Commit 460cdeca authored by Ricardo Ribalda's avatar Ricardo Ribalda Committed by Boris Brezillon
Browse files

mtd: maps: gpio-addr-flash: Use order instead of size 



By using the order of the window instead of the size, we can replace a
lot of expensive division and modulus on the code with simple bit
operations.

Signed-off-by: default avatarRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: default avatarBoris Brezillon <boris.brezillon@bootlin.com>
parent 4edc00ad

drivers/mtd/maps/gpio-addr-flash.c

+21 −18
Original line number Diff line number Diff line
@@ -25,6 +25,8 @@ 
#include <linux/slab.h>

#include <linux/types.h>



#define win_mask(x) ((BIT(x)) - 1)



#define DRIVER_NAME "gpio-addr-flash"



/**
@@ -34,7 +36,7 @@ 
 *	@gpio_count:  number of GPIOs used to address

 *	@gpio_addrs:  array of GPIOs to twiddle

 *	@gpio_values: cached GPIO values

 *	@win_size:    dedicated memory size (if no GPIOs)

 *	@win_order:   dedicated memory size (if no GPIOs)

 */

struct async_state {

	struct mtd_info *mtd;
@@ -42,7 +44,7 @@ struct async_state { 
	size_t gpio_count;

	unsigned *gpio_addrs;

	int *gpio_values;

	unsigned long win_size;

	unsigned int win_order;

};

#define gf_map_info_to_state(mi) ((struct async_state *)(mi)->map_priv_1)
@@ -60,7 +62,8 @@ static void gf_set_gpios(struct async_state *state, unsigned long ofs) 
{

	size_t i = 0;

	int value;

	ofs /= state->win_size;



	ofs >>= state->win_order;

	do {

		value = ofs & (1 << i);

		if (state->gpio_values[i] != value) {
@@ -83,7 +86,7 @@ static map_word gf_read(struct map_info *map, unsigned long ofs) 


	gf_set_gpios(state, ofs);



	word = readw(map->virt + (ofs % state->win_size));

	word = readw(map->virt + (ofs & win_mask(state->win_order)));

	test.x[0] = word;

	return test;

}
@@ -105,13 +108,13 @@ static void gf_copy_from(struct map_info *map, void *to, unsigned long from, ssi 
	int this_len;



	while (len) {

		if ((from % state->win_size) + len > state->win_size)

			this_len = state->win_size - (from % state->win_size);

		else

			this_len = len;

		this_len = from & win_mask(state->win_order);

		this_len = BIT(state->win_order) - this_len;

		this_len = min_t(int, len, this_len);



		gf_set_gpios(state, from);

		memcpy_fromio(to, map->virt + (from % state->win_size),

		memcpy_fromio(to,

			      map->virt + (from & win_mask(state->win_order)),

			      this_len);

		len -= this_len;

		from += this_len;
@@ -132,7 +135,7 @@ static void gf_write(struct map_info *map, map_word d1, unsigned long ofs) 
	gf_set_gpios(state, ofs);



	d = d1.x[0];

	writew(d, map->virt + (ofs % state->win_size));

	writew(d, map->virt + (ofs & win_mask(state->win_order)));

}



/**
@@ -152,13 +155,13 @@ static void gf_copy_to(struct map_info *map, unsigned long to, 
	int this_len;



	while (len) {

		if ((to % state->win_size) + len > state->win_size)

			this_len = state->win_size - (to % state->win_size);

		else

			this_len = len;

		this_len = to & win_mask(state->win_order);

		this_len = BIT(state->win_order) - this_len;

		this_len = min_t(int, len, this_len);



		gf_set_gpios(state, to);

		memcpy_toio(map->virt + (to % state->win_size), from, len);

		memcpy_toio(map->virt + (to & win_mask(state->win_order)),

			    from, len);



		len -= this_len;

		to += this_len;
@@ -224,7 +227,7 @@ static int gpio_flash_probe(struct platform_device *pdev) 
	state->gpio_count     = gpios->end;

	state->gpio_addrs     = (void *)(unsigned long)gpios->start;

	state->gpio_values    = (void *)(state + 1);

	state->win_size       = resource_size(memory);

	state->win_order      = get_bitmask_order(resource_size(memory)) - 1;

	memset(state->gpio_values, 0xff, arr_size);



	state->map.name       = DRIVER_NAME;
@@ -233,7 +236,7 @@ static int gpio_flash_probe(struct platform_device *pdev) 
	state->map.write      = gf_write;

	state->map.copy_to    = gf_copy_to;

	state->map.bankwidth  = pdata->width;

	state->map.size       = state->win_size * (1 << state->gpio_count);

	state->map.size       = BIT(state->win_order + state->gpio_count);

	state->map.virt	      = devm_ioremap_resource(&pdev->dev, memory);

	if (IS_ERR(state->map.virt))

		return PTR_ERR(state->map.virt);