The pl330 device could hang infinitely on certain boards when DMA
channels are terminated.

It was caused by lack of runtime resume when executing
pl330_terminate_all() which calls the _stop() function. _stop() accesses
device register and can loop infinitely while checking for device state.

The hang was confirmed by Dinh Nguyen on Altera SOCFPGA Cyclone V
board during boot. It can be also triggered with:

$ echo 1 > /sys/module/dmatest/parameters/iterations
$ echo dma1chan0 > /sys/module/dmatest/parameters/channel
$ echo 1 > /sys/module/dmatest/parameters/run
$ sleep 1
$ cat /sys/module/dmatest/parameters/run
Reported-by: NDinh Nguyen <dinguyen@opensource.altera.com>
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Fixes: ae43b328 ("ARM: 8202/1: dmaengine: pl330: Add runtime Power Management support v12")
Cc: <stable@vger.kernel.org>
Tested-by: NDinh Nguyen <dinguyen@opensource.altera.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The pl330_tx_status() function returns the desc->status if the
dma_cookie_status() call does indicate the cookie completed,
however the desc->status is not look directly compatible. Sparse
throws the following warning:

pl330.c:2262:35: warning: mixing different enum types
pl330.c:2262:35:     int enum desc_status  versus
pl330.c:2262:35:     int enum dma_status

Attempt to fix this by adding a switch statement to turn the
desc->status into a dma_status.

Note, this has only been tested with the dmatest suite.
Signed-off-by: NBen Dooks <ben.dooks@codethink.co.uk>
--
Vinod Koul <vinod.koul@intel.com>
Dan Williams <dan.j.williams@intel.com>
DMA List <dmaengine@vger.kernel.org>
Maxime Ripard <maxime.ripard@free-electrons.com>
Jassi Brar <jassisinghbrar@gmail.com>
Liviu Dudau <Liviu.Dudau@arm.com>
Linux ARM Kernel <linux-arm-kernel@lists.infradead.org>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Whilst running sparse on pl330 driver it was noticed there are
two functions that are not static but not exported to any other
users in the kernel.

Fix the following warnings by making 'pl330_pause' and the
'pl330_get_current_xferred_count' static:

pl330.c:2165:5: warning: symbol 'pl330_pause' was not declared. Should it be static?
pl330.c:2206:5: warning: symbol 'pl330_get_current_xferred_count' was not declared. Should it be static?
Signed-off-by: NBen Dooks <ben.dooks@codethink.co.uk>
--
Vinod Koul <vinod.koul@intel.com>
Dan Williams <dan.j.williams@intel.com>
DMA List <dmaengine@vger.kernel.org>
Maxime Ripard <maxime.ripard@free-electrons.com>
Jassi Brar <jassisinghbrar@gmail.com>
Liviu Dudau <Liviu.Dudau@arm.com>
Linux ARM Kernel <linux-arm-kernel@lists.infradead.org>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

When running Xilinx Zynq in big-endian mode the pl330 driver
fails to pass the dmatest suite. To fix this, ensure all non
byte values are written in little endian.

As a note, the documentation does not mention if it will do
big-endian descriptor fetches, only that it will swap the
data in flight.
Signed-off-by: NBen Dooks <ben.dooks@codethink.co.uk>
--
Vinod Koul <vinod.koul@intel.com>
Dan Williams <dan.j.williams@intel.com>
DMA List <dmaengine@vger.kernel.org>
Maxime Ripard <maxime.ripard@free-electrons.com>
Jassi Brar <jassisinghbrar@gmail.com>
Liviu Dudau <Liviu.Dudau@arm.com>
Linux ARM Kernel <linux-arm-kernel@lists.infradead.org>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

DMA_PAUSE command is used for halting DMA transfer on chosen channel.
It can be useful when we want to safely read residue before terminating
all requests on channel. Otherwise there can be situation when some data
is transferred before channel termination but after reading residue,
which obviously results with data loss. To avoid this situation we can
pause channel, read residue and then terminate all requests.
This scenario is common, for example, in serial port drivers.
Signed-off-by: NRobert Baldyga <r.baldyga@samsung.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

This patch adds possibility to read residue of DMA transfer. It's useful
when we want to know how many bytes have been transferred before we
terminate channel. It can take place, for example, on timeout interrupt.
Signed-off-by: NLukasz Czerwinski <l.czerwinski@samsung.com>
Signed-off-by: NRobert Baldyga <r.baldyga@samsung.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

This bug will cause NULL pointer after commit dfac17, and cause
wrong package in I2S DMA transfer before commit dfac17.

