platform/x86/intel: Move intel_pmt from MFD to Auxiliary Bus

Intel Platform Monitoring Technology (PMT) support is indicated by presence
of an Intel defined PCIe Designated Vendor Specific Extended Capabilities
(DVSEC) structure with a PMT specific ID. The current MFD implementation
creates child devices for each PMT feature, currently telemetry, watcher,
and crashlog. However DVSEC structures may also be used by Intel to
indicate support for other features. The Out Of Band Management Services
Module (OOBMSM) uses DVSEC to enumerate several features, including PMT.
In order to support them it is necessary to modify the intel_pmt driver to
handle the creation of the child devices more generically. To that end,
modify the driver to create child devices for any VSEC/DVSEC features on
supported devices (indicated by PCI ID).  Additionally, move the
implementation from MFD to the Auxiliary bus.  VSEC/DVSEC features are
really multifunctional PCI devices, not platform devices as MFD was
designed for. Auxiliary bus gives more flexibility by allowing the
definition of custom structures that can be shared between associated
auxiliary devices and the parent device. Also, rename the driver from
intel_pmt to intel_vsec to better reflect the purpose.

This series also removes the current runtime pm support which was not
complete to begin with. None of the current devices require runtime pm.
However the support will be replaced when a device is added that requires
it.

Reviewed-by: Mark Gross <markgross@kernel.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Link: https://lore.kernel.org/r/20211208015015.891275-4-david.e.box@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 408 insertions, 0 deletions

diff --git a/drivers/platform/x86/intel/vsec.c b/drivers/platform/x86/intel/vsec.c
new file mode 100644
index 000000000000..c3bdd75ed690
--- /dev/null
+++ b/drivers/platform/x86/intel/vsec.c
@@ -0,0 +1,408 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Intel Vendor Specific Extended Capabilities auxiliary bus driver
+ *
+ * Copyright (c) 2021, Intel Corporation.
+ * All Rights Reserved.
+ *
+ * Author: David E. Box <david.e.box@linux.intel.com>
+ *
+ * This driver discovers and creates auxiliary devices for Intel defined PCIe
+ * "Vendor Specific" and "Designated Vendor Specific" Extended Capabilities,
+ * VSEC and DVSEC respectively. The driver supports features on specific PCIe
+ * endpoints that exist primarily to expose them.
+ */
+
+#include <linux/auxiliary_bus.h>
+#include <linux/bits.h>
+#include <linux/kernel.h>
+#include <linux/idr.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/types.h>
+
+#include "vsec.h"
+
+/* Intel DVSEC offsets */
+#define INTEL_DVSEC_ENTRIES		0xA
+#define INTEL_DVSEC_SIZE		0xB
+#define INTEL_DVSEC_TABLE		0xC
+#define INTEL_DVSEC_TABLE_BAR(x)	((x) & GENMASK(2, 0))
+#define INTEL_DVSEC_TABLE_OFFSET(x)	((x) & GENMASK(31, 3))
+#define TABLE_OFFSET_SHIFT		3
+
+static DEFINE_IDA(intel_vsec_ida);
+
+/**
+ * struct intel_vsec_header - Common fields of Intel VSEC and DVSEC registers.
