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Message-ID: <67fb2263-003e-71b3-ef6f-9276bded995b@linux.intel.com>
Date: Fri, 27 Jun 2025 11:08:44 +0300 (EEST)
From: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
To: Xi Pardee <xi.pardee@...ux.intel.com>
cc: irenic.rajneesh@...il.com, david.e.box@...ux.intel.com,
Hans de Goede <hdegoede@...hat.com>, platform-driver-x86@...r.kernel.org,
LKML <linux-kernel@...r.kernel.org>, linux-pm@...r.kernel.org
Subject: Re: [PATCH v2 4/5] platform/x86:intel/pmc: Show substate requirement
for S0ix blockers
On Thu, 26 Jun 2025, Xi Pardee wrote:
> Hi Ilpo,
>
> Thanks for reviewing the patch. My response is inline.
>
> On 6/26/2025 9:38 AM, Ilpo Järvinen wrote:
> > On Tue, 24 Jun 2025, Xi Pardee wrote:
> >
> > > Add support to read and show S0ix blocker substate requirements.
> > > Starting from Panther Lake, substate requirement data is provided
> > > based on S0ix blockers instead of all low power mode requirements.
> > > For platforms that support this new feature, add support to display
> > > substate requirements based on S0ix blockers.
> > Empty line.
> Will fix in next version.
> >
> > > Change the "substate_requirements" attribute of Intel PMC Core
> > > driver to show the substate requirements for each S0ix blocker
> > > and the corresponding S0ix blocker value.
> > >
> > > Signed-off-by: Xi Pardee <xi.pardee@...ux.intel.com>
> > > ---
> > > drivers/platform/x86/intel/pmc/arl.c | 2 +
> > > drivers/platform/x86/intel/pmc/core.c | 111 ++++++++++++++++++++++++--
> > > drivers/platform/x86/intel/pmc/core.h | 12 +++
> > > drivers/platform/x86/intel/pmc/lnl.c | 1 +
> > > drivers/platform/x86/intel/pmc/mtl.c | 1 +
> > > 5 files changed, 121 insertions(+), 6 deletions(-)
> > >
> > > diff --git a/drivers/platform/x86/intel/pmc/arl.c
> > > b/drivers/platform/x86/intel/pmc/arl.c
> > > index 9d66d65e75779..1852876be234f 100644
> > > --- a/drivers/platform/x86/intel/pmc/arl.c
> > > +++ b/drivers/platform/x86/intel/pmc/arl.c
> > > @@ -722,6 +722,7 @@ static int arl_h_core_init(struct pmc_dev *pmcdev,
> > > struct pmc_dev_info *pmc_dev_
> > > struct pmc_dev_info arl_pmc_dev = {
> > > .pci_func = 0,
> > > + .telem_info = SUB_REQ_LPM,
> > > .dmu_guid = ARL_PMT_DMU_GUID,
> > > .regmap_list = arl_pmc_info_list,
> > > .map = &arl_socs_reg_map,
> > > @@ -732,6 +733,7 @@ struct pmc_dev_info arl_pmc_dev = {
> > > struct pmc_dev_info arl_h_pmc_dev = {
> > > .pci_func = 2,
> > > + .telem_info = SUB_REQ_LPM,
> > > .dmu_guid = ARL_PMT_DMU_GUID,
> > > .regmap_list = arl_pmc_info_list,
> > > .map = &mtl_socm_reg_map,
> > > diff --git a/drivers/platform/x86/intel/pmc/core.c
> > > b/drivers/platform/x86/intel/pmc/core.c
> > > index 47cc5120e7dd6..e9d281b064462 100644
> > > --- a/drivers/platform/x86/intel/pmc/core.c
> > > +++ b/drivers/platform/x86/intel/pmc/core.c
> > > @@ -844,6 +844,56 @@ static void pmc_core_substate_req_header_show(struct
> > > seq_file *s, int pmc_index,
> > > seq_printf(s, " %9s |\n", name);
> > > }
> > > +static int pmc_core_substate_blk_req_show(struct seq_file *s, void
> > > *unused)
> > > +{
> > > + struct pmc_dev *pmcdev = s->private;
> > > + unsigned int pmc_index;
> > > + u32 *blk_sub_req_regs;
> > Why is this here and the other variable in the inner block?
> Will move the blk_sub_req_regs declaration to the inner block.