Tested on RK3288-pinky2 board.

Detail:
I2S DMA transfer(sound/core/pcm_dmaengine.c):
dmaengine_pcm_prepare_and_submit -->
dmaengine_prep_dma_cyclic -->
pl330_prep_dma_cyclic -->
the case:
1. pl330_submit_req(desc0): thrd->req[0].desc = desc0, thrd->lstenq = 0
2. pl330_submit_req(desc1): thrd->req[1].desc = desc1, thrd->lstenq = 1
3. _start(desc0) by submit_req: thrd->req_running = 0
   because: idx = 1 - thrd->lstenq = 0
4. pl330_update(desc0 OK): thrd->req[0].desc = NULL, desc0 to req_done list
   because: idx = active = thrd->req_running = 0
5. _start(desc1) by pl330_update: thrd->req_running = 1
   because:
   idx = 1 - thrd->lstenq = 0, but thrd->req[0].desc == NULL,
   so:
   idx = thrd->lstenq = 1
6. pl330_submit_req(desc2): thrd->req[0].desc = desc2, thrd->lstenq = 0
7. _start(desc1) by submit_req: thrd->req_running = 1
   because: idx = 1 - thrd->lstenq = 1
   Note: _start started the same descs
         _start should start desc2 here, NOT desc1

8. pl330_update(desc1 OK): thrd->req[1].desc = NULL, desc1 to req_done list
   because: idx = active = thrd->req_running = 1
9. _start(desc2) by pl330_update : thrd->req_running = 0
   because: idx = 1 - thrd->lstenq = 0
10.pl330_update(desc1 OK, NOT desc2): thrd->req[0].desc = NULL,
   desc2 to req_done list
   because: idx = active = thrd->req_running = 0

11.pl330_submit_req(desc3): thrd->req[0].desc = desc3, thrd->lstenq = 0
12.pl330_submit_req(desc4): thrd->req[1].desc = desc4, thrd->lstenq = 1
13._start(desc3) by submit_req: thrd->req_running = 0
   because: idx = 1 - thrd->lstenq = 0
14.pl330_update(desc2 OK NOT desc3): thrd->req[0].desc = NULL
   desc3 to req_done list
   because: idx = active = thrd->req_running = 0
15._start(desc4) by pl330_update: thrd->req_running = 1
   because:
   idx = 1 - thrd->lstenq = 0, but thrd->req[0].desc == NULL,
   so:
   idx = thrd->lstenq = 1
16.pl330_submit_req(desc5): thrd->req[0].desc = desc5, thrd->lstenq = 0
17._start(desc4) by submit_req: thrd->req_running = 1
   because: idx = 1 - thrd->lstenq = 1
18.pl330_update(desc3 OK NOT desc4): thrd->req[1].desc = NULL
   desc4 to req_done list
   because: idx = active = thrd->req_running = 1
19._start(desc4) by pl330_update: thrd->req_running = 0
   because:
   idx = 1 - thrd->lstenq = 1, but thrd->req[1].desc == NULL,
   so:
   idx = thrd->lstenq = 0
20.pl330_update(desc4 OK): thrd->req[0].desc = NULL, desc5 to req_done list
   because: idx = active = thrd->req_running = 0
21.pl330_update(desc4 OK):
   1) before commit dfac17(set req_running -1 in pl330_update/mark_free()):
      because: active = -1, abort
      result: desc0-desc5's callback are all called,
	      but step 10 and step 18 go wrong.
   2) before commit dfac17:
      idx = active = thrd->req_runnig = 0 -->
      descdone = thrd->req[0] = NULL -->
      list_add_tail(&descdone->rqd, &pl330->req_done); -->
      got NULL pointer!!!
Signed-off-by: NAddy Ke <addy.ke@rock-chips.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Now that the generic slave caps code can make use of the device assigned
capabilities, instead of relying on a callback to be implemented.

