Pull #1 ARM updates from Russell King:
"This one covers stuff which Arnd is waiting for me to push, as this is
shared between both our trees and probably other trees elsewhere.
Essentially, this contains:
- AMBA primecell device initializer updates - mostly shrinking the
size of the device declarations in platform code to something more
reasonable.
- Getting rid of the NO_IRQ crap from AMBA primecell stuff.
- Nicolas' idle cleanups. This in combination with the restart
cleanups from the last merge window results in a great many
mach/system.h files being deleted."
Yay: ~80 files, ~2000 lines deleted.
* 'for-armsoc' of git://git.linaro.org/people/rmk/linux-arm: (60 commits)
ARM: remove disable_fiq and arch_ret_to_user macros
ARM: make entry-macro.S depend on !MULTI_IRQ_HANDLER
ARM: rpc: make default fiq handler run-time installed
ARM: make arch_ret_to_user macro optional
ARM: amba: samsung: use common amba device initializers
ARM: amba: spear: use common amba device initializers
ARM: amba: nomadik: use common amba device initializers
ARM: amba: u300: use common amba device initializers
ARM: amba: lpc32xx: use common amba device initializers
ARM: amba: netx: use common amba device initializers
ARM: amba: bcmring: use common amba device initializers
ARM: amba: ep93xx: use common amba device initializers
ARM: amba: omap2: use common amba device initializers
ARM: amba: integrator: use common amba device initializers
ARM: amba: realview: get rid of private platform amba_device initializer
ARM: amba: versatile: get rid of private platform amba_device initializer
ARM: amba: vexpress: get rid of private platform amba_device initializer
ARM: amba: provide common initializers for static amba devices
ARM: amba: make use of -1 IRQs warn
ARM: amba: u300: get rid of NO_IRQ initializers
...
Tell the PCI core about host bridge address translation so it can take
care of bus-to-resource conversion for us.
CC: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Now that most platforms don't need disable_fiq and arch_ret_to_user
macros, we can remove the empty macros or empty entry-macro.S files.
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Ryan Mallon <rmallon@gmail.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
When this is the only content remaining in mach/system.h then the
whole file is removed.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-and-tested-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: David Brown <davidb@codeaurora.org>
Acked-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci: (80 commits)
x86/PCI: Expand the x86_msi_ops to have a restore MSIs.
PCI: Increase resource array mask bit size in pcim_iomap_regions()
PCI: DEVICE_COUNT_RESOURCE should be equal to PCI_NUM_RESOURCES
PCI: pci_ids: add device ids for STA2X11 device (aka ConneXT)
PNP: work around Dell 1536/1546 BIOS MMCONFIG bug that breaks USB
x86/PCI: amd: factor out MMCONFIG discovery
PCI: Enable ATS at the device state restore
PCI: msi: fix imbalanced refcount of msi irq sysfs objects
PCI: kconfig: English typo in pci/pcie/Kconfig
PCI/PM/Runtime: make PCI traces quieter
PCI: remove pci_create_bus()
xtensa/PCI: convert to pci_scan_root_bus() for correct root bus resources
x86/PCI: convert to pci_create_root_bus() and pci_scan_root_bus()
x86/PCI: use pci_scan_bus() instead of pci_scan_bus_parented()
x86/PCI: read Broadcom CNB20LE host bridge info before PCI scan
sparc32, leon/PCI: convert to pci_scan_root_bus() for correct root bus resources
sparc/PCI: convert to pci_create_root_bus()
sh/PCI: convert to pci_scan_root_bus() for correct root bus resources
powerpc/PCI: convert to pci_create_root_bus()
powerpc/PCI: split PHB part out of pcibios_map_io_space()
...
Fix up conflicts in drivers/pci/msi.c and include/linux/pci_regs.h due
to the same patches being applied in other branches.
Convert from pci_scan_bus() to pci_scan_root_bus() and remove root bus
resource fixups. This fixes the problem of "early" and "header" quirks
seeing incorrect root bus resources.
CC: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Remove the now empty arch_reset() from all the mach/system.h includes,
and remove its callsite. Remove arm_machine_restart() as this function
no longer does anything useful.
