+/*
+ * SWAP driver
+ * modules/driver_new/driver_to_buffer.c
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright (C) Samsung Electronics, 2013
+ *
+ * 2013 Alexander Aksenov <a.aksenov@samsung.com>: SWAP device driver implement
+ *
+ */
+
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/splice.h>
/* TODO Get subbuffer for reading */
static size_t driver_to_buffer_get(void)
{
- int result;
-
- /* If there is no readable buffers, return error */
- result = swap_buffer_get(&busy_buffer);
- if (result == -E_SB_NO_READABLE_BUFFERS) {
- busy_buffer = NULL;
- return -E_SD_NO_DATA_TO_READ;
- } else if (result < 0) {
- print_err("swap_buffer_get unhandle error %d\n", result);
- return -E_SD_BUFFER_ERROR;
- }
-
- return busy_buffer->full_buffer_part;
+ int result;
+
+ /* If there is no readable buffers, return error */
+ result = swap_buffer_get(&busy_buffer);
+ if (result == -E_SB_NO_READABLE_BUFFERS) {
+ busy_buffer = NULL;
+ return -E_SD_NO_DATA_TO_READ;
+ } else if (result < 0) {
+ print_err("swap_buffer_get unhandle error %d\n", result);
+ return -E_SD_BUFFER_ERROR;
+ }
+
+ return busy_buffer->full_buffer_part;
}
/* TODO Release subbuffer */
static int driver_to_buffer_release(void)
{
- int result;
+ int result;
- if (!busy_buffer)
- return -E_SD_NO_BUSY_SUBBUFFER;
+ if (!busy_buffer)
+ return -E_SD_NO_BUSY_SUBBUFFER;
- result = swap_buffer_release(&busy_buffer);
- if (result == -E_SB_NO_SUBBUFFER_IN_BUSY) {
- return -E_SD_WRONG_SUBBUFFER_PTR;
- } else if (result < 0) {
- print_err("swap_buffer_release unhandle error %d\n", result);
- return -E_SD_BUFFER_ERROR;
- }
+ result = swap_buffer_release(&busy_buffer);
+ if (result == -E_SB_NO_SUBBUFFER_IN_BUSY) {
+ return -E_SD_WRONG_SUBBUFFER_PTR;
+ } else if (result < 0) {
+ print_err("swap_buffer_release unhandle error %d\n", result);
+ return -E_SD_BUFFER_ERROR;
+ }
- busy_buffer = NULL;
+ busy_buffer = NULL;
- return E_SD_SUCCESS;
+ return E_SD_SUCCESS;
}
/* Buffers callback function */
int driver_to_buffer_callback(void)
{
//XXX: Think of sync with get next
- int result;
+ int result;
- /* Increment buffers_to_read counter */
- buffers_to_read++;
- swap_device_wake_up_process();
+ /* Increment buffers_to_read counter */
+ buffers_to_read++;
+ swap_device_wake_up_process();
- return E_SD_SUCCESS;
+ return E_SD_SUCCESS;
}
/* Write to buffers */
ssize_t driver_to_buffer_write(size_t size, void* data)
{
- ssize_t result;
-
- result = us_msg(data);
-// result = swap_buffer_write(data, size);
- if (result == -E_SB_IS_STOPPED) {
- print_err("Buffer is not run! Initialize it before writing\n");
- return -E_SD_WRITE_ERROR;
- } else if (result < 0) {
- print_err("swap_buffer_write error %d\n", result);
- return -E_SD_WRITE_ERROR;
- }
- print_debug("swap_buffer writed %d\n", result);
-
- return result;
+ ssize_t result;
+
+ result = us_msg(data);
+ if (result == -E_SB_IS_STOPPED) {
+ print_err("Buffer is not run! Initialize it before writing\n");
+ return -E_SD_WRITE_ERROR;
+ } else if (result < 0) {
+ print_err("swap_buffer_write error %d\n", result);
+ return -E_SD_WRITE_ERROR;
+ }
+
+ return result;
}
/* Read buffers */
ssize_t driver_to_buffer_read(char __user *buf, size_t count)
{
- size_t bytes_to_copy;
- size_t bytes_to_read = 0;
- int page_counter = 0;
-
- /* Reading from swap_device means reading only current busy_buffer. So, if
- * there is no busy_buffer, we don't get next to read, we just read nothing.