> >
> > > +
> > > + for (pmc_index = 0; pmc_index < ARRAY_SIZE(pmcdev->pmcs); pmc_index++)
> > > {
> > > + const struct pmc_bit_map **maps;
> > > + unsigned int arr_size, r_idx;
> > > + u32 offset, counter;
> > > + struct pmc *pmc;
> > > +
> > > + pmc = pmcdev->pmcs[pmc_index];
> > > + if (!pmc || !pmc->blk_sub_req_regs)
> > > + continue;
> > > +
> > > + blk_sub_req_regs = pmc->blk_sub_req_regs;
> > > + maps = pmc->map->s0ix_blocker_maps;
> > > + offset = pmc->map->s0ix_blocker_offset;
> > > + arr_size = pmc_core_lpm_get_arr_size(maps);
> > > +
> > > + /* Display the header */
> > > + pmc_core_substate_req_header_show(s, pmc_index, "Value");
> > > +
> > > + for (r_idx = 0; r_idx < arr_size; r_idx++) {
> > > + const struct pmc_bit_map *map;
> > > +
> > > + for (map = maps[r_idx]; map->name; map++) {
> > > + int mode;
> > > +
> > > + if (!map->blk)
> > > + continue;
> > > +
> > > + counter = pmc_core_reg_read(pmc, offset);
> > > + seq_printf(s, "pmc%d: %34s |", pmc_index,
> > > map->name);
> > > + pmc_for_each_mode(mode, pmcdev) {
> > > + bool required = *blk_sub_req_regs &
> > > BIT(mode);
> > > +
> > > + seq_printf(s, " %9s |", required ?
> > > "Required" : " ");
> > > + }
> > > + seq_printf(s, " %9d |\n", counter);
> > > + offset += map->blk * S0IX_BLK_SIZE;
> > > + blk_sub_req_regs++;
> > > + }
> > > + }
> > > + }
> > > + return 0;
> > > +}
> > > +DEFINE_SHOW_ATTRIBUTE(pmc_core_substate_blk_req);
> > > +
> > > static int pmc_core_substate_req_regs_show(struct seq_file *s, void
> > > *unused)
> > > {
> > > struct pmc_dev *pmcdev = s->private;
> > > @@ -1335,7 +1385,10 @@ static void pmc_core_dbgfs_register(struct pmc_dev
> > > *pmcdev)
> > > debugfs_create_file("substate_requirements", 0444,
> > > pmcdev->dbgfs_dir, pmcdev,
> > > &pmc_core_substate_req_regs_fops);
> > > - }
> > > + } else if (primary_pmc->blk_sub_req_regs)
> > > + debugfs_create_file("substate_requirements", 0444,
> > > + pmcdev->dbgfs_dir, pmcdev,
> > > + &pmc_core_substate_blk_req_fops);
> > >
> > > if (primary_pmc->map->pson_residency_offset &&
> > > pmc_core_is_pson_residency_enabled(pmcdev)) {
> > > debugfs_create_file("pson_residency_usec", 0444,
> > > @@ -1441,7 +1494,38 @@ static int pmc_core_pmt_get_lpm_req(struct pmc_dev
> > > *pmcdev, struct pmc *pmc,
> > > return ret;
> > > }
> > > -static int pmc_core_get_telem_info(struct pmc_dev *pmcdev, int func)
> > > +static int pmc_core_pmt_get_blk_sub_req(struct pmc_dev *pmcdev, struct
> > > pmc *pmc,
> > > + struct telem_endpoint *ep)
> > > +{
> > > + u32 num_blocker, sample_id;
> > > + unsigned int index;
> > > + u32 *req_offset;
> > > + int ret;
> > > +
> > > + num_blocker = pmc->map->num_s0ix_blocker;
> > > + sample_id = pmc->map->blocker_req_offset;
> > > +
> > > + pmc->blk_sub_req_regs = devm_kcalloc(&pmcdev->pdev->dev,
> > > + num_blocker, sizeof(u32),
> > > + GFP_KERNEL);
> > Correct alignment.
> >
> > I guess you want to keep those two args on the same line as this would fit
> > on 2 lines.
> Will change the alignment and move two args to be on one line.
