ahci: enable sg segment clustering
The specification states that ahci supports segments up to 4MiB in size,
so enable clustering.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
If PORTS_IMPL register is zero, ahci initialize it to full mask
corresponding to nr_ports in the CAP register. hpriv->cap, which is
initialized at the end of the function, is incorrectly used as value
of CAP causing ahci to always override PORTS_IMPL to 0x1 if it's zero.
Fix it.
This fixes a bug where early ich6 ahci can only access the first port.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Whether a controller needs IDE or SATA ACPI hierarchy is determined by
the programming interface of the controller not by whether the
controller is SATA or PATA, or it supports slave device or not. This
patch adds ATA_FLAG_ACPI_SATA port flags which tells libata-acpi that
the port needs SATA ACPI nodes, and sets the flag for ahci and
sata_sil24.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Add the device ID to AHCI pci table for ATI SB700 SATA controller, the
subsequent chipset of SB600.
Signed-off-by: henry su<henry.su@amd.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Reimplement suspend/resume support using sdev->manage_start_stop.
* Device suspend/resume is now SCSI layer's responsibility and the
code is simplified a lot.
* DPM is dropped. This also simplifies code a lot. Suspend/resume
status is port-wide now.
* ata_scsi_device_suspend/resume() and ata_dev_ready() removed.
* Resume now has to wait for disk to spin up before proceeding. I
couldn't find easy way out as libata is in EH waiting for the
disk to be ready and sd is waiting for EH to complete to issue
START_STOP.
* sdev->manage_start_stop is set to 1 in ata_scsi_slave_config().
This fixes spindown on shutdown and suspend-to-disk.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
For PATA, 0xff status indicates empty port. For SATA, it depends on
how the controller emulates status register. On some controllers,
0xff is used to represent broken link or certain stage during reset.
libata currently deals SATA the same. This hasn't caused any problem
because problematic situations usually only occur after hotplug or
other link disruption events and libata blindly waited for the device
to spin up and settle after hotplug giving the link and device
whatever time to go through those stages.
libata is going to replace unconditional spinup wait with generic
timed sequence of resets, so not only getting 0xff handling right for
SATA is, well, the right thing to do, it's much more important now.
This patch makes the following changes.
* Make ata_bus_softreset() return -ENODEV if any of its wait fails
due to 0xff status.
* Fail soft/hardreset if status wait returns -ENODEV indicating 0xff
status while SStatus says the link is online. e.g. Reset fails if
status is 0xff after reset when SStatus reports the linke is online.
If SCR registers are not available, everything is the same as
before.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Add @deadline to prereset and reset methods and make them honor it.
ata_wait_ready() which directly takes @deadline is implemented to be
used as the wait function. This patch is in preparation for EH timing
improvements.
* ata_wait_ready() never does busy sleep. It's only used from EH and
no wait in EH is that urgent. This function also prints 'be
patient' message automatically after 5 secs of waiting if more than
3 secs is remaining till deadline.
* ata_bus_post_reset() now fails with error code if any of its wait
fails. This is important because earlier reset tries will have
shorter timeout than the spec requires. If a device fails to
respond before the short timeout, reset should be retried with
longer timeout rather than silently ignoring the device.
There are three behavior differences.
1. Timeout is applied to both devices at once, not separately. This
is more consistent with what the spec says.
2. When a device passes devchk but fails to become ready before
deadline. Previouly, post_reset would just succeed and let
device classification remove the device. New code fails the
reset thus causing reset retry. After a few times, EH will give
up disabling the port.
3. When slave device passes devchk but fails to become accessible
(TF-wise) after reset. Original code disables dev1 after 30s
timeout and continues as if the device doesn't exist, while the
patched code fails reset. When this happens, new code fails
reset on whole port rather than proceeding with only the primary
device.
If the failing device is suffering transient problems, new code
retries reset which is a better behavior. If the failing device is
actually broken, the net effect is identical to it, but not to the
other device sharing the channel. In the previous code, reset would
have succeeded after 30s thus detecting the working one. In the new
code, reset fails and whole port gets disabled. IMO, it's a
pathological case anyway (broken device sharing bus with working
one) and doesn't really matter.
