The DECLARE_REG() macro provides a convenient way to create a local
variable initialized from a cpu context in the hyp trap handlers.
However, a common error is to use the macro multiple times in the same
scope with the same register index, but for different logical purposes.
This results in valid C code that compiles without error, but introduces
subtle bugs where a developer expects two different variables to hold
values from two different registers, when in fact they are both sourced
from the same one.
To prevent this entire class of bugs, modify the DECLARE_REG() macro
to declare a dummy variable whose name is derived from the register
index. If the macro is used again with the same index in the same
scope, the compiler will fail with a "redeclaration of variable"
error, turning a subtle runtime bug into an obvious build-time failure.
Signed-off-by: Fuad Tabba <tabba@google.com>
Tested-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
There are currently only three monitor events, all associated with the
RDT_RESOURCE_L3 resource. Growing support for additional events will be easier
with some restructuring to have a single point in file system code where all
attributes of all events are defined.
Place all event descriptions into an array mon_event_all[]. Doing this has the
beneficial side effect of removing the need for rdt_resource::evt_list.
Add resctrl_event_id::QOS_FIRST_EVENT for a lower bound on range checks for
event ids and as the starting index to scan mon_event_all[].
Drop the code that builds evt_list and change the two places where the list is
scanned to scan mon_event_all[] instead using a new helper macro
for_each_mon_event().
Architecture code now informs file system code which events are available with
resctrl_enable_mon_event().
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Fenghua Yu <fenghuay@nvidia.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/cover.1757108044.git.babu.moger@amd.com
schemata_list_destroy() has to be called if schemata_list_create() fails.
rdt_get_tree() calls schemata_list_destroy() in two different ways:
directly if schemata_list_create() itself fails and
on the exit path via the out_schemata_free goto label.
Remove schemata_list_destroy() call on schemata_list_create() failure.
Use existing out_schemata_free goto label instead.
Signed-off-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Koba Ko <kobak@nvidia.com>
Link: https://lore.kernel.org/20250623075051.3610592-1-tan.shaopeng@jp.fujitsu.com
-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.
Use the new TRAILING_OVERLAP() helper to fix the following warnings:
drivers/pwm/pwm-cros-ec.c:53:40: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
drivers/pwm/pwm-cros-ec.c:87:40: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
This helper creates a union between a flexible-array member (FAM)
and a set of members that would otherwise follow it. This overlays
the trailing members onto the FAM while preserving the original
memory layout.
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://lore.kernel.org/r/aJtRPZpc-Lv-C6zD@kspp
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
The PWM controller on Apple's M2 Pro/Max SoCs behaves in the same way as
on previous M1 and M2 SoCs. Add its per SoC compatible.
At the same time fix the order of existing entries. The sort order logic
is having SoC numeric code families in release order, and SoCs within
each family in release order:
- t8xxx (Apple HxxP/G series, "phone"/"tablet" chips)
- t8103 (Apple H13G/M1)
- t8112 (Apple H14G/M2)
- t6xxx (Apple HxxJ series, "desktop" chips)
- t6000/t6001/t6002 (Apple H13J(S/C/D) / M1 Pro/Max/Ultra)
- t6020/t6021/t6022 (Apple H14J(S/C/D) / M2 Pro/Max/Ultra)
Note that SoCs of the t600[0-2] / t602[0-2] family share the
t6000 / t6020 compatible where the hardware is 100% compatible, which is
usually the case in this highly related set of SoCs.
Signed-off-by: Janne Grunau <j@jannau.net>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20250828-dt-apple-t6020-v1-20-507ba4c4b98e@jannau.net
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
The Automotive S32G2 and S32G3 platforms include two FTM timers for
pwm. Each FTM has 6 PWM channels.
The current Freescale FTM driver supports the iMX8 and the Vybrid
Family FTM IP. The FTM IP found on the S32G platforms is almost
identical except for the number of channels and the register mapping.
These changes allow to deal with different number of channels and
support the holes found in the register memory mapping for s32gx for
suspend / resume. The fault register does not exist on the s32gx and
at resume time all the mapping is wrote back leading to a kernel
crash.
/* restore all registers from cache */
regcache_cache_only(fpc->regmap, false);
regcache_sync(fpc->regmap);
The regmap callbacks 'writeable_reg()' and 'readable_reg()' will skip
the address corresponding to a register which is not present.
Tested on a s32g274-rdb2 J5 PWM pin output with signal visualization
on oscilloscope.
