Useful for debugging ILLEGAL_DEV_TABLE_ENTRY events as some of the
DTE settings depends on Control register settings.
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20250227162320.5805-2-vasant.hegde@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This reverts commit ac9a5d522b.
iommu_dma_init_domain() is now only called under the group mutex, as it
should be given that that the default domain belongs to the group, so
the additional internal locking is no longer needed.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/a943d4c198e6a1fffe998337d577dc3aa7f660a9.1740585469.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
K Prateek Nayak <kprateek.nayak@amd.com> says:
Based on the suggestion on the RFC, the treewide conversion of
references to pipe->{head,tail} from unsigned int to pipe_index_t has
been dropped for now. The series contains trivial cleanup suggested to
limit the nr_slots in pipe_resize_ring() to be covered between
pipe_index_t limits of pipe->{head,tail} and using pipe_buf() to remove
the open-coded usage of masks to access pipe buffer building on Linus'
cleanup of fs/fuse/dev.c in commit ebb0f38bb4 ("fs/pipe: fix pipe
buffer index use in FUSE")
* patches from https://lore.kernel.org/r/20250307052919.34542-1-kprateek.nayak@amd.com:
fs/splice: Use pipe_buf() helper to retrieve pipe buffer
fs/pipe: Use pipe_buf() helper to retrieve pipe buffer
kernel/watch_queue: Use pipe_buf() to retrieve the pipe buffer
fs/pipe: Limit the slots in pipe_resize_ring()
Link: https://lore.kernel.org/r/20250307052919.34542-1-kprateek.nayak@amd.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Use pipe_buf() helper to retrieve the pipe buffer throughout the file
replacing the open-coded the logic.
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20250307052919.34542-5-kprateek.nayak@amd.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Use pipe_buf() helper to retrieve the pipe buffer throughout the file
replacing the open-coded the logic.
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20250307052919.34542-4-kprateek.nayak@amd.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Use pipe_buf() helper to retrieve the pipe buffer in
post_one_notification() replacing the open-coded the logic.
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20250307052919.34542-3-kprateek.nayak@amd.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Limit the number of slots in pipe_resize_ring() to the maximum value
representable by pipe->{head,tail}. Values beyond the max limit can
lead to incorrect pipe occupancy related calculations where the pipe
will never appear full.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20250307052919.34542-2-kprateek.nayak@amd.com
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Mainline now contains various changes to pipes that are relevant for
other pipe work this cycle. So merge them into the respective VFS tree.
Signed-off-by: Christian Brauner <brauner@kernel.org>
phy_pm_runtime_allow() and phy_pm_runtime_forbid() were added in 2013
as part of
commit ff76496347 ("drivers: phy: add generic PHY framework")
but have remained unused.
Remove them.
Fix up the (English) docs - I've left the Chinese translation.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Link: https://lore.kernel.org/r/20250306015408.277729-1-linux@treblig.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The Allwinner A523 SoC contains a USB-2.0 PHY fully compatible to the
one used in the D1/T113s SoCs. This PHY controls the two USB-2.0 ports,
there is a separate and quite different PHY for the USB-3.0 port.
Add the new compatible string, with a fallback to the D1 version.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20250307005712.16828-8-andre.przywara@arm.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Despite the compatible already being listed in the bindings, the PHY
driver never gained explicit support for it. This is especially a
problem because the explicitly listed PHY addresses need to be specified
for each SoC.
To solve this, add the compatible, and a PHY config, with the address
gleaned from rk3576.dtsi.
Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Reviewed-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20250306-rk3576-hdptx-phy-v1-1-288cc4b0611a@collabora.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Add code to show what codec drivers will need to do to enable BPT/BRA
transfers. The only difference is to set the 'command_type' file to
'1'. A zero-value will rely on regular read/write commands in Column0.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Liam Girdwood <liam.r.girdwood@intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Tested-by: shumingf@realtek.com
Link: https://lore.kernel.org/r/20250227140615.8147-16-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
When the firmware is involved, the data can be transferred with a
CHAIN_DMA on LNL+.
The CHAIN_DMA needs to be programmed before the DMAs per the
documentation. The states are not exactly symmetrical, on stop we must
do a PAUSE and RESET.
The FIFO size of 10ms was determined experimentally. With the minimum
of 2ms, errors were reported by the codec, likely because of xruns.
The code flow deals with the two TX and RX CHAIN_DMAs in symmetrical
ways, i.e.
alloc TX
alloc RX
enable TX
enable RX
disable RX
disable TX
free RX
free TX
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Liam Girdwood <liam.r.girdwood@intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Tested-by: shumingf@realtek.com
Link: https://lore.kernel.org/r/20250227140615.8147-15-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Add SoundWire BPT DMA helpers as a separate module to avoid circular
dependencies.
