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2019-10-18ACPI: CPPC: Set pcc_data[pcc_ss_id] to NULL in acpi_cppc_processor_exit()John Garry1-1/+1
When enabling KASAN and DEBUG_TEST_DRIVER_REMOVE, I find this KASAN warning: [ 20.872057] BUG: KASAN: use-after-free in pcc_data_alloc+0x40/0xb8 [ 20.878226] Read of size 4 at addr ffff00236cdeb684 by task swapper/0/1 [ 20.884826] [ 20.886309] CPU: 19 PID: 1 Comm: swapper/0 Not tainted 5.4.0-rc1-00009-ge7f7df3db5bf-dirty #289 [ 20.894994] Hardware name: Huawei D06 /D06, BIOS Hisilicon D06 UEFI RC0 - V1.16.01 03/15/2019 [ 20.903505] Call trace: [ 20.905942] dump_backtrace+0x0/0x200 [ 20.909593] show_stack+0x14/0x20 [ 20.912899] dump_stack+0xd4/0x130 [ 20.916291] print_address_description.isra.9+0x6c/0x3b8 [ 20.921592] __kasan_report+0x12c/0x23c [ 20.925417] kasan_report+0xc/0x18 [ 20.928808] __asan_load4+0x94/0xb8 [ 20.932286] pcc_data_alloc+0x40/0xb8 [ 20.935938] acpi_cppc_processor_probe+0x4e8/0xb08 [ 20.940717] __acpi_processor_start+0x48/0xb0 [ 20.945062] acpi_processor_start+0x40/0x60 [ 20.949235] really_probe+0x118/0x548 [ 20.952887] driver_probe_device+0x7c/0x148 [ 20.957059] device_driver_attach+0x94/0xa0 [ 20.961231] __driver_attach+0xa4/0x110 [ 20.965055] bus_for_each_dev+0xe8/0x158 [ 20.968966] driver_attach+0x30/0x40 [ 20.972531] bus_add_driver+0x234/0x2f0 [ 20.976356] driver_register+0xbc/0x1d0 [ 20.980182] acpi_processor_driver_init+0x40/0xe4 [ 20.984875] do_one_initcall+0xb4/0x254 [ 20.988700] kernel_init_freeable+0x24c/0x2f8 [ 20.993047] kernel_init+0x10/0x118 [ 20.996524] ret_from_fork+0x10/0x18 [ 21.000087] [ 21.001567] Allocated by task 1: [ 21.004785] save_stack+0x28/0xc8 [ 21.008089] __kasan_kmalloc.isra.9+0xbc/0xd8 [ 21.012435] kasan_kmalloc+0xc/0x18 [ 21.015913] pcc_data_alloc+0x94/0xb8 [ 21.019564] acpi_cppc_processor_probe+0x4e8/0xb08 [ 21.024343] __acpi_processor_start+0x48/0xb0 [ 21.028689] acpi_processor_start+0x40/0x60 [ 21.032860] really_probe+0x118/0x548 [ 21.036512] driver_probe_device+0x7c/0x148 [ 21.040684] device_driver_attach+0x94/0xa0 [ 21.044855] __driver_attach+0xa4/0x110 [ 21.048680] bus_for_each_dev+0xe8/0x158 [ 21.052591] driver_attach+0x30/0x40 [ 21.056155] bus_add_driver+0x234/0x2f0 [ 21.059980] driver_register+0xbc/0x1d0 [ 21.063805] acpi_processor_driver_init+0x40/0xe4 [ 21.068497] do_one_initcall+0xb4/0x254 [ 21.072322] kernel_init_freeable+0x24c/0x2f8 [ 21.076667] kernel_init+0x10/0x118 [ 21.080144] ret_from_fork+0x10/0x18 [ 21.083707] [ 21.085186] Freed by task 1: [ 21.088056] save_stack+0x28/0xc8 [ 21.091360] __kasan_slab_free+0x118/0x180 [ 21.095445] kasan_slab_free+0x10/0x18 [ 21.099183] kfree+0x80/0x268 [ 21.102139] acpi_cppc_processor_exit+0x1a8/0x1b8 [ 21.106832] acpi_processor_stop+0x70/0x80 [ 21.110917] really_probe+0x174/0x548 [ 21.114568] driver_probe_device+0x7c/0x148 [ 21.118740] device_driver_attach+0x94/0xa0 [ 21.122912] __driver_attach+0xa4/0x110 [ 21.126736] bus_for_each_dev+0xe8/0x158 [ 21.130648] driver_attach+0x30/0x40 [ 21.134212] bus_add_driver+0x234/0x2f0 [ 21.0x10/0x18 [ 21.161764] [ 21.163244] The buggy address belongs to the object at ffff00236cdeb600 [ 21.163244] which belongs to the cache kmalloc-256 of size 256 [ 21.175750] The buggy address is located 132 bytes inside of [ 21.175750] 256-byte region [ffff00236cdeb600, ffff00236cdeb700) [ 21.187473] The buggy address belongs to the page: [ 21.192254] page:fffffe008d937a00 refcount:1 mapcount:0 mapping:ffff002370c0fa00 index:0x0 compound_mapcount: 0 [ 21.202331] flags: 0x1ffff00000010200(slab|head) [ 21.206940] raw: 1ffff00000010200 dead000000000100 dead000000000122 ffff002370c0fa00 [ 21.214671] raw: 0000000000000000 00000000802a002a 00000001ffffffff 0000000000000000 [ 21.222400] page dumped because: kasan: bad access detected [ 21.227959] [ 21.229438] Memory state around the buggy address: [ 21.234218] ffff00236cdeb580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 21.241427] ffff00236cdeb600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 