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Added a fastmsrns test case
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Signed-off-by: Shan Kang <[email protected]>
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@kangshan1157 @ysun
kangshan1157 authored and ysun committed May 29, 2024
1 parent 7056e1b commit ef69935
Showing 1 changed file with 103 additions and 10 deletions.
113 changes: 103 additions & 10 deletions BM/fred/fred_test_driver.c
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Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,9 @@
#include <linux/device.h>
#include <linux/ioctl.h>
#include <linux/err.h>
#include <asm/cpufeatures.h>
#include <asm/msr-index.h>
#include <asm/msr.h>

MODULE_AUTHOR("Shan Kang <[email protected]>");
MODULE_VERSION("1.0");
Expand All @@ -22,8 +25,8 @@ static int __init fred_test_driver_init(void);
static void __exit fred_test_driver_exit(void);
static int fred_test_open(struct inode *inode, struct file *file);
static int fred_test_release(struct inode *inode, struct file *file);
static ssize_t fred_test_read(struct file *filp, char __user *buf, size_t count, loff_t *off);
static ssize_t fred_test_write(struct file *filp, const char *buf, size_t count, loff_t *off);
static ssize_t fred_test_read(struct file *file, char __user *buf, size_t count, loff_t *off);
static ssize_t fred_test_write(struct file *file, const char *buf, size_t count, loff_t *off);
static long fred_test_ioctl(struct file *file, unsigned int cmd, unsigned long arg);

/*
Expand All @@ -38,6 +41,87 @@ static const struct file_operations fops = {
.release = fred_test_release,
};

static inline u64 fred_test_rdmsr(u32 msr)
{
u32 a, d;

__asm__ __volatile__("rdmsr" : "=a"(a), "=d"(d) : "c"(msr) : "memory");

return a | ((u64)d << 32);
}

static inline void fred_test_wrmsr(u32 msr, u64 value)
{
u32 a = value;
u32 d = value >> 32;

__asm__ __volatile__("wrmsr" :: "a"(a), "d"(d), "c"(msr) : "memory");
}

static inline void fred_test_wrmsrns(u32 msr, u64 value)
{
u32 a = value;
u32 d = value >> 32;

__asm__ __volatile__(".byte 0x0f,0x01,0xc6" :: "a"(a), "d"(d), "c"(msr));
}

u64 read_performance_counter(void)
{
u64 value;

rdpmcl(0x40000002, value);

pr_info("REF_TSC Value: %llu\n", value);

return value;
}

static void check_wrmsr_cycles(long loop)
{
u64 start, end, gs_base, elapsed, i;
//if (static_cpu_has(X86_FEATURE_WRMSRNS))
//{
local_irq_disable();
preempt_disable();
gs_base = fred_test_rdmsr(MSR_GS_BASE);
//start = rdtsc();
wrmsrl(0x38f, 0); // clear global_ctrl
wrmsrl(0x30b, 0); // clear fixed counter 2 value (REF_TSC)
wrmsrl(0x38f, BIT_ULL(32 + 2)); // enable fixed counter in global_ctrl
wrmsrl(0x38d, 0x300); // enable fixed counter 2
start = read_performance_counter();
for (i = 0; i < loop; i++)
fred_test_wrmsrns(MSR_GS_BASE, gs_base);
//end = rdtsc();
end = read_performance_counter();
wrmsrl(0x38d, 0); // disable fixed counter 2
wrmsrl(0x38f, 0); // clear global_ctrl
preempt_enable();
local_irq_enable();
elapsed = (end - start) / loop;
pr_info("Elapsed time: wrmsrns used %llu cycles\n", elapsed);
//}

local_irq_disable();
preempt_disable();
gs_base = fred_test_rdmsr(MSR_GS_BASE);
wrmsrl(0x38f, 0); // clear global_ctrl
wrmsrl(0x30b, 0); // clear fixed counter 2 value (REF_TSC)
wrmsrl(0x38f, BIT_ULL(32 + 2)); // enable fixed counter in global_ctrl
wrmsrl(0x38d, 0x300); // enable fixed counter 2
//start = rdtsc();
start = read_performance_counter();
for (i = 0; i < loop; i++)
fred_test_wrmsr(MSR_GS_BASE, gs_base);
//end = rdtsc();
end = read_performance_counter();
preempt_enable();
local_irq_enable();
elapsed = (end - start) / loop;
pr_info("Elapsed time: wrmsr used %llu cycles\n", elapsed);
}

static int fred_enable(void)
{
u64 cr4;
Expand Down Expand Up @@ -89,7 +173,7 @@ static int fred_test_release(struct inode *inode, struct file *file)
return 0;
}

static ssize_t fred_test_read(struct file *filp, char __user *buf, size_t count, loff_t *off)
static ssize_t fred_test_read(struct file *file, char __user *buf, size_t count, loff_t *off)
{
int len;
/* For example - when content of our_buf is "100" - */
Expand All @@ -99,7 +183,7 @@ static ssize_t fred_test_read(struct file *filp, char __user *buf, size_t count,
return len;
}

static ssize_t fred_test_write(struct file *filp, const char *buf, size_t count, loff_t *off)
static ssize_t fred_test_write(struct file *file, const char *buf, size_t count, loff_t *off)
{
long opt;
u64 fred_bit;
Expand All @@ -112,27 +196,35 @@ static ssize_t fred_test_write(struct file *filp, const char *buf, size_t count,
/* Here we read from buf to our_buf */
if (copy_from_user(our_buf, buf, count))
pr_err("Data Write : Err!\n");

else
pr_err("Data Write : %s! count=%ld\n", our_buf, count);
/* we write NULL to end the string */
our_buf[count] = '\0';

if (strncmp(our_buf, "fred_enable ", strlen("fred_enable ")) == 0) {
ret = kstrtol(our_buf + strlen("fred_enable "), 10, &opt);
if (!ret) {
pr_err("kstrtol failed\n");
if (ret) {
pr_err("kstrtol failed ret=%d\n", ret);
return 0;
}
//opt = simple_strtol(our_buf + strlen("fred_enable "), NULL, 10);
pr_info("fred_enable expected %ld\n", opt);
fred_bit = fred_enable();
if (fred_bit == (u64)opt)
pr_info("fred_enable test PASS\n");
else
pr_info("fred_enable test FAIL\n");

} else if (strncmp(our_buf, "double_fault", strlen("double_fault")) == 0) {
pr_info("double_fault test begin\n");
invoke_double_fault();
} else if (strncmp(our_buf, "fast_msr ", strlen("fast_msr ")) == 0) {
pr_info("fast_msr test begin\n");
ret = kstrtol(our_buf + strlen("fast_msr "), 10, &opt);
if (ret) {
pr_err("kstrtol failed ret=%d\n", ret);
return 0;
}
pr_info("fast_msr loop %ld\n", opt);
check_wrmsr_cycles(opt);
} else {
pr_info("Not supported case\n");
}
Expand Down Expand Up @@ -163,7 +255,8 @@ static int __init fred_test_driver_init(void)
goto r_class;
}
/* Creating struct class */
dev_class = class_create(THIS_MODULE, "fred_test_class");
//dev_class = class_create(THIS_MODULE, "fred_test_class");
dev_class = class_create("fred_test_class");
if (IS_ERR(dev_class)) {
pr_err("Cannot create the struct class\n");
goto r_class;
Expand Down

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