* ata_bus_softreset() is changed to return error code from
ata_bus_post_reset(). It used to return 0 unconditionally.
* Spin up waiting is to be removed and not converted to honor
deadline.
* To be on the safe side, deadline is set to 40s for the time being.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Convert ahci, sata_sil, sata_sil24, sata_svw, sata_qstor, sata_mv,
sata_sx4, sata_vsc and sata_inic162x to new init model.
Now that host and ap are available during intialization, functions are
converted to take either host or ap instead of low level parameters
which were inevitable for functions shared between init and other
paths. This simplifies code quite a bit.
* init_one()'s now follow more consistent init order
* ahci_setup_port() and ahci_host_init() collapsed into
ahci_init_one() for init order consistency
* sata_vsc uses port_info instead of setting fields manually
* in sata_svw, k2_board_info converted to port_info (info is now in
port flags). port number is honored now.
Tested on ICH7/8 AHCI, jmb360, sil3112, 3114, 3124 and 3132.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Add PCI ID for new VIA chip. Original patch is from Maarten Vanraes.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Maarten Vanraes <maarten.vanraes@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
SB600 RAID and SB600 SATA is the same controller and share the
same PCI ID 0x4380. There is no such PCI ID 0x4381.
Signed-off-by: Conke Hu <conke.hu@gmail.com>
---------
Signed-off-by: Jeff Garzik <jeff@garzik.org>
->post_internal_cmd is simplified EH for internal commands. Its
primary mission is to stop the controller such that no rogue memory
access or other activities occur after the internal command is
released. It may provide error diagnostics by setting qc->err_mask
but this hasn't been a requirement.
To ignore SETXFER failure for CFA devices, libata needs to know
whether a command was failed by the device or for any other reason.
ie. internal command needs to get AC_ERR_DEV right.
This patch makes the following changes to AC_ERR_DEV handling and
->post_internal_cmd semantics to accomodate this need and simplify
callback implementation.
1. As long as the correct bits in the result TF registers are set,
there is no need to set AC_ERR_DEV explicitly. libata EH core
takes care of that for both normal and internal commands.
2. The only requirement for ->post_internal_cmd() is to put the
controller into quiescent state. It needs not to set any err_mask.
3. ata_exec_internal_sg() performs minimal error analysis such that
AC_ERR_DEV is automatically set as long as result_tf is filled
correctly.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Move cross checking between port_map and cap.n_ports into
ahci_save_initial_config(). After save_initial_config is done,
hpriv->port_map is always setup properly.
Tested on JMB363, ICH7 and ICH8 (with dummy ports).
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
There are several registers which describe how the controller is
configured. These registers are sometimes implemented as r/w
registers which are configured by firmware and get cleared on
controller reset or after suspend/resume cycle. ahci saved and
restored those values inside ahci_reset_controller() which is a bit
messy and doesn't work over suspend/resume cycle.
This patch implements ahci_save/restore_initial_config(). The save
function is called during driver initialization and saves cap and
port_map to hpriv. The restore function is called after the
controller is reset to restore the initial values.
Sometimes the initial firmware values are inconsistent and need to be
fixed up. This is handled by ahci_save_initial_config(). For this,
there are two versions of saved registers. One to write back to the
hardware register, the other to use during driver operation. This is
necessary to keep ahci's behavior unchanged (write back fixed up
port_map while keeping cap as-is).
This patch makes ahci save the register values once before the first
controller reset, not after it's been reset. Also, the same stored
values are used written back after each reset, so the register values
are properly recovered after suspend/resume cycle.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
There is a HW issue in ATI SB600 SATA that PxSERR.E should not be
set on some conditions, for example, when there is no media in SATA
CD/DVD drive or media is not ready, AHCI controller fails to execute
ATAPI commands and reports PORT_IRQ_TF_ERR, but ATI SB600 SATA
controller sets PxSERR.E at the
same time, which is not necessary.
This patch is just to ignore the INTERNAL ERROR in such case.
