Sumit Semwal
d15bd7ee44
dma-buf: Introduce dma buffer sharing mechanism ...
This is the first step in defining a dma buffer sharing mechanism.
A new buffer object dma_buf is added, with operations and API to allow easy
sharing of this buffer object across devices.
The framework allows:
- creation of a buffer object, its association with a file pointer, and
associated allocator-defined operations on that buffer. This operation is
called the 'export' operation.
- different devices to 'attach' themselves to this exported buffer object, to
facilitate backing storage negotiation, using dma_buf_attach() API.
- the exported buffer object to be shared with the other entity by asking for
its 'file-descriptor (fd)', and sharing the fd across.
- a received fd to get the buffer object back, where it can be accessed using
the associated exporter-defined operations.
- the exporter and user to share the scatterlist associated with this buffer
object using map_dma_buf and unmap_dma_buf operations.
Atleast one 'attach()' call is required to be made prior to calling the
map_dma_buf() operation.
Couple of building blocks in map_dma_buf() are added to ease introduction
of sync'ing across exporter and users, and late allocation by the exporter.
For this first version, this framework will work with certain conditions:
- *ONLY* exporter will be allowed to mmap to userspace (outside of this
framework - mmap is not a buffer object operation),
- currently, *ONLY* users that do not need CPU access to the buffer are
allowed.
More details are there in the documentation patch.
This is based on design suggestions from many people at the mini-summits[1],
most notably from Arnd Bergmann <arnd@arndb.de>, Rob Clark <rob@ti.com> and
Daniel Vetter <daniel@ffwll.ch>.
The implementation is inspired from proof-of-concept patch-set from
Tomasz Stanislawski <t.stanislaws@samsung.com>, who demonstrated buffer sharing
between two v4l2 devices. [2]
[1]: https://wiki.linaro.org/OfficeofCTO/MemoryManagement
[2]: http://lwn.net/Articles/454389
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Sumit Semwal <sumit.semwal@ti.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Reviewed-and-Tested-by: Rob Clark <rob.clark@linaro.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-01-06 10:20:21 +00:00
pstore: pass allocated memory region back to caller
2011-11-17 12:58:07 -08:00
pata_of_platform: Add missing CONFIG_OF_IRQ dependency.
2011-12-22 15:00:32 -05:00
dma-buf: Introduce dma buffer sharing mechanism
2012-01-06 10:20:21 +00:00
bcma: fix implicit use of export.h contents
2011-10-31 19:32:02 -04:00
Merge branch 'for-linus' of git://git.kernel.dk/linux-block
2011-12-16 10:05:14 -08:00
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless into for-davem
2011-12-09 14:07:12 -05:00
ipmi_watchdog: restore settings when BMC reset
2011-12-20 10:25:04 -08:00
Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
2011-11-06 19:44:47 -08:00
[CPUFREQ] db8500: fix build error due to undeclared i variable
2011-11-11 22:28:33 -05:00
Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux
2011-11-07 10:13:52 -08:00
Merge git://github.com/herbertx/crypto
2011-11-25 21:55:07 -08:00
drivers/dca: Add export.h for THIS_MODULE to dca-sysfs.c
2011-10-31 19:31:43 -04:00
PM / devfreq: correct Kconfig dependency
2011-11-14 23:31:35 +01:00
dma: MX3_IPU fix depends
2011-12-19 12:26:07 +01:00
drivers/edac/mpc85xx_edac.c: fix memory controller compatible for edac
2011-11-24 01:59:38 -06:00
Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
2011-11-06 19:44:47 -08:00
Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/ibft
2011-12-15 14:16:47 -08:00
gpio: Fix DA9052 GPIO build errors.
2011-12-15 11:25:43 -07:00
drm/radeon/kms/atom: fix possible segfault in pm setup
2012-01-03 09:17:16 +00:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
2011-12-02 08:25:46 -08:00
hwmon: (jz4740) Staticise jz4740_hwmon_driver
2011-12-12 08:31:21 -08:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
2011-11-08 18:34:16 -08:00
i2c-eg20t: correct the driver init order of pch_i2c_probe()
2011-12-18 11:46:42 +00:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide
2011-11-18 22:04:12 -02:00
Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux
2011-11-07 10:13:52 -08:00
Merge branches 'cma', 'mlx4' and 'qib' into for-next
2011-12-19 09:19:49 -08:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
2011-12-30 13:42:41 -08:00
Merge branch 'iommu/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
2011-12-29 17:36:15 -08:00
isdn: avoid copying too long drvid
2011-11-29 18:39:37 -05:00
Revert "leds: save the delay values after a successful call to blink_set()"
2011-11-15 22:41:50 -02:00
lguest: add export.h to lguest files for THIS_MODULE/EXPORT_SYMBOL
2011-10-31 19:32:13 -04:00
m68k/irq: Remove obsolete IRQ_FLG_* users
2011-11-08 22:35:48 +01:00
md/bitmap: It is OK to clear bits during recovery.
