[PATCH] Staging: dt3155_isr: cleanup fbuffer usage

From: H Hartley Sweeten
Date: Fri Jun 25 2010 - 18:15:31 EST


Now that dt3155_drv.c is not dependent on the global symbol
dt3155_fbuffer[], declared in dt3155_isr.c, remove it.

This also fixes many of the coding style problems in dt3155_isr.c.

Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxx>
Cc: Scott Smedley <ss@xxxxxxxxxx>

---

diff --git a/drivers/staging/dt3155/dt3155_isr.c b/drivers/staging/dt3155/dt3155_isr.c
index 59b7bfd..01ab888 100644
--- a/drivers/staging/dt3155/dt3155_isr.c
+++ b/drivers/staging/dt3155/dt3155_isr.c
@@ -59,158 +59,133 @@ Purpose: Buffer management routines, and other routines for the ISR
#define UPPER_10_BITS (0x3FF<<22) /* Can't DMA accross a 4MB boundary!*/


-/* Pointer into global structure for handling buffers */
-struct dt3155_fbuffer *dt3155_fbuffer[MAXBOARDS] = {NULL
-#if MAXBOARDS == 2
- , NULL
-#endif
-};
-
/******************************************************************************
* Simple array based que struct
*
* Some handy functions using the buffering structure.
*****************************************************************************/

-
/***************************
* are_empty_buffers
- * m is minor # of device
***************************/
-bool are_empty_buffers(int m)
+bool are_empty_buffers(int minor)
{
- return dt3155_fbuffer[m]->empty_len;
+ struct dt3155_fbuffer *fb = &dt3155_status[minor].fbuffer;
+
+ return fb->empty_len;
}

/**************************
* push_empty
- * m is minor # of device
*
* This is slightly confusing. The number empty_len is the literal #
* of empty buffers. After calling, empty_len-1 is the index into the
* empty buffer stack. So, if empty_len == 1, there is one empty buffer,
- * given by dt3155_fbuffer[m]->empty_buffers[0].
+ * given by fb->empty_buffers[0].
* empty_buffers should never fill up, though this is not checked.
**************************/
-void push_empty(int index, int m)
+void push_empty(int index, int minor)
{
- dt3155_fbuffer[m]->empty_buffers[dt3155_fbuffer[m]->empty_len] = index;
- dt3155_fbuffer[m]->empty_len++;
+ struct dt3155_fbuffer *fb = &dt3155_status[minor].fbuffer;
+
+ fb->empty_buffers[fb->empty_len] = index;
+ fb->empty_len++;
}

/**************************
- * pop_empty(m)
- * m is minor # of device
+ * pop_empty
**************************/
-int pop_empty(int m)
+int pop_empty(int minor)
{
- dt3155_fbuffer[m]->empty_len--;
- return dt3155_fbuffer[m]->empty_buffers[dt3155_fbuffer[m]->empty_len];
+ struct dt3155_fbuffer *fb = &dt3155_status[minor].fbuffer;
+
+ fb->empty_len--;
+ return fb->empty_buffers[fb->empty_len];
}

/*************************
- * is_ready_buf_empty(m)
- * m is minor # of device
+ * is_ready_buf_empty
*************************/
-bool is_ready_buf_empty(int m)
+bool is_ready_buf_empty(int minor)
{
- return ((dt3155_fbuffer[m]->ready_len) == 0);
+ struct dt3155_fbuffer *fb = &dt3155_status[minor].fbuffer;
+
+ return fb->ready_len == 0;
}

/*************************
- * is_ready_buf_full(m)
- * m is minor # of device
+ * is_ready_buf_full
+ *
* this should *never* be true if there are any active, locked or empty
* buffers, since it corresponds to nbuffers ready buffers!!
* 7/31/02: total rewrite. --NJC
*************************/
-bool is_ready_buf_full(int m)
+bool is_ready_buf_full(int minor)
{
- return dt3155_fbuffer[m]->ready_len == dt3155_fbuffer[m]->nbuffers;
+ struct dt3155_fbuffer *fb = &dt3155_status[minor].fbuffer;
+
+ return fb->ready_len == fb->nbuffers;
}