+ * @rev:         Revision ID of the VSEC/DVSEC register space
+ * @length:      Length of the VSEC/DVSEC register space
+ * @id:          ID of the feature
+ * @num_entries: Number of instances of the feature
+ * @entry_size:  Size of the discovery table for each feature
+ * @tbir:        BAR containing the discovery tables
+ * @offset:      BAR offset of start of the first discovery table
+ */
+struct intel_vsec_header {
+	u8	rev;
+	u16	length;
+	u16	id;
+	u8	num_entries;
+	u8	entry_size;
+	u8	tbir;
+	u32	offset;
+};
+
+/* Platform specific data */
+struct intel_vsec_platform_info {
+	struct intel_vsec_header **capabilities;
+	unsigned long quirks;
+};
+
+enum intel_vsec_id {
+	VSEC_ID_TELEMETRY	= 2,
+	VSEC_ID_WATCHER		= 3,
+	VSEC_ID_CRASHLOG	= 4,
+};
+
+static enum intel_vsec_id intel_vsec_allow_list[] = {
+	VSEC_ID_TELEMETRY,
+	VSEC_ID_WATCHER,
+	VSEC_ID_CRASHLOG,
+};
+
+static const char *intel_vsec_name(enum intel_vsec_id id)
+{
+	switch (id) {
+	case VSEC_ID_TELEMETRY:
+		return "telemetry";
+
+	case VSEC_ID_WATCHER:
+		return "watcher";
+
+	case VSEC_ID_CRASHLOG:
+		return "crashlog";
+
+	default:
+		return NULL;
+	}
+}
+
+static bool intel_vsec_allowed(u16 id)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(intel_vsec_allow_list); i++)
+		if (intel_vsec_allow_list[i] == id)
+			return true;
+
+	return false;
+}
+
+static bool intel_vsec_disabled(u16 id, unsigned long quirks)
+{
+	switch (id) {
+	case VSEC_ID_WATCHER:
+		return !!(quirks & VSEC_QUIRK_NO_WATCHER);
+
+	case VSEC_ID_CRASHLOG:
+		return !!(quirks & VSEC_QUIRK_NO_CRASHLOG);
+
+	default:
+		return false;
+	}
+}
+
+static void intel_vsec_remove_aux(void *data)
+{
+	auxiliary_device_delete(data);
+	auxiliary_device_uninit(data);
+}
+
+static void intel_vsec_dev_release(struct device *dev)
+{
+	struct intel_vsec_device *intel_vsec_dev = dev_to_ivdev(dev);
+
+	ida_free(intel_vsec_dev->ida, intel_vsec_dev->auxdev.id);
+	kfree(intel_vsec_dev->resource);
+	kfree(intel_vsec_dev);
+}
+
+static int intel_vsec_add_aux(struct pci_dev *pdev, struct intel_vsec_device *intel_vsec_dev,
+			      const char *name)
+{
+	struct auxiliary_device *auxdev = &intel_vsec_dev->auxdev;
+	int ret;
+
+	ret = ida_alloc(intel_vsec_dev->ida, GFP_KERNEL);
+	if (ret < 0) {
+		kfree(intel_vsec_dev);
+		return ret;
+	}
+
+	auxdev->id = ret;
+	auxdev->name = name;
+	auxdev->dev.parent = &pdev->dev;
+	auxdev->dev.release = intel_vsec_dev_release;
+
+	ret = auxiliary_device_init(auxdev);
+	if (ret < 0) {
+		ida_free(intel_vsec_dev->ida, auxdev->id);
+		kfree(intel_vsec_dev->resource);
+		kfree(intel_vsec_dev);
+		return ret;
+	}
+
+	ret = auxiliary_device_add(auxdev);
+	if (ret < 0) {
+		auxiliary_device_uninit(auxdev);
+		return ret;
+	}
+
+	return devm_add_action_or_reset(&pdev->dev, intel_vsec_remove_aux, auxdev);
+}
+
+static int intel_vsec_add_dev(struct pci_dev *pdev, struct intel_vsec_header *header,
+			   unsigned long quirks)
+{
+	struct intel_vsec_device *intel_vsec_dev;
+	struct resource *res, *tmp;
+	int i;
+
+	if (!intel_vsec_allowed(header->id) || intel_vsec_disabled(header->id, quirks))
+		return -EINVAL;
+
+	if (!header->num_entries) {
+		dev_dbg(&pdev->dev, "Invalid 0 entry count for header id %d\n", header->id);
+		return -EINVAL;
+	}
+
+	if (!header->entry_size) {
+		dev_dbg(&pdev->dev, "Invalid 0 entry size for header id %d\n", header->id);
+		return -EINVAL;
+	}
+
+	intel_vsec_dev = kzalloc(sizeof(*intel_vsec_dev), GFP_KERNEL);
+	if (!intel_vsec_dev)
+		return -ENOMEM;
+
+	res = kcalloc(header->num_entries, sizeof(*res), GFP_KERNEL);
+	if (!res) {
+		kfree(intel_vsec_dev);
+		return -ENOMEM;
+	}
+
+	if (quirks & VSEC_QUIRK_TABLE_SHIFT)
+		header->offset >>= TABLE_OFFSET_SHIFT;
+
+	/*
+	 * The DVSEC/VSEC contains the starting offset and count for a block of
+	 * discovery tables. Create a resource array of these tables to the
+	 * auxiliary device driver.
