[Cbe-oss-dev] [RFC/PATCH] libspe2: use mapped mailbox registers to speed up mailbox communication
stenzel at de.ibm.com
stenzel at de.ibm.com
Tue May 22 01:15:12 EST 2007
Thanks for the comments so far. I tried to integrate most of them.
This patch replaces the previous one.
The following patch speeds up mailbox communication by
accessing the mailbox registers directly via mapped problem
state if the context was created with the SPE_MAP_PS flag.
Comments are still appreciated.
Signed-off-by: Gerhard Stenzel <stenzel at de.ibm.com>
===================================================================
Index: libspe2/spebase/mbox.c
===================================================================
RCS file: /cvs/stiblade/cvs/sw/naxxar/libspe2/spebase/mbox.c,v
retrieving revision 1.6
diff -u -p -r1.6 mbox.c
--- libspe2/spebase/mbox.c 16 Apr 2007 13:13:11 -0000 1.6
+++ libspe2/spebase/mbox.c 21 May 2007 13:49:01 -0000
@@ -19,6 +19,7 @@
#include <errno.h>
#include <fcntl.h>
+#include <poll.h>
#include <stdio.h>
#include <unistd.h>
@@ -30,6 +31,30 @@
* -------------------------
*/
+static __inline__ int _base_spe_out_mbox_read_ps(spe_context_ptr_t spectx,
+ unsigned int mbox_data[],
+ int count)
+{
+ int rc;
+ int entries;
+
+ volatile struct spe_spu_control_area *cntl_area =
+ spectx->base_private->cntl_mmap_base;
+
+ _base_spe_context_lock(spectx, FD_MBOX);
+ rc = 0;
+ while (rc < count) {
+ entries = cntl_area->SPU_Mbox_Stat & 0xFF;
+ if (entries == 0) break; // no entries
+ if (entries > count) entries = count; // don't read more than we need;
+ while(entries--) {
+ mbox_data[rc] = cntl_area->SPU_Out_Mbox;
+ rc ++;
+ }
+ }
+ _base_spe_context_unlock(spectx, FD_MBOX);
+ return rc;
+}
int _base_spe_out_mbox_read(spe_context_ptr_t spectx,
unsigned int mbox_data[],
@@ -42,20 +67,50 @@ int _base_spe_out_mbox_read(spe_context_
return -1;
}
- rc = read(open_if_closed(spectx,FD_MBOX, 0), mbox_data, count*4);
- DEBUG_PRINTF("%s read rc: %d\n", __FUNCTION__, rc);
- if (rc != -1) {
- rc /= 4;
+ if (spectx->base_private->flags & SPE_MAP_PS) {
+ rc = _base_spe_out_mbox_read_ps(spectx, mbox_data, count);
} else {
- if (errno == EAGAIN ) { // no data ready to be read
- errno = 0;
- rc = 0;
+ rc = read(open_if_closed(spectx,FD_MBOX, 0), mbox_data, count*4);
+ DEBUG_PRINTF("%s read rc: %d\n", __FUNCTION__, rc);
+ if (rc != -1) {
+ rc /= 4;
+ } else {
+ if (errno == EAGAIN ) { // no data ready to be read
+ errno = 0;
+ rc = 0;
+ }
}
}
-
return rc;
}
+static __inline__ int _base_spe_in_mbox_write_ps(spe_context_ptr_t spectx,
+ unsigned int *mbox_data,
+ int count)
+{
+ volatile struct spe_spu_control_area *cntl_area =
+ spectx->base_private->cntl_mmap_base;
+ int total = 0;
+ int i;
+ unsigned int *aux;
+ int space;
+
+ _base_spe_context_lock(spectx, FD_WBOX);
+ aux = mbox_data;
+ while (total < count) {
+ space = (cntl_area->SPU_Mbox_Stat >> 8) & 0xFF;
+ if (space == 0) break; // no space
