Unverified Commit 9b1fe051 authored by Christophe JAILLET's avatar Christophe JAILLET Committed by Mark Brown
Browse files

regmap: Reorder fields in 'struct regmap_config' to save some memory 



On x86_64 and allmodconfig, this shrinks the size of 'struct regmap_config'
from 328 to 312 bytes.

This is usually a win, because this structure is used as a static global
variable.

When moving the kerneldoc fields, I've tried to keep the layout as
consistent as possible, which is not really easy!

Before:
	/* size: 328, cachelines: 6, members: 55 */
	/* sum members: 296, holes: 6, sum holes: 25 */
	/* padding: 7 */
	/* last cacheline: 8 bytes */

After:
	/* size: 312, cachelines: 5, members: 55 */
	/* sum members: 296, holes: 5, sum holes: 16 */
	/* last cacheline: 56 bytes */

For the records, this is also widely used:
	$git grep static.*regmap_config | wc -l
	1327

Signed-off-by: default avatarChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/5e039cd8fe415dd7ab3169948c08a5311db9fb9a.1715024007.git.christophe.jaillet@wanadoo.fr


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 991b5e2a

include/linux/regmap.h

+31 −31
Original line number Diff line number Diff line
@@ -297,15 +297,6 @@ typedef void (*regmap_unlock)(void *); 
 *			performed on such table (a register is no increment

 *			readable if it belongs to one of the ranges specified

 *			by rd_noinc_table).

 * @disable_locking: This regmap is either protected by external means or

 *                   is guaranteed not to be accessed from multiple threads.

 *                   Don't use any locking mechanisms.

 * @lock:	  Optional lock callback (overrides regmap's default lock

 *		  function, based on spinlock or mutex).

 * @unlock:	  As above for unlocking.

 * @lock_arg:	  this field is passed as the only argument of lock/unlock

 *		  functions (ignored in case regular lock/unlock functions

 *		  are not overridden).

 * @reg_read:	  Optional callback that if filled will be used to perform

 *           	  all the reads from the registers. Should only be provided for

 *		  devices whose read operation cannot be represented as a simple
@@ -323,6 +314,7 @@ typedef void (*regmap_unlock)(void *); 
 * @write: Same as above for writing.

 * @max_raw_read: Max raw read size that can be used on the device.

 * @max_raw_write: Max raw write size that can be used on the device.

 * @can_sleep:	  Optional, specifies whether regmap operations can sleep.

 * @fast_io:	  Register IO is fast. Use a spinlock instead of a mutex

 *	     	  to perform locking. This field is ignored if custom lock/unlock

 *	     	  functions are used (see fields lock/unlock of struct regmap_config).
@@ -331,6 +323,15 @@ typedef void (*regmap_unlock)(void *); 
 *		   Use it only for "no-bus" cases.

 * @io_port:	  Support IO port accessors. Makes sense only when MMIO vs. IO port

 *		  access can be distinguished.

 * @disable_locking: This regmap is either protected by external means or

 *		     is guaranteed not to be accessed from multiple threads.

 *		     Don't use any locking mechanisms.

 * @lock:	  Optional lock callback (overrides regmap's default lock

 *		  function, based on spinlock or mutex).

 * @unlock:	  As above for unlocking.

 * @lock_arg:	  This field is passed as the only argument of lock/unlock

 *		  functions (ignored in case regular lock/unlock functions

 *		  are not overridden).

 * @max_register: Optional, specifies the maximum valid register address.

 * @max_register_is_0: Optional, specifies that zero value in @max_register

 *                     should be taken into account. This is a workaround to
@@ -373,6 +374,11 @@ typedef void (*regmap_unlock)(void *); 
 * @reg_defaults_raw: Power on reset values for registers (for use with

 *                    register cache support).

 * @num_reg_defaults_raw: Number of elements in reg_defaults_raw.

 * @use_hwlock: Indicate if a hardware spinlock should be used.

 * @use_raw_spinlock: Indicate if a raw spinlock should be used.

 * @hwlock_id: Specify the hardware spinlock id.

 * @hwlock_mode: The hardware spinlock mode, should be HWLOCK_IRQSTATE,

 *		 HWLOCK_IRQ or 0.

 * @reg_format_endian: Endianness for formatted register addresses. If this is

 *		       DEFAULT, the @reg_format_endian_default value from the

 *		       regmap bus is used.
@@ -382,12 +388,6 @@ typedef void (*regmap_unlock)(void *); 
 *

 * @ranges: Array of configuration entries for virtual address ranges.

 * @num_ranges: Number of range configuration entries.

 * @use_hwlock: Indicate if a hardware spinlock should be used.

 * @use_raw_spinlock: Indicate if a raw spinlock should be used.

 * @hwlock_id: Specify the hardware spinlock id.

 * @hwlock_mode: The hardware spinlock mode, should be HWLOCK_IRQSTATE,

 *		 HWLOCK_IRQ or 0.

 * @can_sleep: Optional, specifies whether regmap operations can sleep.

 */

struct regmap_config {

	const char *name;
@@ -406,11 +406,6 @@ struct regmap_config { 
	bool (*writeable_noinc_reg)(struct device *dev, unsigned int reg);

	bool (*readable_noinc_reg)(struct device *dev, unsigned int reg);



	bool disable_locking;

	regmap_lock lock;

	regmap_unlock unlock;

	void *lock_arg;



	int (*reg_read)(void *context, unsigned int reg, unsigned int *val);

	int (*reg_write)(void *context, unsigned int reg, unsigned int val);

	int (*reg_update_bits)(void *context, unsigned int reg,
@@ -422,9 +417,16 @@ struct regmap_config { 
	size_t max_raw_read;

	size_t max_raw_write;



	bool can_sleep;



	bool fast_io;

	bool io_port;



	bool disable_locking;

	regmap_lock lock;

	regmap_unlock unlock;

	void *lock_arg;



	unsigned int max_register;

	bool max_register_is_0;

	const struct regmap_access_table *wr_table;
@@ -448,18 +450,16 @@ struct regmap_config { 
	bool use_relaxed_mmio;

	bool can_multi_write;



	enum regmap_endian reg_format_endian;

	enum regmap_endian val_format_endian;



	const struct regmap_range_cfg *ranges;

	unsigned int num_ranges;



	bool use_hwlock;

	bool use_raw_spinlock;

	unsigned int hwlock_id;

	unsigned int hwlock_mode;



	bool can_sleep;

	enum regmap_endian reg_format_endian;

	enum regmap_endian val_format_endian;



	const struct regmap_range_cfg *ranges;

	unsigned int num_ranges;

};



/**