For samsung platforms, remove the include of mach/system-reset.h and
plat/system-reset.h from their respective mach/system.h headers as these
just define their arch_reset functions. As a result, the s3c2410 and
plat-samsung system-reset.h files are no longer referenced, so remove
these files entirely.
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Hook these platforms restart code into the new restart hook rather
than using arch_reset().
Acked-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
These files all make use of one of the EXPORT_SYMBOL variants
or the THIS_MODULE macro. So they will need <linux/export.h>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Boards used to specify zreladdr in their Makefile.boot with
zreladdr-y := x, so conflicting zreladdrs were silently overwritten.
This patch changes this to zreladdr-y += x, so that we end
up with multiple words in zreladdr in such a case. We can
detect this later and complain if necessary.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Some platforms (like OMAP not to name it) are doing rather complicated
hacks just to determine the base UART address to use. Let's give their
addruart macro some slack by providing an extra work register which will
allow for much needed cleanups.
This is basically a no-op as this commit is only adding the extra argument
to the macro but no one is using it yet.
Signed-off-by: nicolas Pitre <nicolas.pitre@linaro.org>
Reviewed-by: Kevin Hilman <khilman@ti.com>
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
PCI: remove printks about disabled bridge windows
PCI: fold pci_calc_resource_flags() into decode_bar()
PCI: treat mem BAR type "11" (reserved) as 32-bit, not 64-bit, BAR
PCI: correct pcie_set_readrq write size
PCI: pciehp: change wait time for valid configuration access
x86/PCI: Preserve existing pci=bfsort whitelist for Dell systems
PCI: ARI is a PCIe v2 feature
x86/PCI: quirks: Use pci_dev->revision
PCI: Make the struct pci_dev * argument of pci_fixup_irqs const.
PCI hotplug: cpqphp: use pci_dev->vendor
PCI hotplug: cpqphp: use pci_dev->subsystem_{vendor|device}
x86/PCI: config space accessor functions should not ignore the segment argument
PCI: Assign values to 'pci_obff_signal_type' enumeration constants
x86/PCI: reduce severity of host bridge window conflict warnings
PCI: enumerate the PCI device only removed out PCI hieratchy of OS when re-scanning PCI
PCI: PCIe AER: add aer_recover_queue
x86/PCI: select direct access mode for mmconfig option
PCI hotplug: Rename is_ejectable which also exists in dock.c
* 'next/cross-platform' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/linux-arm-soc:
ARM: Consolidate the clkdev header files
ARM: set vga memory base at run-time
ARM: convert PCI defines to variables
ARM: pci: make pcibios_assign_all_busses use pci_has_flag
ARM: remove unnecessary mach/hardware.h includes
pci: move microblaze and powerpc pci flag functions into asm-generic
powerpc: rename ppc_pci_*_flags to pci_*_flags
Fix up conflicts in arch/microblaze/include/asm/pci-bridge.h
Aside of the usual motivation for constification, this function has a
history of being abused a hook for interrupt and other fixups so I turned
this function const ages ago in the MIPS code but it should be done
treewide.
Due to function pointer passing in varous places a few other functions
had to be constified as well.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
To: Anton Vorontsov <avorontsov@mvista.com>
To: Chris Metcalf <cmetcalf@tilera.com>
To: Colin Cross <ccross@android.com>
Acked-by: "David S. Miller" <davem@davemloft.net>
To: Eric Miao <eric.y.miao@gmail.com>
To: Erik Gilling <konkers@android.com>
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
To: "H. Peter Anvin" <hpa@zytor.com>
To: Imre Kaloz <kaloz@openwrt.org>
To: Ingo Molnar <mingo@redhat.com>
To: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
To: Jesse Barnes <jbarnes@virtuousgeek.org>
To: Krzysztof Halasa <khc@pm.waw.pl>
To: Lennert Buytenhek <kernel@wantstofly.org>
To: Matt Turner <mattst88@gmail.com>
To: Nicolas Pitre <nico@fluxnic.net>
To: Olof Johansson <olof@lixom.net>
Acked-by: Paul Mundt <lethal@linux-sh.org>
To: Richard Henderson <rth@twiddle.net>
To: Russell King <linux@arm.linux.org.uk>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-alpha@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-pci@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: linux-tegra@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: x86@kernel.org
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Convert PCIBIOS_MIN_IO and PCIBIOS_MIN_MEM to variables to allow
multi-platform builds. This also removes the requirement for a platform to
have a mach/hardware.h.