Without this patch, ahci error handler will report many errors as
below:
----------- cut from dmesg -----------
ata9: soft resetting port
ata9: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
ata9.00: configured for UDMA/33
ata9: EH complete
ata9.00: exception Emask 0x40 SAct 0x0 SErr 0x800 action 0x2
ata9.00: (irq_stat 0x40000001)
ata9.00: cmd a0/00:00:00:00:20/00:00:00:00:00/a0 tag 0 cdb 0x0 data 0
res 51/24:03:00:00:20/00:00:00:00:00/a0 Emask 0x40 (internal error)
ata9: soft resetting port
ata9: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
ata9.00: configured for UDMA/33
ata9: EH complete
ata9.00: exception Emask 0x40 SAct 0x0 SErr 0x800 action 0x2
ata9.00: (irq_stat 0x40000001)
ata9.00: cmd a0/01:00:00:00:00/00:00:00:00:00/a0 tag 0 cdb 0x43 data 12 in
res 51/24:03:00:00:00/00:00:00:00:00/a0 Emask 0x40 (internal error)
-------- end cut ---------
Signed-off-by: Conke Hu <conke.hu@amd.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This patch adds the Intel ICH9M RAID controller DID for SATA support.
Signed-off-by: Jason Gaston <jason.d.gaston@intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Add missing #ifdef CONFIG_PM conditionals around all PM related parts
in libata LLDs.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Spurious SDB FIS during NCQ might not contain spurious completions.
It could be spurious TF update or invalid async notification. Treat
as HSM violation iff a spurious SDB FIS contains spurious completions;
otherwise, just whine once about it.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Make jmiron_ata quirk update pdev->class after programming the device
and update ahci and pata_jmicron such that they match class code
instead of checking function number manually. For ahci, it matches
for vendor and class. For pata_jmicron, it matches vendor, device and
class as IDE class isn't as well defined as AHCI class.
This makes jmicron device matching more conventional and script
friendly.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
SDB FIS containing spurious NCQ completions is a clear protocol
violation. Currently, only some Maxtors with early firmware revisions
are showing this problem. Those firmwares have other NCQ related
problems including buggy NCQ error reporting and occasional lock up
after NCQ errors.
Consider spurious NCQ completions HSM violation and freeze the port
after it. EH will turn off NCQ after this happens several times.
Eventually drives which show this behavior should be blacklisted for
NCQ.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there. Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.
To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.
Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm. I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).
Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch is against each libata driver.
Two IRQ calls are added in ata_port_operations.
- irq_on() is used to enable interrupts.
- irq_ack() is used to acknowledge a device interrupt.
In most drivers, ata_irq_on() and ata_irq_ack() are used for
irq_on and irq_ack respectively.
In some drivers (ex: ahci, sata_sil24) which cannot use them
as is, ata_dummy_irq_on() and ata_dummy_irq_ack() are used.
Signed-off-by: Kou Ishizaki <kou.ishizaki@toshiba.co.jp>
Signed-off-by: Akira Iguchi <akira2.iguchi@toshiba.co.jp>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Convert libata core layer and LLDs to use iomap.
* managed iomap is used. Pointer to pcim_iomap_table() is cached at
host->iomap and used through out LLDs. This basically replaces
host->mmio_base.
* if possible, pcim_iomap_regions() is used
Most iomap operation conversions are taken from Jeff Garzik
<jgarzik@pobox.com>'s iomap branch.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Update libata LLDs to use devres. Core layer is already converted to
support managed LLDs. This patch simplifies initialization and fixes
many resource related bugs in init failure and detach path. For
example, all converted drivers now handle ata_device_add() failure
gracefully without excessive resource rollback code.
As most resources are released automatically on driver detach, many
drivers don't need or can do with much simpler ->{port|host}_stop().
In general, stop callbacks are need iff port or host needs to be given
commands to shut it down. Note that freezing is enough in many cases
and ports are automatically frozen before being detached.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Update libata core layer to use devres.
* ata_device_add() acquires all resources in managed mode.
* ata_host is allocated as devres associated with ata_host_release.
* Port attached status is handled as devres associated with
ata_host_attach_release().
* Initialization failure and host removal is handedl by releasing
devres group.
* Except for ata_scsi_release() removal, LLD interface remains the
same. Some functions use hacky is_managed test to support both
managed and unmanaged devices. These will go away once all LLDs are
updated to use devres.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Implement ata_host_detach() which calls ata_port_detach() for each
port in the host and export it. ata_port_detach() is now internal and
thus un-exported. ata_host_detach() will be used as the 'deregister
from libata layer' function after devres conversion.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Handle pci_enable_device() failure while resuming. This patch kills
the "ignoring return value of 'pci_enable_device'" warning message and
propagates __must_check through ata_pci_device_do_resume().