For now this assumes no link DMA, only coupled mode.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Liam Girdwood <liam.r.girdwood@intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Tested-by: shumingf@realtek.com
Link: https://lore.kernel.org/r/20250227140615.8147-12-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The Cadence IP expects a specific format (detailed in the
Documentation). Add helpers to copy the data into the DMA buffer.
The crc8 table is for now only used by the Cadence driver. This table
might be moved to a common module at a later point if needed by other
controller implementations.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Liam Girdwood <liam.r.girdwood@intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Tested-by: shumingf@realtek.com
Link: https://lore.kernel.org/r/20250227140615.8147-10-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Add a convenience pointer to the 'sdw_bus' structure. BPT is a
dedicated stream which will typically not be handled by DAIs or
dailinks. Since there's only one BPT stream per link, storing the
pointer at the link level seems rather natural.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Liam Girdwood <liam.r.girdwood@intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Tested-by: shumingf@realtek.com
Link: https://lore.kernel.org/r/20250227140615.8147-9-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Add definitions and helpers for the BPT/BRA protocol. Peripheral
drivers (aka ASoC codec drivers) can use this API to send bulk data
such as firmware or tables. The design intent is however NOT to
directly use this API but to rely on an intermediate regmap layer.
The API is only available when no other audio streams have been
allocated, and only one BTP/BRA stream is allowed per link. To avoid
the addition of yet another lock, the refcount tests are handled in
the stream master_runtime alloc/free routines where the bus_lock is
already held. Another benefit of this approach is that the same
bus_lock is used to handle runtime and port linked lists, which
reduces the potential for misaligned configurations.
In addition to exclusion with audio streams, BPT transfers have a lot
of overhead, specifically registers writes are needed to enable
transport in DP0. Most DMAs don't handle too well very small data sets
and they may have alignment limitations.
The size and alignment requirements are for now not handled by the
core but must be checked by platform-specific drivers.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Liam Girdwood <liam.r.girdwood@intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Tested-by: shumingf@realtek.com
Link: https://lore.kernel.org/r/20250227140615.8147-8-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
DP0 (Data Port 0) is very similar to regular data ports, with minor
tweaks we can reuse the same code.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Liam Girdwood <liam.r.girdwood@intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Tested-by: shumingf@realtek.com
Link: https://lore.kernel.org/r/20250227140615.8147-7-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
In the existing definition of sdw_stream_runtime, the 'type' member is
never set and defaults to PCM. To prepare for the BPT/BRA support, we
need to special-case streams and make use of the 'type'.
No functional change for now, the implicit PCM type is now explicit.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Liam Girdwood <liam.r.girdwood@intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Tested-by: shumingf@realtek.com
Link: https://lore.kernel.org/r/20250227140615.8147-5-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
BPT/BRA need to be special cased, i.e. there's no point in using the
bandwidth allocation since the entire frame can be used.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Liam Girdwood <liam.r.girdwood@intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Tested-by: shumingf@realtek.com
Link: https://lore.kernel.org/r/20250227140615.8147-4-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The register definitions are missing a BULK_ENABLE bitfield which must
be set for DP0.
In addition, the existing mapping from PDI to Data Port is 1:1. That's
fine for PCM streams which are by construction in one direction
only. The BTP/BRA protocol is bidirectional and relies on DP0 only,
which breaks the 1:1 mapping. DP0 MUST be mapped to both PDI0 and
PDI1, with PDI0 taking care of the TX direction and PDI1 of the RX
direction.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Liam Girdwood <liam.r.girdwood@intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Tested-by: shumingf@realtek.com
Link: https://lore.kernel.org/r/20250227140615.8147-3-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The Bulk Register Access protocol was left as a TODO topic since
2018. It's time to document this protocol and the design of its Linux
support.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Liam Girdwood <liam.r.girdwood@intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Tested-by: shumingf@realtek.com
Link: https://lore.kernel.org/r/20250227140615.8147-2-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Some register groups reserve a byte at the end of their continuous
address space. Depending on the variant of silicon, this field may
share the same memory space as the lower byte of the system status
register (0x10).
In these cases, caching the reserved byte and writing it later may
effectively reset the device depending on what happened in between
the read and write operations.
Solve this problem by avoiding any access to this last byte within
offending register groups. This method replaces a workaround which
attempted to write the reserved byte with up-to-date contents, but
left a small window in which updates by the device could have been
clobbered.
