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platform/x86: intel_pmc_core: Get LPM requirements for Tiger Lake

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Platforms that support low power modes (LPM) such as Tiger Lake maintain
requirements for each sub-state that a readable in the PMC. However, unlike
LPM status registers, requirement registers are not memory mapped but are
available from an ACPI _DSM. Collect the requirements for Tiger Lake using
the _DSM method and store in a buffer.

Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com>
Co-developed-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20210417031252.3020837-6-david.e.box@linux.intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
This commit is contained in:
Gayatri Kammela 2021-04-16 20:12:48 -07:00 committed by Hans de Goede
parent 29c2dd88ac
commit 428131364f
2 changed files with 58 additions and 0 deletions
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56
drivers/platform/x86/intel_pmc_core.c
View File

@ -23,7 +23,9 @@
#include <linux/slab.h>
#include <linux/suspend.h>
#include <linux/uaccess.h>
#include <linux/uuid.h>
#include <acpi/acpi_bus.h>
#include <asm/cpu_device_id.h>
#include <asm/intel-family.h>
#include <asm/msr.h>
@ -31,6 +33,9 @@
#include "intel_pmc_core.h"
#define ACPI_S0IX_DSM_UUID "57a6512e-3979-4e9d-9708-ff13b2508972"
#define ACPI_GET_LOW_MODE_REGISTERS 1
/* PKGC MSRs are common across Intel Core SoCs */
static const struct pmc_bit_map msr_map[] = {
{"Package C2", MSR_PKG_C2_RESIDENCY},
@ -590,6 +595,53 @@ static const struct pmc_reg_map tgl_reg_map = {
.etr3_offset = ETR3_OFFSET,
};
static void pmc_core_get_tgl_lpm_reqs(struct platform_device *pdev)
{
struct pmc_dev *pmcdev = platform_get_drvdata(pdev);
const int num_maps = pmcdev->map->lpm_num_maps;
u32 lpm_size = LPM_MAX_NUM_MODES * num_maps * 4;
union acpi_object *out_obj;
struct acpi_device *adev;
guid_t s0ix_dsm_guid;
u32 *lpm_req_regs, *addr;
adev = ACPI_COMPANION(&pdev->dev);
if (!adev)
return;
guid_parse(ACPI_S0IX_DSM_UUID, &s0ix_dsm_guid);
out_obj = acpi_evaluate_dsm(adev->handle, &s0ix_dsm_guid, 0,
ACPI_GET_LOW_MODE_REGISTERS, NULL);
if (out_obj && out_obj->type == ACPI_TYPE_BUFFER) {
u32 size = out_obj->buffer.length;
if (size != lpm_size) {
acpi_handle_debug(adev->handle,
"_DSM returned unexpected buffer size, have %u, expect %u\n",
size, lpm_size);
goto free_acpi_obj;
}
} else {
acpi_handle_debug(adev->handle,
"_DSM function 0 evaluation failed\n");
goto free_acpi_obj;
}
addr = (u32 *)out_obj->buffer.pointer;
lpm_req_regs = devm_kzalloc(&pdev->dev, lpm_size * sizeof(u32),
GFP_KERNEL);
if (!lpm_req_regs)
goto free_acpi_obj;
memcpy(lpm_req_regs, addr, lpm_size);
pmcdev->lpm_req_regs = lpm_req_regs;
free_acpi_obj:
ACPI_FREE(out_obj);
}
static inline u32 pmc_core_reg_read(struct pmc_dev *pmcdev, int reg_offset)
{
return readl(pmcdev->regbase + reg_offset);
@ -1424,10 +1476,14 @@ static int pmc_core_probe(struct platform_device *pdev)
return -ENOMEM;
mutex_init(&pmcdev->lock);
pmcdev->pmc_xram_read_bit = pmc_core_check_read_lock_bit(pmcdev);
pmc_core_get_low_power_modes(pmcdev);
pmc_core_do_dmi_quirks(pmcdev);
if (pmcdev->map == &tgl_reg_map)
pmc_core_get_tgl_lpm_reqs(pdev);
/*
* On TGL, due to a hardware limitation, the GBE LTR blocks PC10 when
* a cable is attached. Tell the PMC to ignore it.

2
drivers/platform/x86/intel_pmc_core.h
View File

@ -294,6 +294,7 @@ struct pmc_reg_map {
* @s0ix_counter: S0ix residency (step adjusted)
* @num_lpm_modes: Count of enabled modes
* @lpm_en_modes: Array of enabled modes from lowest to highest priority
* @lpm_req_regs: List of substate requirements
*
* pmc_dev contains info about power management controller device.
*/
@ -310,6 +311,7 @@ struct pmc_dev {
u64 s0ix_counter;
int num_lpm_modes;
int lpm_en_modes[LPM_MAX_NUM_MODES];
u32 *lpm_req_regs;
};
#define pmc_for_each_mode(i, mode, pmcdev) \