path: root/arch/x86/events/intel/uncore_discovery.c

/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Support Intel uncore PerfMon discovery mechanism.
 * Copyright(c) 2021 Intel Corporation.
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include "uncore.h"
#include "uncore_discovery.h"

static struct rb_root discovery_tables = RB_ROOT;
static int num_discovered_types[UNCORE_ACCESS_MAX];

static bool has_generic_discovery_table(void)
{
	struct pci_dev *dev;
	int dvsec;

	dev = pci_get_device(PCI_VENDOR_ID_INTEL, UNCORE_DISCOVERY_TABLE_DEVICE, NULL);
	if (!dev)
		return false;

	/* A discovery table device has the unique capability ID. */
	dvsec = pci_find_next_ext_capability(dev, 0, UNCORE_EXT_CAP_ID_DISCOVERY);
	pci_dev_put(dev);
	if (dvsec)
		return true;

	return false;
}

static int logical_die_id;

static int get_device_die_id(struct pci_dev *dev)
{
	int cpu, node = pcibus_to_node(dev->bus);

	/*
	 * If the NUMA info is not available, assume that the logical die id is
	 * continuous in the order in which the discovery table devices are
	 * detected.
	 */
	if (node < 0)
		return logical_die_id++;

	for_each_cpu(cpu, cpumask_of_node(node)) {
		struct cpuinfo_x86 *c = &cpu_data(cpu);

		if (c->initialized && cpu_to_node(cpu) == node)
			return c->logical_die_id;
	}

	/*
	 * All CPUs of a node may be offlined. For this case,
	 * the PCI and MMIO type of uncore blocks which are
	 * enumerated by the device will be unavailable.
	 */
	return -1;
}

#define __node_2_type(cur)	\
	rb_entry((cur), struct intel_uncore_discovery_type, node)

static inline int __type_cmp(const void *key, const struct rb_node *b)
{
	struct intel_uncore_discovery_type *type_b = __node_2_type(b);
	const u16 *type_id = key;

	if (type_b->type > *type_id)
		return -1;
	else if (type_b->type < *type_id)
		return 1;

	return 0;
}

static inline struct intel_uncore_discovery_type *
search_uncore_discovery_type(u16 type_id)
{
	struct rb_node *node = rb_find(&type_id, &discovery_tables, __type_cmp);

	return (node) ? __node_2_type(node) : NULL;
}

static inline bool __type_less(struct rb_node *a, const struct rb_node *b)
{
	return (__node_2_type(a)->type < __node_2_type(b)->type);
}

static struct intel_uncore_discovery_type *
add_uncore_discovery_type(struct uncore_unit_discovery *unit)
{
	struct intel_uncore_discovery_type *type;

	if (unit->access_type >= UNCORE_ACCESS_MAX) {
		pr_warn("Unsupported access type %d\n", unit->access_type);
		return NULL;
	}

	type = kzalloc(sizeof(struct intel_uncore_discovery_type), GFP_KERNEL);
	if (!type)
		return NULL;

	type->box_ctrl_die = kcalloc(__uncore_max_dies, sizeof(u64), GFP_KERNEL);
	if (!type->box_ctrl_die)
		goto free_type;

	type->access_type = unit->access_type;
	num_discovered_types[type->access_type]++;
	type->type = unit->box_type;

	rb_add(&type->node, &discovery_tables, __type_less);

	return type;

free_type:
	kfree(type);

	return NULL;

}

static struct intel_uncore_discovery_type *
get_uncore_discovery_type(struct uncore_unit_discovery *unit)
{
	struct intel_uncore_discovery_type *type;

	type = search_uncore_discovery_type(unit->box_type);
	if (type)
		return type;

	return add_uncore_discovery_type(unit);
}

static void
uncore_insert_box_info(struct uncore_unit_discovery *unit,
		       int die, bool parsed)
{
	struct intel_uncore_discovery_type *type;
	unsigned int *box_offset, *ids;
	int i;

	if (WARN_ON_ONCE(!unit->ctl || !unit->ctl_offset || !unit->ctr_offset))
		return;

	if (parsed) {
		type = search_uncore_discovery_type(unit->box_type);
		if (WARN_ON_ONCE(!type))
			return;
		/* Store the first box of each die */
		if (!type->box_ctrl_die[die])
			type->box_ctrl_die[die] = unit->ctl;
		return;
	}

	type = get_uncore_discovery_type(unit);
	if (!type)
		return;

	box_offset = kcalloc(type->num_boxes + 1, sizeof(unsigned int), GFP_KERNEL);
	if (!box_offset)
		return;

	ids = kcalloc(type->num_boxes + 1, sizeof(unsigned int), GFP_KERNEL);
	if (!ids)
		goto free_box_offset;