> >
> > > + if (!pmc->blk_sub_req_regs)
> > > + return -ENOMEM;
> > > +
> > > + req_offset = pmc->blk_sub_req_regs;
> > > + for (index = 0; index < num_blocker; index++) {
> > > + ret = pmt_telem_read32(ep, sample_id, req_offset, 1);
> > > + if (ret) {
> > > + dev_err(&pmcdev->pdev->dev,
> > > + "couldn't read Low Power Mode requirements:
> > > %d\n", ret);
> > > + return ret;
> > > + }
> > > + sample_id++;
> > > + req_offset++;
> > > + }
> > > + return 0;
> > > +}
> > > +
> > > +static int pmc_core_get_telem_info(struct pmc_dev *pmcdev, int func,
> > > unsigned int telem_info)
> > > {
> > > struct pci_dev *pcidev __free(pci_dev_put) = NULL;
> > > struct telem_endpoint *ep;
> > > @@ -1470,13 +1554,26 @@ static int pmc_core_get_telem_info(struct pmc_dev
> > > *pmcdev, int func)
> > > return -EPROBE_DEFER;
> > > }
> > > - ret = pmc_core_pmt_get_lpm_req(pmcdev, pmc, ep);
> > > + if (telem_info & SUB_REQ_LPM) {
> > > + ret = pmc_core_pmt_get_lpm_req(pmcdev, pmc, ep);
> > > + if (ret)
> > > + goto unregister_ep;
> > > + }
> > > +
> > > + if (telem_info & SUB_REQ_BLK) {
> > These two are mutually exclusive? I'm really wondering cuold pointers be
> > used instead to avoid these ifs here and in debugfs fops selection.
> The SUB_REQ_BLK and SUB_REQ_LPM are mutually exclusive. We will also introduce
> more
> types of data from the telemetry endpoint but not mutually exclusive in the
> next series, therefore
> using bit to identify the type of data sounds appropriate to me. I am not sure
> how to use pointer to
> select data type in this scenario, Could you please give an example?
Perhaps there isn't, I didn't have a crystal ball what's coming after this
series at hand. :-)
I just noted there are these mutually exclusive pointers:
debugfs_create_file("substate_requirements", ..., &pmc_core_substate_req_regs_fops);
vs
debugfs_create_file("substate_requirements", ..., &pmc_core_substate_blk_req_fops);
and
ret = pmc_core_pmt_get_lpm_req(pmcdev, pmc, ep);
vs
ret = pmc_core_pmt_get_blk_sub_req(pmcdev, pmc, ep);
As both look like they're decided based on what platform we're running on,
it looks similar to what pmc_dev_info already contains, having these as
pointers in pmc_dev_info would avoid having to create those two branches
just to use a different pointer.
(BTW, those two places also use a different way to decide which one to
use, which feels slightly inconsistent).
Whether using pointers in pmc_dev_info makes sense given the extra info
you provided now, I'm not any more entirely sure.
> > > + ret = pmc_core_pmt_get_blk_sub_req(pmcdev, pmc, ep);
> > > + if (ret)
> > > + goto unregister_ep;
> > > + }
> > > +
> > > pmt_telem_unregister_endpoint(ep);
> > > - if (ret)
> > > - return ret;
> > > }
> > > return 0;
> > > +
> > > +unregister_ep:
> > > + pmt_telem_unregister_endpoint(ep);
> > > + return ret;
> > > }
> > > static const struct pmc_reg_map *pmc_core_find_regmap(struct pmc_info
> > > *list, u16 devid)
> > > @@ -1585,7 +1682,9 @@ int generic_core_init(struct pmc_dev *pmcdev, struct
> > > pmc_dev_info *pmc_dev_info)
> > > pmc_core_punit_pmt_init(pmcdev, pmc_dev_info->dmu_guid);
> > > if (ssram) {
> > > - ret = pmc_core_get_telem_info(pmcdev, pmc_dev_info->pci_func);
> > > + ret = pmc_core_get_telem_info(pmcdev,
> > > + pmc_dev_info->pci_func,
> > > + pmc_dev_info->telem_info);
> > > if (ret)
> > > goto unmap_regbase;
> > > }
> > > diff --git a/drivers/platform/x86/intel/pmc/core.h
> > > b/drivers/platform/x86/intel/pmc/core.h
> > > index 4a94a4ee031e6..d8c7b28493055 100644
> > > --- a/drivers/platform/x86/intel/pmc/core.h
> > > +++ b/drivers/platform/x86/intel/pmc/core.h
> > > @@ -29,6 +29,10 @@ struct telem_endpoint;
> > > #define LPM_REG_COUNT 28
> > > #define LPM_MODE_OFFSET 1
> > > +/* Telemetry Endpoint Info bits */
> > > +#define SUB_REQ_LPM 0x01 /* Substate requirement for
> > > low power mode requirements */
> > > +#define SUB_REQ_BLK 0x02 /* Substate requirement for
> > > S0ix blockers */
> > > +
> > > /* Sunrise Point Power Management Controller PCI Device ID */
> > > #define SPT_PMC_PCI_DEVICE_ID 0x9d21
> > > #define SPT_PMC_BASE_ADDR_OFFSET 0x48
> > > @@ -344,6 +348,8 @@ struct pmc_bit_map {
> > > * @pm_read_disable_bit: Bit index to read PMC_READ_DISABLE
> > > * @slps0_dbg_offset: PWRMBASE offset to SLP_S0_DEBUG_REG*
> > > * @s0ix_blocker_offset PWRMBASE offset to S0ix blocker counter
> > > + * @num_s0ix_blocker: Number of S0ix blockers
> > > + * @blocker_req_offset: Telemetry offset to S0ix blocker low power
> > > mode substate requirement table
> > > *
> > > * Each PCH has unique set of register offsets and bit indexes. This
> > > structure
> > > * captures them to have a common implementation.