Signed-off-by: Ghennadi Procopciuc <Ghennadi.Procopciuc@nxp.com>
Co-developed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20250812200036.3432917-3-daniel.lezcano@linaro.org
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
duty_cycle and period were silently cast from u64 to int losing
relevant bits. Dividing by the result of a division (resolution) looses
precision. clkdiv was determined using a loop while it can be done
without one. Also too low period values were not catched.
Improve all these issues. Handling period and duty_cycle being u64 now
requires a bit more care to prevent overflows, so mul_u64_u64_div_u64()
is used.
The changes implemented in this change also align the chosen hardware
settings to match the usual PWM rules (i.e. round down instead round
nearest) and so .apply() also matches .get_state() silencing several
warnings with PWM_DEBUG=y. While this probably doesn't result in
problems, this aspect makes this change---though it might be considered
a fix---unsuitable for backporting.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20250725154506.2610172-16-u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
The general register layout contains some per-chip registers starting at
offset 0 and then at a higher address there are n nearly identical and
equidistant blocks for the registers of the n channels.
This allows to represent the offsets of per-channel registers as $base +
i * $width instead of listing all (or too many) offsets explicitly in an
array. So for a small additional effort in pwm_mediatek_writel() the
three arrays with the channel offsets can be dropped.
The size changes according to bloat-o-meter are:
add/remove: 0/3 grow/shrink: 1/0 up/down: 12/-96 (-84)
Function old new delta
pwm_mediatek_apply 696 708 +12
mtk_pwm_reg_offset_v3 32 - -32
mtk_pwm_reg_offset_v2 32 - -32
mtk_pwm_reg_offset_v1 32 - -32
Total: Before=5347, After=5263, chg -1.57%
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20250725154506.2610172-11-u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
A PWM is a more general concept than an output-only GPIO. When using
duty_length = period_length the PWM looks like an active GPIO, with
duty_length = 0 like an inactive GPIO. With the waveform abstraction
there is enough control over the configuration to ensure that PWMs that
cannot generate a constant signal at both levels error out.
The pwm-pca9685 driver already provides a gpio chip. When this driver is
converted to the waveform callbacks, the gpio part can just be dropped.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://lore.kernel.org/r/20250717151117.1828585-2-u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
When a PWM is requested to be disabled, the result is unspecified, the only
intention is to save some power. So skip all checks in this case.
All but two checks already only triggered for states with .enabled = true.
The first resulted in some false positive diagnostics, the other checked
for a condition that depending on hardware might not be implementable.
Similar if the lowlevel driver disabled the hardware this might be a valid
reaction and with .enabled = false all other state parameters are
unreliable, so skip further tests in this case, too.
All later usages of .enabled can be assumed to yield true, and so several
if conditions can be simplified.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/16d29212b09b66c286c1232b1ab0ec0f8d510aae.1751994988.git.u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
The function set_prescale_div() is responsible for calculating the clock
divisor settings such that the input clock rate is divided down such that
the required period length is at most 0x10000 clock ticks. If period_cycles
is an integer multiple of 0x10000, the divisor period_cycles / 0x10000 is
good enough. So round up in the calculation of the required divisor and
compare it using >= instead of >.
Fixes: 19891b20e7 ("pwm: pwm-tiehrpwm: PWM driver support for EHRPWM")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/85488616d7bfcd9c32717651d0be7e330e761b9c.1754927682.git.u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
In Up-Count Mode the timer is reset to zero one tick after it reaches
TBPRD, so the period length is (TBPRD + 1) * T_TBCLK. This matches both
the documentation and measurements. So the value written to the TBPRD has
to be one less than the calculated period_cycles value.
A complication here is that for a 100% relative duty-cycle the value
written to the CMPx register has to be TBPRD + 1 which might overflow if
TBPRD is 0xffff. To handle that the calculation of the AQCTLx register
has to be moved to ehrpwm_pwm_config() and the edge at CTR = CMPx has to
be skipped.
Additionally the AQCTL_PRD register field has to be 0 because that defines
the hardware's action when the maximal counter value is reached, which is
(as above) one clock tick before the period's end. The period start edge
has to happen when the counter is reset and so is defined in the AQCTL_ZRO
field.
Fixes: 19891b20e7 ("pwm: pwm-tiehrpwm: PWM driver support for EHRPWM")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/dc818c69b7cf05109ecda9ee6b0043a22de757c1.1754927682.git.u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
The pwm driver calls pm_runtime_get_sync() when the hardware becomes
enabled and pm_runtime_put_sync() when it becomes disabled. The PWM's
state is kept when a consumer goes away, so the call to
pm_runtime_put_sync() in the .free() callback is unbalanced resulting in
a non-functional device and a reference underlow for the second consumer.
