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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: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
hifive-unleashed-5.1
Ricardo Ribalda Delgado 2018-10-04 15:01:06 +02:00 committed by Boris Brezillon
parent 4edc00adfd
commit 460cdeca54
1 changed files with 21 additions and 18 deletions
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39
drivers/mtd/maps/gpio-addr-flash.c
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@ -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;
}
@ -105,14 +108,14 @@ 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),
this_len);
memcpy_fromio(to,
map->virt + (from & win_mask(state->win_order)),
this_len);
len -= this_len;
from += this_len;
to += 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);