1 files changed, 298 insertions, 0 deletions
diff --git a/drivers/platform/x86/intel_pmt_class.c b/drivers/platform/x86/intel_pmt_class.c
new file mode 100644
index 000000000000..c8939fba4509
--- /dev/null
+++ b/drivers/platform/x86/intel_pmt_class.c
@@ -0,0 +1,298 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Intel Platform Monitory Technology Telemetry driver
+ *
+ * Copyright (c) 2020, Intel Corporation.
+ * All Rights Reserved.
+ *
+ * Author: "Alexander Duyck" <alexander.h.duyck@linux.intel.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/pci.h>
+
+#include "intel_pmt_class.h"
+
+#define PMT_XA_START		0
+#define PMT_XA_MAX		INT_MAX
+#define PMT_XA_LIMIT		XA_LIMIT(PMT_XA_START, PMT_XA_MAX)
+
+/*
+ * sysfs
+ */
+static ssize_t
+intel_pmt_read(struct file *filp, struct kobject *kobj,
+	       struct bin_attribute *attr, char *buf, loff_t off,
+	       size_t count)
+{
+	struct intel_pmt_entry *entry = container_of(attr,
+						     struct intel_pmt_entry,
+						     pmt_bin_attr);
+
+	if (off < 0)
+		return -EINVAL;
+
+	if (off >= entry->size)
+		return 0;
+
+	if (count > entry->size - off)
+		count = entry->size - off;
+
+	memcpy_fromio(buf, entry->base + off, count);
+
+	return count;
+}
+
+static int
+intel_pmt_mmap(struct file *filp, struct kobject *kobj,
+		struct bin_attribute *attr, struct vm_area_struct *vma)
+{
+	struct intel_pmt_entry *entry = container_of(attr,
+						     struct intel_pmt_entry,
+						     pmt_bin_attr);
+	unsigned long vsize = vma->vm_end - vma->vm_start;
+	struct device *dev = kobj_to_dev(kobj);
+	unsigned long phys = entry->base_addr;
+	unsigned long pfn = PFN_DOWN(phys);
+	unsigned long psize;
+
+	if (vma->vm_flags & (VM_WRITE | VM_MAYWRITE))
+		return -EROFS;
+
+	psize = (PFN_UP(entry->base_addr + entry->size) - pfn) * PAGE_SIZE;
+	if (vsize > psize) {
+		dev_err(dev, "Requested mmap size is too large\n");
+		return -EINVAL;
+	}
+
+	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+	if (io_remap_pfn_range(vma, vma->vm_start, pfn,
+		vsize, vma->vm_page_prot))
+		return -EAGAIN;
+
+	return 0;
+}
+
+static ssize_t
+guid_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct intel_pmt_entry *entry = dev_get_drvdata(dev);
+
+	return sprintf(buf, "0x%x\n", entry->guid);
+}
+static DEVICE_ATTR_RO(guid);
+
+static ssize_t size_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct intel_pmt_entry *entry = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%zu\n", entry->size);
+}
+static DEVICE_ATTR_RO(size);
+
+static ssize_t
+offset_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct intel_pmt_entry *entry = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%lu\n", offset_in_page(entry->base_addr));
+}
+static DEVICE_ATTR_RO(offset);
+
+static struct attribute *intel_pmt_attrs[] = {
+	&dev_attr_guid.attr,
+	&dev_attr_size.attr,
+	&dev_attr_offset.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(intel_pmt);
+
+static struct class intel_pmt_class = {
+	.name = "intel_pmt",
+	.owner = THIS_MODULE,
+	.dev_groups = intel_pmt_groups,
+};
+
+static int intel_pmt_populate_entry(struct intel_pmt_entry *entry,
+				    struct intel_pmt_header *header,
+				    struct device *dev,
+				    struct resource *disc_res)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev->parent);
+	u8 bir;
+
+	/*
+	 * The base offset should always be 8 byte aligned.
+	 *
+	 * For non-local access types the lower 3 bits of base offset
+	 * contains the index of the base address register where the
+	 * telemetry can be found.
+	 */
+	bir = GET_BIR(header->base_offset);
+
+	/* Local access and BARID only for now */
+	switch (header->access_type) {
+	case ACCESS_LOCAL:
+		if (bir) {
+			dev_err(dev,
+				"Unsupported BAR index %d for access type %d\n",
+				bir, header->access_type);
+			return -EINVAL;
+		}
+		/*
+		 * For access_type LOCAL, the base address is as follows:
+		 * base address = end of discovery region + base offset
+		 */
+		entry->base_addr = disc_res->end + 1 + header->base_offset;
+		break;
+	case ACCESS_BARID:
+		/*
+		 * If another BAR was specified then the base offset
+		 * represents the offset within that BAR. SO retrieve the
+		 * address from the parent PCI device and add offset.