- * In this case, or if there is nothing to read from busy_buffer - return
- * -E_SD_NO_DATA_TO_READ. It should be correctly handled in device_driver */
- if (!busy_buffer || !busy_buffer->full_buffer_part)
- return -E_SD_NO_DATA_TO_READ;
-
- /* Bytes count that we're going to copy to user buffer is equal to user
- * buffer size or to subbuffer readable size whichever is less */
- bytes_to_copy = (count > busy_buffer->full_buffer_part) ?
- busy_buffer->full_buffer_part : count;
-
- /* Copy data from each page to buffer */
- while(bytes_to_copy > 0) {
- /* Get size that should be copied from current page */
- size_t read_from_this_page = (bytes_to_copy > PAGE_SIZE) ? PAGE_SIZE
- : bytes_to_copy;
-
- /* Copy and add size to copied bytes count */
-
- // TODO Check with more than one page
- bytes_to_read += read_from_this_page -
- copy_to_user(buf, page_address(busy_buffer->data_buffer) +
- (sizeof(struct page*) *
- page_counter),
- read_from_this_page);
- bytes_to_copy -= read_from_this_page;
- page_counter++;
- }
-
- return bytes_to_read;
+ size_t bytes_to_copy;
+ size_t bytes_to_read = 0;
+ int page_counter = 0;
+
+ /* Reading from swap_device means reading only current busy_buffer. So, if
+ * there is no busy_buffer, we don't get next to read, we just read nothing.
+ * In this case, or if there is nothing to read from busy_buffer - return
+ * -E_SD_NO_DATA_TO_READ. It should be correctly handled in device_driver */
+ if (!busy_buffer || !busy_buffer->full_buffer_part)
+ return -E_SD_NO_DATA_TO_READ;
+
+ /* Bytes count that we're going to copy to user buffer is equal to user
+ * buffer size or to subbuffer readable size whichever is less */
+ bytes_to_copy = (count > busy_buffer->full_buffer_part) ?
+ busy_buffer->full_buffer_part : count;
+
+ /* Copy data from each page to buffer */
+ while(bytes_to_copy > 0) {
+ /* Get size that should be copied from current page */
+ size_t read_from_this_page = (bytes_to_copy > PAGE_SIZE) ? PAGE_SIZE
+ : bytes_to_copy;
+
+ /* Copy and add size to copied bytes count */
+
+ // TODO Check with more than one page
+ bytes_to_read += read_from_this_page -
+ copy_to_user(buf, page_address(busy_buffer->data_buffer) +
+ (sizeof(struct page*) *
+ page_counter),
+ read_from_this_page);
+ bytes_to_copy -= read_from_this_page;
+ page_counter++;
+ }
+
+ return bytes_to_read;
}
/* Flush swap_buffer */
int driver_to_buffer_flush(void)
{
- int result;
+ int result;
- result = swap_buffer_flush();
+ result = swap_buffer_flush();
- if (result >= 0)
- buffers_to_read = result;
- else if (result < 0)
- return -E_SD_BUFFER_ERROR;
+ if (result >= 0)
+ buffers_to_read = result;
+ else if (result < 0)
+ return -E_SD_BUFFER_ERROR;
- swap_device_wake_up_process();
+ swap_device_wake_up_process();
- return E_SD_SUCCESS;
+ return E_SD_SUCCESS;
}
/* Fills spd structure */
/* FIXME: maybe there is more efficient way */
memcpy(page_address(pages[spd->nr_pages]),
- page_address(&busy_buffer->data_buffer[spd->nr_pages]),
- read_from_current_page);
+ page_address(&busy_buffer->data_buffer[spd->nr_pages]),
+ read_from_current_page);
/* Always beginning of the page */
partial[spd->nr_pages].offset = 0;
/* if (spd->nr_pages == pipe->buffers) { */
/* break; */
/* } */
- }
- return 0;
+ }
+ return 0;
}
/* Check for subbuffers ready to be read */
int driver_to_buffer_buffer_to_read(void)
{
- return busy_buffer ? 1 : 0;
+ return busy_buffer ? 1 : 0;
}
/* Set buffers size and count */
int driver_to_buffer_initialize(size_t size, unsigned int count)
{
- int result;
-
- if (size == 0 && count == 0) {
- return -E_SD_WRONG_ARGS;
- }
-
- result = swap_buffer_init(size, count, (void*)&driver_to_buffer_callback);