/*****************************************************
- * push_ready(m, buffer)
- * m is minor # of device
- *
+ * push_ready
*****************************************************/
-void push_ready(int m, int index)
+void push_ready(int minor, int index)
{
- int head = dt3155_fbuffer[m]->ready_head;
-
- dt3155_fbuffer[m]->ready_que[head] = index;
- dt3155_fbuffer[m]->ready_head = ((head + 1) %
- (dt3155_fbuffer[m]->nbuffers));
- dt3155_fbuffer[m]->ready_len++;
+ struct dt3155_fbuffer *fb = &dt3155_status[minor].fbuffer;
+ int head = fb->ready_head;

+ fb->ready_que[head] = index;
+ fb->ready_head = (head + 1) % fb->nbuffers;
+ fb->ready_len++;
}

/*****************************************************
- * get_tail()
- * m is minor # of device
+ * get_tail
*
* Simply comptutes the tail given the head and the length.
*****************************************************/
-static int get_tail(int m)
+static int get_tail(int minor)
{
- int ncount;
- ncount = (dt3155_fbuffer[m]->ready_head -
- dt3155_fbuffer[m]->ready_len +
- dt3155_fbuffer[m]->nbuffers)%
- (dt3155_fbuffer[m]->nbuffers);
- return ncount;
-}
-
+ struct dt3155_fbuffer *fb = &dt3155_status[minor].fbuffer;

+ return (fb->ready_head - fb->ready_len + fb->nbuffers) % fb->nbuffers;
+}

/*****************************************************
- * pop_ready()
- * m is minor # of device
+ * pop_ready
*
* This assumes that there is a ready buffer ready... should
* be checked (e.g. with is_ready_buf_empty() prior to call.
*****************************************************/
-int pop_ready(int m)
+int pop_ready(int minor)
{
- int tail;
- tail = get_tail(m);
- dt3155_fbuffer[m]->ready_len--;
- return dt3155_fbuffer[m]->ready_que[tail];
-}
+ struct dt3155_fbuffer *fb = &dt3155_status[minor].fbuffer;
+ int tail = get_tail(minor);

+ fb->ready_len--;
+ return fb->ready_que[tail];
+}

/*****************************************************
* printques
- * m is minor # of device
*****************************************************/
-void printques(int m)
+void printques(int minor)
{
- int head = dt3155_fbuffer[m]->ready_head;
- int tail;
- int num = dt3155_fbuffer[m]->nbuffers;
- int frame_index;
- int index;
-
- tail = get_tail(m);
-
- printk(KERN_INFO "\n R:");
- for (index = tail; index != head; index++, index = index % (num)) {
- frame_index = dt3155_fbuffer[m]->ready_que[index];
- printk(" %d ", frame_index);
- }
+ struct dt3155_fbuffer *fb = &dt3155_status[minor].fbuffer;
+ int i;

- printk(KERN_INFO "\n E:");
- for (index = 0; index < dt3155_fbuffer[m]->empty_len; index++) {
- frame_index = dt3155_fbuffer[m]->empty_buffers[index];
- printk(" %d ", frame_index);
- }
+ printk(KERN_INFO "\n R:");
+ for (i = get_tail(minor); i != fb->ready_head; i++, i %= fb->nbuffers)
+ printk(" %d ", fb->ready_que[i]);

- frame_index = dt3155_fbuffer[m]->active_buf;
- printk(KERN_INFO "\n A: %d", frame_index);
+ printk(KERN_INFO "\n E:");
+ for (i = 0; i < fb->empty_len; i++)
+ printk(" %d ", fb->empty_buffers[i]);

- frame_index = dt3155_fbuffer[m]->locked_buf;
- printk(KERN_INFO "\n L: %d\n", frame_index);
+ printk(KERN_INFO "\n A: %d", fb->active_buf);

+ printk(KERN_INFO "\n L: %d\n", fb->locked_buf);
}

/*****************************************************
@@ -304,6 +279,7 @@ void allocate_buffers(u32 *buf_addr, u32* total_size_kbs,
u32 dt3155_setup_buffers(u32 *allocatorAddr)

{
+ struct dt3155_fbuffer *fb;
u32 index;
u32 rambuff_addr; /* start of allocation */
u32 rambuff_size; /* total size allocated to driver */
@@ -312,18 +288,12 @@ u32 dt3155_setup_buffers(u32 *allocatorAddr)
u32 rambuff_end; /* end of rambuff */
u32 numbufs; /* number of useful buffers allocated (per device) */
u32 bufsize = DT3155_MAX_ROWS * DT3155_MAX_COLS;
- int m; /* minor # of device, looped for all devs */
+ int minor;