The easiest fix for that issue is to just not drop the runtime PM
reference in .free(), so do that.
Fixes: 19891b20e7 ("pwm: pwm-tiehrpwm: PWM driver support for EHRPWM")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/bbb089c4b5650cc1f7b25cf582d817543fd25384.1754927682.git.u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Xiumei reported a regression in IPsec offload tests over xfrmi, where
the traffic for IPv6 over IPv4 tunnels is processed in SW instead of
going through crypto offload, after commit
cc18f482e8 ("xfrm: provide common xdo_dev_offload_ok callback
implementation").
Commit cc18f482e8 added a generic version of existing checks
attempting to prevent packets with IPv4 options or IPv6 extension
headers from being sent to HW that doesn't support offloading such
packets. The check mistakenly uses x->props.family (the outer family)
to determine the inner packet's family and verify if
options/extensions are present.
In the case of IPv6 over IPv4, the check compares some of the traffic
class bits to the expected no-options ihl value (5). The original
check was introduced in commit 2ac9cfe782 ("net/mlx5e: IPSec, Add
Innova IPSec offload TX data path"), and then duplicated in the other
drivers. Before commit cc18f482e8, the loose check (ihl > 5) passed
because those traffic class bits were not set to a value that
triggered the no-offload codepath. Packets with options/extension
headers that should have been handled in SW went through the offload
path, and were likely dropped by the NIC or incorrectly
processed. Since commit cc18f482e8, the check is now strict (ihl !=
5), and in a basic setup (no traffic class configured), all packets go
through the no-offload codepath.
The commits that introduced the incorrect family checks in each driver
are:
2ac9cfe782 ("net/mlx5e: IPSec, Add Innova IPSec offload TX data path")
8362ea16f6 ("crypto: chcr - ESN for Inline IPSec Tx")
859a497fe8 ("nfp: implement xfrm callbacks and expose ipsec offload feature to upper layer")
32188be805 ("cn10k-ipsec: Allow ipsec crypto offload for skb with SA")
[ixgbe/ixgbevf commits are ignored, as that HW does not support tunnel
mode, thus no cross-family setups are possible]
Fixes: cc18f482e8 ("xfrm: provide common xdo_dev_offload_ok callback implementation")
Reported-by: Xiumei Mu <xmu@redhat.com>
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
* kvm-arm64/ffa-1.2:
: .
: FFA 1.2 support for pKVM, courtesy of Per Larsen.
:
: From the cover letter at [1]:
:
: "The FF-A 1.2 specification introduces a new SEND_DIRECT2 ABI which
: allows registers x4-x17 to be used for the message payload. This patch
: set prevents the host from using a lower FF-A version than what has
: already been negotiated with the hypervisor. This is necessary because
: the hypervisor does not have the necessary compatibility paths to
: translate from the hypervisor FF-A version to a previous version."
:
: [1] https://lore.kernel.org/r/20250820-virtio-msg-ffa-v11-0-497ef43550a3@google.com
: .
KVM: arm64: Bump the supported version of FF-A to 1.2
KVM: arm64: Mask response to FFA_FEATURE call
KVM: arm64: Mark optional FF-A 1.2 interfaces as unsupported
KVM: arm64: Mark FFA_NOTIFICATION_* calls as unsupported
KVM: arm64: Use SMCCC 1.2 for FF-A initialization and in host handler
KVM: arm64: Correct return value on host version downgrade attempt
Signed-off-by: Marc Zyngier <maz@kernel.org>
Commit 82ef440f9a ("powerpc/603: Copy kernel PGD entries into all
PGDIRs and preallocate execmem page tables") was supposed to extend
to powerpc 603 the copy of kernel PGD entries into all PGDIRs
implemented in a previous patch on the 8xx. But 603 is book3s/32 and
uses a duplicate of pgd_alloc() defined in another header.
So really do the copy at the correct place for the 603.
Fixes: 82ef440f9a ("powerpc/603: Copy kernel PGD entries into all PGDIRs and preallocate execmem page tables")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/752ab7514cae089a2dd7cc0f3d5e35849f76adb9.1755757797.git.christophe.leroy@csgroup.eu
Commit ac9f97ff8b ("powerpc/8xx: Inconditionally use task PGDIR in
DTLB misses") removed the test that needed the valeur in SPRN_EPN but
failed to remove the read.
Remove it.
And remove related comments, including the very same comment
in InstructionTLBMiss that should have been removed by
commit 33c527522f ("powerpc/8xx: Inconditionally use task PGDIR in
ITLB misses").