Make use of this code.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Split the device_control callback of the AMBA PL330 DMA driver to make use
of the newly introduced callbacks, that will eventually be used to retrieve
slave capabilities.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The dmaengine header abbreviates destination as at least two different strings.
Make a coherent use of a single one.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: NMark Brown <broonie@kernel.org>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NStephen Warren <swarren@wwwdotorg.org>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Update email-id to a personal one, as I have changed employment.
Signed-off-by: NJassi Brar <jassisinghbrar@gmail.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Add system suspend/resume capabilities to the pl330 driver so the amba
bus clock could be also unprepared to conserve energy.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This patch adds runtime PM support to pl330 DMA engine driver.

The runtime power management for pl330 DMA driver allows gating of AMBA
clock (PDMA) in FSYS clock domain, when the device is not processing any
requests. This is necessary to enter low power modes on Exynos SoCs
(e.g. LPA on Exynos4x12 or W-AFTR on Exynos3250).

Runtime PM resuming of the device may happen in atomic context (during
call device_issue_pending()) so pm_runtime_irq_safe() is used. This will
lead only to disabling/enabling of the clock but this is sufficient for
gating the clock and for reducing energy usage.

Driver uses runtime PM callbacks from amba/bus.c driver only.
Suggested-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NVinod Koul <vinod.koul@intel.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Commit f6f2421c removed pl330_info structure by embedding it into
pl330_dmac structure, but did not ensure that the dmac->ddma.dev
pointer gets initialised before use. When dma_alloc_coherent() gets
called on arm64 a WARN() gets triggered due to dev being NULL.

------------[ cut here ]------------
WARNING: CPU: 1 PID: 1 at arch/arm64/mm/dma-mapping.c:49 __dma_alloc_coherent+0xd0/0xe0()
Use an actual device structure for DMA allocation
Modules linked in:
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 3.17.0+ #5
Call trace:
[<ffffffc000087f24>] dump_backtrace+0x0/0x130
[<ffffffc000088064>] show_stack+0x10/0x1c
[<ffffffc0004e8af8>] dump_stack+0x74/0xb8
[<ffffffc0000aa444>] warn_slowpath_common+0x8c/0xb4
[<ffffffc0000aa4b8>] warn_slowpath_fmt+0x4c/0x58
[<ffffffc000092580>] __dma_alloc_coherent+0xcc/0xe0
[<ffffffc000092734>] __dma_alloc_noncoherent+0x64/0x158
[<ffffffc000312cd8>] pl330_probe+0x650/0x8f0
[<ffffffc00030e1d4>] amba_probe+0xa0/0xc8
[<ffffffc000350240>] really_probe+0xc4/0x22c
[<ffffffc0003504b4>] __driver_attach+0xa0/0xa8
[<ffffffc00034e5fc>] bus_for_each_dev+0x54/0x98
[<ffffffc00034fd8c>] driver_attach+0x1c/0x28
[<ffffffc00034fa08>] bus_add_driver+0x14c/0x204
[<ffffffc000350b84>] driver_register+0x64/0x130
[<ffffffc00030dcf8>] amba_driver_register+0x50/0x5c
[<ffffffc0006a60d0>] pl330_driver_init+0x10/0x1c
[<ffffffc0000814ac>] do_one_initcall+0x88/0x19c
[<ffffffc00068dab8>] kernel_init_freeable+0x140/0x1e0
[<ffffffc0004e5e18>] kernel_init+0x10/0xd4
---[ end trace 76f2d47a444e523e ]---
(NULL device *): dmac_alloc_resources:1821 Can't allocate memory!
(NULL device *): Unable to create channels for DMAC

This patch will also ensure that any dev_err messages are printed
with the appropriate device name.
Signed-off-by: NLiviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: NAndrew Jackson <Andrew.Jackson@arm.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The datasheet for PL330 says that the data buffer value in the CRD
register is 10bits wide. However, the value stored is "minus one",
which the driver corrects for. Maximum value that the data buffer
depth can have is 1024 lines, which requires 11 bits for storage.

