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path: root/drivers/platform/x86/intel/tpmi.c
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Diffstat (limited to 'drivers/platform/x86/intel/tpmi.c')
-rw-r--r--drivers/platform/x86/intel/tpmi.c415
1 files changed, 415 insertions, 0 deletions
diff --git a/drivers/platform/x86/intel/tpmi.c b/drivers/platform/x86/intel/tpmi.c
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+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * intel-tpmi : Driver to enumerate TPMI features and create devices
+ *
+ * Copyright (c) 2023, Intel Corporation.
+ * All Rights Reserved.
+ *
+ * The TPMI (Topology Aware Register and PM Capsule Interface) provides a
+ * flexible, extendable and PCIe enumerable MMIO interface for PM features.
+ *
+ * For example Intel RAPL (Running Average Power Limit) provides a MMIO
+ * interface using TPMI. This has advantage over traditional MSR
+ * (Model Specific Register) interface, where a thread needs to be scheduled
+ * on the target CPU to read or write. Also the RAPL features vary between
+ * CPU models, and hence lot of model specific code. Here TPMI provides an
+ * architectural interface by providing hierarchical tables and fields,
+ * which will not need any model specific implementation.
+ *
+ * The TPMI interface uses a PCI VSEC structure to expose the location of
+ * MMIO region.
+ *
+ * This VSEC structure is present in the PCI configuration space of the
+ * Intel Out-of-Band (OOB) device, which is handled by the Intel VSEC
+ * driver. The Intel VSEC driver parses VSEC structures present in the PCI
+ * configuration space of the given device and creates an auxiliary device
+ * object for each of them. In particular, it creates an auxiliary device
+ * object representing TPMI that can be bound by an auxiliary driver.
+ *
+ * This TPMI driver will bind to the TPMI auxiliary device object created
+ * by the Intel VSEC driver.
+ *
+ * The TPMI specification defines a PFS (PM Feature Structure) table.
+ * This table is present in the TPMI MMIO region. The starting address
+ * of PFS is derived from the tBIR (Bar Indicator Register) and "Address"
+ * field from the VSEC header.
+ *
+ * Each TPMI PM feature has one entry in the PFS with a unique TPMI
+ * ID and its access details. The TPMI driver creates device nodes
+ * for the supported PM features.
+ *
+ * The names of the devices created by the TPMI driver start with the
+ * "intel_vsec.tpmi-" prefix which is followed by a specific name of the
+ * given PM feature (for example, "intel_vsec.tpmi-rapl.0").
+ *
+ * The device nodes are create by using interface "intel_vsec_add_aux()"
+ * provided by the Intel VSEC driver.
+ */
+
+#include <linux/auxiliary_bus.h>
+#include <linux/intel_tpmi.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+
+#include "vsec.h"
+
+/**
+ * struct intel_tpmi_pfs_entry - TPMI PM Feature Structure (PFS) entry
+ * @tpmi_id: TPMI feature identifier (what the feature is and its data format).
+ * @num_entries: Number of feature interface instances present in the PFS.
+ * This represents the maximum number of Power domains in the SoC.
+ * @entry_size: Interface instance entry size in 32-bit words.
+ * @cap_offset: Offset from the PM_Features base address to the base of the PM VSEC
+ * register bank in KB.
+ * @attribute: Feature attribute: 0=BIOS. 1=OS. 2-3=Reserved.
+ * @reserved: Bits for use in the future.
+ *
+ * Represents one TPMI feature entry data in the PFS retrieved as is
+ * from the hardware.
+ */
+struct intel_tpmi_pfs_entry {
+ u64 tpmi_id:8;
+ u64 num_entries:8;
+ u64 entry_size:16;
+ u64 cap_offset:16;
+ u64 attribute:2;
+ u64 reserved:14;
+} __packed;
+
+/**
+ * struct intel_tpmi_pm_feature - TPMI PM Feature information for a TPMI ID
+ * @pfs_header: PFS header retireved from the hardware.
+ * @vsec_offset: Starting MMIO address for this feature in bytes. Essentially
+ * this offset = "Address" from VSEC header + PFS Capability
+ * offset for this feature entry.
+ *
+ * Represents TPMI instance information for one TPMI ID.
