summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--arch/x86/include/asm/x86_init.h1
-rw-r--r--arch/x86/kernel/cpu/microcode/core.c6
-rw-r--r--arch/x86/kernel/cpu/mtrr/if.c33
-rw-r--r--arch/x86/kernel/i8237.c25
-rw-r--r--arch/x86/kernel/platform-quirks.c7
5 files changed, 47 insertions, 25 deletions
diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
index ce8b4da07e35..db98e3ab3295 100644
--- a/arch/x86/include/asm/x86_init.h
+++ b/arch/x86/include/asm/x86_init.h
@@ -301,5 +301,6 @@ extern struct x86_apic_ops x86_apic_ops;
extern void x86_early_init_platform_quirks(void);
extern void x86_init_noop(void);
extern void x86_init_uint_noop(unsigned int unused);
+extern bool x86_pnpbios_disabled(void);
#endif
diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index 77e201301528..08286269fd24 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -70,7 +70,7 @@ static DEFINE_MUTEX(microcode_mutex);
/*
* Serialize late loading so that CPUs get updated one-by-one.
*/
-static DEFINE_SPINLOCK(update_lock);
+static DEFINE_RAW_SPINLOCK(update_lock);
struct ucode_cpu_info ucode_cpu_info[NR_CPUS];
@@ -560,9 +560,9 @@ static int __reload_late(void *info)
if (__wait_for_cpus(&late_cpus_in, NSEC_PER_SEC))
return -1;
- spin_lock(&update_lock);
+ raw_spin_lock(&update_lock);
apply_microcode_local(&err);
- spin_unlock(&update_lock);
+ raw_spin_unlock(&update_lock);
/* siblings return UCODE_OK because their engine got updated already */
if (err > UCODE_NFOUND) {
diff --git a/arch/x86/kernel/cpu/mtrr/if.c b/arch/x86/kernel/cpu/mtrr/if.c
index 558444b23923..c610f47373e4 100644
--- a/arch/x86/kernel/cpu/mtrr/if.c
+++ b/arch/x86/kernel/cpu/mtrr/if.c
@@ -106,17 +106,9 @@ mtrr_write(struct file *file, const char __user *buf, size_t len, loff_t * ppos)
memset(line, 0, LINE_SIZE);
- length = len;
- length--;
-
- if (length > LINE_SIZE - 1)
- length = LINE_SIZE - 1;
-
+ length = strncpy_from_user(line, buf, LINE_SIZE - 1);
if (length < 0)
- return -EINVAL;
-
- if (copy_from_user(line, buf, length))
- return -EFAULT;
+ return length;
linelen = strlen(line);
ptr = line + linelen - 1;
@@ -149,17 +141,16 @@ mtrr_write(struct file *file, const char __user *buf, size_t len, loff_t * ppos)
return -EINVAL;
ptr = skip_spaces(ptr + 5);
- for (i = 0; i < MTRR_NUM_TYPES; ++i) {
- if (strcmp(ptr, mtrr_strings[i]))
- continue;
- base >>= PAGE_SHIFT;
- size >>= PAGE_SHIFT;
- err = mtrr_add_page((unsigned long)base, (unsigned long)size, i, true);
- if (err < 0)
- return err;
- return len;
- }
- return -EINVAL;
+ i = match_string(mtrr_strings, MTRR_NUM_TYPES, ptr);
+ if (i < 0)
+ return i;
+
+ base >>= PAGE_SHIFT;
+ size >>= PAGE_SHIFT;
+ err = mtrr_add_page((unsigned long)base, (unsigned long)size, i, true);
+ if (err < 0)
+ return err;
+ return len;
}
static long
diff --git a/arch/x86/kernel/i8237.c b/arch/x86/kernel/i8237.c
index 8eeaa81de066..0a3e70fd00d6 100644
--- a/arch/x86/kernel/i8237.c
+++ b/arch/x86/kernel/i8237.c
@@ -9,10 +9,12 @@
* your option) any later version.
*/
+#include <linux/dmi.h>
#include <linux/init.h>
#include <linux/syscore_ops.h>
#include <asm/dma.h>
+#include <asm/x86_init.h>
/*
* This module just handles suspend/resume issues with the
@@ -49,6 +51,29 @@ static struct syscore_ops i8237_syscore_ops = {
static int __init i8237A_init_ops(void)
{
+ /*
+ * From SKL PCH onwards, the legacy DMA device is removed in which the
+ * I/O ports (81h-83h, 87h, 89h-8Bh, 8Fh) related to it are removed
+ * as well. All removed ports must return 0xff for a inb() request.
+ *
+ * Note: DMA_PAGE_2 (port 0x81) should not be checked for detecting
+ * the presence of DMA device since it may be used by BIOS to decode
+ * LPC traffic for POST codes. Original LPC only decodes one byte of
+ * port 0x80 but some BIOS may choose to enhance PCH LPC port 0x8x
+ * decoding.
+ */
+ if (dma_inb(DMA_PAGE_0) == 0xFF)
+ return -ENODEV;
+
+ /*
+ * It is not required to load this driver as newer SoC may not
+ * support 8237 DMA or bus mastering from LPC. Platform firmware
+ * must announce the support for such legacy devices via
+ * ACPI_FADT_LEGACY_DEVICES field in FADT table.
+ */
+ if (x86_pnpbios_disabled() && dmi_get_bios_year() >= 2017)
+ return -ENODEV;
+
register_syscore_ops(&i8237_syscore_ops);
return 0;
}
diff --git a/arch/x86/kernel/platform-quirks.c b/arch/x86/kernel/platform-quirks.c
index 235fe6008ac8..b348a672f71d 100644
--- a/arch/x86/kernel/platform-quirks.c
+++ b/arch/x86/kernel/platform-quirks.c
@@ -33,9 +33,14 @@ void __init x86_early_init_platform_quirks(void)
x86_platform.set_legacy_features();
}
+bool __init x86_pnpbios_disabled(void)
+{
+ return x86_platform.legacy.devices.pnpbios == 0;
+}
+
#if defined(CONFIG_PNPBIOS)
bool __init arch_pnpbios_disabled(void)
{
- return x86_platform.legacy.devices.pnpbios == 0;
+ return x86_pnpbios_disabled();
}
#endif