linux-toradex.git/drivers/acpi/cppc_acpi.c, branch v4.11 Linux kernel for Apalis and Colibri modules ACPI / CPPC: Fix per-CPU pointer management in acpi_cppc_processor_probe() 2016-12-12T22:52:34+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2016-12-09T23:52:28+00:00 28076483afac9dd77df269f5d460e51a09dfb19f 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> 
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>
ACPI / CPPC: Fix crash in acpi_cppc_processor_exit() 2016-12-12T22:51:36+00:00 Sebastian Andrzej Siewior bigeasy@linutronix.de 2016-12-07T19:06:08+00:00 9e9d68dad58c70f40f50adfeabd2fdaa39a743fd 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> 
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>
ACPI / CPPC: set an error code on probe error path 2016-11-30T22:16:31+00:00 Dan Carpenter dan.carpenter@oracle.com 2016-11-30T19:22:54+00:00 501634759d55a5b56967de6d9465acf02bbc3565 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> 
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>
ACPI / CPPC: Support PCC with interrupt flag 2016-09-16T23:14:24+00:00 Hoan Tran hotran@apm.com 2016-09-14T17:54:58+00:00 b59c4b3dcd2e63d7a5483df3460d47278df716f7 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> 
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>
ACPI / CPPC: Add prefix cppc to cpudata structure name 2016-09-08T21:02:15+00:00 Srinivas Pandruvada srinivas.pandruvada@linux.intel.com 2016-09-01T20:37:11+00:00 41dd64038970139c562d07ee7ff4e41245611b4a 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> 
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>
ACPI / CPPC: Add support for functional fixed hardware address 2016-09-08T21:02:14+00:00 Srinivas Pandruvada srinivas.pandruvada@linux.intel.com 2016-09-01T20:37:10+00:00 a6cbcdd5ab5f242d49f511127f0a601b71be2cc4 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> 
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>
ACPI / CPPC: check for error bit in PCC status field 2016-08-30T23:02:34+00:00 Prakash, Prashanth pprakash@codeaurora.org 2016-08-16T20:39:44+00:00 139aee73f0c23b95a7e919b8f7e51ccf2d221181 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> 
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>
ACPI / CPPC: move all PCC related information into pcc_data 2016-08-30T23:02:34+00:00 Prakash, Prashanth pprakash@codeaurora.org 2016-08-16T20:39:43+00:00 8482ef8c6e684a1bba703c330e0bafe2d1d29ef7 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> 
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>
ACPI / CPPC: add sysfs support to compute delivered performance 2016-08-30T23:02:34+00:00 Ashwin Chaugule ashwin.chaugule@linaro.org 2016-08-16T20:39:42+00:00 158c998ea44ba30ae3d1bde535581c4436417530 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> 
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>
ACPI / CPPC: set a non-zero value for transition_latency 2016-08-30T23:02:33+00:00 Prakash, Prashanth pprakash@codeaurora.org 2016-08-16T20:39:41+00:00 be8b88d7d9877114172b32817d8eb3e85d3d8f99 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> 
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>