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path: root/drivers/soc/qcom/rpmh.c
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2024-05-27soc: qcom: rpmh-rsc: Ensure irqs aren't disabled by rpmh_rsc_send_data() callersStephen Boyd1-1/+0
Dan pointed out that Smatch is concerned about this code because it uses spin_lock_irqsave() and then calls wait_event_lock_irq() which enables irqs before going to sleep. The comment above the function says it should be called with interrupts enabled, but we simply hope that's true without really confirming that. Let's add a might_sleep() here to confirm that interrupts and preemption aren't disabled. Once we do that, we can change the lock to be non-saving, spin_lock_irq(), to clarify that we don't expect irqs to be disabled. If irqs are disabled by callers they're going to be enabled anyway in the wait_event_lock_irq() call which would be bad. This should make Smatch happier and find bad callers faster with the might_sleep(). We can drop the WARN_ON() in the caller because we have the might_sleep() now, simplifying the code. Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/r/911181ed-c430-4592-ad26-4dc948834e08@moroto.mountain Fixes: 2bc20f3c8487 ("soc: qcom: rpmh-rsc: Sleep waiting for tcs slots to be free") Cc: Douglas Anderson <dianders@chromium.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20240509184129.3924422-1-swboyd@chromium.org Signed-off-by: Bjorn Andersson <andersson@kernel.org>
2023-09-28soc: qcom: Switch to EXPORT_SYMBOL_GPL()Unnathi Chalicheemala1-4/+4
Switch to GPL version of EXPORT_SYMBOL for Qualcomm SoC drivers. Signed-off-by: Unnathi Chalicheemala <quic_uchalich@quicinc.com> Reviewed-by: Trilok Soni <quic_tsoni@quicinc.com> Link: https://lore.kernel.org/r/20230922184817.5183-1-quic_uchalich@quicinc.com Signed-off-by: Bjorn Andersson <andersson@kernel.org>
2022-12-06soc: qcom: rpmh-rsc: Avoid unnecessary checks on irq-done responseAbel Vesa1-8/+2
The RSC interrupt is issued only after the request is complete. For fire-n-forget requests, the irq-done interrupt is sent after issuing the RPMH request and for response-required request, the interrupt is triggered only after all the requests are complete. These unnecessary checks in the interrupt handler issues AHB reads from a critical path. Lets remove them and clean up error handling in rpmh_request data structures. Co-developed-by: Lina Iyer <ilina@codeaurora.org> Signed-off-by: Lina Iyer <ilina@codeaurora.org> Signed-off-by: Abel Vesa <abel.vesa@linaro.org> Signed-off-by: Bjorn Andersson <andersson@kernel.org> Link: https://lore.kernel.org/r/20221116112246.2640648-2-abel.vesa@linaro.org
2022-11-10soc: qcom: rpmh-rsc: Write CONTROL_TCS with next timer wakeupMaulik Shah1-1/+3
The next wakeup timer value needs to be set in always on domain timer as the arch timer interrupt can not wakeup the SoC if after the deepest CPUidle states the SoC also enters deepest low power state. To wakeup the SoC in such scenarios the earliest wakeup time is set in CONTROL_TCS and the firmware takes care of setting up its own timer in always on domain with next wakeup time. The timer wakes up the RSC and sets resources back to wake state. Signed-off-by: Maulik Shah <quic_mkshah@quicinc.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> # SM8450 Signed-off-by: Bjorn Andersson <andersson@kernel.org> Link: https://lore.kernel.org/r/20221018152837.619426-7-ulf.hansson@linaro.org
2020-11-26soc: qcom: rpmh: Use __fill_rpmh_msg API during rpmh_write()Maulik Shah1-9/+3
Use __fill_rpmh_msg API during rpmh_write(). This allows to remove duplication of code in error checking, copying commands and setting message state. Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Maulik Shah <mkshah@codeaurora.org> Link: https://lore.kernel.org/r/1606379490-4052-1-git-send-email-mkshah@codeaurora.org Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2020-11-11soc: qcom: rpmh: Fix possible doc-rot in rpmh_write()'s headerLee Jones1-1/+1