21.248637] >ffff00236cdeb680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 21.255845] ^ [ 21.259062] ffff00236cdeb700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 21.266272] ffff00236cdeb780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 21.273480] ================================================================== It seems that global pcc_data[pcc_ss_id] can be freed in acpi_cppc_processor_exit(), but we may later reference this value, so NULLify it when freed. Also remove the useless setting of data "pcc_channel_acquired", which we're about to free. Fixes: 85b1407bf6d2 ("ACPI / CPPC: Make CPPC ACPI driver aware of PCC subspace IDs") Signed-off-by: John Garry <john.garry@huawei.com> Cc: 4.15+ <stable@vger.kernel.org> # 4.15+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-08-28ACPI / CPPC: do not require the _PSD methodAl Stone1-2/+4
According to the ACPI 6.3 specification, the _PSD method is optional when using CPPC. The underlying assumption is that each CPU can change frequency independently from all other CPUs; _PSD is provided to tell the OS that some processors can NOT do that. However, the acpi_get_psd() function returns ENODEV if there is no _PSD method present, or an ACPI error status if an error occurs when evaluating _PSD, if present. This makes _PSD mandatory when using CPPC, in violation of the specification, and only on Linux. This has forced some firmware writers to provide a dummy _PSD, even though it is irrelevant, but only because Linux requires it; other OSPMs follow the spec. We really do not want to have OS specific ACPI tables, though. So, correct acpi_get_psd() so that it does not return an error if there is no _PSD method present, but does return a failure when the method can not be executed properly. This allows _PSD to be optional as it should be. Signed-off-by: Al Stone <ahs3@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441Thomas Gleixner1-5/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation version 2 of the license extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 315 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Armijn Hemel <armijn@tjaldur.nl> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-06Merge branches 'acpi-scan', 'acpi-tables', 'acpi-misc' and 'acpi-pm'Rafael J. Wysocki1-17/+17
* acpi-scan: ACPI / scan: Add labels for PNP button devices ACPI / scan: Simplify acpi_bus_extract_wakeup_device_power_package() * acpi-tables: ACPI / tables: Clean up whitespace * acpi-misc: ACPI / DPTF: Use dev_get_drvdata() ACPI: event: replace strcpy() by strscpy() ACPI: Fix comment typos * acpi-pm: ACPI: PM: Print debug messages when enabling GPEs for wakeup
2019-03-27ACPI: Fix comment typosBjorn Helgaas1-17/+17
Fix some misspellings in comments. No functional change intended. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-03-26ACPI / CPPC: Fix guaranteed performance handlingSrinivas Pandruvada1-2/+7
As per the ACPI specification, "Guaranteed Performance Register" is a "Buffer" field and it cannot be "Integer", so treat the "Integer" type for "Guaranteed Performance Register" field as invalid and ignore its value in that case. Also save one cpc_read() call when "Guaranteed Performance Register" is not present, which means a register defined as: "Register(SystemMemory, 0, 0, 0, 0)". Fixes: 29523f095397 ("ACPI / CPPC: Add support for guaranteed performance") Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: 4.20+ <stable@vger.kernel.org> # 4.20+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-02-18ACPI / CPPC: Add a helper to get desired performanceXiongfeng Wang1-0/+42
This patch add a helper to get the value of desired performance register. Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> [ rjw: More white space ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-10-16ACPI / CPPC: Add support for guaranteed performanceSrinivas Pandruvada1-2/+6