Now that the driver does not touch these reserved bytes, the order
in which the device's registers are written no longer matters, and
they can be written in their natural order. The new method is also
much more generic, and can be more easily extended to new variants
of silicon with different register maps.
As part of this change, the register read and write functions must
be gently updated to support byte access instead of word access.
Fixes: 2e70ef525b ("Input: iqs7222 - acknowledge reset before writing registers")
Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/Z85Alw+d9EHKXx2e@nixie71
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This functionally brings tegra186 in line with tegra210 and tegra194,
sharing a cpufreq policy between all cores in a cluster.
Reviewed-by: Sumit Gupta <sumitg@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Aaron Kling <webgeek1234@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
In relocate_32.S, function clear_utlb_entry() goes into real mode. To
do so, it has to calculate the physical address based on the virtual
address. To get the virtual address it uses 'bl' which is problematic
(see commit c974809a26 ("powerpc/vdso: Avoid link stack corruption
in __get_datapage()")). In addition, the calculation is done on a
wrong address because 'bl' loads LR with the address of the following
instruction, not the address of the target. So when the target is not
the instruction following the 'bl' instruction, it may lead to
unexpected behaviour.
Fix it by re-writing the code so that is goes via another path which
is based 'bcl 20,31,.+4' which is the right instruction to use for that.
Fixes: 6834302003 ("powerpc/47x: Kernel support for KEXEC")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/dc4f9616fba9c05c5dbf9b4b5480eb1c362adc17.1741256651.git.christophe.leroy@csgroup.eu
The following build warning has been reported:
arch/powerpc/crypto/ghashp8-ppc.o: warning: objtool: .text+0x22c: unannotated intra-function call
This happens due to commit bb7f054f4d ("objtool/powerpc: Add support
for decoding all types of uncond branches")
Disassembly of arch/powerpc/crypto/ghashp8-ppc.o shows:
arch/powerpc/crypto/ghashp8-ppc.o: file format elf64-powerpcle
Disassembly of section .text:
0000000000000140 <gcm_ghash_p8>:
140: f8 ff 00 3c lis r0,-8
...
20c: 20 00 80 4e blr
210: 00 00 00 00 .long 0x0
214: 00 0c 14 00 .long 0x140c00
218: 00 00 04 00 .long 0x40000
21c: 00 00 00 00 .long 0x0
220: 47 48 41 53 rlwimi. r1,r26,9,1,3
224: 48 20 66 6f xoris r6,r27,8264
228: 72 20 50 6f xoris r16,r26,8306
22c: 77 65 72 49 bla 1726574 <gcm_ghash_p8+0x1726434> <==
...
It corresponds to the following code in ghashp8-ppc.o :
_GLOBAL(gcm_ghash_p8)
lis 0,0xfff8
...
blr
.long 0
.byte 0,12,0x14,0,0,0,4,0
.long 0
.size gcm_ghash_p8,.-gcm_ghash_p8
.byte 71,72,65,83,72,32,102,111,114,32,80,111,119,101,114,73,83,65,32,50,46,48,55,44,32,67,82,89,80,84,79,71,65,77,83,32,98,121,32,60,97,112,112,114,111,64,111,112,101,110,115,115,108,46,111,114,103,62,0
.align 2
.align 2
In fact this is raw data that is after the function end and that is
not text so shouldn't be disassembled as text. But ghashp8-ppc.S is
generated by a perl script and should have been marked as
OBJECT_FILES_NON_STANDARD.
Now that 'bla' is understood as a call instruction, that raw data
is mis-interpreted as an infra-function call.
Mark ghashp8-ppc.o as a OBJECT_FILES_NON_STANDARD to avoid this
warning.
Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Closes: https://lore.kernel.org/all/8c4c3fc2-2bd7-4148-af68-2f504d6119e0@linux.ibm.com
Fixes: 109303336a ("crypto: vmx - Move to arch/powerpc/crypto")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Tested-By: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Sathvika Vasireddy <sv@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/7aa7eb73fe6bc95ac210510e22394ca0ae227b69.1741128786.git.christophe.leroy@csgroup.eu
The following build warning have been reported:
arch/powerpc/kvm/book3s_hv_rmhandlers.o: warning: objtool: .text+0xe84: intra_function_call not a direct call
arch/powerpc/kernel/switch.o: warning: objtool: .text+0x4: intra_function_call not a direct call
This happens due to commit bb7f054f4d ("objtool/powerpc: Add support
for decoding all types of uncond branches") because that commit decodes
'bl .+4' as a normal instruction because that instruction is used by
clang instead of 'bcl 20,31,+.4' for relocatable code.