+	 */
+	for (i = 0, tmp = res; i < header->num_entries; i++, tmp++) {
+		tmp->start = pdev->resource[header->tbir].start +
+			     header->offset + i * (header->entry_size * sizeof(u32));
+		tmp->end = tmp->start + (header->entry_size * sizeof(u32)) - 1;
+		tmp->flags = IORESOURCE_MEM;
+	}
+
+	intel_vsec_dev->pcidev = pdev;
+	intel_vsec_dev->resource = res;
+	intel_vsec_dev->num_resources = header->num_entries;
+	intel_vsec_dev->quirks = quirks;
+	intel_vsec_dev->ida = &intel_vsec_ida;
+
+	return intel_vsec_add_aux(pdev, intel_vsec_dev, intel_vsec_name(header->id));
+}
+
+static bool intel_vsec_walk_header(struct pci_dev *pdev, unsigned long quirks,
+				struct intel_vsec_header **header)
+{
+	bool have_devices = false;
+	int ret;
+
+	for ( ; *header; header++) {
+		ret = intel_vsec_add_dev(pdev, *header, quirks);
+		if (ret)
+			dev_info(&pdev->dev, "Could not add device for DVSEC id %d\n",
+				 (*header)->id);
+		else
+			have_devices = true;
+	}
+
+	return have_devices;
+}
+
+static bool intel_vsec_walk_dvsec(struct pci_dev *pdev, unsigned long quirks)
+{
+	bool have_devices = false;
+	int pos = 0;
+
+	do {
+		struct intel_vsec_header header;
+		u32 table, hdr;
+		u16 vid;
+		int ret;
+
+		pos = pci_find_next_ext_capability(pdev, pos, PCI_EXT_CAP_ID_DVSEC);
+		if (!pos)
+			break;
+
+		pci_read_config_dword(pdev, pos + PCI_DVSEC_HEADER1, &hdr);
+		vid = PCI_DVSEC_HEADER1_VID(hdr);
+		if (vid != PCI_VENDOR_ID_INTEL)
+			continue;
+
+		/* Support only revision 1 */
+		header.rev = PCI_DVSEC_HEADER1_REV(hdr);
+		if (header.rev != 1) {
+			dev_info(&pdev->dev, "Unsupported DVSEC revision %d\n", header.rev);
+			continue;
+		}
+
+		header.length = PCI_DVSEC_HEADER1_LEN(hdr);
+
+		pci_read_config_byte(pdev, pos + INTEL_DVSEC_ENTRIES, &header.num_entries);
+		pci_read_config_byte(pdev, pos + INTEL_DVSEC_SIZE, &header.entry_size);
+		pci_read_config_dword(pdev, pos + INTEL_DVSEC_TABLE, &table);
+
+		header.tbir = INTEL_DVSEC_TABLE_BAR(table);
+		header.offset = INTEL_DVSEC_TABLE_OFFSET(table);
+
+		pci_read_config_dword(pdev, pos + PCI_DVSEC_HEADER2, &hdr);
+		header.id = PCI_DVSEC_HEADER2_ID(hdr);
+
+		ret = intel_vsec_add_dev(pdev, &header, quirks);
+		if (ret)
+			continue;
+
+		have_devices = true;
+	} while (true);
+
+	return have_devices;
+}
+
+static bool intel_vsec_walk_vsec(struct pci_dev *pdev, unsigned long quirks)
+{
+	bool have_devices = false;
+	int pos = 0;
+
+	do {
+		struct intel_vsec_header header;
+		u32 table, hdr;
+		int ret;
+
+		pos = pci_find_next_ext_capability(pdev, pos, PCI_EXT_CAP_ID_VNDR);
+		if (!pos)
+			break;
+
+		pci_read_config_dword(pdev, pos + PCI_VNDR_HEADER, &hdr);
+
+		/* Support only revision 1 */
+		header.rev = PCI_VNDR_HEADER_REV(hdr);
+		if (header.rev != 1) {
+			dev_info(&pdev->dev, "Unsupported VSEC revision %d\n", header.rev);