While making updates I found printing the peripheral ID as a hex
value to be more useful as the datasheet shows the values that way.
Signed-off-by: NLiviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The MFIFO is shared by all channels so restrict each memcpy to it's fair
share. This is being over cautious, but without a global view of DMA
channel usage on a system it's not possible to come up with a more
optimum safe limit.
Signed-off-by: NJon Medhurst <tixy@linaro.org>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The algorithm used for programming the DMA Controller doesn't take into
consideration the requirements of transfers that are not aligned to the
bus width. This failure may result in DMA transferring one too few MFIFO
entries (so too few bytes are copied) or the DMA trying to write one too
many MFIFO entries and hanging because this is never provided.

See "MFIFO Usage Overview" chapter in the the TRM for "CoreLink DMA
Controller DMA-330", Revision r1p1.

We work around these shortcomings by making sure we pick a burst size
and length which ensures no bursts straddle an MFIFO entry.
Signed-off-by: NJon Medhurst <tixy@linaro.org>
[squashed linker error "undefined reference to `__aeabi_uldivmod]
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Fix a NULL pointer dereference after unbinding the driver, if channel
resources were not yet allocated (no call to
pl330_alloc_chan_resources()):
$ echo 12850000.mdma > /sys/bus/amba/drivers/dma-pl330/unbind
[   13.606533] DMA pl330_control: removing pch: eeab6800, chan: eeab6814, thread:   (null)
[   13.614472] Unable to handle kernel NULL pointer dereference at virtual address 0000000c
[   13.622537] pgd = ee284000
[   13.625228] [0000000c] *pgd=6e1e4831, *pte=00000000, *ppte=00000000
[   13.631482] Internal error: Oops: 17 [#1] PREEMPT SMP ARM
[   13.636859] Modules linked in:
[   13.639903] CPU: 0 PID: 1 Comm: sh Not tainted 3.17.0-rc3-next-20140904-00004-g7020ffc33ca3-dirty #420
[   13.649187] task: ee80a800 ti: ee888000 task.ti: ee888000
[   13.654589] PC is at _stop+0x8/0x2c8
[   13.658131] LR is at pl330_control+0x70/0x2e8
[   13.662468] pc : [<c0206028>]    lr : [<c020649c>]    psr: 60000093
[   13.662468] sp : ee889e58  ip : 00000001  fp : 000bab70
[   13.673922] r10: eeab6814  r9 : ee16debc  r8 : 00000000
[   13.679131] r7 : eeab685c  r6 : 60000013  r5 : ee16de10  r4 : eeab6800
[   13.685641] r3 : 00000002  r2 : 00000000  r1 : 00010000  r0 : 00000000
[   13.692153] Flags: nZCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment user
[   13.699357] Control: 10c5387d  Table: 6e28404a  DAC: 00000015
