1 files changed, 324 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-imc.c b/arch/powerpc/platforms/powernv/opal-imc.c
new file mode 100644
index 000000000..828fc4d88
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal-imc.c
@@ -0,0 +1,324 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * OPAL IMC interface detection driver
+ * Supported on POWERNV platform
+ *
+ * Copyright	(C) 2017 Madhavan Srinivasan, IBM Corporation.
+ *		(C) 2017 Anju T Sudhakar, IBM Corporation.
+ *		(C) 2017 Hemant K Shaw, IBM Corporation.
+ */
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/crash_dump.h>
+#include <linux/debugfs.h>
+#include <asm/opal.h>
+#include <asm/io.h>
+#include <asm/imc-pmu.h>
+#include <asm/cputhreads.h>
+
+static struct dentry *imc_debugfs_parent;
+
+/* Helpers to export imc command and mode via debugfs */
+static int imc_mem_get(void *data, u64 *val)
+{
+	*val = cpu_to_be64(*(u64 *)data);
+	return 0;
+}
+
+static int imc_mem_set(void *data, u64 val)
+{
+	*(u64 *)data = cpu_to_be64(val);
+	return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(fops_imc_x64, imc_mem_get, imc_mem_set, "0x%016llx\n");
+
+static void imc_debugfs_create_x64(const char *name, umode_t mode,
+				   struct dentry *parent, u64  *value)
+{
+	debugfs_create_file_unsafe(name, mode, parent, value, &fops_imc_x64);
+}
+
+/*
+ * export_imc_mode_and_cmd: Create a debugfs interface
+ *                     for imc_cmd and imc_mode
+ *                     for each node in the system.
+ *  imc_mode and imc_cmd can be changed by echo into
+ *  this interface.
+ */
+static void export_imc_mode_and_cmd(struct device_node *node,
+				    struct imc_pmu *pmu_ptr)
+{
+	static u64 loc, *imc_mode_addr, *imc_cmd_addr;
+	char mode[16], cmd[16];
+	u32 cb_offset;
+	struct imc_mem_info *ptr = pmu_ptr->mem_info;
+
+	imc_debugfs_parent = debugfs_create_dir("imc", arch_debugfs_dir);
+
+	if (of_property_read_u32(node, "cb_offset", &cb_offset))
+		cb_offset = IMC_CNTL_BLK_OFFSET;
+
+	while (ptr->vbase != NULL) {
+		loc = (u64)(ptr->vbase) + cb_offset;
+		imc_mode_addr = (u64 *)(loc + IMC_CNTL_BLK_MODE_OFFSET);
+		sprintf(mode, "imc_mode_%d", (u32)(ptr->id));
+		imc_debugfs_create_x64(mode, 0600, imc_debugfs_parent,
+				       imc_mode_addr);
+
+		imc_cmd_addr = (u64 *)(loc + IMC_CNTL_BLK_CMD_OFFSET);
+		sprintf(cmd, "imc_cmd_%d", (u32)(ptr->id));
+		imc_debugfs_create_x64(cmd, 0600, imc_debugfs_parent,
+				       imc_cmd_addr);
+		ptr++;
+	}
+}
+
+/*
+ * imc_get_mem_addr_nest: Function to get nest counter memory region
+ * for each chip
+ */
+static int imc_get_mem_addr_nest(struct device_node *node,
+				 struct imc_pmu *pmu_ptr,
+				 u32 offset)
+{
+	int nr_chips = 0, i;
+	u64 *base_addr_arr, baddr;
+	u32 *chipid_arr;
+
+	nr_chips = of_property_count_u32_elems(node, "chip-id");
+	if (nr_chips <= 0)
+		return -ENODEV;
+
+	base_addr_arr = kcalloc(nr_chips, sizeof(*base_addr_arr), GFP_KERNEL);
+	if (!base_addr_arr)
+		return -ENOMEM;
+
+	chipid_arr = kcalloc(nr_chips, sizeof(*chipid_arr), GFP_KERNEL);
+	if (!chipid_arr) {
+		kfree(base_addr_arr);
+		return -ENOMEM;
+	}
+
+	if (of_property_read_u32_array(node, "chip-id", chipid_arr, nr_chips))
+		goto error;
+
+	if (of_property_read_u64_array(node, "base-addr", base_addr_arr,
+								nr_chips))
+		goto error;
+
+	pmu_ptr->mem_info = kcalloc(nr_chips + 1, sizeof(*pmu_ptr->mem_info),
+				    GFP_KERNEL);
+	if (!pmu_ptr->mem_info)
+		goto error;
+
+	for (i = 0; i < nr_chips; i++) {
+		pmu_ptr->mem_info[i].id = chipid_arr[i];
+		baddr = base_addr_arr[i] + offset;
+		pmu_ptr->mem_info[i].vbase = phys_to_virt(baddr);
+	}
+
+	pmu_ptr->imc_counter_mmaped = true;
+	kfree(base_addr_arr);
+	kfree(chipid_arr);
+	return 0;
+
+error:
+	kfree(base_addr_arr);
+	kfree(chipid_arr);
+	return -1;
+}
+
+/*
+ * imc_pmu_create : Takes the parent device which is the pmu unit, pmu_index
+ *		    and domain as the inputs.