The Continuous Performance Control package may contain an optional guaranteed performance field. Add support to read guaranteed performance from _CPC. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-05-10ACPI / CPPC: Fix invalid PCC channel status errorsPrakash, Prashanth1-29/+19
Replace the faulty PCC status register polling code with a iopoll.h macro to fix incorrect reporting of PCC check errors ("PCC check channel failed"). There were potential codepaths where we could incorrectly return PCC channel status as busy even without checking the PCC status register once or not checking the status register before breaking out of the polling loop. For example, if the thread polling PCC status register was preempted and scheduled back after we have crossed the deadline then we can report that the channel is busy even without checking the status register. Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-04-24ACPI / CPPC: Check for valid PCC subspace only if PCC is usedPrashanth Prakash1-9/+21
Changes the behavior where we return error if there are no valid PCC subspace for a given performance domain. The ACPI spec does not mandate the use PCC, so it is possible to have platforms where a PCC subspace may not be present, so we need to check for a valid PCC subspace ID only if the register is a PCC register. Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-04-24ACPI / CPPC: Add support for CPPC v3Prashanth Prakash1-16/+65
CPPC V3 introduces two new entries to make it easier to convert between abstract processor performance and frequency. The two new entries are lowest frequency and nominal frequency. These are the frequencies corresponding to lowest and nominal abstract performance. Add support to read the new entries and populate them as part of the CPPC performance capabilities which can be used by cpufreq drivers Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-02-23ACPI / CPPC: Update all pr_(debug/err) messages to log the susbspace idGeorge Cherian1-11/+16
CPPC dirver is aware of multiple PCC subspace IDs. Enhance the debug and error messages in the driver to print the subspace id. In case of error it will be helpful to find which particular subspace is failing. Signed-off-by: George Cherian <george.cherian@cavium.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-02-07ACPI / CPPC: Use 64-bit arithmetic instead of 32-bitGustavo A. R. Silva1-1/+1
Add suffix ULL to constant 500 in order to give the compiler complete information about the proper arithmetic to use. Notice that this constant is used in a context that expects an expression of type u64 (64 bits, unsigned). The expression NUM_RETRIES * cppc_ss->latency at line 578, which at preprocessing time translates to 500 * cppc_ss->latency is currently being evaluated using 32-bit arithmetic. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-12-18ACPI: CPPC: remove initial assignment of pcc_ss_dataColin Ian King1-1/+1
The initialization of pcc_ss_data from pcc_data[pcc_ss_id] before pcc_ss_id is being range checked could lead to an out-of-bounds array read. This very same initialization is also being performed after the range check on pcc_ss_id, so we can just remove this problematic and also redundant assignment to fix the issue. Detected by cppcheck: warning: Value stored to 'pcc_ss_data' during its initialization is never read Fixes: 85b1407bf6d2 (ACPI / CPPC: Make CPPC ACPI driver aware of PCC subspace IDs) Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-12-06ACPI / CPPC: Fix KASAN global out of bounds warningGeorge Cherian1-8/+15