[   13.705085] Process sh (pid: 1, stack limit = 0xee888240)
[   13.710466] Stack: (0xee889e58 to 0xee88a000)
[   13.714808] 9e40:                                                       00000002 eeab6800
[   13.722969] 9e60: ee16de10 eeab6800 ee16de10 60000013 eeab685c c020649c 00000000 c040280c
[   13.731128] 9e80: ee889e80 ee889e80 ee16de18 ee16de10 eeab6880 eeab6814 00200200 eeab68a8
[   13.739287] 9ea0: 00100100 c0208048 00000000 c0409fc4 eea80800 eea808f8 c0605c44 0000000e
[   13.747446] 9ec0: 0000000e eeb3960c eeb39600 c0203c48 eea80800 c0605c44 c0605a8c c023f694
[   13.755605] 9ee0: ee80a800 eea80834 eea80800 c023f704 ee80a800 eea80800 c0605c44 c023e8ec
[   13.763764] 9f00: 0000000e ee149780 ee29e580 ee889f80 ee29e580 c023e19c 0000000e c01167e4
[   13.771923] 9f20: c01167a0 00000000 00000000 c0115e88 00000000 00000000 ee0b1a00 0000000e
[   13.780082] 9f40: b6f48000 ee889f80 0000000e ee888000 b6f48000 c00bfadc 00000000 00000003
[   13.788241] 9f60: 00000000 00000000 00000000 ee0b1a00 ee0b1a00 0000000e b6f48000 c00bfdf4
[   13.796401] 9f80: 00000000 00000000 ffffffff 0000000e b6f48000 b6edc5d0 00000004 c000e7a4
[   13.804560] 9fa0: 00000000 c000e620 0000000e b6f48000 00000001 b6f48000 0000000e 00000000
[   13.812719] 9fc0: 0000000e b6f48000 b6edc5d0 00000004 0000000e b6f4c8c0 000c3470 000bab70
[   13.820879] 9fe0: 00000000 bed2aa50 b6e18bdc b6e6b52c 60000010 00000001 c0c0c0c0 c0c0c0c0
[   13.829058] [<c0206028>] (_stop) from [<c020649c>] (pl330_control+0x70/0x2e8)
[   13.836165] [<c020649c>] (pl330_control) from [<c0208048>] (pl330_remove+0xb0/0xdc)
[   13.843800] [<c0208048>] (pl330_remove) from [<c0203c48>] (amba_remove+0x24/0xc0)
[   13.851272] [<c0203c48>] (amba_remove) from [<c023f694>] (__device_release_driver+0x70/0xc4)
[   13.859685] [<c023f694>] (__device_release_driver) from [<c023f704>] (device_release_driver+0x1c/0x28)
[   13.868971] [<c023f704>] (device_release_driver) from [<c023e8ec>] (unbind_store+0x58/0x90)
[   13.877303] [<c023e8ec>] (unbind_store) from [<c023e19c>] (drv_attr_store+0x20/0x2c)
[   13.885036] [<c023e19c>] (drv_attr_store) from [<c01167e4>] (sysfs_kf_write+0x44/0x48)
[   13.892928] [<c01167e4>] (sysfs_kf_write) from [<c0115e88>] (kernfs_fop_write+0xc0/0x17c)
[   13.901090] [<c0115e88>] (kernfs_fop_write) from [<c00bfadc>] (vfs_write+0xa0/0x1a8)
[   13.908812] [<c00bfadc>] (vfs_write) from [<c00bfdf4>] (SyS_write+0x40/0x8c)
[   13.915850] [<c00bfdf4>] (SyS_write) from [<c000e620>] (ret_fast_syscall+0x0/0x30)
[   13.923392] Code: e5813010 e12fff1e e92d40f0 e24dd00c (e590200c)
[   13.929467] ---[ end trace 10064e15a5929cf8 ]---

