Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
platform/x86/intel/pmc: Retrieve LPM information using Intel PMT
On supported platforms, the low power mode (LPM) requirements for entering
each idle substate are described in Platform Monitoring Technology (PMT)
telemetry entries. Provide a function for platform code to attempt to find
and read the requirements from the telemetry entries.
Signed-off-by: Xi Pardee <xi.pardee@intel.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20231129222132.2331261-18-david.e.box@linux.intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
authored by
Xi Pardee
and committed by
Hans de Goede
4d621c3f
0f601dec
+138
+3
drivers/platform/x86/intel/pmc/core.h
+3
drivers/platform/x86/intel/pmc/core.h
···
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const u32 lpm_status_offset;
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const u32 lpm_live_status_offset;
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const u32 etr3_offset;
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const u8 *lpm_reg_index;
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};
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/**
···
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* specific attributes
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*/
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struct pmc_info {
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u32 guid;
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u16 devid;
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const struct pmc_reg_map *map;
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};
···
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extern const struct pmc_reg_map mtl_ioem_reg_map;
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extern void pmc_core_get_tgl_lpm_reqs(struct platform_device *pdev);
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extern int pmc_core_ssram_get_lpm_reqs(struct pmc_dev *pmcdev);
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extern int pmc_core_send_ltr_ignore(struct pmc_dev *pmcdev, u32 value);
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int pmc_core_resume_common(struct pmc_dev *pmcdev);
+135
drivers/platform/x86/intel/pmc/core_ssram.c
+135
drivers/platform/x86/intel/pmc/core_ssram.c
···
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#define SSRAM_IOE_OFFSET 0x68
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#define SSRAM_DEVID_OFFSET 0x70
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/* PCH query */
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#define LPM_HEADER_OFFSET 1
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#define LPM_REG_COUNT 28
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#define LPM_MODE_OFFSET 1
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DEFINE_FREE(pmc_core_iounmap, void __iomem *, iounmap(_T));
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static u32 pmc_core_find_guid(struct pmc_info *list, const struct pmc_reg_map *map)
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{
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for (; list->map; ++list)
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if (list->map == map)
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return list->guid;
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return 0;
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}
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static int pmc_core_get_lpm_req(struct pmc_dev *pmcdev, struct pmc *pmc)
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{
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struct telem_endpoint *ep;
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const u8 *lpm_indices;
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int num_maps, mode_offset = 0;
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int ret, mode, i;
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int lpm_size;
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u32 guid;
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lpm_indices = pmc->map->lpm_reg_index;
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num_maps = pmc->map->lpm_num_maps;
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lpm_size = LPM_MAX_NUM_MODES * num_maps;
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guid = pmc_core_find_guid(pmcdev->regmap_list, pmc->map);
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if (!guid)
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return -ENXIO;
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ep = pmt_telem_find_and_register_endpoint(pmcdev->ssram_pcidev, guid, 0);
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if (IS_ERR(ep)) {
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dev_dbg(&pmcdev->pdev->dev, "couldn't get telem endpoint %ld",
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PTR_ERR(ep));
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return -EPROBE_DEFER;
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}
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pmc->lpm_req_regs = devm_kzalloc(&pmcdev->pdev->dev,
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lpm_size * sizeof(u32),
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GFP_KERNEL);
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if (!pmc->lpm_req_regs) {
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ret = -ENOMEM;
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goto unregister_ep;
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}
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/*
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* PMC Low Power Mode (LPM) table
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*
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* In telemetry space, the LPM table contains a 4 byte header followed
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* by 8 consecutive mode blocks (one for each LPM mode). Each block
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* has a 4 byte header followed by a set of registers that describe the
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* IP state requirements for the given mode. The IP mapping is platform
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* specific but the same for each block, making for easy analysis.
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* Platforms only use a subset of the space to track the requirements
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* for their IPs. Callers provide the requirement registers they use as
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* a list of indices. Each requirement register is associated with an
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* IP map that's maintained by the caller.
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*
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* Header
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* +----+----------------------------+----------------------------+
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* | 0 | REVISION | ENABLED MODES |
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* +----+--------------+-------------+-------------+--------------+
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*
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* Low Power Mode 0 Block
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* +----+--------------+-------------+-------------+--------------+
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* | 1 | SUB ID | SIZE | MAJOR | MINOR |
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* +----+--------------+-------------+-------------+--------------+
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* | 2 | LPM0 Requirements 0 |
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* +----+---------------------------------------------------------+
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* | | ... |
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* +----+---------------------------------------------------------+
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* | 29 | LPM0 Requirements 27 |
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* +----+---------------------------------------------------------+
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*
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* ...
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*
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* Low Power Mode 7 Block
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* +----+--------------+-------------+-------------+--------------+
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* | | SUB ID | SIZE | MAJOR | MINOR |
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* +----+--------------+-------------+-------------+--------------+
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* | 60 | LPM7 Requirements 0 |
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* +----+---------------------------------------------------------+
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* | | ... |
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* +----+---------------------------------------------------------+
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* | 87 | LPM7 Requirements 27 |
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* +----+---------------------------------------------------------+
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*
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*/
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mode_offset = LPM_HEADER_OFFSET + LPM_MODE_OFFSET;
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pmc_for_each_mode(i, mode, pmcdev) {
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u32 *req_offset = pmc->lpm_req_regs + (mode * num_maps);
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int m;
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for (m = 0; m < num_maps; m++) {
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u8 sample_id = lpm_indices[m] + mode_offset;
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ret = pmt_telem_read32(ep, sample_id, req_offset, 1);
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if (ret) {
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dev_err(&pmcdev->pdev->dev,
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"couldn't read Low Power Mode requirements: %d\n", ret);
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devm_kfree(&pmcdev->pdev->dev, pmc->lpm_req_regs);
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goto unregister_ep;
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}
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++req_offset;
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}
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mode_offset += LPM_REG_COUNT + LPM_MODE_OFFSET;
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}
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unregister_ep:
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pmt_telem_unregister_endpoint(ep);
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return ret;
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}
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int pmc_core_ssram_get_lpm_reqs(struct pmc_dev *pmcdev)
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{
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int ret, i;
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if (!pmcdev->ssram_pcidev)
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return -ENODEV;
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for (i = 0; i < ARRAY_SIZE(pmcdev->pmcs); ++i) {
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if (!pmcdev->pmcs[i])
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continue;
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ret = pmc_core_get_lpm_req(pmcdev, pmcdev->pmcs[i]);
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if (ret)
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return ret;
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}
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return 0;
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}
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static void
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pmc_add_pmt(struct pmc_dev *pmcdev, u64 ssram_base, void __iomem *ssram)
···
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return ret;
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}
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MODULE_IMPORT_NS(INTEL_VSEC);
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MODULE_IMPORT_NS(INTEL_PMT_TELEMETRY);