Fixes the following W=1 kernel build warning(s): drivers/soc/qcom/rpmh.c:266: warning: Function parameter or member 'dev' not described in 'rpmh_write' drivers/soc/qcom/rpmh.c:266: warning: Excess function parameter 'rc' description in 'rpmh_write' Cc: Andy Gross <agross@kernel.org> Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Cc: linux-arm-msm@vger.kernel.org Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Lee Jones <lee.jones@linaro.org> Link: https://lore.kernel.org/r/20201103152838.1290217-16-lee.jones@linaro.org Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2020-06-23soc: qcom: rpmh: Update rpmh_invalidate function to return voidMaulik Shah1-3/+1
Currently rpmh_invalidate() always returns success. Update its return type to void. Reviewed-by: Lina Iyer <ilina@codeaurora.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Suggested-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Maulik Shah <mkshah@codeaurora.org> Link: https://lore.kernel.org/r/1592485553-29163-1-git-send-email-mkshah@codeaurora.org Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2020-05-15soc: qcom: rpmh-rsc: Remove the pm_lockDouglas Anderson1-9/+16
It has been postulated that the pm_lock is bad for performance because a CPU currently running rpmh_flush() could block other CPUs from coming out of idle. Similarly CPUs coming out of / going into idle all need to contend with each other for the spinlock just to update the variable tracking who's in PM. Let's optimize this a bit. Specifically: - Use a count rather than a bitmask. This is faster to access and also means we can use the atomic_inc_return() function to really detect who the last one to enter PM was. - Accept that it's OK if we race and are doing the flush (because we think we're last) while another CPU is coming out of idle. As long as we block that CPU if/when it tries to do an active-only transfer we're OK. Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/20200504104917.v6.5.I295cb72bc5334a2af80313cbe97cb5c9dcb1442c@changeid Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2020-04-21soc: qcom: rpmh: Dirt can only make you dirtier, not cleanerDouglas Anderson1-4/+4
Adding an item into the cache should never be able to make the cache cleaner. Use "|=" rather than "=" to update the dirty flag. Reviewed-by: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Maulik Shah <mkshah@codeaurora.org> Thanks, Maulik Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Fixes: bb7000677a1b ("soc: qcom: rpmh: Update dirty flag only when data changes") Reported-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20200417141531.1.Ia4b74158497213eabad7c3d474c50bfccb3f342e@changeid Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2020-04-14soc: qcom: rpmh-rsc: Caller handles tcs_invalidate() exclusivityDouglas Anderson1-4/+1
Auditing tcs_invalidate() made me worried. Specifically I saw that it used spin_lock(), not spin_lock_irqsave(). That always worries me unless I can trace for sure that I'm in the interrupt handler or that someone else already disabled interrupts. Looking more at it, there is actually no reason for these locks anyway. Specifically the only reason you'd ever call rpmh_rsc_invalidate() is if you cared that the sleep/wake TCSes were empty. That means that they need to continue to be empty even after rpmh_rsc_invalidate() returns. The only way that can happen is if the caller already has done something to keep all other RPMH users out. It should be noted that even though the caller is only worried about making sleep/wake TCSes empty, they also need to worry about stopping active-only transfers if they need to handle the case where active-only transfers might borrow the wake TCS. At the moment rpmh_rsc_invalidate() is only called in PM code from the last CPU. If that later changes the caller will still need to solve the above problems themselves, so these locks will never be useful. Continuing to audit tcs_invalidate(), I found a bug. The function didn't properly check for a borrowed TCS if we hadn't recently written anything into the TCS. Specifically, if we've never written to the WAKE_TCS (or we've flushed it recently) then tcs->slots is empty. We'll early-out and we'll never call tcs_is_free(). I thought about fixing this bug by either deleting the early check for bitmap_empty() or possibly only doing it if we knew we weren't on a TCS that could be borrowed. However, I think it's