The default values for i/o and mem are 0x1000 and 0x01000000, respectively.
Per Arnd Bergmann, other values are likely to be incorrect, but this commit
does not try to address that issue.
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Convert pcibios_assign_all_busses from a define to inline so platforms can
control this setting.
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Remove linux/mm.h inclusion from netdevice.h -- it's unused (I've checked manually).
To prevent mm.h inclusion via other channels also extract "enum dma_data_direction"
definition into separate header. This tiny piece is what gluing netdevice.h with mm.h
via "netdevice.h => dmaengine.h => dma-mapping.h => scatterlist.h => mm.h".
Removal of mm.h from scatterlist.h was tried and was found not feasible
on most archs, so the link was cutoff earlier.
Hope people are OK with tiny include file.
Note, that mm_types.h is still dragged in, but it is a separate story.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This uncouple PHYS_OFFSET from the platform definitions, thereby
facilitating run-time computation of the physical memory offset.
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@st.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Magnus Damm <damm@opensource.se>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Wan ZongShun <mcuos.com@gmail.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Acked-by: Eric Miao <eric.y.miao@gmail.com>
Acked-by: Jiandong Zheng <jdzheng@broadcom.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Replace the page_to_dma() and dma_to_page() macros with their PFN
equivalents. This allows us to map parts of memory which do not have
a struct page allocated to them to bus addresses. This will be used
internally by dma_alloc_coherent()/dma_alloc_writecombine().
Build tested on Versatile, OMAP1, IOP13xx and KS8695.
Tested-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Defining iounmap() with arguments prevents it from being used as a
function pointer, causing platforms to work around this. Instead,
define it to be a simple macro.
Do the same for __arch_io(re|un)map too.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (278 commits)
arm: remove machine_desc.io_pg_offst and .phys_io
arm: use addruart macro to establish debug mappings
arm: return both physical and virtual addresses from addruart
arm/debug: consolidate addruart macros for CONFIG_DEBUG_ICEDCC
ARM: make struct machine_desc definition coherent with its comment
eukrea_mbimxsd-baseboard: Pass the correct GPIO to gpio_free
cpuimx27: fix compile when ULPI is selected
mach-pcm037_eet: fix compile errors
Fixing ethernet driver compilation error for i.MX31 ADS board
cpuimx51: update board support
mx5: add cpuimx51sd module and its baseboard
iomux-mx51: fix GPIO_1_xx 's IOMUX configuration
imx-esdhc: update devices registration
mx51: add resources for SD/MMC on i.MX51
iomux-mx51: fix SD1 and SD2's iomux configuration
clock-mx51: rename CLOCK1 to CLOCK_CCGR for better readability
clock-mx51: factorize clk_set_parent and clk_get_rate
eukrea_mbimxsd: add support for DVI displays
cpuimx25 & cpuimx35: fix OTG port registration in host mode
i.MX31 and i.MX35 : fix errate TLSbo65953 and ENGcm09472
...
Since we're now using addruart to establish the debug mapping, we can
remove the io_pg_offst and phys_io members of struct machine_desc.
The various declarations were removed using the following script:
grep -rl MACHINE_START arch/arm | xargs \
sed -i '/MACHINE_START/,/MACHINE_END/ { /\.\(phys_io\|io_pg_offst\)/d }'
[ Initial patch was from Jeremy Kerr, example script from Russell King ]
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Eric Miao <eric.miao at canonical.com>
Rather than checking the MMU status in every instance of addruart, do it
once in kernel/debug.S, and change the existing addruart macros to
return both physical and virtual addresses. The main debug code can then
select the appropriate address to use.
This will also allow us to retreive the address of a uart for the MMU
state that we're not current in.
Updated with fixes for OMAP from Jason Wang <jason77.wang@gmail.com>
and Tony Lindgren <tony@atomide.com>, and fix for versatile express from
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>.
Signed-off-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Jason Wang <jason77.wang@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Tested-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Russell King <linux@arm.linux.org.uk>
Add one more parameter to hook_fault_code() to be able to set 'code'
field of struct fsr_info.