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
The AHCI set up is handled properly along with the other bits in the
JMICRON quirk. Remove the code whacking it in ahci.c as its un-needed and
also blindly fiddles with bits it doesn't own.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
ap->id is logcial port ID which is unique among all ATA ports and
doesn't have anything to do with hardware port index. ap->port_no is
the hardware port index and thus should be used when clearing IRQ mask
in ahci_thaw().
This problem has been spotted by Jeff Garzik <jgarzik@pobox.com>.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Before hardreset, ahci initialized stat part of received FIS area to
0xff to wait for the first D2H Reg FIS which would change the value to
device ready state. This used to work but now libata considers status
value of 0xff as device not present making this wait prone to failure.
This patch makes ahci use 0x80 for the wait stat value instead of
0xff to fix the above problem.
Signed-off-by: Tejun Heo <htejun@gmail.com>
drivers/ata/ahci.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Signed-off-by: Jeff Garzik <jeff@garzik.org>
We're still seeing a lot of issues with NCQ implementation in drive
firmwares. Sprious FISes during NCQ command phase occur on many
drives and some of them seem potentially dangerous (at least to me).
Until we find the solution, spurious messages can give us more info.
Improve and limit them such that more info can be reported while not
disturbing users too much.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Some ATA/ATAPI devices act weirdly after the link is put into slumber
mode. Some hang completely requiring physical power removal while
others fail to wake up till the link is hardreset a couple of times.
The addition of slumber on power down was never driven by real need.
It just followed what ahci spec said literally. The spec itself seems
faulty in that it doesn't consider devices (not controllers) which
don't support link powersaving mode.
Theory never matches reality when it comes to dark allys of cheap
ATA/ATAPI world. It's just unrealistic to expect vendors to test
rarely used link powersaving feature rigorously. This patch makes
ahci more friendly to the coldness of reality.
This shouldn't have any negative effect - when suspend operation
succeeds, we power off the whole machine; otherwise, we wake up
everything. I can't see any reason to be so elaborate with powering
down the link in the first place.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
As with JMicron controllers, ULi M5288 sets interface fatal error bit
on device error including ATAPI CC. This makes libata hardreset the
port on ATAPI CC thus making it impossible to use. Ignore interface
fatal error bit on ULi M5288. This fixes bugzilla bug #7837.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
The content of memory map io of BAR5 have been change from MCP65 then
sata_nv can't work fine on the platform based on MCP65 and MCP67, so move
their IDs from sata_nv.c to ahci.c.
Signed-off-by: Peer Chen <pchen@nvidia.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Do not mangle with HOST_CAP while resetting controller. The code is
there for a historical reason. The mangling breaks controller feature
detection and 0 PORTS_IMPL workaround code.
This problem was spotted by Manoj Kasichainula.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Manoj Kasichainula <manoj@io.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
ahci_init_controller() calls ahci_deinit_port() to make sure the
controller is stopped before initializing the controller. In turn,
ahci_deinit_port() invokes ahci_power_down() to power down the port.
If the controller supports slumber mode, the link is put into it.
Unfortunately, some devices don't implement link powersaving mode
properly and show erratic behavior after link is put into slumber
mode. For example, HL-DT-ST DVD-RAM GSA-H30N completely locks up on
slumber transition and can only be recovered with the *REAL* hard
reset - power removal and reapply.
Note that this makes the first probing reset different from all
others. If the above dvd-ram is hotplugged after ahci is initialized,
no problem occurs because ahci is already fully initialized with phy
powered up. So, this might also be the reason for other weird AHCI
initial probing abnormalities.
This patch moves power up/down out of port init/deinit and call them
only when needed.