The solution is simply to remove the ANNOTATE_INTRA_FUNCTION_CALL
annotation now that the instruction is not seen as a function call
anymore.
Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Closes: https://lore.kernel.org/all/8c4c3fc2-2bd7-4148-af68-2f504d6119e0@linux.ibm.com
Fixes: bb7f054f4d ("objtool/powerpc: Add support for decoding all types of uncond branches")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Tested-By: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Sathvika Vasireddy <sv@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/88876fb4e412203452e57d1037a1341cf15ccc7b.1741128981.git.christophe.leroy@csgroup.eu
Due to wrong `.. kernel-doc` directive in Documentation/gpu/rfc/gpusvm.rst
the documentation was actually not parsing anything from
drivers/gpu/drm/drm_gpusvm.c. This fixes the kernel-doc include and all
warnings/errors created when doing so.
Cc: Simona Vetter <simona.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: dri-devel@lists.freedesktop.org
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/intel-xe/20250307195239.57abcd2d@canb.auug.org.au/
Fixes: 99624bdff8 ("drm/gpusvm: Add support for GPU Shared Virtual Memory")
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250307-fix-svm-kerneldoc-v2-1-03c74b199620@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
The hypercall in hv_mark_gpa_visibility() is invoked with an input
argument and an output argument. The output argument ostensibly returns
the number of pages that were processed. But in fact, the hypercall does
not provide any output, so the output argument is spurious.
The spurious argument is harmless because Hyper-V ignores it, but in the
interest of correctness and to avoid the potential for future problems,
remove it.
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Link: https://lore.kernel.org/r/20250226200612.2062-2-mhklinux@outlook.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20250226200612.2062-2-mhklinux@outlook.com>
When a Hyper-V framebuffer device is unbind, hyperv_fb driver tries to
release the framebuffer forcefully. If this framebuffer is in use it
produce the following WARN and hence this framebuffer is never released.
[ 44.111220] WARNING: CPU: 35 PID: 1882 at drivers/video/fbdev/core/fb_info.c:70 framebuffer_release+0x2c/0x40
< snip >
[ 44.111289] Call Trace:
[ 44.111290] <TASK>
[ 44.111291] ? show_regs+0x6c/0x80
[ 44.111295] ? __warn+0x8d/0x150
[ 44.111298] ? framebuffer_release+0x2c/0x40
[ 44.111300] ? report_bug+0x182/0x1b0
[ 44.111303] ? handle_bug+0x6e/0xb0
[ 44.111306] ? exc_invalid_op+0x18/0x80
[ 44.111308] ? asm_exc_invalid_op+0x1b/0x20
[ 44.111311] ? framebuffer_release+0x2c/0x40
[ 44.111313] ? hvfb_remove+0x86/0xa0 [hyperv_fb]
[ 44.111315] vmbus_remove+0x24/0x40 [hv_vmbus]
[ 44.111323] device_remove+0x40/0x80
[ 44.111325] device_release_driver_internal+0x20b/0x270
[ 44.111327] ? bus_find_device+0xb3/0xf0
Fix this by moving the release of framebuffer and assosiated memory
to fb_ops.fb_destroy function, so that framebuffer framework handles
it gracefully.
While we fix this, also replace manual registrations/unregistration of
framebuffer with devm_register_framebuffer.
Fixes: 68a2d20b79 ("drivers/video: add Hyper-V Synthetic Video Frame Buffer Driver")
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/1740845791-19977-3-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <1740845791-19977-3-git-send-email-ssengar@linux.microsoft.com>
The device object required in 'hvfb_release_phymem' function
for 'dma_free_coherent' can also be obtained from the 'info'
pointer, making 'hdev' parameter in 'hvfb_putmem' redundant.
Remove the unnecessary 'hdev' argument from 'hvfb_putmem'.
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/1740845791-19977-2-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <1740845791-19977-2-git-send-email-ssengar@linux.microsoft.com>
Gen 2 Hyper-V VMs boot via EFI and have a standard EFI framebuffer
device. When the kdump kernel runs in such a VM, loading the efifb
driver may hang because of accessing the framebuffer at the wrong
memory address.