- if (result == -E_SB_NO_MEM_QUEUE_BUSY
- || result == -E_SB_NO_MEM_BUFFER_STRUCT) {
- return -E_SD_NO_MEMORY;
- }
-
- // TODO Race condition: buffer can be used in other thread till we're in
- // this func
- /* Initialize driver_to_buffer variables */
- pages_per_buffer = result;
- busy_buffer = NULL;
- buffers_to_read = 0;
-
- return E_SD_SUCCESS;
+ int result;
+
+ if (size == 0 && count == 0) {
+ return -E_SD_WRONG_ARGS;
+ }
+
+ result = swap_buffer_init(size, count, (void*)&driver_to_buffer_callback);
+ if (result == -E_SB_NO_MEM_QUEUE_BUSY
+ || result == -E_SB_NO_MEM_BUFFER_STRUCT) {
+ return -E_SD_NO_MEMORY;
+ }
+
+ // TODO Race condition: buffer can be used in other thread till we're in
+ // this func
+ /* Initialize driver_to_buffer variables */
+ pages_per_buffer = result;
+ busy_buffer = NULL;
+ buffers_to_read = 0;
+
+ return E_SD_SUCCESS;
}
/* Uninitialize buffer */
int driver_to_buffer_uninitialize(void)
{
- int result;
-
- /* Release occupied buffer */
- if (busy_buffer) {
- result = driver_to_buffer_release();
- // TODO Maybe release anyway
- if (result < 0) {
- return result;
- }
- busy_buffer = NULL;
- }
-
- result = swap_buffer_uninit();
- if (result == -E_SB_UNRELEASED_BUFFERS) {
- print_err("Can't uninit buffer! There are busy subbuffers!\n");
- result = -E_SD_BUFFER_ERROR;
- } else if (result < 0) {
- print_err("swap_buffer_uninit error %d\n", result);
- result = -E_SD_BUFFER_ERROR;
- } else {
- result = E_SD_SUCCESS;
- }
-
- /* Reinit driver_to_buffer vars */
- buffers_to_read = 0;
- pages_per_buffer = 0;
-
- return result;
+ int result;
+
+ /* Release occupied buffer */
+ if (busy_buffer) {
+ result = driver_to_buffer_release();
+ // TODO Maybe release anyway
+ if (result < 0) {
+ return result;
+ }
+ busy_buffer = NULL;
+ }
+
+ result = swap_buffer_uninit();
+ if (result == -E_SB_UNRELEASED_BUFFERS) {
+ print_err("Can't uninit buffer! There are busy subbuffers!\n");
+ result = -E_SD_BUFFER_ERROR;
+ } else if (result < 0) {
+ print_err("swap_buffer_uninit error %d\n", result);
+ result = -E_SD_BUFFER_ERROR;
+ } else {
+ result = E_SD_SUCCESS;
+ }
+
+ /* Reinit driver_to_buffer vars */
+ buffers_to_read = 0;
+ pages_per_buffer = 0;
+
+ return result;
}
/* Get next buffer to read */
int driver_to_buffer_next_buffer_to_read(void)
{
//XXX: Think of sync with callback
- int result;
-
- /* If there is busy_buffer first release it */
- if (busy_buffer) {
- result = driver_to_buffer_release();
- if (result)
- return result;
- }
-
- /* If there is no buffers to read, return E_SD_NO_DATA_TO_READ.
- * SHOULD BE POSITIVE, cause there is no real error. */
- if (!buffers_to_read) {
- return E_SD_NO_DATA_TO_READ;
- }
-
- /* Get next buffer to read */
- result = driver_to_buffer_get();
- if (result < 0) {
- print_err("buffer_to_reads > 0, but there are no buffers to read\n");
- return result;
- }
-
- /* Decrement buffers_to_read counter */
- buffers_to_read--;
-
- return E_SD_SUCCESS;
+ int result;
+
+ /* If there is busy_buffer first release it */
+ if (busy_buffer) {
+ result = driver_to_buffer_release();
+ if (result)
+ return result;
+ }
+
+ /* If there is no buffers to read, return E_SD_NO_DATA_TO_READ.
+ * SHOULD BE POSITIVE, cause there is no real error. */
+ if (!buffers_to_read) {
+ return E_SD_NO_DATA_TO_READ;
+ }
+
+ /* Get next buffer to read */
+ result = driver_to_buffer_get();
+ if (result < 0) {
+ print_err("buffer_to_reads > 0, but there are no buffers to read\n");
+ return result;
+ }
+
+ /* Decrement buffers_to_read counter */
+ buffers_to_read--;
+
+ return E_SD_SUCCESS;
}
projects / kernel / swap-modules.git / commitdiff