Terminate the thread and free channel resource only if channel resources
were allocated (thread is not NULL).
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: <stable@vger.kernel.org>
Fixes: b3040e40 ("DMA: PL330: Add dma api driver")
Reviewed-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

If dma_async_device_register() returns error and probe should clean up
and return error, a NULL pointer exception happens because of
dereference of not allocated channel thread:

Dmesg log (from early printk):
dma-pl330 12680000.pdma: unable to register DMAC
DMA pl330_control: removing pch: eeac4000, chan: eeac4014, thread:   (null)
Unable to handle kernel NULL pointer dereference at virtual address 0000000c
pgd = c0004000
[0000000c] *pgd=00000000
Internal error: Oops: 5 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 2 PID: 1 Comm: swapper/0 Not tainted 3.17.0-rc3-next-20140904-00005-g6cc4c1937d90-dirty #427
task: ee80a800 ti: ee888000 task.ti: ee888000
PC is at _stop+0x8/0x2c8
LR is at pl330_control+0x70/0x2e8
pc : [<c0205dc8>]    lr : [<c020623c>]    psr: 60000193
sp : ee889df8  ip : 00000002  fp : 00000000
r10: eeac4014  r9 : ee0e62bc  r8 : 00000000
r7 : eeac405c  r6 : 60000113  r5 : ee0e6210  r4 : eeac4000
r3 : 00000002  r2 : 00000002  r1 : 00010000  r0 : 00000000
Flags: nZCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
Control: 10c5387d  Table: 4000404a  DAC: 00000015
Process swapper/0 (pid: 1, stack limit = 0xee888240)
Stack: (0xee889df8 to 0xee88a000)
9de0:                                                       00000002 eeac4000
9e00: ee0e6210 eeac4000 ee0e6210 60000113 eeac405c c020623c 00000000 c020725c
9e20: ee889e20 ee889e20 ee0e6210 eeac4080 00200200 00100100 eeac4014 00000020
9e40: ee0e6218 c0208374 00000000 ee9bb340 ee0e6210 00000000 00000000 c0605cd8
9e60: ee970000 c0605c84 ee9700f8 00000000 c05c4270 00000000 00000000 c0203b3c
9e80: ee970000 c06624a8 00000000 c0605c84 00000000 c023f890 ee970000 c0605c84
9ea0: ee970034 00000000 c05b23d0 c023fa3c 00000000 c0605c84 c023f9b0 c023e0d4
9ec0: ee947e78 ee9b9440 c0605c84 eea1e780 c0605acc c023f094 c0513b50 c0605c84
9ee0: c05ecbd8 c0605c84 c05ecbd8 ee11ba40 c0626500 c0240064 00000000 c05ecbd8
9f00: c05ecbd8 c0008964 c040f13c 0000009f c0626500 c057465c ee80a800 60000113
9f20: 00000000 c05efdb0 60000113 00000000 ef7fc89d c0421168 0000008f c003787c
9f40: c0573d6c 00000006 ef7fc8bb 00000006 c05efd50 ef7fc800 c05dfbc4 00000006
9f60: c05c4264 c0626500 0000008f c05c4270 c059b518 c059bcb4 00000006 00000006
9f80: c059b518 c003c08c 00000000 c040091c 00000000 00000000 00000000 00000000
9fa0: 00000000 c0400924 00000000 c000e7b8 00000000 00000000 00000000 00000000
9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 c0c0c0c0 c0c0c0c0
[<c0205dc8>] (_stop) from [<c020623c>] (pl330_control+0x70/0x2e8)
[<c020623c>] (pl330_control) from [<c0208374>] (pl330_probe+0x594/0x75c)
[<c0208374>] (pl330_probe) from [<c0203b3c>] (amba_probe+0xb8/0x120)
[<c0203b3c>] (amba_probe) from [<c023f890>] (driver_probe_device+0x10c/0x22c)
[<c023f890>] (driver_probe_device) from [<c023fa3c>] (__driver_attach+0x8c/0x90)
[<c023fa3c>] (__driver_attach) from [<c023e0d4>] (bus_for_each_dev+0x54/0x88)
[<c023e0d4>] (bus_for_each_dev) from [<c023f094>] (bus_add_driver+0xd4/0x1d0)
[<c023f094>] (bus_add_driver) from [<c0240064>] (driver_register+0x78/0xf4)
[<c0240064>] (driver_register) from [<c0008964>] (do_one_initcall+0x80/0x1d0)
[<c0008964>] (do_one_initcall) from [<c059bcb4>] (kernel_init_freeable+0x108/0x1d4)
[<c059bcb4>] (kernel_init_freeable) from [<c0400924>] (kernel_init+0x8/0xec)
[<c0400924>] (kernel_init) from [<c000e7b8>] (ret_from_fork+0x14/0x3c)
Code: e5813010 e12fff1e e92d40f0 e24dd00c (e590200c)
---[ end trace c94b2f4f38dff3bf ]---

This happens because the necessary resources were not yet allocated - no
call to pl330_alloc_chan_resources().

Terminate the thread and free channel resource only if channel thread is not NULL.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: <stable@vger.kernel.org>
Fixes: 0b94c577 ("DMA: PL330: Add check if device tree compatible")
Reviewed-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The 'void __iomem *regs' is not used in pl330_submit_req() function.
Remove it.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The pl330_submit_req() checked supplied 'struct pl330_thread thrd' and
'struct dma_pl330_desc desc' parameters for non-NULL. However these
checks are useless because supplied arguments won't be NULL.