+		 */
+		entry->base_addr = pci_resource_start(pci_dev, bir) +
+				   GET_ADDRESS(header->base_offset);
+		break;
+	default:
+		dev_err(dev, "Unsupported access type %d\n",
+			header->access_type);
+		return -EINVAL;
+	}
+
+	entry->guid = header->guid;
+	entry->size = header->size;
+
+	return 0;
+}
+
+static int intel_pmt_dev_register(struct intel_pmt_entry *entry,
+				  struct intel_pmt_namespace *ns,
+				  struct device *parent)
+{
+	struct resource res;
+	struct device *dev;
+	int ret;
+
+	ret = xa_alloc(ns->xa, &entry->devid, entry, PMT_XA_LIMIT, GFP_KERNEL);
+	if (ret)
+		return ret;
+
+	dev = device_create(&intel_pmt_class, parent, MKDEV(0, 0), entry,
+			    "%s%d", ns->name, entry->devid);
+
+	if (IS_ERR(dev)) {
+		dev_err(parent, "Could not create %s%d device node\n",
+			ns->name, entry->devid);
+		ret = PTR_ERR(dev);
+		goto fail_dev_create;
+	}
+
+	entry->kobj = &dev->kobj;
+
+	if (ns->attr_grp) {
+		ret = sysfs_create_group(entry->kobj, ns->attr_grp);
+		if (ret)
+			goto fail_sysfs;
+	}
+
+	/* if size is 0 assume no data buffer, so no file needed */
+	if (!entry->size)
+		return 0;
+
+	res.start = entry->base_addr;
+	res.end = res.start + entry->size - 1;
+	res.flags = IORESOURCE_MEM;
+
+	entry->base = devm_ioremap_resource(dev, &res);
+	if (IS_ERR(entry->base)) {
+		ret = PTR_ERR(entry->base);
+		goto fail_ioremap;
+	}
+
+	sysfs_bin_attr_init(&entry->pmt_bin_attr);
+	entry->pmt_bin_attr.attr.name = ns->name;
+	entry->pmt_bin_attr.attr.mode = 0440;
+	entry->pmt_bin_attr.mmap = intel_pmt_mmap;
+	entry->pmt_bin_attr.read = intel_pmt_read;
+	entry->pmt_bin_attr.size = entry->size;
+
+	ret = sysfs_create_bin_file(&dev->kobj, &entry->pmt_bin_attr);
+	if (!ret)
+		return 0;
+
+fail_ioremap:
+	if (ns->attr_grp)
+		sysfs_remove_group(entry->kobj, ns->attr_grp);
+fail_sysfs:
+	device_unregister(dev);
+fail_dev_create:
+	xa_erase(ns->xa, entry->devid);
+
+	return ret;
+}
+
+int intel_pmt_dev_create(struct intel_pmt_entry *entry,
+			 struct intel_pmt_namespace *ns,
+			 struct platform_device *pdev, int idx)
+{
+	struct intel_pmt_header header;
+	struct resource	*disc_res;
+	int ret = -ENODEV;
+
+	disc_res = platform_get_resource(pdev, IORESOURCE_MEM, idx);
+	if (!disc_res)
+		return ret;
+
+	entry->disc_table = devm_platform_ioremap_resource(pdev, idx);
+	if (IS_ERR(entry->disc_table))
+		return PTR_ERR(entry->disc_table);
+
+	ret = ns->pmt_header_decode(entry, &header, &pdev->dev);
+	if (ret)
+		return ret;
+
+	ret = intel_pmt_populate_entry(entry, &header, &pdev->dev, disc_res);
+	if (ret)
+		return ret;
+
+	return intel_pmt_dev_register(entry, ns, &pdev->dev);
+
+}
+EXPORT_SYMBOL_GPL(intel_pmt_dev_create);
+
+void intel_pmt_dev_destroy(struct intel_pmt_entry *entry,
+			   struct intel_pmt_namespace *ns)
+{
+	struct device *dev = kobj_to_dev(entry->kobj);
+
+	if (entry->size)
+		sysfs_remove_bin_file(entry->kobj, &entry->pmt_bin_attr);
+
+	if (ns->attr_grp)
+		sysfs_remove_group(entry->kobj, ns->attr_grp);
+
+	device_unregister(dev);
+	xa_erase(ns->xa, entry->devid);
+}
+EXPORT_SYMBOL_GPL(intel_pmt_dev_destroy);
+
+static int __init pmt_class_init(void)
+{
+	return class_register(&intel_pmt_class);
+}
+
+static void __exit pmt_class_exit(void)
+{
+	class_unregister(&intel_pmt_class);
+}
+
+module_init(pmt_class_init);
+module_exit(pmt_class_exit);
+
+MODULE_AUTHOR("Alexander Duyck <alexander.h.duyck@linux.intel.com>");
+MODULE_DESCRIPTION("Intel PMT Class driver");
+MODULE_LICENSE("GPL v2");