Default value of pcc_subspace_idx is -1. Make sure to check pcc_subspace_idx before using the same as array index. This will avoid following KASAN warnings too. [ 15.113449] ================================================================== [ 15.116983] BUG: KASAN: global-out-of-bounds in cppc_get_perf_caps+0xf3/0x3b0 [ 15.116983] Read of size 8 at addr ffffffffb9a5c0d8 by task swapper/0/1 [ 15.116983] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.15.0-rc2+ #2 [ 15.116983] Hardware name: Dell Inc. OptiPlex 7040/0Y7WYT, BIOS 1.2.8 01/26/2016 [ 15.116983] Call Trace: [ 15.116983] dump_stack+0x7c/0xbb [ 15.116983] print_address_description+0x1df/0x290 [ 15.116983] kasan_report+0x28a/0x370 [ 15.116983] ? cppc_get_perf_caps+0xf3/0x3b0 [ 15.116983] cppc_get_perf_caps+0xf3/0x3b0 [ 15.116983] ? cpc_read+0x210/0x210 [ 15.116983] ? __rdmsr_on_cpu+0x90/0x90 [ 15.116983] ? rdmsrl_on_cpu+0xa9/0xe0 [ 15.116983] ? rdmsr_on_cpu+0x100/0x100 [ 15.116983] ? wrmsrl_on_cpu+0x9c/0xd0 [ 15.116983] ? wrmsrl_on_cpu+0x9c/0xd0 [ 15.116983] ? wrmsr_on_cpu+0xe0/0xe0 [ 15.116983] __intel_pstate_cpu_init.part.16+0x3a2/0x530 [ 15.116983] ? intel_pstate_init_cpu+0x197/0x390 [ 15.116983] ? show_no_turbo+0xe0/0xe0 [ 15.116983] ? __lockdep_init_map+0xa0/0x290 [ 15.116983] intel_pstate_cpu_init+0x30/0x60 [ 15.116983] cpufreq_online+0x155/0xac0 [ 15.116983] cpufreq_add_dev+0x9b/0xb0 [ 15.116983] subsys_interface_register+0x1ae/0x290 [ 15.116983] ? bus_unregister_notifier+0x40/0x40 [ 15.116983] ? mark_held_locks+0x83/0xb0 [ 15.116983] ? _raw_write_unlock_irqrestore+0x32/0x60 [ 15.116983] ? intel_pstate_setup+0xc/0x104 [ 15.116983] ? intel_pstate_setup+0xc/0x104 [ 15.116983] ? cpufreq_register_driver+0x1ce/0x2b0 [ 15.116983] cpufreq_register_driver+0x1ce/0x2b0 [ 15.116983] ? intel_pstate_setup+0x104/0x104 [ 15.116983] intel_pstate_register_driver+0x3a/0xa0 [ 15.116983] intel_pstate_init+0x3c4/0x434 [ 15.116983] ? intel_pstate_setup+0x104/0x104 [ 15.116983] ? intel_pstate_setup+0x104/0x104 [ 15.116983] do_one_initcall+0x9c/0x206 [ 15.116983] ? parameq+0xa0/0xa0 [ 15.116983] ? initcall_blacklisted+0x150/0x150 [ 15.116983] ? lock_downgrade+0x2c0/0x2c0 [ 15.116983] kernel_init_freeable+0x327/0x3f0 [ 15.116983] ? start_kernel+0x612/0x612 [ 15.116983] ? _raw_spin_unlock_irq+0x29/0x40 [ 15.116983] ? finish_task_switch+0xdd/0x320 [ 15.116983] ? finish_task_switch+0x8e/0x320 [ 15.116983] ? rest_init+0xd0/0xd0 [ 15.116983] kernel_init+0xf/0x11a [ 15.116983] ? rest_init+0xd0/0xd0 [ 15.116983] ret_from_fork+0x24/0x30 [ 15.116983] The buggy address belongs to the variable: [ 15.116983] __key.36299+0x38/0x40 [ 15.116983] Memory state around the buggy address: [ 15.116983] ffffffffb9a5bf80: fa fa fa fa 00 fa fa fa fa fa fa fa 00 fa fa fa [ 15.116983] ffffffffb9a5c000: fa fa fa fa 00 fa fa fa fa fa fa fa 00 fa fa fa [ 15.116983] >ffffffffb9a5c080: fa fa fa fa 00 fa fa fa fa fa fa fa 00 00 00 00 [ 15.116983] ^ [ 15.116983] ffffffffb9a5c100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 15.116983] ffffffffb9a5c180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 15.116983] ================================================================== Fixes: 85b1407bf6d2 (ACPI / CPPC: Make CPPC ACPI driver aware of PCC subspace IDs) Reported-by: Changbin Du <changbin.du@intel.com> Signed-off-by: George Cherian <george.cherian@cavium.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-11-09ACPI / CPPC: Make CPPC ACPI driver aware of PCC subspace IDsGeorge Cherian1-89/+151
Based on ACPI 6.2 Section 8.4.7.1.9 If the PCC register space is used, all PCC registers, for all processors in the same performance domain (as defined by _PSD), must be defined to be in the same subspace. Based on Section 14.1 of ACPI specification, it is possible to have a maximum of 256 PCC subspace IDs. Add support of multiple PCC subspace ID instead of using a single global pcc_data structure. While at that, fix the time_delta check in send_pcc_cmd() so that last_mpar_reset and mpar_count are initialized properly. Signed-off-by: George Cherian <george.cherian@cavium.com> Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-05-09scripts/spelling.txt: add regsiter -> register spelling mistakeStephen Boyd1-1/+1
This typo is quite common. Fix it and add it to the spelling file so that checkpatch catches it earlier. Link: http://lkml.kernel.org/r/20170317011131.6881-2-sboyd@codeaurora.org Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-04-19ACPI / CPPC: add sysfs entries for CPPC perf capabilitiesPrakash, Prashanth1-28/+33
