clear-pkgs-linux-iot-lts2018/0486-ACRNTrace-add-acrn-trace-module.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: "Li, Fei1" <fei1.li@intel.com>
Date: Fri, 31 Aug 2018 10:58:57 +0800
Subject: [PATCH] ACRNTrace: add acrn trace module

Change-Id: I9bf3a0a13e411e15063eb50905875e86e5731d1b
Tracked-On: https://rtc.intel.com/ccm0001001/resource/itemName/com.ibm.team.workitem.WorkItem/216912
Signed-off-by: Li, Fei1 <fei1.li@intel.com>
---
 drivers/acrn/Kconfig      |   8 +
 drivers/acrn/Makefile     |   1 +
 drivers/acrn/acrn_trace.c | 297 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 306 insertions(+)
 create mode 100644 drivers/acrn/acrn_trace.c

diff --git a/drivers/acrn/Kconfig b/drivers/acrn/Kconfig
index f25f0ae77727..08b24a168167 100644
--- a/drivers/acrn/Kconfig
+++ b/drivers/acrn/Kconfig
@@ -3,3 +3,11 @@ config ACRN_SHARED_BUFFER
 	---help---
 	  Ring buffer shared between ACRN Hypervisor and its SOS.
 	  Help ACRN performance profiling.
+
+config ACRN_TRACE
+	tristate "Intel ACRN Hypervisor Trace support"
+	select ACRN_SHARED_BUFFER
+	---help---
+		This is the Trace driver for the Intel ACRN hypervisor.
+		You can say y to build it into the kernel, or m to build
+		it as a module.
diff --git a/drivers/acrn/Makefile b/drivers/acrn/Makefile
index bc475f8116e3..5430f4fa06fd 100644
--- a/drivers/acrn/Makefile
+++ b/drivers/acrn/Makefile
@@ -1 +1,2 @@
 obj-$(CONFIG_ACRN_SHARED_BUFFER) += sbuf.o
+obj-$(CONFIG_ACRN_TRACE) += acrn_trace.o
\ No newline at end of file
diff --git a/drivers/acrn/acrn_trace.c b/drivers/acrn/acrn_trace.c
new file mode 100644
index 000000000000..31470a3de6ac
--- /dev/null
+++ b/drivers/acrn/acrn_trace.c
@@ -0,0 +1,297 @@
+/*
+*
+* ACRN Trace module
+*
+* This file is provided under a dual BSD/GPLv2 license.  When using or
+* redistributing this file, you may do so under either license.
+*
+* GPL LICENSE SUMMARY
+*
+* Copyright (c) 2017 Intel Corporation. All rights reserved.
+*
+* This program is free software; you can redistribute it and/or modify
+* it under the terms of version 2 of the GNU General Public License as
+* published by the Free Software Foundation.
+*
+* This program is distributed in the hope that it will be useful, but
+* WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+* General Public License for more details.
+*
+* Contact Information: Yan, Like <like.yan@intel.com>
+*
+* BSD LICENSE
+*
+* Copyright (c) 2017 Intel Corporation. All rights reserved.
+*
+* Redistribution and use in source and binary forms, with or without
+* modification, are permitted provided that the following conditions
+* are met:
+*
+*   * Redistributions of source code must retain the above copyright
+*     notice, this list of conditions and the following disclaimer.
+*   * Redistributions in binary form must reproduce the above copyright
+*     notice, this list of conditions and the following disclaimer in
+*     the documentation and/or other materials provided with the
+*     distribution.
+*   * Neither the name of Intel Corporation nor the names of its
+*     contributors may be used to endorse or promote products derived
+*     from this software without specific prior written permission.