The pl330_submit_req() is called in only one place and:
1. 'desc' is already dereferenced in fill_queue() before calling
   pl330_submit_req().
2. 'thrd' is always dereferenced after calling
   fill_queue()->pl330_submit_req().

Removing the checks for non-NULL values fixes following warning:
drivers/dma/pl330.c:1376 pl330_submit_req() warn: variable dereferenced before check 'thrd' (see line 1367)
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The argument is always set to NULL and never used. Remove it.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Commit 6079d38c ("dmaengine: pl330: Remove useless xfer_cb indirection")
removed the __callback() function which created an unnecessary level of
indirection to execute the tranfer callback .xfer_cb

Unfortunately the commit also changed the semantics slightly since that
function used to check if the request was not NULL before attempting to
execute the callback function. Not checking this could lead to a kernel
NULL pointer dereference error.
Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Acked-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The pl330_chan_ctrl() function has 3 internal code paths which, except for the
locking, do not share any code outside of their sections. One code path is never
exercised and can be removed. The other two are mostly just forwards to the
_start() and _stop() calls. This patch modifies the code to instead of going via
pl330_chan_ctrl() to call _start() and _stop() directly. This allows to
completely remove pl330_chan_ctrl().
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Instead of storing a special instruction in the command buffer to mark a request
as currently unused just set the descriptor field to NULL.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The pl330_req struct is embedded into the dma_pl330_desc struct. But half of the
pl330_req struct are pointers to other fields of the dma_pl330_desc struct it is
embedded to. By directly embedding the fields from the pl330_req struct into the
dma_pl330_desc struct and reworking the code to work with the dma_pl330_desc
struct those pointers can be eliminated. This slightly simplifies the code.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Both the dma_pl330_dmac and the pl330_dmac struct have the same lifetime and the
separation of them is a relict of this having been two different drivers in the
past. Merging them into one struct makes the code a bit simpler as it for
example allows to remove the pointers going back and forth between the two
structs.

While we are at it also directly embed the pl330_info struct into the
pl330_dmac struct as this allows to remove some more redundant fields.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Since we keep a pointer to the manager thread it is fairly easy to check if a
thread is the manager thread.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

We know that we do not create invalid ccr settings in this driver. There is no
need to validate them.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The pl330_chid field of the dma_pl330_chan struct always holds a pointer to the
thread that is associated with the channel. Changing its type form void * to
struct pl330_thread makes things more type safe and removes the need for
unnecessary typecasts. While we are at it also rename the field from the cryptic
pl330_chid to thread.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The xfer_cb callback of the pl330_req struct is always set to the same function.
This adds an unnecessary step of indirection. Instead just call the callback
function directly.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The mc_len is initialized but its value is never read again, so remove it.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The next field is always NULL, so we can remove it.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The field is completely unused, remove it.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The dmac_reset() callaback of the pl330_info struct is always set to NULL, so
remove it.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The pl330_chanstatus struct is completely unused, so remove it.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The settings for destination and source cache control are exactly the same. This
patch removes the duplicated enum and uses the same for both destination and
source cache control.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The pl330 driver has the custom pl330_reqtype enum which has the same possible
settings as the generic dma_transfer_direction enum. Switching over to the
generic enum internally makes it possible to directly initialize it from the
transfer request direction.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Currently the driver uses dma_request_channel() with a custom filter function to
find the requested channel. This will loop over all available channels until the
one we want has been found, but we already know which channel we want to
request, so we can dma_get_slave_channel(). This also makes the code a bit
shorter cleaner.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The pl330 dmaengine driver currently does not differentiate between submitted
and issued descriptors. It won't start transferring a newly submitted
descriptor until issue_pending() is called, but only if it is idle. If it is
active and a new descriptor is submitted before it goes idle it will happily
start the newly submitted descriptor once all earlier submitted descriptors have
been completed. This is not a 100% correct with regards to the dmaengine
interface semantics. A descriptor is not supposed to be started until the next
issue_pending() call after the descriptor has been submitted. This patch adds a
second per channel list that keeps track of the submitted descriptors. Once
issue_pending() is called the submitted descriptors are moved to the working
list and only descriptors on the working list are started.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>