Computed delivered performance using CPPC feedback counters are in the CPPC abstract scale, whereas cppc_cpufreq driver operates in KHz scale. Exposing the CPPC performance capabilities (highest,lowest, nominal, lowest non-linear) will allow userspace to figure out the conversion factor from CPPC abstract scale to KHz. Also rename ctr_wrap_time to wraparound_time so that show_cppc_data() macro will work with it. Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-04-19ACPI / CPPC: Read lowest nonlinear perf in cppc_get_perf_caps()Prakash, Prashanth1-8/+11
Read lowest non linear perf in cppc_get_perf_caps so that it can be exposed via sysfs to the usespace. Lowest non linear perf is the lowest performance level at which nonlinear power savings are achieved. Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-12-13ACPI / CPPC: Fix per-CPU pointer management in acpi_cppc_processor_probe()Rafael J. Wysocki1-4/+6
Fix a possible use-after-free scenario in acpi_cppc_processor_probe() that can happen if the function returns without cleaning up the per-CPU pointer set by it previously. Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-12-13ACPI / CPPC: Fix crash in acpi_cppc_processor_exit()Sebastian Andrzej Siewior1-0/+2
First I had crashed what I bisected down to de966cf4a4fa (sched/x86: Change CONFIG_SCHED_ITMT to CONFIG_SCHED_MC_PRIO) because it made SCHED_ITMT the default. Then I run another bisect round and got here with the same backtrace: |BUG: unable to handle kernel NULL pointer dereference at (null) |IP: [<ffffffff812aab6e>] acpi_cppc_processor_exit+0x40/0x60 |PGD 0 [ 0.577616] |Oops: 0000 [#1] SMP |Modules linked in: |CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.9.0-rc6-00146-g17669006adf6 #51 |task: ffff88003f878000 task.stack: ffffc90000008000 |RIP: 0010:[<ffffffff812aab6e>] [<ffffffff812aab6e>] acpi_cppc_processor_exit+0x40/0x60 |RSP: 0000:ffffc9000000bd48 EFLAGS: 00010296 |RAX: 00000000000137e0 RBX: 0000000000000000 RCX: 0000000000000001 |RDX: ffff88003fc00000 RSI: 0000000000000000 RDI: ffff88003fbca130 |RBP: ffffc9000000bd60 R08: 0000000000000514 R09: 0000000000000000 |R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000002 |R13: 0000000000000020 R14: ffffffff8167cb00 R15: 0000000000000000 |FS: 0000000000000000(0000) GS:ffff88003fcc0000(0000) knlGS:0000000000000000 |CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 |CR2: 0000000000000000 CR3: 0000000001618000 CR4: 00000000000406e0 |Stack: | ffff88003f939848 ffff88003fbca130 0000000000000001 ffffc9000000bd80 | ffffffff812a4ccb ffff88003fc0cee8 0000000000000000 ffffc9000000bdb8 | ffffffff812dc20d ffff88003fc0cee8 ffffffff8167cb00 ffff88003fc0cf48 |Call Trace: | [<ffffffff812a4ccb>] acpi_processor_stop+0xb2/0xc5 | [<ffffffff812dc20d>] driver_probe_device+0x14d/0x2f0 | [<ffffffff812dc41e>] __driver_attach+0x6e/0x90 | [<ffffffff812da234>] bus_for_each_dev+0x54/0x90 | [<ffffffff812dbbf9>] driver_attach+0x19/0x20 | [<ffffffff812db6a6>] bus_add_driver+0xe6/0x200 | [<ffffffff812dcb23>] driver_register+0x83/0xc0 | [<ffffffff816f050a>] acpi_processor_driver_init+0x20/0x94 | [<ffffffff81000487>] do_one_initcall+0x97/0x180 | [<ffffffff816ccf5c>] kernel_init_freeable+0x112/0x1a6 | [<ffffffff813a0fc9>] kernel_init+0x9/0xf0 | [<ffffffff813acf35>] ret_from_fork+0x25/0x30 |Code: 02 00 00 00 48 8b 14 d5 e0 c3 55 81 48 8b 1c 02 4c 8d 6b 20 eb 15 49 8b 7d 00 48 85 ff 74 05 e8 39 8c d9 ff 41 ff c4 49 83 c5 20 <44> 3b 23 72 e6 48 8d bb a0 02 00 00 e8 b1 6f f9 ff 48 89 df e8 |RIP [<ffffffff812aab6e>] acpi_cppc_processor_exit+0x40/0x60 | RSP <ffffc9000000bd48> |CR2: 0000000000000000 |---[ end trace 917a625107b09711 ]--- Fix it. Fixes: 17669006adf6 (cpufreq/intel_pstate: Use CPPC to get max performance) Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-12-01ACPI / CPPC: set an error code on probe error pathDan Carpenter1-1/+3
We should return -EINVAL (instead of 0) if get_cpu_device() fails. Fixes: 158c998ea44b (ACPI / CPPC: add sysfs support to compute delivered performance) Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-09-17ACPI / CPPC: Support PCC with interrupt flagHoan Tran1-1/+4