The scenario occurs when the hyperv_fb driver in the original kernel
moves the framebuffer to a different MMIO address because of conflicts
with an already-running efifb or simplefb driver. The hyperv_fb driver
then informs Hyper-V of the change, which is allowed by the Hyper-V FB
VMBus device protocol. However, when the kexec command loads the kdump
kernel into crash memory via the kexec_file_load() system call, the
system call doesn't know the framebuffer has moved, and it sets up the
kdump screen_info using the original framebuffer address. The transition
to the kdump kernel does not go through the Hyper-V host, so Hyper-V
does not reset the framebuffer address like it would do on a reboot.
When efifb tries to run, it accesses a non-existent framebuffer
address, which traps to the Hyper-V host. After many such accesses,
the Hyper-V host thinks the guest is being malicious, and throttles
the guest to the point that it runs very slowly or appears to have hung.
When the kdump kernel is loaded into crash memory via the kexec_load()
system call, the problem does not occur. In this case, the kexec command
builds the screen_info table itself in user space from data returned
by the FBIOGET_FSCREENINFO ioctl against /dev/fb0, which gives it the
new framebuffer location.
This problem was originally reported in 2020 [1], resulting in commit
3cb73bc3fa ("hyperv_fb: Update screen_info after removing old
framebuffer"). This commit solved the problem by setting orig_video_isVGA
to 0, so the kdump kernel was unaware of the EFI framebuffer. The efifb
driver did not try to load, and no hang occurred. But in 2024, commit
c25a19afb8 ("fbdev/hyperv_fb: Do not clear global screen_info")
effectively reverted 3cb73bc3fa. Commit c25a19afb8 has no reference
to 3cb73bc3fa, so perhaps it was done without knowing the implications
that were reported with 3cb73bc3fa. In any case, as of commit
c25a19afb8, the original problem came back again.
Interestingly, the hyperv_drm driver does not have this problem because
it never moves the framebuffer. The difference is that the hyperv_drm
driver removes any conflicting framebuffers *before* allocating an MMIO
address, while the hyperv_fb drivers removes conflicting framebuffers
*after* allocating an MMIO address. With the "after" ordering, hyperv_fb
may encounter a conflict and move the framebuffer to a different MMIO
address. But the conflict is essentially bogus because it is removed
a few lines of code later.
Rather than fix the problem with the approach from 2020 in commit
3cb73bc3fa, instead slightly reorder the steps in hyperv_fb so
conflicting framebuffers are removed before allocating an MMIO address.
Then the default framebuffer MMIO address should always be available, and
there's never any confusion about which framebuffer address the kdump
kernel should use -- it's always the original address provided by
the Hyper-V host. This approach is already used by the hyperv_drm
driver, and is consistent with the usage guidelines at the head of
the module with the function aperture_remove_conflicting_devices().
This approach also solves a related minor problem when kexec_load()
is used to load the kdump kernel. With current code, unbinding and
rebinding the hyperv_fb driver could result in the framebuffer moving
back to the default framebuffer address, because on the rebind there
are no conflicts. If such a move is done after the kdump kernel is
loaded with the new framebuffer address, at kdump time it could again
have the wrong address.
This problem and fix are described in terms of the kdump kernel, but
it can also occur with any kernel started via kexec.
See extensive discussion of the problem and solution at [2].
[1] https://lore.kernel.org/linux-hyperv/20201014092429.1415040-1-kasong@redhat.com/
[2] https://lore.kernel.org/linux-hyperv/BLAPR10MB521793485093FDB448F7B2E5FDE92@BLAPR10MB5217.namprd10.prod.outlook.com/
Reported-by: Thomas Tai <thomas.tai@oracle.com>
Fixes: c25a19afb8 ("fbdev/hyperv_fb: Do not clear global screen_info")
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/20250218230130.3207-1-mhklinux@outlook.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20250218230130.3207-1-mhklinux@outlook.com>
When a Hyper-V DRM device is probed, the driver allocates MMIO space for
the vram, and maps it cacheable. If the device removed, or in the error
path for device probing, the MMIO space is released but no unmap is done.
Consequently the kernel address space for the mapping is leaked.
Fix this by adding iounmap() calls in the device removal path, and in the
error path during device probing.
Fixes: f1f63cbb70 ("drm/hyperv: Fix an error handling path in hyperv_vmbus_probe()")
Fixes: a0ab5abced ("drm/hyperv : Removing the restruction of VRAM allocation with PCI bar size")
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Tested-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Link: https://lore.kernel.org/r/20250210193441.2414-1-mhklinux@outlook.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20250210193441.2414-1-mhklinux@outlook.com>
We intentionally truncate the string and store only up to 20 characters
since the LCD display does not provide more chars. For that use
scnprintf() instead of snprintf() to avoid the warning.
Signed-off-by: Helge Deller <deller@gmx.de>