+ */
+struct intel_tpmi_pm_feature {
+ struct intel_tpmi_pfs_entry pfs_header;
+ unsigned int vsec_offset;
+};
+
+/**
+ * struct intel_tpmi_info - TPMI information for all IDs in an instance
+ * @tpmi_features: Pointer to a list of TPMI feature instances
+ * @vsec_dev: Pointer to intel_vsec_device structure for this TPMI device
+ * @feature_count: Number of TPMI of TPMI instances pointed by tpmi_features
+ * @pfs_start: Start of PFS offset for the TPMI instances in this device
+ * @plat_info: Stores platform info which can be used by the client drivers
+ *
+ * Stores the information for all TPMI devices enumerated from a single PCI device.
+ */
+struct intel_tpmi_info {
+ struct intel_tpmi_pm_feature *tpmi_features;
+ struct intel_vsec_device *vsec_dev;
+ int feature_count;
+ u64 pfs_start;
+ struct intel_tpmi_plat_info plat_info;
+};
+
+/**
+ * struct tpmi_info_header - CPU package ID to PCI device mapping information
+ * @fn: PCI function number
+ * @dev: PCI device number
+ * @bus: PCI bus number
+ * @pkg: CPU Package id
+ * @reserved: Reserved for future use
+ * @lock: When set to 1 the register is locked and becomes read-only
+ * until next reset. Not for use by the OS driver.
+ *
+ * The structure to read hardware provided mapping information.
+ */
+struct tpmi_info_header {
+ u64 fn:3;
+ u64 dev:5;
+ u64 bus:8;
+ u64 pkg:8;
+ u64 reserved:39;
+ u64 lock:1;
+} __packed;
+
+/*
+ * List of supported TMPI IDs.
+ * Some TMPI IDs are not used by Linux, so the numbers are not consecutive.
+ */
+enum intel_tpmi_id {
+ TPMI_ID_RAPL = 0, /* Running Average Power Limit */
+ TPMI_ID_PEM = 1, /* Power and Perf excursion Monitor */
+ TPMI_ID_UNCORE = 2, /* Uncore Frequency Scaling */
+ TPMI_ID_SST = 5, /* Speed Select Technology */
+ TPMI_INFO_ID = 0x81, /* Special ID for PCI BDF and Package ID information */
+};
+
+/* Used during auxbus device creation */
+static DEFINE_IDA(intel_vsec_tpmi_ida);
+
+struct intel_tpmi_plat_info *tpmi_get_platform_data(struct auxiliary_device *auxdev)
+{
+ struct intel_vsec_device *vsec_dev = auxdev_to_ivdev(auxdev);
+
+ return vsec_dev->priv_data;
+}
+EXPORT_SYMBOL_NS_GPL(tpmi_get_platform_data, INTEL_TPMI);
+
+int tpmi_get_resource_count(struct auxiliary_device *auxdev)
+{
+ struct intel_vsec_device *vsec_dev = auxdev_to_ivdev(auxdev);
+
+ if (vsec_dev)
+ return vsec_dev->num_resources;
+
+ return 0;
+}
+EXPORT_SYMBOL_NS_GPL(tpmi_get_resource_count, INTEL_TPMI);
+
+struct resource *tpmi_get_resource_at_index(struct auxiliary_device *auxdev, int index)
+{
+ struct intel_vsec_device *vsec_dev = auxdev_to_ivdev(auxdev);
+
+ if (vsec_dev && index < vsec_dev->num_resources)
+ return &vsec_dev->resource[index];
+
+ return NULL;