+ * Allocates memory for the struct imc_pmu, sets up its domain, size and offsets
+ */
+static struct imc_pmu *imc_pmu_create(struct device_node *parent, int pmu_index, int domain)
+{
+	int ret = 0;
+	struct imc_pmu *pmu_ptr;
+	u32 offset;
+
+	/* Return for unknown domain */
+	if (domain < 0)
+		return NULL;
+
+	/* memory for pmu */
+	pmu_ptr = kzalloc(sizeof(*pmu_ptr), GFP_KERNEL);
+	if (!pmu_ptr)
+		return NULL;
+
+	/* Set the domain */
+	pmu_ptr->domain = domain;
+
+	ret = of_property_read_u32(parent, "size", &pmu_ptr->counter_mem_size);
+	if (ret)
+		goto free_pmu;
+
+	if (!of_property_read_u32(parent, "offset", &offset)) {
+		if (imc_get_mem_addr_nest(parent, pmu_ptr, offset))
+			goto free_pmu;
+	}
+
+	/* Function to register IMC pmu */
+	ret = init_imc_pmu(parent, pmu_ptr, pmu_index);
+	if (ret) {
+		pr_err("IMC PMU %s Register failed\n", pmu_ptr->pmu.name);
+		kfree(pmu_ptr->pmu.name);
+		if (pmu_ptr->domain == IMC_DOMAIN_NEST)
+			kfree(pmu_ptr->mem_info);
+		kfree(pmu_ptr);
+		return NULL;
+	}
+
+	return pmu_ptr;
+
+free_pmu:
+	kfree(pmu_ptr);
+	return NULL;
+}
+
+static void disable_nest_pmu_counters(void)
+{
+	int nid, cpu;
+	const struct cpumask *l_cpumask;
+
+	cpus_read_lock();
+	for_each_node_with_cpus(nid) {
+		l_cpumask = cpumask_of_node(nid);
+		cpu = cpumask_first_and(l_cpumask, cpu_online_mask);
+		if (cpu >= nr_cpu_ids)
+			continue;
+		opal_imc_counters_stop(OPAL_IMC_COUNTERS_NEST,
+				       get_hard_smp_processor_id(cpu));
+	}
+	cpus_read_unlock();
+}
+
+static void disable_core_pmu_counters(void)
+{
+	int cpu, rc;
+
+	cpus_read_lock();
+	/* Disable the IMC Core functions */
+	for_each_online_cpu(cpu) {
+		if (cpu_first_thread_sibling(cpu) != cpu)
+			continue;
+		rc = opal_imc_counters_stop(OPAL_IMC_COUNTERS_CORE,
+					    get_hard_smp_processor_id(cpu));
+		if (rc)
+			pr_err("%s: Failed to stop Core (cpu = %d)\n",
+				__func__, cpu);
+	}
+	cpus_read_unlock();
+}
+
+int get_max_nest_dev(void)
+{
+	struct device_node *node;
+	u32 pmu_units = 0, type;
+
+	for_each_compatible_node(node, NULL, IMC_DTB_UNIT_COMPAT) {
+		if (of_property_read_u32(node, "type", &type))
+			continue;
+
+		if (type == IMC_TYPE_CHIP)
+			pmu_units++;
+	}
+
+	return pmu_units;
+}
+
+static int opal_imc_counters_probe(struct platform_device *pdev)
+{
+	struct device_node *imc_dev = pdev->dev.of_node;
+	struct imc_pmu *pmu;
+	int pmu_count = 0, domain;
+	bool core_imc_reg = false, thread_imc_reg = false;
+	u32 type;
+
+	/*
+	 * Check whether this is kdump kernel. If yes, force the engines to
+	 * stop and return.
+	 */
+	if (is_kdump_kernel()) {
+		disable_nest_pmu_counters();
+		disable_core_pmu_counters();
+		return -ENODEV;
+	}
+
+	for_each_compatible_node(imc_dev, NULL, IMC_DTB_UNIT_COMPAT) {
+		pmu = NULL;
+		if (of_property_read_u32(imc_dev, "type", &type)) {
+			pr_warn("IMC Device without type property\n");
+			continue;
+		}
+
+		switch (type) {
+		case IMC_TYPE_CHIP:
+			domain = IMC_DOMAIN_NEST;
+			break;
+		case IMC_TYPE_CORE:
+			domain =IMC_DOMAIN_CORE;
+			break;
+		case IMC_TYPE_THREAD:
+			domain = IMC_DOMAIN_THREAD;
+			break;
+		case IMC_TYPE_TRACE:
+			domain = IMC_DOMAIN_TRACE;
+			break;
+		default:
+			pr_warn("IMC Unknown Device type \n");
+			domain = -1;
+			break;
+		}
+
+		pmu = imc_pmu_create(imc_dev, pmu_count, domain);
+		if (pmu != NULL) {
+			if (domain == IMC_DOMAIN_NEST) {
+				if (!imc_debugfs_parent)
+					export_imc_mode_and_cmd(imc_dev, pmu);
+				pmu_count++;
+			}
+			if (domain == IMC_DOMAIN_CORE)
+				core_imc_reg = true;
+			if (domain == IMC_DOMAIN_THREAD)
+				thread_imc_reg = true;
+		}
+	}
+
+	/* If core imc is not registered, unregister thread-imc */
+	if (!core_imc_reg && thread_imc_reg)
+		unregister_thread_imc();
+
+	return 0;
+}
+
+static void opal_imc_counters_shutdown(struct platform_device *pdev)
+{
+	/*
+	 * Function only stops the engines which is bare minimum.
+	 * TODO: Need to handle proper memory cleanup and pmu
+	 * unregister.
+	 */
+	disable_nest_pmu_counters();
+	disable_core_pmu_counters();
+}
+
+static const struct of_device_id opal_imc_match[] = {
+	{ .compatible = IMC_DTB_COMPAT },
+	{},
+};
+
+static struct platform_driver opal_imc_driver = {
+	.driver = {
+		.name = "opal-imc-counters",
+		.of_match_table = opal_imc_match,
+	},
+	.probe = opal_imc_counters_probe,
+	.shutdown = opal_imc_counters_shutdown,
+};
+
+builtin_platform_driver(opal_imc_driver);