better to just delete the checks. As argued above it's up to the caller to make sure that all other users of RPMH are quiet before tcs_invalidate() is called. Since callers need to handle the zero-active-TCS case anyway that means they need to make sure that the active-only transfers are quiet before calling too. The one way tcs_invalidate() gets called today is through rpmh_rsc_cpu_pm_callback() which calls rpmh_rsc_ctrlr_is_busy() to handle this. When we have another path to get to tcs_invalidate() it will also need to come up with something similar and it won't need this extra check either. If we later find some code path that actually needs this check back in (and somehow manages to be race free) we can always add it back in. Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Maulik Shah <mkshah@codeaurora.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Tested-by: Maulik Shah <mkshah@codeaurora.org> Link: https://lore.kernel.org/r/20200413100321.v4.9.I07c1f70e0e8f2dc0004bd38970b4e258acdc773e@changeid Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2020-04-14soc: qcom: rpmh: Invoke rpmh_flush() for dirty cachesMaulik Shah1-17/+12
Add changes to invoke rpmh flush() from CPU PM notification. This is done when the last the cpu is entering deep CPU idle states and controller is not busy. Controllers that have 'HW solver' mode like display RSC do not need to register for CPU PM notification. They may be in autonomous mode executing low power mode and do not require rpmh_flush() to happen from CPU PM notification. Signed-off-by: Maulik Shah <mkshah@codeaurora.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/1586703004-13674-5-git-send-email-mkshah@codeaurora.org Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2020-04-14soc: qcom: rpmh: Invalidate SLEEP and WAKE TCSes before flushing new dataMaulik Shah1-23/+18
TCSes have previously programmed data when rpmh_flush() is called. This can cause old data to trigger along with newly flushed. Fix this by cleaning SLEEP and WAKE TCSes before new data is flushed. With this there is no need to invoke rpmh_rsc_invalidate() call from rpmh_invalidate(). Simplify rpmh_invalidate() by moving invalidate_batch() inside. Fixes: 600513dfeef3 ("drivers: qcom: rpmh: cache sleep/wake state requests") Signed-off-by: Maulik Shah <mkshah@codeaurora.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/1586703004-13674-4-git-send-email-mkshah@codeaurora.org Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2020-04-14soc: qcom: rpmh: Update dirty flag only when data changesMaulik Shah1-8/+11
Currently rpmh ctrlr dirty flag is set for all cases regardless of data is really changed or not. Add changes to update dirty flag when data is changed to newer values. Update dirty flag everytime when data in batch cache is updated since rpmh_flush() may get invoked from any CPU instead of only last CPU going to low power mode. Also move dirty flag updates to happen from within cache_lock and remove unnecessary INIT_LIST_HEAD() call and a default case from switch. Fixes: 600513dfeef3 ("drivers: qcom: rpmh: cache sleep/wake state requests") Signed-off-by: Maulik Shah <mkshah@codeaurora.org> Reviewed-by: Srinivas Rao L <lsrao@codeaurora.org> Reviewed-by: Evan Green <evgreen@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/1586703004-13674-3-git-send-email-mkshah@codeaurora.org Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2020-02-12drivers: qcom: rpmh: remove rpmh_flush exportMaulik Shah1-10/+8
rpmh_flush() was exported with the idea that an external entity operation during CPU idle would know when to flush the sleep and wake TCS. Since, this is not the case when defining a power domain for the RSC. Remove the function export and instead allow the function to be called internally. Signed-off-by: Maulik Shah <mkshah@codeaurora.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/1580736940-6985-3-git-send-email-mkshah@codeaurora.org Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2020-02-12drivers: qcom: rpmh: fix macro to accept NULL argumentMaulik Shah1-2/+2
