Commit fbfddae6 authored by Toshi Kani's avatar Toshi Kani Committed by Rafael J. Wysocki
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ACPI: Add acpi_handle_<level>() interfaces 



This patch introduces acpi_handle_<level>(), where <level> is
a kernel message level such as err/warn/info, to support improved
logging messages for ACPI, esp. hot-plug operations.
acpi_handle_<level>() appends "ACPI" prefix and ACPI object path
to the messages.  This improves diagnosis of hotplug operations
since an error message in a log file identifies an object that
caused an issue.  This interface acquires the global namespace
mutex to obtain an object path.  In interrupt context, it shows
the object path as <n/a>.

acpi_handle_<level>() takes acpi_handle as an argument, which is
passed to ACPI hotplug notify handlers from the ACPICA.  Therefore,
it is always available unlike other kernel objects, such as device.

For example:
  acpi_handle_err(handle, "Device don't exist, dropping EJECT\n");
logs an error message like this at KERN_ERR.
  ACPI: \_SB_.SCK4.CPU4: Device don't exist, dropping EJECT

ACPI hot-plug drivers can use acpi_handle_<level>() when they need
to identify a target ACPI object path in their messages, such as
error cases.  The usage model is similar to dev_<level>().
acpi_handle_<level>() can be used when a device is not created or
is invalid during hot-plug operations.  ACPI object path is also
consistent on the platform, unlike device name that gets incremented
over hotplug operations.

ACPI drivers should use dev_<level>() when a device object is valid.
Device name provides more user friendly information, and avoids
acquiring the global ACPI namespace mutex.  ACPI drivers also
continue to use pr_<level>() when they do not need to specify device
information, such as boot-up messages.

Note: ACPI_[WARNING|INFO|ERROR]() are intended for the ACPICA and
are not associated with the kernel message level.

Signed-off-by: default avatarToshi Kani <toshi.kani@hp.com>
Tested-by: default avatarVijay Mohan Pandarathil <vijaymohan.pandarathil@hp.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent b59bc2fb

drivers/acpi/utils.c

+38 −0
Original line number Diff line number Diff line
@@ -28,6 +28,8 @@ 
#include <linux/slab.h>

#include <linux/init.h>

#include <linux/types.h>

#include <linux/hardirq.h>

#include <linux/acpi.h>

#include <acpi/acpi_bus.h>

#include <acpi/acpi_drivers.h>
@@ -457,3 +459,39 @@ acpi_evaluate_hotplug_ost(acpi_handle handle, u32 source_event, 
#endif

}

EXPORT_SYMBOL(acpi_evaluate_hotplug_ost);



/**

 * acpi_handle_printk: Print message with ACPI prefix and object path

 *

 * This function is called through acpi_handle_<level> macros and prints

 * a message with ACPI prefix and object path.  This function acquires

 * the global namespace mutex to obtain an object path.  In interrupt

 * context, it shows the object path as <n/a>.

 */

void

acpi_handle_printk(const char *level, acpi_handle handle, const char *fmt, ...)

{

	struct va_format vaf;

	va_list args;

	struct acpi_buffer buffer = {

		.length = ACPI_ALLOCATE_BUFFER,

		.pointer = NULL

	};

	const char *path;



	va_start(args, fmt);

	vaf.fmt = fmt;

	vaf.va = &args;



	if (in_interrupt() ||

	    acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer) != AE_OK)

		path = "<n/a>";

	else

		path = buffer.pointer;



	printk("%sACPI: %s: %pV", level, path, &vaf);



	va_end(args);

	kfree(buffer.pointer);

}

EXPORT_SYMBOL(acpi_handle_printk);

include/linux/acpi.h

+43 −0
Original line number Diff line number Diff line
@@ -434,4 +434,47 @@ acpi_status acpi_os_prepare_sleep(u8 sleep_state, 
#define acpi_os_set_prepare_sleep(func, pm1a_ctrl, pm1b_ctrl) do { } while (0)

#endif



#ifdef CONFIG_ACPI

__printf(3, 4)

void acpi_handle_printk(const char *level, acpi_handle handle,

			const char *fmt, ...);

#else	/* !CONFIG_ACPI */

static inline __printf(3, 4) void

acpi_handle_printk(const char *level, void *handle, const char *fmt, ...) {}

#endif	/* !CONFIG_ACPI */



/*

 * acpi_handle_<level>: Print message with ACPI prefix and object path

 *

 * These interfaces acquire the global namespace mutex to obtain an object

 * path.  In interrupt context, it shows the object path as <n/a>.

 */

#define acpi_handle_emerg(handle, fmt, ...)				\

	acpi_handle_printk(KERN_EMERG, handle, fmt, ##__VA_ARGS__)

#define acpi_handle_alert(handle, fmt, ...)				\

	acpi_handle_printk(KERN_ALERT, handle, fmt, ##__VA_ARGS__)

#define acpi_handle_crit(handle, fmt, ...)				\

	acpi_handle_printk(KERN_CRIT, handle, fmt, ##__VA_ARGS__)

#define acpi_handle_err(handle, fmt, ...)				\

	acpi_handle_printk(KERN_ERR, handle, fmt, ##__VA_ARGS__)

#define acpi_handle_warn(handle, fmt, ...)				\

	acpi_handle_printk(KERN_WARNING, handle, fmt, ##__VA_ARGS__)

#define acpi_handle_notice(handle, fmt, ...)				\

	acpi_handle_printk(KERN_NOTICE, handle, fmt, ##__VA_ARGS__)

#define acpi_handle_info(handle, fmt, ...)				\

	acpi_handle_printk(KERN_INFO, handle, fmt, ##__VA_ARGS__)



/* REVISIT: Support CONFIG_DYNAMIC_DEBUG when necessary */

#if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)

#define acpi_handle_debug(handle, fmt, ...)				\

	acpi_handle_printk(KERN_DEBUG, handle, fmt, ##__VA_ARGS__)

#else

#define acpi_handle_debug(handle, fmt, ...)				\

({									\

	if (0)								\

		acpi_handle_printk(KERN_DEBUG, handle, fmt, ##__VA_ARGS__); \

	0;								\

})

#endif



#endif	/*_LINUX_ACPI_H*/

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