1 files changed, 415 insertions, 0 deletions
diff --git a/drivers/platform/x86/intel/tpmi.c b/drivers/platform/x86/intel/tpmi.c
new file mode 100644
index 000000000000..c60733261c89
--- /dev/null
+++ b/drivers/platform/x86/intel/tpmi.c
@@ -0,0 +1,415 @@
+// 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");