/* zero the fbuffer status and address structure */
- for (m = 0; m < ndevices; m++) {
- dt3155_fbuffer[m] = &(dt3155_status[m].fbuffer);
-
- /* Make sure the buffering variables are consistent */
- {
- u8 *ptr = (u8 *) dt3155_fbuffer[m];
- for (index = 0; index < sizeof(struct dt3155_fbuffer); index++)
- *(ptr++) = 0;
- }
+ for (minor = 0; minor < ndevices; minor++) {
+ fb = &dt3155_status[minor].fbuffer;
+ memset(fb, 0, sizeof(*fb));
}

/* allocate a large contiguous chunk of RAM */
@@ -362,11 +332,12 @@ u32 dt3155_setup_buffers(u32 *allocatorAddr)
/* now that we have board memory we spit it up */
/* between the boards and the buffers */
rambuff_acm = rambuff_addr;
- for (m = 0; m < ndevices; m++) {
+ for (minor = 0; minor < ndevices; minor++) {
+ fb = &dt3155_status[minor].fbuffer;
rambuff_acm = adjust_4MB(rambuff_acm, bufsize);

/* Save the start of this boards buffer space (for mmap). */
- dt3155_status[m].mem_addr = rambuff_acm;
+ dt3155_status[minor].mem_addr = rambuff_acm;

for (index = 0; index < numbufs; index++) {
rambuff_acm = adjust_4MB(rambuff_acm, bufsize);
@@ -377,31 +348,29 @@ u32 dt3155_setup_buffers(u32 *allocatorAddr)
return -ENOMEM;
}

- dt3155_fbuffer[m]->frame_info[index].addr = rambuff_acm;
- push_empty(index, m);
- /* printk(" - Buffer : %lx\n",
- * dt3155_fbuffer[m]->frame_info[index].addr);
- */
- dt3155_fbuffer[m]->nbuffers += 1;
+ fb->frame_info[index].addr = rambuff_acm;
+ push_empty(index, minor);
+ /* printk(" - Buffer : %lx\n", fb->frame_info[index].addr); */
+ fb->nbuffers += 1;
rambuff_acm += bufsize;
}

/* Make sure there is an active buffer there. */
- dt3155_fbuffer[m]->active_buf = pop_empty(m);
- dt3155_fbuffer[m]->even_happened = 0;
- dt3155_fbuffer[m]->even_stopped = 0;
+ fb->active_buf = pop_empty(minor);
+ fb->even_happened = 0;
+ fb->even_stopped = 0;

/* make sure there is no locked_buf JML 2/28/00 */
- dt3155_fbuffer[m]->locked_buf = -1;
+ fb->locked_buf = -1;

- dt3155_status[m].mem_size =
- rambuff_acm - dt3155_status[m].mem_addr;
+ dt3155_status[minor].mem_size = rambuff_acm -
+ dt3155_status[minor].mem_addr;

/* setup the ready queue */
- dt3155_fbuffer[m]->ready_head = 0;
- dt3155_fbuffer[m]->ready_len = 0;
+ fb->ready_head = 0;
+ fb->ready_len = 0;
printk(KERN_INFO "Available buffers for device %d: %d\n",
- m, dt3155_fbuffer[m]->nbuffers);
+ minor, fb->nbuffers);
}

return 1;
@@ -412,103 +381,100 @@ u32 dt3155_setup_buffers(u32 *allocatorAddr)
*
* The internal function for releasing a locked buffer.
* It assumes interrupts are turned off.
- *
- * m is minor number of device
*****************************************************/
-static void internal_release_locked_buffer(int m)
+static void internal_release_locked_buffer(int minor)
{
- /* Pointer into global structure for handling buffers */
- if (dt3155_fbuffer[m]->locked_buf >= 0) {
- push_empty(dt3155_fbuffer[m]->locked_buf, m);
- dt3155_fbuffer[m]->locked_buf = -1;
- }
-}
+ struct dt3155_fbuffer *fb = &dt3155_status[minor].fbuffer;

+ if (fb->locked_buf >= 0) {
+ push_empty(fb->locked_buf, minor);
+ fb->locked_buf = -1;
+ }
+}

