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Brooklyn/drivers/gpu/drm/i915/i915_mitigations.c
crowetic a94b3d14aa Brooklyn+ (PLUS) changes
Changes included (and more):

1. Dynamic RAM merge

2. Real-time page scan and allocation

3. Cache compression

4. Real-time IRQ checks

5. Dynamic I/O allocation for Java heap

6. Java page migration

7. Contiguous memory allocation

8. Idle pages tracking

9. Per CPU RAM usage tracking

10. ARM NEON scalar multiplication library

11. NEON/ARMv8 crypto extensions

12. NEON SHA, Blake, RIPEMD crypto extensions

13. Parallel NEON crypto engine for multi-algo based CPU stress reduction
2022-05-12 10:47:00 -07:00

148 lines
3.1 KiB
C

// SPDX-License-Identifier: MIT
/*
* Copyright © 2021 Intel Corporation
*/
#include <linux/kernel.h>
#include <linux/moduleparam.h>
#include <linux/slab.h>
#include <linux/string.h>
#include "i915_driver.h"
#include "i915_drv.h"
#include "i915_mitigations.h"
static unsigned long mitigations __read_mostly = ~0UL;
enum {
CLEAR_RESIDUALS = 0,
};
static const char * const names[] = {
[CLEAR_RESIDUALS] = "residuals",
};
bool i915_mitigate_clear_residuals(void)
{
return READ_ONCE(mitigations) & BIT(CLEAR_RESIDUALS);
}
static int mitigations_set(const char *val, const struct kernel_param *kp)
{
unsigned long new = ~0UL;
char *str, *sep, *tok;
bool first = true;
int err = 0;
BUILD_BUG_ON(ARRAY_SIZE(names) >= BITS_PER_TYPE(mitigations));
str = kstrdup(val, GFP_KERNEL);
if (!str)
return -ENOMEM;
for (sep = str; (tok = strsep(&sep, ","));) {
bool enable = true;
int i;
/* Be tolerant of leading/trailing whitespace */
tok = strim(tok);
if (first) {
first = false;
if (!strcmp(tok, "auto"))
continue;
new = 0;
if (!strcmp(tok, "off"))
continue;
}
if (*tok == '!') {
enable = !enable;
tok++;
}
if (!strncmp(tok, "no", 2)) {
enable = !enable;
tok += 2;
}
if (*tok == '\0')
continue;
for (i = 0; i < ARRAY_SIZE(names); i++) {
if (!strcmp(tok, names[i])) {
if (enable)
new |= BIT(i);
else
new &= ~BIT(i);
break;
}
}
if (i == ARRAY_SIZE(names)) {
pr_err("Bad \"%s.mitigations=%s\", '%s' is unknown\n",
DRIVER_NAME, val, tok);
err = -EINVAL;
break;
}
}
kfree(str);
if (err)
return err;
WRITE_ONCE(mitigations, new);
return 0;
}
static int mitigations_get(char *buffer, const struct kernel_param *kp)
{
unsigned long local = READ_ONCE(mitigations);
int count, i;
bool enable;
if (!local)
return scnprintf(buffer, PAGE_SIZE, "%s\n", "off");
if (local & BIT(BITS_PER_LONG - 1)) {
count = scnprintf(buffer, PAGE_SIZE, "%s,", "auto");
enable = false;
} else {
enable = true;
count = 0;
}
for (i = 0; i < ARRAY_SIZE(names); i++) {
if ((local & BIT(i)) != enable)
continue;
count += scnprintf(buffer + count, PAGE_SIZE - count,
"%s%s,", enable ? "" : "!", names[i]);
}
buffer[count - 1] = '\n';
return count;
}
static const struct kernel_param_ops ops = {
.set = mitigations_set,
.get = mitigations_get,
};
module_param_cb_unsafe(mitigations, &ops, NULL, 0600);
MODULE_PARM_DESC(mitigations,
"Selectively enable security mitigations for all Intel® GPUs in the system.\n"
"\n"
" auto -- enables all mitigations required for the platform [default]\n"
" off -- disables all mitigations\n"
"\n"
"Individual mitigations can be enabled by passing a comma-separated string,\n"
"e.g. mitigations=residuals to enable only clearing residuals or\n"
"mitigations=auto,noresiduals to disable only the clear residual mitigation.\n"
"Either '!' or 'no' may be used to switch from enabling the mitigation to\n"
"disabling it.\n"
"\n"
"Active mitigations for Ivybridge, Baytrail, Haswell:\n"
" residuals -- clear all thread-local registers between contexts"
);