For PCC mailbox with interrupt flag, CPPC should call mbox_chan_txdone() function to notify the mailbox framework about TX completion. Signed-off-by: Hoan Tran <hotran@apm.com> Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-09-09ACPI / CPPC: Add prefix cppc to cpudata structure nameSrinivas Pandruvada1-2/+2
Since struct cpudata is defined in a header file, add prefix cppc_ to make it not a generic name. Otherwise it causes compile issue in locally define structure with the same name. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-09-09ACPI / CPPC: Add support for functional fixed hardware addressSrinivas Pandruvada1-13/+62
The CPPC registers can also be accessed via functional fixed hardware addresse(FFH) in X86. Add support by modifying cpc_read and cpc_write to be able to read/write MSRs on x86 platform on per cpu basis. Also with this change, acpi_cppc_processor_probe doesn't bail out if address space id is not equal to PCC or memory address space and FFH is supported on the system. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-31ACPI / CPPC: check for error bit in PCC status fieldPrakash, Prashanth1-35/+31
PCC status field exposes an error bit(2) to indicate any errors during the execution of last comamnd. This patch checks the error bit before notifying success/failure to the cpufreq driver. Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-31ACPI / CPPC: move all PCC related information into pcc_dataPrakash, Prashanth1-80/+87
There are several global variables in cppc driver that are related to PCC channel used for CPPC. This patch collects all such information into a single consolidated structure(cppc_pcc_data). Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-31ACPI / CPPC: add sysfs support to compute delivered performanceAshwin Chaugule1-18/+117
The CPPC tables contain entries for per CPU feedback counters which allows us to compute the delivered performance over a given interval of time. The math for delivered performance per the CPPCv5.0+ spec is: reference perf * delta(delivered perf ctr)/delta(ref perf ctr) Maintaining deltas of the counters in the kernel is messy, as it depends on when the reads are triggered. (e.g. via the cpufreq ->get() interface). Also the ->get() interace only returns one value, so cant return raw values. So instead, leave it to userspace to keep track of raw values and do its math for CPUs it cares about. delivered and reference perf counters are exposed via the same sysfs file to avoid the potential "skid", if these values are read individually from userspace. Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-31ACPI / CPPC: set a non-zero value for transition_latencyPrakash, Prashanth1-2/+44
Compute the expected transition latency for frequency transitions using the values from the PCCT tables when the desired perf register is in PCC. Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Reviewed-by: Alexey Klimov <alexey.klimov@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-31ACPI / CPPC: support for batching CPPC requestsPrakash, Prashanth1-34/+164
CPPC defined in section 8.4.7 of ACPI 6.0 specification suggests "To amortize the cost of PCC transactions, OSPM should read or write all PCC registers via a single read or write command when possible" This patch enables opportunistic batching of frequency transition requests whenever the request happen to overlap in time. Currently the access to pcc is serialized by a spin lock which does not scale well as we increase the number of cores in the system. This patch improves the scalability by allowing the differnt CPU cores to update PCC subspace in parallel and by batching requests which will reduce the certain types of operation(checking command completion bit, ringing doorbell) by a significant margin. Profiling shows significant improvement in the overall effeciency to service freq. transition requests. With this patch we observe close to 30% of the frequency transition requests being batched with other requests while running apache bench on a ARM platform with 6 independent domains(or sets of related cpus). Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-31ACPI / CPPC: acquire pcc_lock only while accessing PCC subspacePrakash, Prashanth1-14/+16