Also update the comment about absence of a second level table which
has been handled implicitely since commit 5ddb75cee5 ("powerpc/8xx:
remove tests on PGDIR entry validity").
Fixes: ac9f97ff8b ("powerpc/8xx: Inconditionally use task PGDIR in DTLB misses")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/5811c8d1d6187f280ad140d6c0ad6010e41eeaeb.1755361995.git.christophe.leroy@csgroup.eu
The hypervisor assigns one pipe per partition for all sources and
assigns new pipe after migration. Also the partition ID that is
used by source as its target ID may be changed after the migration.
So disable hvpipe during SUSPEND event with ‘hvpipe enable’ system
parameter value = 0 and enable it after migration during RESUME
event with hvpipe enable’ system parameter value = 1.
The user space calls such as ioctl()/ read() / write() / poll()
returns -ENXIO between SUSPEND and RESUME events. The user space
process can close FD and reestablish connection with new FD after
migration if needed (Example: source IDs are changed).
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Tested-by: Shashank MS <shashank.gowda@in.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250909084402.1488456-10-haren@linux.ibm.com
The partition uses “Hypervisor Pipe OS Enablement Notification”
system parameter token (value = 64) to enable / disable hvpipe in
the hypervisor. Once hvpipe is enabled, the hypervisor notifies
OS if the payload is pending for that partition from any source.
This system parameter token takes 1 byte length of data with
1 = Enable and 0 = Disable.
Enable hvpipe in the hypervisor with ibm,set-system-parameter
RTAS after registering hvpipe event source interrupt.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Tested-by: Shashank MS <shashank.gowda@in.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250909084402.1488456-9-haren@linux.ibm.com
The hypervisor signals the OS via a Hypervisor Pipe Event external
interrupt when data is available to be received from the pipe.
Then the OS should call RTAS check-exception and provide the input
Event Mask as defined for the ‘ibm,hvpipe-msg-events’. In response,
check-exception will return an event log containing an Pipe Events
message. This message contains the source ID for which this
message is intended to and the pipe status such as whether the
payload is pending in the hypervisor or pipe to source is closed.
If there is any user space process waiting in the wait_queue for
the payload from this source ID, wake up that process which can
issue read() to obtain payload with ibm,receive-hvpipe-msg RTAS
or close FD if the pipe to source is closed.
The hypervisor has one pipe per partition for all sources and it
will not deliver another hvpipe event message until the partition
reads the payload for the previous hvpipe event. So if the source
ID is not found in the source list, issue the dummy
ibm,receive-hvpipe-msg RTAS so that pipe will not blocked.
Register hvpipe event source interrupt based on entries from
/proc/device-tree//event-sources/ibm,hvpipe-msg-events property.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Tested-by: Shashank MS <shashank.gowda@in.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250909084402.1488456-8-haren@linux.ibm.com
The user space polls on the wait_queue for the payload from the
specific source. The hypervisor interrupts the OS when the pipe
status for the specific source is changed such as payload is
available for the partition or pipe to the source is closed. The
OS retrieves the HVPIPE event message with check-exception RTAS
and event message contains the source ID and the pipe status.
Then wakes up all FDs waiting on the wait_queue so that the user
space can read the payload or close the FD if the pipe to source
in the hypervisor is closed.
The hypervisor assigns one pipe per partition for all sources.
Hence issue ibm,receive-hvpipe-msg() to read the pending
payload during release() before closing FD so that pipe to the
partition will not be blocked.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Tested-by: Shashank MS <shashank.gowda@in.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250909084402.1488456-7-haren@linux.ibm.com
ibm,receive-hvpipe-msg RTAS call is used to receive data from the
source (Ex: Hardware Management Console) over the hypervisor
pipe. The hypervisor will signal the OS via a Hypervisor Pipe
Event external interrupt when data is available to be received
from the pipe and the event message has the source ID and the
message type such as payload or closed pipe to the specific
source. The hypervisor will not generate another interrupt for
the next payload until the partition reads the previous payload.
It means the hvpipe is blocked and will not deliver other events
for any source. The maximum data length of 4048 bytes is
supported with this RTAS call right now.