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Everything should now be using sparsemem rather than discontigmem, so
remove the code supporting discontigmem from ARM.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
This allows the procfs vmallocinfo file to show who created the ioremap
regions. Note: __builtin_return_address(0) doesn't do what's expected
if its used in an inline function, so we leave __arm_ioremap callers
in such places alone.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Otherwise more complicated uart configuration won't be possible.
We can use r1 for tmp register for both head.S and debug.S.
NOTE: This patch depends on another patch to add the the tmp register
into all debug-macro.S files. That can be done with:
$ sed -i -e "s/addruart,rx|addruart, rx/addruart, rx, tmp/"
arch/arm/*/include/*/debug-macro.S
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This updates the IOP platform to use the kernel's generic time
framework. With clockevent support in place, this reduces to
selecting GENERIC_TIME and removing the platform's private timer
->offset() operation (iop_gettimeoffset).
Tested on n2100, compile-tested for all plat-iop machines.
Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This updates the IOP platform to expose the interrupting
timer 0 as a clockevent object. The timer interrupt handler
is changed to call the clockevent ->event_handler() instead
of timer_tick(), and ->set_next_event() and ->set_mode()
operations are added to allow the mode of the timer to be
updated (required for ONESHOT/NOHZ mode).
Timer 0 must now be properly initialised, which requires
a new write_tcr0() function from the mach-specific code.
The mode of timer 0 must be read at the start of ->set_mode(),
which requires a new read_tmr0() function from the mach-
specific code.
Initial setup of timer 0 is also rewritten to be more robust.
Tested on n2100, compile-tested for all plat-iop machines.
Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This updates the IOP platform to expose the free-running
timer 1 as a clocksource object. This timer is now also
properly initialised, which requires a new write_tcr1()
function from the mach-specific code. Apart from the
explicit initialisation, there is no functional change
in how timer 1 is programmed.
Tested on n2100, compile-tested for all plat-iop machines.
Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
iop33x support is not included because that engine is a bit more awkward
to handle in that it can either be in xor mode or pq mode. The
dmaengine/async_tx layers currently only comprehend static capabilities.
Note iop13xx does not support hardware PQ continuation so the driver
must handle the DMA_PREP_CONTINUE flag for operations across > 16
sources. From the comment for dma_maxpq:
/* When an engine does not support native continuation we need 3 extra
* source slots to reuse P and Q with the following coefficients:
* 1/ {00} * P : remove P from Q', but use it as a source for P'
* 2/ {01} * Q : use Q to continue Q' calculation
* 3/ {00} * Q : subtract Q from P' to cancel (2)
*/
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
[ Based on an original patch by Yuri Tikhonov ]
This adds support for doing asynchronous GF multiplication by adding
two additional functions to the async_tx API:
async_gen_syndrome() does simultaneous XOR and Galois field
multiplication of sources.
async_syndrome_val() validates the given source buffers against known P
and Q values.
When a request is made to run async_pq against more than the hardware
maximum number of supported sources we need to reuse the previous
generated P and Q values as sources into the next operation. Care must
be taken to remove Q from P' and P from Q'. For example to perform a 5
source pq op with hardware that only supports 4 sources at a time the
following approach is taken:
p, q = PQ(src0, src1, src2, src3, COEF({01}, {02}, {04}, {08}))
p', q' = PQ(p, q, q, src4, COEF({00}, {01}, {00}, {10}))
p' = p + q + q + src4 = p + src4
q' = {00}*p + {01}*q + {00}*q + {10}*src4 = q + {10}*src4
Note: 4 is the minimum acceptable maxpq otherwise we punt to
synchronous-software path.
The DMA_PREP_CONTINUE flag indicates to the driver to reuse p and q as
sources (in the above manner) and fill the remaining slots up to maxpq
with the new sources/coefficients.
Note1: Some devices have native support for P+Q continuation and can skip
this extra work. Devices with this capability can advertise it with
dma_set_maxpq. It is up to each driver how to handle the
DMA_PREP_CONTINUE flag.
Note2: The api supports disabling the generation of P when generating Q,
this is ignored by the synchronous path but is implemented by some dma
devices to save unnecessary writes. In this case the continuation
algorithm is simplified to only reuse Q as a source.
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Reviewed-by: Andre Noll <maan@systemlinux.org>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
