powercap: intel_rapl: Fix locking in TPMI RAPL

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The RAPL framework uses CPU hotplug locking to protect the rapl_packages
list and rp->lead_cpu to guarantee that

 1. the RAPL package device is not unprobed and freed
 2. the cached rp->lead_cpu is always valid

for operations like powercap sysfs accesses.

Current RAPL APIs assume being called from CPU hotplug callbacks which
hold the CPU hotplug lock, but TPMI RAPL driver invokes the APIs in the
driver's .probe() function without acquiring the CPU hotplug lock.

Fix the problem by providing both locked and lockless versions of RAPL
APIs.

Fixes: 9eef7f9da9 ("powercap: intel_rapl: Introduce RAPL TPMI interface driver")
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Cc: 6.5+ <stable@vger.kernel.org> # 6.5+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

...

This commit is contained in:

Zhang Rui 2024-01-31 19:37:09 +08:00 • committed by Rafael J. Wysocki

parent 2d1f5006ff

commit 1aa09b9379

4 changed files with 40 additions and 11 deletions

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29

drivers/powercap/intel_rapl_common.c

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8

drivers/powercap/intel_rapl_msr.c

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8

drivers/thermal/intel/int340x_thermal/processor_thermal_rapl.c

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6

include/linux/intel_rapl.h

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