+}
+EXPORT_SYMBOL_NS_GPL(tpmi_get_resource_at_index, INTEL_TPMI);
+
+static const char *intel_tpmi_name(enum intel_tpmi_id id)
+{
+ switch (id) {
+ case TPMI_ID_RAPL:
+ return "rapl";
+ case TPMI_ID_PEM:
+ return "pem";
+ case TPMI_ID_UNCORE:
+ return "uncore";
+ case TPMI_ID_SST:
+ return "sst";
+ default:
+ return NULL;
+ }
+}
+
+/* String Length for tpmi-"feature_name(upto 8 bytes)" */
+#define TPMI_FEATURE_NAME_LEN 14
+
+static int tpmi_create_device(struct intel_tpmi_info *tpmi_info,
+ struct intel_tpmi_pm_feature *pfs,
+ u64 pfs_start)
+{
+ struct intel_vsec_device *vsec_dev = tpmi_info->vsec_dev;
+ char feature_id_name[TPMI_FEATURE_NAME_LEN];
+ struct intel_vsec_device *feature_vsec_dev;
+ struct resource *res, *tmp;
+ const char *name;
+ int ret, i;
+
+ name = intel_tpmi_name(pfs->pfs_header.tpmi_id);
+ if (!name)
+ return -EOPNOTSUPP;
+
+ feature_vsec_dev = kzalloc(sizeof(*feature_vsec_dev), GFP_KERNEL);
+ if (!feature_vsec_dev)
+ return -ENOMEM;
+
+ res = kcalloc(pfs->pfs_header.num_entries, sizeof(*res), GFP_KERNEL);
+ if (!res) {
+ ret = -ENOMEM;
+ goto free_vsec;
+ }
+
+ snprintf(feature_id_name, sizeof(feature_id_name), "tpmi-%s", name);
+
+ for (i = 0, tmp = res; i < pfs->pfs_header.num_entries; i++, tmp++) {
+ u64 entry_size_bytes = pfs->pfs_header.entry_size * 4;
+
+ tmp->start = pfs->vsec_offset + entry_size_bytes * i;
+ tmp->end = tmp->start + entry_size_bytes - 1;
+ tmp->flags = IORESOURCE_MEM;
+ }
+
+ feature_vsec_dev->pcidev = vsec_dev->pcidev;
+ feature_vsec_dev->resource = res;
+ feature_vsec_dev->num_resources = pfs->pfs_header.num_entries;
+ feature_vsec_dev->priv_data = &tpmi_info->plat_info;
+ feature_vsec_dev->priv_data_size = sizeof(tpmi_info->plat_info);
+ feature_vsec_dev->ida = &intel_vsec_tpmi_ida;
+
+ /*
+ * intel_vsec_add_aux() is resource managed, no explicit
+ * delete is required on error or on module unload.
+ */
+ ret = intel_vsec_add_aux(vsec_dev->pcidev, &vsec_dev->auxdev.dev,
+ feature_vsec_dev, feature_id_name);
+ if (ret)
+ goto free_res;
+
+ return 0;
+
+free_res:
+ kfree(res);
+free_vsec:
+ kfree(feature_vsec_dev);
+
+ return ret;
+}
+
+static int tpmi_create_devices(struct intel_tpmi_info *tpmi_info)
+{
+ struct intel_vsec_device *vsec_dev = tpmi_info->vsec_dev;
+ int ret, i;
+
+ for (i = 0; i < vsec_dev->num_resources; i++) {
+ ret = tpmi_create_device(tpmi_info, &tpmi_info->tpmi_features[i],
+ tpmi_info->pfs_start);
+ /*
+ * Fail, if the supported features fails to create device,
+ * otherwise, continue. Even if one device failed to create,
+ * fail the loading of driver. Since intel_vsec_add_aux()
+ * is resource managed, no clean up is required for the
+ * successfully created devices.