> > > @@ -369,6 +375,8 @@ struct pmc_reg_map {
> > > const u32 ltr_ignore_max;
> > > const u32 pm_vric1_offset;
> > > const u32 s0ix_blocker_offset;
> > > + const u32 num_s0ix_blocker;
> > > + const u32 blocker_req_offset;
> > > /* Low Power Mode registers */
> > > const int lpm_num_maps;
> > > const int lpm_num_modes;
> > > @@ -404,6 +412,7 @@ struct pmc_info {
> > > * @map: pointer to pmc_reg_map struct that contains platform
> > > * specific attributes
> > > * @lpm_req_regs: List of substate requirements
> > > + * @blk_sub_req_reqs: List of registers showing substate
> > > requirements for S0ix blockers
> > > * @ltr_ign: Holds LTR ignore data while suspended
> > > *
> > > * pmc contains info about one power management controller device.
> > > @@ -413,6 +422,7 @@ struct pmc {
> > > void __iomem *regbase;
> > > const struct pmc_reg_map *map;
> > > u32 *lpm_req_regs;
> > > + u32 *blk_sub_req_regs;
> > > u32 ltr_ign;
> > > };
> > > @@ -468,6 +478,7 @@ enum pmc_index {
> > > /**
> > > * struct pmc_dev_info - Structure to keep PMC device info
> > > * @pci_func: Function number of the primary PMC
> > > + * @telem_info: Bitmask to indicate which telemetry info is
> > > available
> > > * @dmu_guid: Die Management Unit GUID
> > > * @regmap_list: Pointer to a list of pmc_info structure that could be
> > > * available for the platform. When set, this
> > > field implies
> > > @@ -480,6 +491,7 @@ enum pmc_index {
> > > */
> > > struct pmc_dev_info {
> > > u8 pci_func;
> > > + u8 telem_info;
> > > u32 dmu_guid;
> > > struct pmc_info *regmap_list;
> > > const struct pmc_reg_map *map;
> > > diff --git a/drivers/platform/x86/intel/pmc/lnl.c
> > > b/drivers/platform/x86/intel/pmc/lnl.c
> > > index e08a77c778c2c..ec9e79f6cd913 100644
> > > --- a/drivers/platform/x86/intel/pmc/lnl.c
> > > +++ b/drivers/platform/x86/intel/pmc/lnl.c
> > > @@ -572,6 +572,7 @@ static int lnl_core_init(struct pmc_dev *pmcdev,
> > > struct pmc_dev_info *pmc_dev_in
> > > struct pmc_dev_info lnl_pmc_dev = {
> > > .pci_func = 2,
> > > + .telem_info = SUB_REQ_LPM,
> > > .regmap_list = lnl_pmc_info_list,
> > > .map = &lnl_socm_reg_map,
> > > .suspend = cnl_suspend,
> > > diff --git a/drivers/platform/x86/intel/pmc/mtl.c
> > > b/drivers/platform/x86/intel/pmc/mtl.c
> > > index faa13a7ee688f..c58a871e2e0df 100644
> > > --- a/drivers/platform/x86/intel/pmc/mtl.c
> > > +++ b/drivers/platform/x86/intel/pmc/mtl.c
> > > @@ -994,6 +994,7 @@ static int mtl_core_init(struct pmc_dev *pmcdev,
> > > struct pmc_dev_info *pmc_dev_in
> > > struct pmc_dev_info mtl_pmc_dev = {
> > > .pci_func = 2,
> > > + .telem_info = SUB_REQ_LPM,
> > > .dmu_guid = MTL_PMT_DMU_GUID,
> > > .regmap_list = mtl_pmc_info_list,
> > > .map = &mtl_socm_reg_map,
> > >
>
--
i.
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