The user space uses read() to receive data from HMC which issues
ibm,receive-hvpipe-msg RTAS and the kernel returns the buffer
length (including papr_hvpipe_hdr length) to the user space for
success or RTAS failure error. If the message is regarding the
pipe closed, kernel just returns the papr_hvpipe_hdr with
flags = HVPIPE_LOST_CONNECTION and expects the user space to
close FD for the corresponding source.
ibm,receive-hvpipe-msg RTAS call passes the buffer and returns
the source ID from where this payload is received and the
payload length.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Tested-by: Shashank MS <shashank.gowda@in.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250909084402.1488456-6-haren@linux.ibm.com
ibm,send-hvpipe-msg RTAS call is used to send data to the source
(Ex: Hardware Management Console) over the hypervisor pipe. The
maximum data length of 4048 bytes is supported with this RTAS call
right now. The user space uses write() to send this payload which
invokes this RTAS. Then the write returns the buffer length
(including papr_hvpipe_hdr length) to the user space for success
or RTAS failure error.
ibm,send-hvpipe-msg call takes source ID as target and the buffer
in the form of buffer list. The buffer list format consists of
work area of size 4K to hold buffer list and number of 4K work
areas depends on buffers is as follows:
Length of Buffer List in bytes
Address of 4K buffer 1
Length of 4K buffer 1 used
...
Address of 4K buffer n
Length of 4K buffer n used
Only one buffer is used right now because of max payload size is
4048 bytes. writev() can be used in future when supported more
than one buffer.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Tested-by: Shashank MS <shashank.gowda@in.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250909084402.1488456-5-haren@linux.ibm.com
The hypervisor provides ibm,send-hvpipe-msg and
ibm,receive-hvpipe-msg RTAS calls which can be used by the
partition to communicate through an inband hypervisor channel with
different external sources such as Hardware Management Console
(HMC). The information exchanged, whether it be messages, raw or
formatted data, etc., is only known to between applications in the
OS and the source (HMC). This patch adds papr-hvpipe character
driver and provides the standard interfaces such as open / ioctl/
read / write to user space for exchanging information with HMC
using send/recevive HVPIPE RTAS functions.
PAPR (7.3.32 Hypervisor Pipe Information Exchange) defines the
HVPIPE usage:
- The hypervisor has one HVPIPE per partition for all sources.
- OS can determine this feature’s availability by detecting the
“ibm,hypervisor-pipe-capable” property in the /rtas node of the
device tree.
- Each source is represented by the source ID which is used in
send / recv HVPIPE RTAS. (Ex: source ID is the target for the
payload in send RTAS).
- Return status of ibm,send-hvpipe-msg can be considered as
delivered the payload.
- Return status of ibm,receive-hvpipe-msg can be considered as
ACK to source.
- The hypervisor generates hvpipe message event interrupt when
the partition has the payload to receive.
Provide the interfaces to the user space with /dev/papr-hvpipe
character device using the following programming model:
int devfd = open("/dev/papr-hvpipe")
int fd = ioctl(devfd, PAPR_HVPIPE_IOC_CREATE_HANDLE, &srcID);
- Restrict the user space to use the same source ID and do not
expect more than one process access with the same source.
char *buf = malloc(size);
- SIZE should be 4K and the buffer contains header and the
payload.
length = write(fd, buf, size);
- OS issues ibm,send-hvpipe-msg RTAS and returns the RTAS status
to the user space.
ret = poll(fd,...)
- The HVPIPE event message IRQ wakes up for any waiting FDs.
length = read(fd, buf, size);
- OS issues ibm,receive-hvpipe-msg to receive payload from the
hypervisor.
release(fd);
- OS issues ibm,receive-hvpipe-msg if any payload is pending so
that pipe is not blocked.
The actual implementation of these calls are added in the
next patches.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Tested-by: Shashank MS <shashank.gowda@in.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250909084402.1488456-4-haren@linux.ibm.com
PowerPC FW introduced HVPIPE RTAS calls such as
ibm,send-hvpipe-msg and ibm,receive-hvpipe-msg for the user space
to exchange information with different sources such as Hardware
Management Consoles (HMC).
HVPIPE_IOC_CREATE_HANDLE is defined to use /dev/papr-hvpipe
interface for ibm,send-hvpipe-msg and ibm,receive-hvpipe-msg
RTAS calls.
Also defined papr_hvpipe_hdr which will added in the payload
that is passed between the kernel and the user space.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Tested-by: Shashank MS <shashank.gowda@in.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250909084402.1488456-2-haren@linux.ibm.com
Fuad Tabba
Tony Luck
Shaopeng Tan
Gustavo A. R. Silva
Ivaylo Ivanov
Janne Grunau
Krzysztof Kozlowski
Uwe Kleine-König
Ghennadi Procopciuc
Daniel Lezcano
Colin Ian King
Jisheng Zhang
Xi Ruoyao
Sabrina Dubroca
Ben Horgan
Marc Zyngier
Thomas Zimmermann
Johannes Berg
Christophe Leroy
Shiraz Saleem
Haren Myneni