+ */
+ if (ret && ret != -EOPNOTSUPP)
+ return ret;
+ }
+
+ return 0;
+}
+
+#define TPMI_INFO_BUS_INFO_OFFSET 0x08
+
+static int tpmi_process_info(struct intel_tpmi_info *tpmi_info,
+ struct intel_tpmi_pm_feature *pfs)
+{
+ struct tpmi_info_header header;
+ void __iomem *info_mem;
+
+ info_mem = ioremap(pfs->vsec_offset + TPMI_INFO_BUS_INFO_OFFSET,
+ pfs->pfs_header.entry_size * 4 - TPMI_INFO_BUS_INFO_OFFSET);
+ if (!info_mem)
+ return -ENOMEM;
+
+ memcpy_fromio(&header, info_mem, sizeof(header));
+
+ tpmi_info->plat_info.package_id = header.pkg;
+ tpmi_info->plat_info.bus_number = header.bus;
+ tpmi_info->plat_info.device_number = header.dev;
+ tpmi_info->plat_info.function_number = header.fn;
+
+ iounmap(info_mem);
+
+ return 0;
+}
+
+static int tpmi_fetch_pfs_header(struct intel_tpmi_pm_feature *pfs, u64 start, int size)
+{
+ void __iomem *pfs_mem;
+
+ pfs_mem = ioremap(start, size);
+ if (!pfs_mem)
+ return -ENOMEM;
+
+ memcpy_fromio(&pfs->pfs_header, pfs_mem, sizeof(pfs->pfs_header));
+
+ iounmap(pfs_mem);
+
+ return 0;
+}
+
+static int intel_vsec_tpmi_init(struct auxiliary_device *auxdev)
+{
+ struct intel_vsec_device *vsec_dev = auxdev_to_ivdev(auxdev);
+ struct pci_dev *pci_dev = vsec_dev->pcidev;
+ struct intel_tpmi_info *tpmi_info;
+ u64 pfs_start = 0;
+ int i;
+
+ tpmi_info = devm_kzalloc(&auxdev->dev, sizeof(*tpmi_info), GFP_KERNEL);
+ if (!tpmi_info)
+ return -ENOMEM;
+
+ tpmi_info->vsec_dev = vsec_dev;
+ tpmi_info->feature_count = vsec_dev->num_resources;
+ tpmi_info->plat_info.bus_number = pci_dev->bus->number;
+
+ tpmi_info->tpmi_features = devm_kcalloc(&auxdev->dev, vsec_dev->num_resources,
+ sizeof(*tpmi_info->tpmi_features),
+ GFP_KERNEL);
+ if (!tpmi_info->tpmi_features)
+ return -ENOMEM;
+
+ for (i = 0; i < vsec_dev->num_resources; i++) {
+ struct intel_tpmi_pm_feature *pfs;
+ struct resource *res;
+ u64 res_start;
+ int size, ret;
+
+ pfs = &tpmi_info->tpmi_features[i];
+
+ res = &vsec_dev->resource[i];
+ if (!res)
+ continue;
+
+ res_start = res->start;
+ size = resource_size(res);
+ if (size < 0)
+ continue;
+
+ ret = tpmi_fetch_pfs_header(pfs, res_start, size);
+ if (ret)
+ continue;
+
+ if (!pfs_start)
+ pfs_start = res_start;
+
+ pfs->pfs_header.cap_offset *= 1024;
+
+ pfs->vsec_offset = pfs_start + pfs->pfs_header.cap_offset;
+
+ /*
+ * Process TPMI_INFO to get PCI device to CPU package ID.
+ * Device nodes for TPMI features are not created in this
+ * for loop. So, the mapping information will be available
+ * when actual device nodes created outside this
+ * loop via tpmi_create_devices().
+ */
+ if (pfs->pfs_header.tpmi_id == TPMI_INFO_ID)
+ tpmi_process_info(tpmi_info, pfs);
+ }
+
+ tpmi_info->pfs_start = pfs_start;
+
+ auxiliary_set_drvdata(auxdev, tpmi_info);
+
+ return tpmi_create_devices(tpmi_info);
+}
+
+static int tpmi_probe(struct auxiliary_device *auxdev,
+ const struct auxiliary_device_id *id)
+{
+ return intel_vsec_tpmi_init(auxdev);
+}
+
+/*
+ * Remove callback is not needed currently as there is no
+ * cleanup required. All memory allocs are device managed. All
+ * devices created by this modules are also device managed.
+ */
+
+static const struct auxiliary_device_id tpmi_id_table[] = {
+ { .name = "intel_vsec.tpmi" },
+ {}
+};
+MODULE_DEVICE_TABLE(auxiliary, tpmi_id_table);
+
+static struct auxiliary_driver tpmi_aux_driver = {
+ .id_table = tpmi_id_table,
+ .probe = tpmi_probe,
+};
+
+module_auxiliary_driver(tpmi_aux_driver);
+
+MODULE_IMPORT_NS(INTEL_VSEC);
+MODULE_DESCRIPTION("Intel TPMI enumeration module");
+MODULE_LICENSE("GPL");