+ if (space > count) space = count; // don't write more than we have
+ while (space --) {
+ cntl_area->SPU_In_Mbox = *aux++;
+ total++;
+ }
+ }
+ _base_spe_context_unlock(spectx, FD_WBOX);
+
+ return total;
+}
+
int _base_spe_in_mbox_write(spe_context_ptr_t spectx,
unsigned int *mbox_data,
int count,
@@ -63,6 +118,8 @@ int _base_spe_in_mbox_write(spe_context_
{
int rc;
int total;
+ unsigned int *aux;
+ struct pollfd fds;
if (mbox_data == NULL || count < 1){
errno = EINVAL;
@@ -72,27 +129,63 @@ int _base_spe_in_mbox_write(spe_context_
switch (behavior_flag) {
case SPE_MBOX_ALL_BLOCKING: // write all, even if blocking
total = rc = 0;
- while (total < 4*count) {
- rc = write(open_if_closed(spectx,FD_WBOX, 0),
- (const char *)mbox_data + total, 4*count - total);
- if (rc == -1) {
- break;
+ if (spectx->base_private->flags & SPE_MAP_PS) {
+ do {
+ aux = mbox_data + total;
+ total += _base_spe_in_mbox_write_ps(spectx, aux, count);
+ if (total < count) { // we could not write everything, wait for space
+ fds.fd = open_if_closed(spectx, FD_WBOX, 0);
+ fds.events = POLLOUT;
+ rc = poll(&fds, 1, -1);
+ if (rc == -1 )
+ return -1;
+ }
+ } while (total < count);
+ } else {
+ while (total < 4*count) {
+ rc = write(open_if_closed(spectx,FD_WBOX, 0),
+ (const char *)mbox_data + total, 4*count - total);
+ if (rc == -1) {
+ break;
+ }
+ total += rc;
}
- total += rc;
+ total /=4;
}
break;
case SPE_MBOX_ANY_BLOCKING: // write at least one, even if blocking
- total = rc = write(open_if_closed(spectx,FD_WBOX, 0), mbox_data, 4*count);
+ total = rc = 0;
+ if (spectx->base_private->flags & SPE_MAP_PS) {
+ do {
+ total = _base_spe_in_mbox_write_ps(spectx, mbox_data, count);
+ if (total == 0) { // we could not write anything, wait for space
+ fds.fd = open_if_closed(spectx, FD_WBOX, 0);
+ fds.events = POLLOUT;
+ rc = poll(&fds, 1, -1);
+ if (rc == -1 )
+ return -1;
+ }
+ } while (total == 0);
+ } else {
+ rc = write(open_if_closed(spectx,FD_WBOX, 0), mbox_data, 4*count);
+ total = rc/4;
+ }
break;
case SPE_MBOX_ANY_NONBLOCKING: // only write, if non blocking
- rc = write(open_if_closed(spectx,FD_WBOX_NB, 0), mbox_data, 4*count);
- if (rc == -1 && errno == EAGAIN) {
- rc = 0;
- errno = 0;
+ total = rc = 0;
+ // write directly if we map the PS else write via spufs
+ if (spectx->base_private->flags & SPE_MAP_PS) {
+ total = _base_spe_in_mbox_write_ps(spectx, mbox_data, count);
+ } else {
+ rc = write(open_if_closed(spectx,FD_WBOX_NB, 0), mbox_data, 4*count);
+ if (rc == -1 && errno == EAGAIN) {
+ rc = 0;
+ errno = 0;
+ }
+ total = rc/4;
}
- total = rc;
break;
default:
@@ -105,16 +198,22 @@ int _base_spe_in_mbox_write(spe_context_
return -1;
}
- return total / 4;
+ return total;
}
int _base_spe_in_mbox_status(spe_context_ptr_t spectx)
{
int rc, ret;
+ volatile struct spe_spu_control_area *cntl_area =
+ spectx->base_private->cntl_mmap_base;
- rc = read(open_if_closed(spectx,FD_WBOX_STAT, 0), &ret, 4);
- if (rc != 4)
- ret = -1;