	/* Store generic information for the first box */
	if (!type->num_boxes) {
		type->box_ctrl = unit->ctl;
		type->box_ctrl_die[die] = unit->ctl;
		type->num_counters = unit->num_regs;
		type->counter_width = unit->bit_width;
		type->ctl_offset = unit->ctl_offset;
		type->ctr_offset = unit->ctr_offset;
		*ids = unit->box_id;
		goto end;
	}

	for (i = 0; i < type->num_boxes; i++) {
		ids[i] = type->ids[i];
		box_offset[i] = type->box_offset[i];

		if (WARN_ON_ONCE(unit->box_id == ids[i]))
			goto free_ids;
	}
	ids[i] = unit->box_id;
	box_offset[i] = unit->ctl - type->box_ctrl;
	kfree(type->ids);
	kfree(type->box_offset);
end:
	type->ids = ids;
	type->box_offset = box_offset;
	type->num_boxes++;
	return;

free_ids:
	kfree(ids);

free_box_offset:
	kfree(box_offset);

}

static int parse_discovery_table(struct pci_dev *dev, int die,
				 u32 bar_offset, bool *parsed)
{
	struct uncore_global_discovery global;
	struct uncore_unit_discovery unit;
	void __iomem *io_addr;
	resource_size_t addr;
	unsigned long size;
	u32 val;
	int i;

	pci_read_config_dword(dev, bar_offset, &val);

	if (val & UNCORE_DISCOVERY_MASK)
		return -EINVAL;

	addr = (resource_size_t)(val & ~UNCORE_DISCOVERY_MASK);
	size = UNCORE_DISCOVERY_GLOBAL_MAP_SIZE;
	io_addr = ioremap(addr, size);
	if (!io_addr)
		return -ENOMEM;

	/* Read Global Discovery State */
	memcpy_fromio(&global, io_addr, sizeof(struct uncore_global_discovery));
	if (uncore_discovery_invalid_unit(global)) {
		pr_info("Invalid Global Discovery State: 0x%llx 0x%llx 0x%llx\n",
			global.table1, global.ctl, global.table3);
		iounmap(io_addr);
		return -EINVAL;
	}
	iounmap(io_addr);

	size = (1 + global.max_units) * global.stride * 8;
	io_addr = ioremap(addr, size);
	if (!io_addr)
		return -ENOMEM;

	/* Parsing Unit Discovery State */
	for (i = 0; i < global.max_units; i++) {
		memcpy_fromio(&unit, io_addr + (i + 1) * (global.stride * 8),
			      sizeof(struct uncore_unit_discovery));

		if (uncore_discovery_invalid_unit(unit))
			continue;

		if (unit.access_type >= UNCORE_ACCESS_MAX)
			continue;

		uncore_insert_box_info(&unit, die, *parsed);
	}

	*parsed = true;
	iounmap(io_addr);
	return 0;
}

bool intel_uncore_has_discovery_tables(void)
{
	u32 device, val, entry_id, bar_offset;
	int die, dvsec = 0, ret = true;
	struct pci_dev *dev = NULL;
	bool parsed = false;

	if (has_generic_discovery_table())
		device = UNCORE_DISCOVERY_TABLE_DEVICE;
	else
		device = PCI_ANY_ID;

	/*
	 * Start a new search and iterates through the list of
	 * the discovery table devices.
	 */
	while ((dev = pci_get_device(PCI_VENDOR_ID_INTEL, device, dev)) != NULL) {
		while ((dvsec = pci_find_next_ext_capability(dev, dvsec, UNCORE_EXT_CAP_ID_DISCOVERY))) {
			pci_read_config_dword(dev, dvsec + UNCORE_DISCOVERY_DVSEC_OFFSET, &val);
			entry_id = val & UNCORE_DISCOVERY_DVSEC_ID_MASK;
			if (entry_id != UNCORE_DISCOVERY_DVSEC_ID_PMON)
				continue;

			pci_read_config_dword(dev, dvsec + UNCORE_DISCOVERY_DVSEC2_OFFSET, &val);

			if (val & ~UNCORE_DISCOVERY_DVSEC2_BIR_MASK) {
				ret = false;
				goto err;
			}
			bar_offset = UNCORE_DISCOVERY_BIR_BASE +
				     (val & UNCORE_DISCOVERY_DVSEC2_BIR_MASK) * UNCORE_DISCOVERY_BIR_STEP;

			die = get_device_die_id(dev);
			if (die < 0)
				continue;

			parse_discovery_table(dev, die, bar_offset, &parsed);
		}
	}

	/* None of the discovery tables are available */
	if (!parsed)
		ret = false;
err:
	pci_dev_put(dev);

	return ret;
}

void intel_uncore_clear_discovery_tables(void)
{
	struct intel_uncore_discovery_type *type, *next;

	rbtree_postorder_for_each_entry_safe(type, next, &discovery_tables, node) {
		kfree(type->box_ctrl_die);
		kfree(type);
	}
}