Device argument matches with dev variable declared in RPMH message. Compiler reports error when the argument is NULL since the argument matches the name of the property. Rename dev argument to device to fix this. Signed-off-by: Maulik Shah <mkshah@codeaurora.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/1580736940-6985-2-git-send-email-mkshah@codeaurora.org Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2019-02-02soc: qcom: rpmh: Avoid accessing freed memory from batch APIStephen Boyd1-13/+21
Using the batch API from the interconnect driver sometimes leads to a KASAN error due to an access to freed memory. This is easier to trigger with threadirqs on the kernel commandline. BUG: KASAN: use-after-free in rpmh_tx_done+0x114/0x12c Read of size 1 at addr fffffff51414ad84 by task irq/110-apps_rs/57 CPU: 0 PID: 57 Comm: irq/110-apps_rs Tainted: G W 4.19.10 #72 Call trace: dump_backtrace+0x0/0x2f8 show_stack+0x20/0x2c __dump_stack+0x20/0x28 dump_stack+0xcc/0x10c print_address_description+0x74/0x240 kasan_report+0x250/0x26c __asan_report_load1_noabort+0x20/0x2c rpmh_tx_done+0x114/0x12c tcs_tx_done+0x450/0x768 irq_forced_thread_fn+0x58/0x9c irq_thread+0x120/0x1dc kthread+0x248/0x260 ret_from_fork+0x10/0x18 Allocated by task 385: kasan_kmalloc+0xac/0x148 __kmalloc+0x170/0x1e4 rpmh_write_batch+0x174/0x540 qcom_icc_set+0x8dc/0x9ac icc_set+0x288/0x2e8 a6xx_gmu_stop+0x320/0x3c0 a6xx_pm_suspend+0x108/0x124 adreno_suspend+0x50/0x60 pm_generic_runtime_suspend+0x60/0x78 __rpm_callback+0x214/0x32c rpm_callback+0x54/0x184 rpm_suspend+0x3f8/0xa90 pm_runtime_work+0xb4/0x178 process_one_work+0x544/0xbc0 worker_thread+0x514/0x7d0 kthread+0x248/0x260 ret_from_fork+0x10/0x18 Freed by task 385: __kasan_slab_free+0x12c/0x1e0 kasan_slab_free+0x10/0x1c kfree+0x134/0x588 rpmh_write_batch+0x49c/0x540 qcom_icc_set+0x8dc/0x9ac icc_set+0x288/0x2e8 a6xx_gmu_stop+0x320/0x3c0 a6xx_pm_suspend+0x108/0x124 adreno_suspend+0x50/0x60 cr50_spi spi5.0: SPI transfer timed out pm_generic_runtime_suspend+0x60/0x78 __rpm_callback+0x214/0x32c rpm_callback+0x54/0x184 rpm_suspend+0x3f8/0xa90 pm_runtime_work+0xb4/0x178 process_one_work+0x544/0xbc0 worker_thread+0x514/0x7d0 kthread+0x248/0x260 ret_from_fork+0x10/0x18 The buggy address belongs to the object at fffffff51414ac80 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 260 bytes inside of 512-byte region [fffffff51414ac80, fffffff51414ae80) The buggy address belongs to the page: page:ffffffbfd4505200 count:1 mapcount:0 mapping:fffffff51e00c680 index:0x0 compound_mapcount: 0 flags: 0x4000000000008100(slab|head) raw: 4000000000008100 ffffffbfd4529008 ffffffbfd44f9208 fffffff51e00c680 raw: 0000000000000000 0000000000200020 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: fffffff51414ac80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fffffff51414ad00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >fffffff51414ad80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ fffffff51414ae00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fffffff51414ae80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc The batch API sets the same completion for each rpmh message that's sent and then loops through all the messages and waits for that single completion declared on the stack to be completed before returning from the function and freeing the message structures. Unfortunately, some messages may still be in process and 'stuck' in the TCS. At some later point, the tcs_tx_done() interrupt will run and try to process messages that have already been freed at the end of rpmh_write_batch(). This will in turn access the 'needs_free' member of the rpmh_request structure and cause KASAN to complain. Furthermore, if there's a message that's completed in rpmh_tx_done() and freed immediately after the complete() call is made we'll be racing with potentially freed memory when accessing the 'needs_free' member: CPU0 CPU1 ---- ---- rpmh_tx_done() complete(&compl) wait_for_completion(&compl) kfree(rpm_msg) if (rpm_msg->needs_free) <KASAN warning splat> Let's fix this by allocating a chunk of completions for each message and waiting for all of them to be completed before returning from the batch API. Alternatively, we could wait for the last message in the batch, but that may be a more complicated change because it looks like tcs_tx_done() just iterates through the indices of the queue and completes each message instead of tracking the last inserted message and completing that first. Fixes: c8790cb6da58 ("drivers: qcom: rpmh: add support for batch RPMH request") Cc: Lina Iyer <ilina@codeaurora.org> Cc: "Raju P.L.S.S.S.N" <rplsssn@codeaurora.org> Cc: Matthias Kaehlcke <mka@chromium.org> Cc: Evan Green <evgreen@chromium.org> Cc: stable@vger.kernel.org Reviewed-by: Lina Iyer <ilina@codeaurora.org> Reviewed-by: Evan Green <evgreen@chromium.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Andy Gross <andy.gross@linaro.org>