+ if (spectx->base_private->flags & SPE_MAP_PS) {
+ ret = (cntl_area->SPU_Mbox_Stat >> 8) & 0xFF;
+ } else {
+ rc = read(open_if_closed(spectx,FD_WBOX_STAT, 0), &ret, 4);
+ if (rc != 4)
+ ret = -1;
+ }
return ret;
@@ -123,10 +222,16 @@ int _base_spe_in_mbox_status(spe_context
int _base_spe_out_mbox_status(spe_context_ptr_t spectx)
{
int rc, ret;
+ volatile struct spe_spu_control_area *cntl_area =
+ spectx->base_private->cntl_mmap_base;
- rc = read(open_if_closed(spectx,FD_MBOX_STAT, 0), &ret, 4);
- if (rc != 4)
- ret = -1;
+ if (spectx->base_private->flags & SPE_MAP_PS) {
+ ret = cntl_area->SPU_Mbox_Stat & 0xFF;
+ } else {
+ rc = read(open_if_closed(spectx,FD_MBOX_STAT, 0), &ret, 4);
+ if (rc != 4)
+ ret = -1;
+ }
return ret;
@@ -135,11 +240,17 @@ int _base_spe_out_mbox_status(spe_contex
int _base_spe_out_intr_mbox_status(spe_context_ptr_t spectx)
{
int rc, ret;
+ volatile struct spe_spu_control_area *cntl_area =
+ spectx->base_private->cntl_mmap_base;
- rc = read(open_if_closed(spectx,FD_IBOX_STAT, 0), &ret, 4);
- if (rc != 4)
- ret = -1;
+ if (spectx->base_private->flags & SPE_MAP_PS) {
+ ret = (cntl_area->SPU_Mbox_Stat >> 16) & 0xFF;
+ } else {
+ rc = read(open_if_closed(spectx,FD_IBOX_STAT, 0), &ret, 4);
+ if (rc != 4)
+ ret = -1;
+ }
return ret;
}
@@ -200,23 +311,39 @@ int _base_spe_out_intr_mbox_read(spe_con
unsigned int data )
{
int rc;
+ volatile struct spe_spu_control_area *cntl_area =
+ spectx->base_private->cntl_mmap_base;
+
+ if (spectx->base_private->flags & SPE_MAP_PS) {
+ if (signal_reg == SPE_SIG_NOTIFY_REG_1) {
+ spe_sig_notify_1_area_t *sig = spectx->base_private->signal1_mmap_base;
+
+ sig->SPU_Sig_Notify_1 = data;
+ } else if (signal_reg == SPE_SIG_NOTIFY_REG_2) {
+ spe_sig_notify_2_area_t *sig = spectx->base_private->signal2_mmap_base;
+
+ sig->SPU_Sig_Notify_2 = data;
+ }
+ rc = 0;
+ } else {
+ if (signal_reg == SPE_SIG_NOTIFY_REG_1)
+ rc = write(open_if_closed(spectx,FD_SIG1, 0), &data, 4);
+ else if (signal_reg == SPE_SIG_NOTIFY_REG_2)
+ rc = write(open_if_closed(spectx,FD_SIG2, 0), &data, 4);
+ else
+ return -1;
- if (signal_reg == SPE_SIG_NOTIFY_REG_1)
- rc = write(open_if_closed(spectx,FD_SIG1, 0), &data, 4);
- else if (signal_reg == SPE_SIG_NOTIFY_REG_2)
- rc = write(open_if_closed(spectx,FD_SIG2, 0), &data, 4);
- else
- return -1;
+ if (rc == 4)
+ rc = 0;
- if (rc == 4)
- rc = 0;
-
- if (signal_reg == SPE_SIG_NOTIFY_REG_1)
- close_if_open(spectx,FD_SIG1);
- else if (signal_reg == SPE_SIG_NOTIFY_REG_2)
- close_if_open(spectx,FD_SIG2);
+ if (signal_reg == SPE_SIG_NOTIFY_REG_1)
+ close_if_open(spectx,FD_SIG1);
+ else if (signal_reg == SPE_SIG_NOTIFY_REG_2)
+ close_if_open(spectx,FD_SIG2);
+ }
return rc;
}
+
===================================================================
Best regards,
Gerhard Stenzel, Linux on Cell Development, LTC
-------------------------------------------------------------------------------------
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