC: xprt_connect() don't abort the task if the transport isn't bound
SUNRPC: Fix an Oops due to socket not set up yet...
Bug 11061, NFS mounts dropped
NFS: Handle -ESTALE error in access()
NLM: Fix GRANT callback address comparison when IPv6 is enabled
NLM: Shrink the IPv4-only version of nlm_cmp_addr()
NFSv3: Fix posix ACL code
NFS: Fix misparsing of nfsv4 fs_locations attribute (take 2)
SUNRPC: Tighten up the task locking rules in __rpc_execute()
dma_map_sg could return a value different to 'nents' argument of
dma_map_sg so the ide stack needs to save it for the later usage
(e.g. for_each_sg).
The ide stack also needs to save the original sg_nents value for
pci_unmap_sg.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
[bart: backport to Linus' tree]
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
cpumask: mm_cpumask for accessing the struct mm_struct's cpu_vm_mask.
cpumask: tsk_cpumask for accessing the struct task_struct's cpus_allowed.
This is a fix for the following crash observed in 2.6.29-rc3:
http://lkml.org/lkml/2009/1/29/150
On ARM it doesn't make sense to trace a naked function because then
mcount is called without stack and frame pointer being set up and there
is no chance to restore the lr register to the value before mcount was
called.
Reported-by: Matthias Kaehlcke <matthias@kaehlcke.net>
Tested-by: Matthias Kaehlcke <matthias@kaehlcke.net>
Cc: Abhishek Sagar <sagar.abhishek@gmail.com>
Cc: Steven Rostedt <rostedt@home.goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This allows us to change the representation (to a dangling bitmap or
cpumask_var_t) without breaking all the callers: they can use
mm_cpumask() now and won't see a difference as the changes roll into
linux-next.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This allows us to change the representation (to a dangling bitmap or
cpumask_var_t) without breaking all the callers: they can use
tsk_cpumask() now and won't see a difference as the changes roll into
linux-next.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Comparing the layouts of struct detail_pixel_timing with
x.org's struct detailed_timings and how those are handled,
it appears that the hsync_positive and vsync_positive
fields are backwards.
This patch fixes https://bugs.freedesktop.org/show_bug.cgi?id=20019
for me. It was tested on 2 monitors, LG FLATRON L225WS 22" and
a YAKUMO 17" for which more details are unknown.
Signed-off-by: Pantelis Koukousoulas <pktoss@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Clean up/micro-optimatization: Make the AF_INET-only version of
nlm_cmp_addr() smaller. This matches the style of
nlm_privileged_requester(), and makes the AF_INET-only version of
nlm_cmp_addr() nearly the same size as it was before IPv6 support.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Fix a memory leak due to allocation in the XDR layer. In cases where the
RPC call needs to be retransmitted, we end up allocating new pages without
clearing the old ones. Fix this by moving the allocation into
nfs3_proc_setacls().
Also fix an issue discovered by Kevin Rudd, whereby the amount of memory
reserved for the acls in the xdr_buf->head was miscalculated, and causing
corruption.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
frames followed by these errors in log.
[sdp] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE,SUGGEST_OK
[sdp] Sense Key : Aborted Command [current]
[sdp] Add. Sense: Data phase error
This was causing some test apps to exit due to write failure under heavy
load.
This was due to a race around adding and removing tx frame skb in
fcoe_pending_queue, Chris Leech helped me to find that brief unlocking
period when pulling skb from fcoe_pending_queue in various contexts
(fcoe_watchdog and fcoe_xmit) and then adding skb back into fcoe_pending_queue
up on a failed fcoe_start_io could change skb/tx frame order in
fcoe_pending_queue. Thanks Chris.
This patch allows only single context to pull skb from fcoe_pending_queue
at any time to prevent above described ordering issue/race by use of
fcoe_pending_queue_active flag.
This patch simplified fcoe_watchdog with modified fcoe_check_wait_queue by
use of FCOE_LOW_QUEUE_DEPTH instead previously used several conditionals
to clear and set lp->qfull.
I think FCOE_MAX_QUEUE_DEPTH with FCOE_LOW_QUEUE_DEPTH will work better
in re/setting lp->qfull and these could be fine tuned for performance.
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Comment from "Andrew Morton <akpm@linux-foundation.org>"
> +{
> + return (struct fcoe_softc *)lport_priv(lp);
unneeded/undesirable cast of void*. There are probably zillions of
instances of this - there always are.
This whole inline function was unnecessary. The FCoE layer knows
that it's data structure is stored in the lport private data, it
can just access it from lport_priv().