We need to acquire pcc_lock only when we are accessing registers that are in the PCC subspsace. Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-31ACPI / CPPC: restructure read/writes for efficient sys mapped reg opsAshwin Chaugule1-37/+71
For cases where sys mapped CPC registers need to be accessed frequently, it helps immensly to pre-map them rather than map and unmap for each operation. e.g. case where feedback counters are sys mem map registers. Restructure cpc_read/write and the cpc_regs structure to allow pre-mapping the system addresses and unmap them when the CPU exits. Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org> Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-25ACPI / CPPC: Prevent cpc_desc_ptr points to the invalid dataHoan Tran1-3/+3
When CPPC fails to request a PCC channel, the CPC data is freed and cpc_desc_ptr points to the invalid data. Avoid this issue by moving the cpc_desc_ptr assignment after the PCC channel request. Signed-off-by: Hoan Tran <hotran@apm.com> Acked-by: Ashwin Chaugule <ashwin.chaugule@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-24ACPI: CPPC: Return error if _CPC is invalid on a CPUHoan Tran1-6/+12
Based on 8.4.7.1 section of ACPI 6.1 specification, if the platform supports CPPC, the _CPC object must exist under all processor objects. If cpc_desc_ptr pointer is invalid on any CPUs, acpi_get_psd_map() should return error and CPPC cpufreq driver can not be registered. Signed-off-by: Hoan Tran <hotran@apm.com> Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-10ACPI / CPPC: use MRTT/MPAR to decide if/when a req can be sentPrakash, Prashanth1-1/+55
The ACPI spec defines Minimum Request Turnaround Time(MRTT) and Maximum Periodic Access Rate(MPAR) to prevent the OSPM from sending too many requests than the platform can handle. For further details on these parameters please refer to section 14.1.3 of ACPI 6.0 spec. This patch includes MRTT/MPAR in deciding if or when a CPPC request can be sent to the platform to make sure CPPC implementation is compliant to the spec. Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Acked-by: Ashwin Chaugule <ashwin.chaugule@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-10ACPI / CPPC: replace writeX/readX to PCC with relaxed versionPrakash, Prashanth1-10/+10
We do not have a strict read/write order requirement while accessing PCC subspace. The only requirement is all access should be committed before triggering the PCC doorbell to transfer the ownership of PCC to the platform and this requirement is enforced by the PCC driver. Profiling on a many core system shows improvement of about 1.8us on average per freq change request(about 10% improvement on average). Since these operations are executed while holding the pcc_lock, reducing this time helps the CPPC implementation to scale much better as the number of cores increases. Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Acked-by: Ashwin Chaugule <ashwin.chaugule@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-10ACPI / CPPC: optimized cpc_read and cpc_writePrakash, Prashanth1-16/+64
cpc_read and cpc_write are used while holding the pcc_lock spin_lock, so they need to be as fast as possible. acpi_os_read/write_memory APIs linearly search through a list for cached mapping which is quite expensive. Since the PCC subspace is already mapped into virtual address space during initialization, we can just add the offset and access the necessary CPPC registers. This patch + similar changes to PCC driver reduce the time per freq. transition from around 200us to about 20us for the CPPC cpufreq driver. Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Acked-by: Ashwin Chaugule <ashwin.chaugule@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-10ACPI / CPPC: Optimize PCC Read Write operationsAshwin Chaugule1-29/+72