2019-02-02drivers: qcom: rpmh: avoid sending sleep/wake sets immediatelyRaju P.L.S.S.S.N1-2/+1
Fix the redundant call being made to send the sleep and wake requests immediately to the controller. As per the patch [1], the sleep and wake request votes are cached in rpmh controller and sent during rpmh_flush(). These requests needs to be sent only during entry of deeper system low power modes or suspend. [1] https://patchwork.kernel.org/patch/10477533/ Reviewed-by: Lina Iyer <ilina@codeaurora.org> Reviewed-by: Evan Green <evgreen@chromium.org> Signed-off-by: Raju P.L.S.S.S.N <rplsssn@codeaurora.org> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Andy Gross <andy.gross@linaro.org>
2018-07-21drivers: qcom: rpmh: add support for batch RPMH requestLina Iyer1-2/+157
Platform drivers need make a lot of resource state requests at the same time, say, at the start or end of an usecase. It can be quite inefficient to send each request separately. Instead they can give the RPMH library a batch of requests to be sent and wait on the whole transaction to be complete. rpmh_write_batch() is a blocking call that can be used to send multiple RPMH command sets. Each RPMH command set is set asynchronously and the API blocks until all the command sets are complete and receive their tx_done callbacks. Signed-off-by: Lina Iyer <ilina@codeaurora.org> Signed-off-by: Raju P.L.S.S.S.N <rplsssn@codeaurora.org> Reviewed-by: Matthias Kaehlcke <mka@chromium.org> Signed-off-by: Andy Gross <andy.gross@linaro.org>
2018-07-21drivers: qcom: rpmh: allow requests to be sent asynchronouslyLina Iyer1-0/+51
Platform drivers that want to send a request but do not want to block until the RPMH request completes have now a new API - rpmh_write_async(). The API allocates memory and send the requests and returns the control back to the platform driver. The tx_done callback from the controller is handled in the context of the controller's thread and frees the allocated memory. This API allows RPMH requests from atomic contexts as well. Signed-off-by: Lina Iyer <ilina@codeaurora.org> Signed-off-by: Raju P.L.S.S.S.N <rplsssn@codeaurora.org> Signed-off-by: Andy Gross <andy.gross@linaro.org>
2018-07-21drivers: qcom: rpmh: cache sleep/wake state requestsLina Iyer1-5/+196
Active state requests are sent immediately to the RSC controller, while sleep and wake state requests are cached in this driver to avoid taxing the RSC controller repeatedly. The cached values will be sent to the controller when the rpmh_flush() is called. Generally, flushing is a system PM activity and may be called from the system PM drivers when the system is entering suspend or deeper sleep modes during cpuidle. Also allow invalidating the cached requests, so they may be re-populated again. Signed-off-by: Lina Iyer <ilina@codeaurora.org> [rplsssn: remove unneeded semicolon, address line over 80chars error] Signed-off-by: Raju P.L.S.S.S.N <rplsssn@codeaurora.org> Reviewed-by: Evan Green <evgreen@chromium.org> Reviewed-by: Matthias Kaehlcke <mka@chromium.org> Signed-off-by: Andy Gross <andy.gross@linaro.org>
2018-07-21drivers: qcom: rpmh: add RPMH helper functionsLina Iyer1-0/+116
Sending RPMH requests and waiting for response from the controller through a callback is common functionality across all platform drivers. To simplify drivers, add a library functions to create RPMH client and send resource state requests. rpmh_write() is a synchronous blocking call that can be used to send active state requests. Signed-off-by: Lina Iyer <ilina@codeaurora.org> Signed-off-by: Raju P.L.S.S.S.N <rplsssn@codeaurora.org> Signed-off-by: Andy Gross <andy.gross@linaro.org>