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thermal: intel: Avoid updating unsupported THERM_STATUS_CLEAR mask bits
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Some older processors don't allow BIT(13) and BIT(15) in the current
mask set by "THERM_STATUS_CLEAR_CORE_MASK". This results in:

unchecked MSR access error: WRMSR to 0x19c (tried to
write 0x000000000000aaa8) at rIP: 0xffffffff816f66a6
(throttle_active_work+0xa6/0x1d0)

To avoid unchecked MSR issues, check CPUID for each relevant feature and
use that information to set the supported feature bits only in the
"clear" mask for cores. Do the same for the analogous package mask set
by "THERM_STATUS_CLEAR_PKG_MASK".

Introduce functions thermal_intr_init_core_clear_mask() and
thermal_intr_init_pkg_clear_mask() to set core and package mask bits,
respectively. These functions are called during initialization.

Fixes: 6fe1e64 ("thermal: intel: Prevent accidental clearing of HFI status")
Reported-by: Rui Salvaterra <rsalvaterra@gmail.com>
Link: https://lore.kernel.org/lkml/cdf43fb423368ee3994124a9e8c9b4f8d00712c6.camel@linux.intel.com/T/
Tested-by: Rui Salvaterra <rsalvaterra@gmail.com>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: 6.2+ <stable@kernel.org> # 6.2+
[ rjw: Renamed 2 funtions and 2 static variables, edited subject and
  changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Srinivas Pandruvada authored and Rafael J. Wysocki committed Apr 11, 2023
1 parent 09a9639 commit 117e4e5
Showing 1 changed file with 66 additions and 7 deletions.
73 changes: 66 additions & 7 deletions drivers/thermal/intel/therm_throt.c
Original file line number Diff line number Diff line change
Expand Up @@ -193,8 +193,67 @@ static const struct attribute_group thermal_attr_group = {
#define THERM_THROT_POLL_INTERVAL HZ
#define THERM_STATUS_PROCHOT_LOG BIT(1)

#define THERM_STATUS_CLEAR_CORE_MASK (BIT(1) | BIT(3) | BIT(5) | BIT(7) | BIT(9) | BIT(11) | BIT(13) | BIT(15))
#define THERM_STATUS_CLEAR_PKG_MASK (BIT(1) | BIT(3) | BIT(5) | BIT(7) | BIT(9) | BIT(11))
static u64 therm_intr_core_clear_mask;
static u64 therm_intr_pkg_clear_mask;

static void thermal_intr_init_core_clear_mask(void)
{
if (therm_intr_core_clear_mask)
return;

/*
* Reference: Intel SDM Volume 4
* "Table 2-2. IA-32 Architectural MSRs", MSR 0x19C
* IA32_THERM_STATUS.
*/

/*
* Bit 1, 3, 5: CPUID.01H:EDX[22] = 1. This driver will not
* enable interrupts, when 0 as it checks for X86_FEATURE_ACPI.
*/
therm_intr_core_clear_mask = (BIT(1) | BIT(3) | BIT(5));

/*
* Bit 7 and 9: Thermal Threshold #1 and #2 log
* If CPUID.01H:ECX[8] = 1
*/
if (boot_cpu_has(X86_FEATURE_TM2))
therm_intr_core_clear_mask |= (BIT(7) | BIT(9));

/* Bit 11: Power Limitation log (R/WC0) If CPUID.06H:EAX[4] = 1 */
if (boot_cpu_has(X86_FEATURE_PLN))
therm_intr_core_clear_mask |= BIT(11);

/*
* Bit 13: Current Limit log (R/WC0) If CPUID.06H:EAX[7] = 1
* Bit 15: Cross Domain Limit log (R/WC0) If CPUID.06H:EAX[7] = 1
*/
if (boot_cpu_has(X86_FEATURE_HWP))
therm_intr_core_clear_mask |= (BIT(13) | BIT(15));
}

static void thermal_intr_init_pkg_clear_mask(void)
{
if (therm_intr_pkg_clear_mask)
return;

/*
* Reference: Intel SDM Volume 4
* "Table 2-2. IA-32 Architectural MSRs", MSR 0x1B1
* IA32_PACKAGE_THERM_STATUS.
*/

/* All bits except BIT 26 depend on CPUID.06H: EAX[6] = 1 */
if (boot_cpu_has(X86_FEATURE_PTS))
therm_intr_pkg_clear_mask = (BIT(1) | BIT(3) | BIT(5) | BIT(7) | BIT(9) | BIT(11));

/*
* Intel SDM Volume 2A: Thermal and Power Management Leaf
* Bit 26: CPUID.06H: EAX[19] = 1
*/
if (boot_cpu_has(X86_FEATURE_HFI))
therm_intr_pkg_clear_mask |= BIT(26);
}

/*
* Clear the bits in package thermal status register for bit = 1
Expand All @@ -207,13 +266,10 @@ void thermal_clear_package_intr_status(int level, u64 bit_mask)

if (level == CORE_LEVEL) {
msr = MSR_IA32_THERM_STATUS;
msr_val = THERM_STATUS_CLEAR_CORE_MASK;
msr_val = therm_intr_core_clear_mask;
} else {
msr = MSR_IA32_PACKAGE_THERM_STATUS;
msr_val = THERM_STATUS_CLEAR_PKG_MASK;
if (boot_cpu_has(X86_FEATURE_HFI))
msr_val |= BIT(26);

msr_val = therm_intr_pkg_clear_mask;
}

msr_val &= ~bit_mask;
Expand Down Expand Up @@ -708,6 +764,9 @@ void intel_init_thermal(struct cpuinfo_x86 *c)
h = THERMAL_APIC_VECTOR | APIC_DM_FIXED | APIC_LVT_MASKED;
apic_write(APIC_LVTTHMR, h);

thermal_intr_init_core_clear_mask();
thermal_intr_init_pkg_clear_mask();

rdmsr(MSR_IA32_THERM_INTERRUPT, l, h);
if (cpu_has(c, X86_FEATURE_PLN) && !int_pln_enable)
wrmsr(MSR_IA32_THERM_INTERRUPT,
Expand Down

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