/*****************************************************
- * dt3155_release_locked_buffer()
- * m is minor # of device
+ * dt3155_release_locked_buffer
*
* The user function of the above.
- *
*****************************************************/
-void dt3155_release_locked_buffer(int m)
+void dt3155_release_locked_buffer(int minor)
{
unsigned long int flags;
+
local_save_flags(flags);
local_irq_disable();
- internal_release_locked_buffer(m);
+ internal_release_locked_buffer(minor);
local_irq_restore(flags);
}

-
/*****************************************************
- * dt3155_flush()
- * m is minor # of device
- *
+ * dt3155_flush
*****************************************************/
-int dt3155_flush(int m)
+int dt3155_flush(int minor)
{
- int index;
- unsigned long int flags;
- local_save_flags(flags);
- local_irq_disable();
+ struct dt3155_fbuffer *fb = &dt3155_status[minor].fbuffer;
+ unsigned long int flags;
+ int index;

- internal_release_locked_buffer(m);
- dt3155_fbuffer[m]->empty_len = 0;
+ local_save_flags(flags);
+ local_irq_disable();

- for (index = 0; index < dt3155_fbuffer[m]->nbuffers; index++)
- push_empty(index, m);
+ internal_release_locked_buffer(minor);
+ fb->empty_len = 0;

- /* Make sure there is an active buffer there. */
- dt3155_fbuffer[m]->active_buf = pop_empty(m);
+ for (index = 0; index < fb->nbuffers; index++)
+ push_empty(index, minor);

- dt3155_fbuffer[m]->even_happened = 0;
- dt3155_fbuffer[m]->even_stopped = 0;
+ /* Make sure there is an active buffer there. */
+ fb->active_buf = pop_empty(minor);

- /* setup the ready queue */
- dt3155_fbuffer[m]->ready_head = 0;
- dt3155_fbuffer[m]->ready_len = 0;
+ fb->even_happened = 0;
+ fb->even_stopped = 0;

- local_irq_restore(flags);
+ /* setup the ready queue */
+ fb->ready_head = 0;
+ fb->ready_len = 0;

- return 0;
+ local_irq_restore(flags);
+
+ return 0;
}

/*****************************************************
- * dt3155_get_ready_buffer()
- * m is minor # of device
+ * dt3155_get_ready_buffer
*
* get_ready_buffer will grab the next chunk of data
* if it is already there, otherwise it returns 0.
* If the user has a buffer locked it will unlock
* that buffer before returning the new one.
*****************************************************/
-int dt3155_get_ready_buffer(int m)
+int dt3155_get_ready_buffer(int minor)
{
- int frame_index;
- unsigned long int flags;
- local_save_flags(flags);
- local_irq_disable();
+ struct dt3155_fbuffer *fb = &dt3155_status[minor].fbuffer;
+ unsigned long int flags;
+ int frame_index;
+
+ local_save_flags(flags);
+ local_irq_disable();

#ifdef DEBUG_QUES_A
- printques(m);
+ printques(minor);
#endif

- internal_release_locked_buffer(m);
+ internal_release_locked_buffer(minor);

- if (is_ready_buf_empty(m))
- frame_index = -1;
- else {
- frame_index = pop_ready(m);
- dt3155_fbuffer[m]->locked_buf = frame_index;
+ if (is_ready_buf_empty(minor)) {
+ frame_index = -1;
+ } else {
+ frame_index = pop_ready(minor);
+ fb->locked_buf = frame_index;
}

#ifdef DEBUG_QUES_B
- printques(m);
+ printques(minor);
#endif

- local_irq_restore(flags);
+ local_irq_restore(flags);

- return frame_index;
+ return frame_index;
}
diff --git a/drivers/staging/dt3155/dt3155_isr.h b/drivers/staging/dt3155/dt3155_isr.h
index 7d474cf..c4cf865 100644
--- a/drivers/staging/dt3155/dt3155_isr.h
+++ b/drivers/staging/dt3155/dt3155_isr.h
@@ -36,8 +36,6 @@ MA 02111-1307 USA
#ifndef DT3155_ISR_H
#define DT3155_ISR_H

-extern struct dt3155_fbuffer *dt3155_fbuffer[MAXBOARDS];
-
/* User functions for buffering */
/* Initialize the buffering system. This should */
/* be called prior to enabling interrupts */
--
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