+			continue;
+		}
+
+		header.id = PCI_VNDR_HEADER_ID(hdr);
+		header.length = PCI_VNDR_HEADER_LEN(hdr);
+
+		/* entry, size, and table offset are the same as DVSEC */
+		pci_read_config_byte(pdev, pos + INTEL_DVSEC_ENTRIES, &header.num_entries);
+		pci_read_config_byte(pdev, pos + INTEL_DVSEC_SIZE, &header.entry_size);
+		pci_read_config_dword(pdev, pos + INTEL_DVSEC_TABLE, &table);
+
+		header.tbir = INTEL_DVSEC_TABLE_BAR(table);
+		header.offset = INTEL_DVSEC_TABLE_OFFSET(table);
+
+		ret = intel_vsec_add_dev(pdev, &header, quirks);
+		if (ret)
+			continue;
+
+		have_devices = true;
+	} while (true);
+
+	return have_devices;
+}
+
+static int intel_vsec_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+	struct intel_vsec_platform_info *info;
+	bool have_devices = false;
+	unsigned long quirks = 0;
+	int ret;
+
+	ret = pcim_enable_device(pdev);
+	if (ret)
+		return ret;
+
+	info = (struct intel_vsec_platform_info *)id->driver_data;
+	if (info)
+		quirks = info->quirks;
+
+	if (intel_vsec_walk_dvsec(pdev, quirks))
+		have_devices = true;
+
+	if (intel_vsec_walk_vsec(pdev, quirks))
+		have_devices = true;
+
+	if (info && (info->quirks & VSEC_QUIRK_NO_DVSEC) &&
+	    intel_vsec_walk_header(pdev, quirks, info->capabilities))
+		have_devices = true;
+
+	if (!have_devices)
+		return -ENODEV;
+
+	return 0;
+}
+
+/* TGL info */
+static const struct intel_vsec_platform_info tgl_info = {
+	.quirks = VSEC_QUIRK_NO_WATCHER | VSEC_QUIRK_NO_CRASHLOG | VSEC_QUIRK_TABLE_SHIFT,
+};
+
+/* DG1 info */
+static struct intel_vsec_header dg1_telemetry = {
+	.length = 0x10,
+	.id = 2,
+	.num_entries = 1,
+	.entry_size = 3,
+	.tbir = 0,
+	.offset = 0x466000,
+};
+
+static struct intel_vsec_header *dg1_capabilities[] = {
+	&dg1_telemetry,
+	NULL
+};
+
+static const struct intel_vsec_platform_info dg1_info = {
+	.capabilities = dg1_capabilities,
+	.quirks = VSEC_QUIRK_NO_DVSEC,
+};
+
+#define PCI_DEVICE_ID_INTEL_VSEC_ADL		0x467d
+#define PCI_DEVICE_ID_INTEL_VSEC_DG1		0x490e
+#define PCI_DEVICE_ID_INTEL_VSEC_OOBMSM		0x09a7
+#define PCI_DEVICE_ID_INTEL_VSEC_TGL		0x9a0d
+static const struct pci_device_id intel_vsec_pci_ids[] = {
+	{ PCI_DEVICE_DATA(INTEL, VSEC_ADL, &tgl_info) },
+	{ PCI_DEVICE_DATA(INTEL, VSEC_DG1, &dg1_info) },
+	{ PCI_DEVICE_DATA(INTEL, VSEC_OOBMSM, NULL) },
+	{ PCI_DEVICE_DATA(INTEL, VSEC_TGL, &tgl_info) },
+	{ }
+};
+MODULE_DEVICE_TABLE(pci, intel_vsec_pci_ids);
+
+static struct pci_driver intel_vsec_pci_driver = {
+	.name = "intel_vsec",
+	.id_table = intel_vsec_pci_ids,
+	.probe = intel_vsec_pci_probe,
+};
+module_pci_driver(intel_vsec_pci_driver);
+
+MODULE_AUTHOR("David E. Box <david.e.box@linux.intel.com>");
+MODULE_DESCRIPTION("Intel Extended Capabilities auxiliary bus driver");
+MODULE_LICENSE("GPL v2");