2011-12-23 09:57:48 +11:00
gspca: Fix falling back to lower isoc alt settings
2011-12-31 11:53:58 -08:00
drivers/memstick: Add module.h to the prev. implicit modular users
2011-10-31 19:31:52 -04:00
drivers/message: Add module.h to i2o/pci.c
2011-10-31 19:31:53 -04:00
mfd: Include linux/io.h to jz4740-adc
2011-12-20 18:53:26 +01:00
Merge branch 'char-misc-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
2011-11-21 20:36:05 -08:00
Merge branch 'fixes' of http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm
2011-12-30 13:45:34 -08:00
mtd: plat_ram: call mtd_device_register only if partition data exists
2011-12-19 11:13:52 +00:00
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless into for-davem
2012-01-04 11:37:30 -05:00
drivers/nfc: add module.h to nfcwilink.c
2011-10-31 19:31:54 -04:00
dt/device: Fix auxdata matching to handle entries without a name override
2011-12-12 14:41:45 -07:00
oprofile: Fix uninitialized memory access when writing to writing to oprofilefs
2011-12-19 17:18:43 +01:00
parisc: add module.h to files really requiring it
2011-10-31 19:31:01 -04:00
pci: Fix hotplug of Express Module with pci bridges
2011-12-18 14:10:16 -08:00
Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
2011-11-06 19:44:47 -08:00
pinctrl: hide subsystem from the populace
2011-11-10 09:02:12 +01:00
toshiba_acpi: Fix machines that don't support HCI_SYSTEM_EVENT
2011-12-05 13:07:28 -05:00
Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux
2011-11-07 10:13:52 -08:00
x86/mrst: Battery fixes
2011-12-05 17:06:37 +01:00
pps gpio client: add missing dependency
2011-11-02 16:07:02 -07:00
powerpc/ps3: irq: Remove IRQF_DISABLED
2011-11-08 14:51:46 +11:00
ptp: Fix clock_getres() implementation
2011-12-06 11:38:32 +01:00
rapidio/tsi721: modify PCIe capability settings
2011-12-09 07:50:29 -08:00
regulator: twl: fix twl4030 support for smps regulators
2011-11-28 18:58:31 +00:00
Revert "rtc: Expire alarms after the time is set."
2012-01-04 07:57:22 -08:00
[SCSI] zfcp: return early from slave_destroy if slave_alloc returned early
2011-12-14 15:40:43 +04:00
sbus: convert drivers/sbus/char/* to use module_platform_driver()
2011-12-04 10:46:58 -08:00
[SCSI] fcoe: fix fcoe in a DCB environment by adding DCB notifiers to set skb priority
2011-12-15 11:02:07 +04:00
drivers/sfi: sfi_acpi.c needs sysfs.h
2011-10-31 19:31:57 -04:00
Merge branches 'sh/pm-runtime' and 'common/clkfwk' into sh-fixes-for-linus
2011-11-11 16:16:25 +09:00
spi/gpio: fix section mismatch warning
2011-12-07 22:17:39 +01:00
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless into for-davem
2011-12-09 14:07:12 -05:00
staging: r8712u: Add new USB ID
2011-12-13 16:13:15 -08:00
iscsi-target: Fix hex2bin warn_unused compile message
2011-12-06 06:00:59 +00:00
thermal: Prevent polling from happening during system suspend
2011-11-06 20:38:49 -05:00
Merge branch 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
2011-11-21 20:36:46 -08:00
uio: Add module.h to implicit drivers/uio users
2011-10-31 19:32:10 -04:00
Merge branch 'for-greg' of git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb into usb-linus
2011-12-21 14:42:49 -08:00
uwb: Add export.h for EXPORT_SYMBOL/THIS_MODULE as required
2011-10-31 19:32:19 -04:00
viafb: correct sync polarity for OLPC DCON
2011-11-22 00:56:17 +00:00
drivers/virt: add ioctl for 32-bit compat on 64-bit to fsl-hv-manager
2011-10-14 02:56:02 -05:00
virtio-pci: make reset operation safer
2011-11-24 13:04:48 +10:30
Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
2011-11-06 19:44:47 -08:00
watchdog: iTCO_wdt.c - problems with newer hardware due to SMI clearing (part 2)
2011-12-27 20:35:59 +01:00
Revert "xen/pv-on-hvm kexec: add xs_reset_watches to shutdown watches from old kernel"
2011-12-19 09:30:35 -05:00
drivers/zorro: Add export.h to proc.c
2011-10-31 19:32:01 -04:00
d15bd7ee44