Previously the send_pcc_cmd() code checked if the PCC operation had completed before returning from the function. This check was performed regardless of the PCC op type (i.e. Read/Write). Knowing the type of cmd can be used to optimize the check and avoid needless waiting. e.g. with Write ops, the actual Writing is done before calling send_pcc_cmd(). And the subsequent Writes will check if the channel is free at the entry of send_pcc_cmd() anyway. However, for Read cmds, we need to wait for the cmd completion bit to be flipped, since the actual Read ops follow after returning from the send_pcc_cmd(). So, only do the looping check at the end for Read ops. Also, instead of using udelay() calls, use ktime as a means to check for deadlines. The current deadline in which the Remote should flip the cmd completion bit is defined as N * Nominal latency. Where N is arbitrary and large enough to work on slow emulators and Nominal latency comes from the ACPI table (PCCT). This helps in working around the CONFIG_HZ effects on udelay() and also avoids needing different ACPI tables for Silicon and Emulation platforms. Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org> Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-20Merge branches 'pm-cpufreq' and 'acpi-cppc'Rafael J. Wysocki1-1/+1
* pm-cpufreq: Revert "Documentation: kernel_parameters for Intel P state driver" cpufreq: mediatek: fix build error cpufreq: intel_pstate: Add separate support for Airmont cores cpufreq: intel_pstate: Replace BYT with ATOM Revert "cpufreq: intel_pstate: Use ACPI perf configuration" Revert "cpufreq: intel_pstate: Avoid calculation for max/min" * acpi-cppc: ACPI / CPPC: Use h/w reduced version of the PCCT structure
2015-11-14ACPI / CPPC: Use h/w reduced version of the PCCT structureAshwin Chaugule1-1/+1
CPPC is enabled only on platforms which support the h/w reduced ACPI specification, so use the h/w reduced version of the PCCT consistently when deferencing PCCT contents. Fixes: 337aadff8e45 (ACPI: Introduce CPU performance controls using CPPC) Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-26ACPI / CPPC: Fix potential memory leakAshwin Chaugule1-1/+0
Commit 337aadff8e45 (ACPI: Introduce CPU performance controls using CPPC) leads to the following static checker warning: drivers/acpi/cppc_acpi.c:527 acpi_cppc_processor_probe() warn: overwrite may leak 'cpc_ptr' Fix the warning by removing the bogus per-CPU pointer dereference. Fixes: 337aadff8e45 (ACPI: Introduce CPU performance controls using CPPC) Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-26ACPI / CPPC: signedness bug in register_pcc_channel()Dan Carpenter1-1/+1
The "pcc_subspace_idx" is -1 if it hasn't been initialized yet. We need it to be signed. Fixes: 337aadff8e45 (ACPI: Introduce CPU performance controls using CPPC) Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Ashwin Chaugule <ashwin.chaugule@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-12ACPI: Introduce CPU performance controls using CPPCAshwin Chaugule1-0/+734
CPPC stands for Collaborative Processor Performance Controls and is defined in the ACPI v5.0+ spec. It describes CPU performance controls on an abstract and continuous scale allowing the platform (e.g. remote power processor) to flexibly optimize CPU performance with its knowledge of power budgets and other architecture specific knowledge. This patch adds a shim which exports commonly used functions to get and set CPPC specific controls for each CPU. This enables CPUFreq drivers to gather per CPU performance data and use with exisiting governors or even allows for customized governors which are implemented inside CPUFreq drivers. Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org> Reviewed-by: Al Stone <al.stone@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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