summaryrefslogtreecommitdiffstats
path: root/arch
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2017-05-01 23:00:21 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-05-01 23:00:21 -0700
commit7d6a31c394722c914c61292b457e1999c8bef5ea (patch)
tree3e7e1544d95a7839e651dd5736bb5b325b067c7d /arch
parent2cc12e2e8cb65aec9a95a3d3de4d70e7b6b8c881 (diff)
parent1b326277798aa820c1043617786609b9bb4bee78 (diff)
downloadlinux-7d6a31c394722c914c61292b457e1999c8bef5ea.tar.bz2
Merge branch 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 debug updates from Ingo Molnar: "The biggest update is the addition of USB3 debug port based early-console. Greg was fine with the USB changes and with the routing of these patches: https://www.spinics.net/lists/linux-usb/msg155093.html" * 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: usb/doc: Add document for USB3 debug port usage usb/serial: Add DBC debug device support to usb_debug x86/earlyprintk: Add support for earlyprintk via USB3 debug port usb/early: Add driver for xhci debug capability x86/timers: Add simple udelay calibration
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/Kconfig.debug27
-rw-r--r--arch/x86/kernel/early_printk.c5
-rw-r--r--arch/x86/kernel/setup.c26
3 files changed, 56 insertions, 2 deletions
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index 63c1d13aaf9f..fcb7604172ce 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -5,6 +5,9 @@ config TRACE_IRQFLAGS_SUPPORT
source "lib/Kconfig.debug"
+config EARLY_PRINTK_USB
+ bool
+
config X86_VERBOSE_BOOTUP
bool "Enable verbose x86 bootup info messages"
default y
@@ -23,19 +26,20 @@ config EARLY_PRINTK
This is useful for kernel debugging when your machine crashes very
early before the console code is initialized. For normal operation
it is not recommended because it looks ugly and doesn't cooperate
- with klogd/syslogd or the X server. You should normally N here,
+ with klogd/syslogd or the X server. You should normally say N here,
unless you want to debug such a crash.
config EARLY_PRINTK_DBGP
bool "Early printk via EHCI debug port"
depends on EARLY_PRINTK && PCI
+ select EARLY_PRINTK_USB
---help---
Write kernel log output directly into the EHCI debug port.
This is useful for kernel debugging when your machine crashes very
early before the console code is initialized. For normal operation
it is not recommended because it looks ugly and doesn't cooperate
- with klogd/syslogd or the X server. You should normally N here,
+ with klogd/syslogd or the X server. You should normally say N here,
unless you want to debug such a crash. You need usb debug device.
config EARLY_PRINTK_EFI
@@ -48,6 +52,25 @@ config EARLY_PRINTK_EFI
This is useful for kernel debugging when your machine crashes very
early before the console code is initialized.
+config EARLY_PRINTK_USB_XDBC
+ bool "Early printk via the xHCI debug port"
+ depends on EARLY_PRINTK && PCI
+ select EARLY_PRINTK_USB
+ ---help---
+ Write kernel log output directly into the xHCI debug port.
+
+ One use for this feature is kernel debugging, for example when your
+ machine crashes very early before the regular console code is
+ initialized. Other uses include simpler, lockless logging instead of
+ a full-blown printk console driver + klogd.
+
+ For normal production environments this is normally not recommended,
+ because it doesn't feed events into klogd/syslogd and doesn't try to
+ print anything on the screen.
+
+ You should normally say N here, unless you want to debug early
+ crashes or need a very simple printk logging facility.
+
config X86_PTDUMP_CORE
def_bool n
diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c
index 8a121991e5ba..0f0840304452 100644
--- a/arch/x86/kernel/early_printk.c
+++ b/arch/x86/kernel/early_printk.c
@@ -17,6 +17,7 @@
#include <asm/intel-mid.h>
#include <asm/pgtable.h>
#include <linux/usb/ehci_def.h>
+#include <linux/usb/xhci-dbgp.h>
#include <linux/efi.h>
#include <asm/efi.h>
#include <asm/pci_x86.h>
@@ -381,6 +382,10 @@ static int __init setup_early_printk(char *buf)
if (!strncmp(buf, "efi", 3))
early_console_register(&early_efi_console, keep);
#endif
+#ifdef CONFIG_EARLY_PRINTK_USB_XDBC
+ if (!strncmp(buf, "xdbc", 4))
+ early_xdbc_parse_parameter(buf + 4);
+#endif
buf++;
}
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 62a1c74855e5..0b4d3c686b1e 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -70,6 +70,7 @@
#include <linux/tboot.h>
#include <linux/jiffies.h>
+#include <linux/usb/xhci-dbgp.h>
#include <video/edid.h>
#include <asm/mtrr.h>
@@ -811,6 +812,26 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
return 0;
}
+static void __init simple_udelay_calibration(void)
+{
+ unsigned int tsc_khz, cpu_khz;
+ unsigned long lpj;
+
+ if (!boot_cpu_has(X86_FEATURE_TSC))
+ return;
+
+ cpu_khz = x86_platform.calibrate_cpu();
+ tsc_khz = x86_platform.calibrate_tsc();
+
+ tsc_khz = tsc_khz ? : cpu_khz;
+ if (!tsc_khz)
+ return;
+
+ lpj = tsc_khz * 1000;
+ do_div(lpj, HZ);
+ loops_per_jiffy = lpj;
+}
+
/*
* Determine if we were loaded by an EFI loader. If so, then we have also been
* passed the efi memmap, systab, etc., so we should use these data structures
@@ -959,6 +980,8 @@ void __init setup_arch(char **cmdline_p)
*/
x86_configure_nx();
+ simple_udelay_calibration();
+
parse_early_param();
#ifdef CONFIG_MEMORY_HOTPLUG
@@ -1095,6 +1118,9 @@ void __init setup_arch(char **cmdline_p)
memblock_set_current_limit(ISA_END_ADDRESS);
e820__memblock_setup();
+ if (!early_xdbc_setup_hardware())
+ early_xdbc_register_console();
+
reserve_bios_regions();
if (efi_enabled(EFI_MEMMAP)) {