Power down is now called only when suspending. As system suspend
usually involves powering down 12v for storage devices, this shouldn't
cause problem even if the attached device doesn't support slumber
mode. However, in partial power management and suspend failure cases,
devices might lock up after suspend attempt. I thought about removing
transition to slumber mode altogether but ahci spec mandates it before
HBA D3 state transition. Blacklisting such devices might be the
solution.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Some ICH8s use non-linear port mapping. ahci driver didn't use to
honor PORTS_IMPL and this made ports after hole nonfunctional. This
patch makes ahci mark those ports as dummy and properly initialize all
the implemented ports after the dummies.
As it's unknown whether other AHCIs implement PORTS_IMPL register
properly, new board id board_ahci_pi is added and selectively applied
to ICH8s. All other AHCIs continue to use linear mapping regardless
of PORTS_IMPL value.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Robin H. Johnson <robbat2@gentoo.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Instead of writing 0xf blindly, preserve the content of write-once
PORTS_IMPL register over host resets.
This patch is taken from Jeff Garzik's AHCI init update patch.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
ahci-vt8251
* requires hardreset after PHY status change
* doesn't clear BSY on signature FIS after hardreset
* needs SError cleared for the port to operate after hardreset
This patch implements ahci_vt8251_hardreset() and sets
ATA_FLAG_HRST_TO_RESUME to handle the above behaviors. This fixes EH
including hotplug on vt8251.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Now that ahci_softreset() is fixed to automatically perform CLO if
BSY/DRQ is set on entry, AHCI_FLAG_RESET_NEEDS_CLO is redundant. Kill
it.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
JMicron AHCI controllers set PORT_IRQ_IF_ERR on device errors. The
IRQ status bit indicates interface error or protocol mismatch and ahci
driver interprets it into AC_ERR_ATA_BUS. So, whenever an ATAPI
device raises check condition, ahci interprets it as ATA bus error and
thus resets it which, in turn, raises check condition thus creating a
reset loop and rendering the device unuseable.
This patch makes JMB controllers ignore PORT_IRQ_IF_ERR when
interpreting error condition.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Justin Tsai <justin@jmicron.com>
This patch adds the Intel ICH9 AHCI controller DID's for SATA support.
Signed-off-by: Jason Gaston <jason.d.gaston@intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
ahci_softreset() used to use ahci_tf_read() which reads D2H_REG area
to check for the Status register. However, this area is zeroed on
initialization and not set by initial signature FIS. Replace it with
ahci_check_status().
This bug prevented CLO code from being activated whenever BSY and/or
DRQ is set prior to softreset. This fix makes
AHCI_FLAG_RESET_NEEDS_CLO flag redundant.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.
The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around. On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).
Where appropriate, an arch may override the generic storage facility and do
something different with the variable. On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.
Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions. Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller. A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.
I've build this code with allyesconfig for x86_64 and i386. I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.
This will affect all archs. Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:
struct pt_regs *old_regs = set_irq_regs(regs);
And put the old one back at the end:
set_irq_regs(old_regs);
Don't pass regs through to generic_handle_irq() or __do_IRQ().
In timer_interrupt(), this sort of change will be necessary:
- update_process_times(user_mode(regs));
- profile_tick(CPU_PROFILING, regs);
+ update_process_times(user_mode(get_irq_regs()));
+ profile_tick(CPU_PROFILING);
I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().
Some notes on the interrupt handling in the drivers:
(*) input_dev() is now gone entirely. The regs pointer is no longer stored in
the input_dev struct.
(*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does
something different depending on whether it's been supplied with a regs
pointer or not.
(*) Various IRQ handler function pointers have been moved to type
irq_handler_t.
Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
The biggest change is that ata_host_set is renamed to ata_host.
* ata_host_set => ata_host
* ata_probe_ent->host_flags => ata_probe_ent->port_flags
* ata_probe_ent->host_set_flags => ata_probe_ent->_host_flags
* ata_host_stats => ata_port_stats
* ata_port->host => ata_port->scsi_host
* ata_port->host_set => ata_port->host
* ata_port_info->host_flags => ata_port_info->flags
* ata_(.*)host_set(.*)\(\) => ata_\1host\2()
The leading underscore in ata_probe_ent->_host_flags is to avoid
reusing ->host_flags for different purpose. Currently, the only user
of the field is libata-bmdma.c and probe_ent itself is scheduled to be
removed.
ata_port->host is reused for different purpose but this field is used
inside libata core proper and of different type.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