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
1) Added '()' for function names in kerneldoc comments
2) Changed comment bookends from '**/' to '*/'. The comment on the the
mailing list was that '**/' "is consistently unconventional. Not
wrong, just odd." The Documentation/kernel-doc-nano-HOWTO.txt
states that kerneldoc comment blocks should end with '**/' but most
(if not all) instance I found under drivers/scsi/ were only using
the '*/' so I converted to that style.
3) Removed incorrect linebreaks in kerneldoc comments where found
4) Removed a few unnecessary blank comment lines in kerneldoc comment
blocks
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This reverts commit e088e4c9cd.
Removing the sysfs interface for p4-clockmod was flagged as a
regression in bug 12826.
Course of action:
- Find out the remaining causes of overheating, and fix them
if possible. ACPI should be doing the right thing automatically.
If it isn't, we need to fix that.
- mark p4-clockmod ui as deprecated
- try again with the removal in six months.
It's not really feasible to printk about the deprecation, because
it needs to happen at all the sysfs entry points, which means adding
a lot of strcmp("p4-clockmod".. calls to the core, which.. bleuch.
Signed-off-by: Dave Jones <davej@redhat.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (29 commits)
p54: fix race condition in memory management
cfg80211: test before subtraction on unsigned
iwlwifi: fix error flow in iwl*_pci_probe
rt2x00 : more devices to rt73usb.c
rt2x00 : more devices to rt2500usb.c
bonding: Fix device passed into ->ndo_neigh_setup().
vlan: Fix vlan-in-vlan crashes.
net: Fix missing dev->neigh_setup in register_netdevice().
tmspci: fix request_irq race
pkt_sched: act_police: Fix a rate estimator test.
tg3: Fix 5906 link problems
SCTP: change sctp_ctl_sock_init() to try IPv4 if IPv6 fails
IPv6: add "disable" module parameter support to ipv6.ko
sungem: another error printed one too early
aoe: error printed 1 too early
net pcmcia: worklimit reaches -1
net: more timeouts that reach -1
net: fix tokenring license
dm9601: new vendor/product IDs
netlink: invert error code in netlink_set_err()
...
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx:
dmatest: fix use after free in dmatest_exit
ipu_idmac: fix spinlock type
iop-adma, mv_xor: fix mem leak on self-test setup failure
fsldma: fix off by one in dma_halt
I/OAT: fail self-test if callback test reaches timeout
I/OAT: update driver version and copyright dates
I/OAT: list usage cleanup
I/OAT: set tcp_dma_copybreak to 256k for I/OAT ver.3
I/OAT: cancel watchdog before dma remove
I/OAT: fail initialization on zero channels detection
I/OAT: do not set DCACTRL_CMPL_WRITE_ENABLE for I/OAT ver.3
I/OAT: add verification for proper APICID_TAG_MAP setting by BIOS
dmaengine: update kerneldoc
* git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6:
ata: add CFA specific identify data words
remove stale comment from <linux/hdreg.h>
AT91: initialize Compact Flash on AT91SAM9263 cpu
ide: add at91_ide driver
ide: allow to wrap interrupt handler
ide-iops: fix odd-length ATAPI PIO transfers
ide: NULL noise: drivers/ide/ide-*.c
ide: expiry() returns int, negative expiry() return values won't be noticed
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
libata: Don't trust current capacity values in identify words 57-58
libata: make sure port is thawed when skipping resets
sata_nv: fix module parameter description
ahci: Add the Device IDs for MCP89 and remove IDs of MCP7B to/from ahci.c
libata: don't use on-stack sense buffer
libata: align ap->sector_buf
libata: fix dma_unmap_sg misuse
libata: change drive ready wait after hard reset to 5s
Protocol 0x37 has been reserved for iNexio devices and Sahara
was supposed to get 0x38.
Reported-by: Claudio Nieder <private@claudio.ch>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Made the comments more like the comments for struct scsi_host_template.
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This allows any rport ELS to retry on LS_RJT.
The rport error handling would only retry on resource allocation failures
and exchange timeouts. I have a target that will occasionally reject PLOGI
when we do a quick LOGO/PLOGI. When a critical ELS was rejected, libfc would
fail silently leaving the rport in a dead state.
The retry count and delay are managed by fc_rport_error_retry. If the retry
count is exceeded fc_rport_error will be called. When retrying is not the
correct course of action, fc_rport_error can be called directly.
Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
The fcoe_xmit could call fc_pause in case the pending skb queue len is larger
than FCOE_MAX_QUEUE_DEPTH, the fc_pause was trying to grab lport->lp_muex to
change lport->link_status and that had these issues :-
1. The fcoe_xmit was getting called with bh disabled, thus causing
"BUG: scheduling while atomic" when grabbing lport->lp_muex with bh disabled.
2. fc_linkup and fc_linkdown function calls lport_enter function with
lport->lp_mutex held and these enter function in turn calls fcoe_xmit to send
lport related FC frame, e.g. fc_linkup => fc_lport_enter_flogi to send flogi
req. In this case grabbing the same lport->lp_mutex again in fc_puase from
fcoe_xmit would cause deadlock.
The lport->lp_mutex was used for setting FC_PAUSE in fcoe_xmit path but
FC_PAUSE bit was not used anywhere beside just setting and clear this
bit in lport->link_status, instead used a separate field qfull in fc_lport
to eliminate need for lport->lp_mutex to track pending queue full condition
and in turn avoid above described two locking issues.
Also added check for lp->qfull in fc_fcp_lport_queue_ready to trigger
SCSI_MLQUEUE_HOST_BUSY when lp->qfull is set to prevent more scsi-ml cmds
while lp->qfull is set.
This patch eliminated FC_LINK_UP and FC_PAUSE and instead used dedicated
fields in fc_lport for this, this simplified all related conditional
code.
Also removed fc_pause and fc_unpause functions and instead used newly added
lport->qfull directly in fcoe.
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
fc_exch_mgr structure is private to fc_exch.c. To export exch_mgr_reset to
transport, transport needs access to the exch manager. Change
exch_mgr_reset to use lport param which is the shared structure between
libFC and transport.
Alternatively, fc_exch_mgr definition can be moved to libfc.h so that lport
can be accessed from mp*.
Signed-off-by: Abhijeet Joglekar <abjoglek@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Declare CFA specific identify data words 162 and 163 for future use.
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
[bart: update patch summary/description]
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
ap->sector_buf is used as DMA target and should at least be aligned on
cacheline. This caused problems on some embedded machines.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
libata passes the returned value of dma_map_sg() to
dma_unmap_sg(),which is the misuse of dma_unmap_sg().
DMA-mapping.txt says:
To unmap a scatterlist, just call:
pci_unmap_sg(pdev, sglist, nents, direction);
Again, make sure DMA activity has already finished.
PLEASE NOTE: The 'nents' argument to the pci_unmap_sg call must be
the _same_ one you passed into the pci_map_sg call,
it should _NOT_ be the 'count' value _returned_ from the
pci_map_sg call.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This fixes problems during resume with drives that take longer than 1s to
be ready. The ATA-6 spec appears to allow 5 seconds for a drive to be
ready.
On one affected system, this patch changes "PM: resume devices took..."
message from 17 seconds to 4 seconds, and gets rid of a lot of ugly
timeout/error messages.
Without this patch, the libata code moves on after 1s, tries to send a
soft reset (which the drive doesn't see because it isn't ready) which also
times out, then an IDENTIFY command is sent to the drive which times out,
and finally the error handler will try to send another hard reset which
will finally get things working.
Signed-off-by: Stuart Hayes <stuart_hayes@dell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
As analyzed by Patrick McHardy, vlan needs to reset it's
netdev_ops pointer in it's ->init() function but this
leaves the compat method pointers stale.
Add a netdev_resync_ops() and call it from the vlan code.
Any other driver which changes ->netdev_ops after register_netdevice()
will need to call this new function after doing so too.
With help from Patrick McHardy.
Tested-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: don't allow setuid to succeed if the user does not have rt bandwidth
sched_rt: don't start timer when rt bandwidth disabled
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
rcu: Teach RCU that idle task is not quiscent state at boot
It turns out that net_alive is unnecessary, and the original problem
that led to it being added was simply that the icmp code thought
it was a network device and wound up being unable to handle packets
while there were still packets in the network namespace.
Now that icmp and tcp have been fixed to properly register themselves
this problem is no longer present and we have a stronger guarantee
that packets will not arrive in a network namespace then that provided
by net_alive in netif_receive_skb. So remove net_alive allowing
packet reception run a little faster.
Additionally document the strong reason why network namespace cleanup
is safe so that if something happens again someone else will have
a chance of figuring it out.
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
fix warning in io_mapping_map_wc()
x86: i915 needs pgprot_writecombine() and is_io_mapping_possible()
Rafael J. Wysocki