kernel/drivers/acpi/cppc_acpi.c, branch linux-5.1.y

ACPI / CPPC: Fix guaranteed performance handling

2019-03-25T22:57:21Z

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 Signed-off-by: Srinivas Pandruvada Cc: 4.20+ # 4.20+ Signed-off-by: Rafael J. Wysocki

ACPI / CPPC: Add a helper to get desired performance

2019-02-18T10:27:42Z

This patch add a helper to get the value of desired performance register. Signed-off-by: Xiongfeng Wang [ rjw: More white space ] Signed-off-by: Rafael J. Wysocki

ACPI / CPPC: Add support for guaranteed performance

2018-10-16T08:33:38Z

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 Signed-off-by: Rafael J. Wysocki

ACPI / CPPC: Fix invalid PCC channel status errors

2018-05-10T15:16:22Z

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 Signed-off-by: Rafael J. Wysocki

ACPI / CPPC: Check for valid PCC subspace only if PCC is used

2018-04-24T10:33:28Z

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 Signed-off-by: Rafael J. Wysocki

ACPI / CPPC: Add support for CPPC v3

2018-04-24T10:33:28Z

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 Signed-off-by: Rafael J. Wysocki

ACPI / CPPC: Update all pr_(debug/err) messages to log the susbspace id

2018-02-22T21:54:00Z

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 Signed-off-by: Rafael J. Wysocki

ACPI / CPPC: Use 64-bit arithmetic instead of 32-bit

2018-02-07T10:15:02Z

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 Signed-off-by: Rafael J. Wysocki

ACPI: CPPC: remove initial assignment of pcc_ss_data

2017-12-18T11:10:37Z

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 Signed-off-by: Rafael J. Wysocki

ACPI / CPPC: Fix KASAN global out of bounds warning

2017-12-05T22:25:49Z

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 Signed-off-by: George Cherian Signed-off-by: Rafael J. Wysocki