+*
+* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*
+* Like Yan <like.yan@intel.com>
+*
+*/
+
+#define pr_fmt(fmt) "ACRNTrace: " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/major.h>
+#include <linux/miscdevice.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+
+#include "sbuf.h"
+
+
+#define TRACE_SBUF_SIZE		(4 * 1024 * 1024)
+#define TRACE_ELEMENT_SIZE	32 /* byte */
+#define TRACE_ELEMENT_NUM	((TRACE_SBUF_SIZE - SBUF_HEAD_SIZE) /	\
+				TRACE_ELEMENT_SIZE)
+
+#define foreach_cpu(cpu, cpu_num)					\
+	for ((cpu) = 0; (cpu) < (cpu_num); (cpu)++)
+
+#define MAX_NR_CPUS	4
+/* actual physical cpu number, initialized by module init */
+static int pcpu_num;
+
+static int nr_cpus = MAX_NR_CPUS;
+module_param(nr_cpus, int, S_IRUSR | S_IWUSR);
+
+static atomic_t open_cnt[MAX_NR_CPUS];
+static shared_buf_t *sbuf_per_cpu[MAX_NR_CPUS];
+
+static inline int get_id_from_devname(struct file *filep)
+{
+	uint32_t cpuid;
+	int err;
+	char id_str[16];
+	struct miscdevice *dev = filep->private_data;
+
+	strncpy(id_str, (void *)dev->name + sizeof("acrn_trace_") - 1, 16);
+	id_str[15] = '\0';
+	err = kstrtoul(&id_str[0], 10, (unsigned long *)&cpuid);
+
+	if (err)
+		return err;
+
+	if (cpuid >= pcpu_num) {
+		pr_err("%s, failed to get cpuid, cpuid %d\n",
+			__func__, cpuid);
+		return -1;
+	}
+
+	return cpuid;
+}
+
+/************************************************************************
+ *
+ * file_operations functions
+ *
+ ***********************************************************************/
+static int acrn_trace_open(struct inode *inode, struct file *filep)
+{
+	int cpuid = get_id_from_devname(filep);
+
+	pr_debug("%s, cpu %d\n", __func__, cpuid);
+	if (cpuid < 0)
+		return -ENXIO;
+
+	/* More than one reader at the same time could get data messed up */
+	if (atomic_read(&open_cnt[cpuid]))
+		return -EBUSY;
+
+	atomic_inc(&open_cnt[cpuid]);
+
+	return 0;
+}
+
+static int acrn_trace_release(struct inode *inode, struct file *filep)
+{
+	int cpuid = get_id_from_devname(filep);
+
+	pr_debug("%s, cpu %d\n", __func__, cpuid);
+	if (cpuid < 0)
+		return -ENXIO;
+
+	atomic_dec(&open_cnt[cpuid]);
+
+	return 0;
+}
+
+static int acrn_trace_mmap(struct file *filep, struct vm_area_struct *vma)
+{
+	int cpuid = get_id_from_devname(filep);
+	phys_addr_t paddr;
+
+	pr_debug("%s, cpu %d\n", __func__, cpuid);
+	if (cpuid < 0)
+		return -ENXIO;
+
+	BUG_ON(!virt_addr_valid(sbuf_per_cpu[cpuid]));
+	paddr = virt_to_phys(sbuf_per_cpu[cpuid]);
+
+	if (remap_pfn_range(vma, vma->vm_start,
+				paddr >> PAGE_SHIFT,
+				vma->vm_end - vma->vm_start,
+				vma->vm_page_prot)) {
+		pr_err("Failed to mmap sbuf for cpu%d\n", cpuid);
+		return -EAGAIN;
+	}
+
+	return 0;
+}
+
+static const struct file_operations acrn_trace_fops = {
+	.owner  = THIS_MODULE,
+	.open   = acrn_trace_open,
+	.release = acrn_trace_release,
+	.mmap   = acrn_trace_mmap,
+};
+
+static struct miscdevice acrn_trace_dev0 = {
+	.name   = "acrn_trace_0",
+	.minor  = MISC_DYNAMIC_MINOR,
+	.fops   = &acrn_trace_fops,
+};
+
+static struct miscdevice acrn_trace_dev1 = {
+	.name   = "acrn_trace_1",
+	.minor  = MISC_DYNAMIC_MINOR,
+	.fops   = &acrn_trace_fops,
+};
+
+static struct miscdevice acrn_trace_dev2 = {
+	.name   = "acrn_trace_2",
+	.minor  = MISC_DYNAMIC_MINOR,
+	.fops   = &acrn_trace_fops,
+};
+
+static struct miscdevice acrn_trace_dev3 = {
+	.name   = "acrn_trace_3",
+	.minor  = MISC_DYNAMIC_MINOR,
+	.fops   = &acrn_trace_fops,
+};
+
+static struct miscdevice *acrn_trace_devs[4] = {
+	&acrn_trace_dev0,
+	&acrn_trace_dev1,
+	&acrn_trace_dev2,
+	&acrn_trace_dev3,
+};
+
+/*
+ * acrn_trace_init()
+ */
+static int __init acrn_trace_init(void)
+{
+	int ret = 0;
+	int i, cpu;
+
+	/* TBD: we could get the native cpu number by hypercall later */
+	pr_info("%s, cpu_num %d\n", __func__, nr_cpus);
+	if (nr_cpus > MAX_NR_CPUS) {
+		pr_err("nr_cpus %d exceed MAX_NR_CPUS %d !\n",
+			nr_cpus, MAX_NR_CPUS);
+		return -EINVAL;
+	}
+	pcpu_num = nr_cpus;
+
+	foreach_cpu(cpu, pcpu_num) {
+		/* allocate shared_buf */
+		sbuf_per_cpu[cpu] = sbuf_allocate(TRACE_ELEMENT_NUM,
+							TRACE_ELEMENT_SIZE);
+		if (!sbuf_per_cpu[cpu]) {
+			pr_err("Failed alloc SBuf, cpuid %d\n", cpu);
+			ret = -ENOMEM;
+			goto out_free;
+		}
+	}
+
+	foreach_cpu(cpu, pcpu_num) {
+		ret = sbuf_share_setup(cpu, 0, sbuf_per_cpu[cpu]);
+		if (ret < 0) {
+			pr_err("Failed to setup SBuf, cpuid %d\n", cpu);
+			goto out_sbuf;
+		}
+	}
+
+	foreach_cpu(cpu, pcpu_num) {
+		ret = misc_register(acrn_trace_devs[cpu]);
+		if (ret < 0) {
+			pr_err("Failed to register acrn_trace_%d, errno %d\n",
+				cpu, ret);
+			goto out_dereg;
+		}
+	}
+
+	return ret;
+
+out_dereg:
+	for (i = --cpu; i >= 0; i--)
+		misc_deregister(acrn_trace_devs[i]);
+	cpu = pcpu_num;
+
+out_sbuf:
+	for (i = --cpu; i >= 0; i--)
+		sbuf_share_setup(i, 0, NULL);
+	cpu = pcpu_num;
+
+out_free:
+	for (i = --cpu; i >= 0; i--)
+		sbuf_free(sbuf_per_cpu[i]);
+
+	return ret;
+}
+
+/*
+ * acrn_trace_exit()
+ */
+static void __exit acrn_trace_exit(void)
+{
+	int cpu;
+
+	pr_info("%s, cpu_num %d\n", __func__, pcpu_num);
+
+	foreach_cpu(cpu, pcpu_num) {
+		/* deregister devices */
+		misc_deregister(acrn_trace_devs[cpu]);
+
+		/* set sbuf pointer to NULL in HV */
+		sbuf_share_setup(cpu, 0, NULL);
+
+		/* free sbuf, sbuf_per_cpu[cpu] should be set NULL */
+		sbuf_free(sbuf_per_cpu[cpu]);
+	}
+}
+
+module_init(acrn_trace_init);
+module_exit(acrn_trace_exit);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Intel Corp., http://www.intel.com");
+MODULE_DESCRIPTION("Driver for the Intel ACRN Hypervisor Trace");
+MODULE_VERSION("0.1");
-- 
https://clearlinux.org