blob: d4b1766608b0e269319efb7c20b8966f4b020ee1 [file] [log] [blame]
/* via_dma.c -- DMA support for the VIA Unichrome/Pro
*
* Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
* All Rights Reserved.
*
* Copyright 2004 Digeo, Inc., Palo Alto, CA, U.S.A.
* All Rights Reserved.
*
* Copyright 2004 The Unichrome project.
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sub license,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
* USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* Authors:
* Tungsten Graphics,
* Erdi Chen,
* Thomas Hellstrom.
*/
#include "drmP.h"
#include "drm.h"
#include "via_drm.h"
#include "via_drv.h"
#include "via_3d_reg.h"
#define CMDBUF_ALIGNMENT_SIZE (0x100)
#define CMDBUF_ALIGNMENT_MASK (0x0ff)
/* defines for VIA 3D registers */
#define VIA_REG_STATUS 0x400
#define VIA_REG_TRANSET 0x43C
#define VIA_REG_TRANSPACE 0x440
/* VIA_REG_STATUS(0x400): Engine Status */
#define VIA_CMD_RGTR_BUSY 0x00000080 /* Command Regulator is busy */
#define VIA_2D_ENG_BUSY 0x00000001 /* 2D Engine is busy */
#define VIA_3D_ENG_BUSY 0x00000002 /* 3D Engine is busy */
#define VIA_VR_QUEUE_BUSY 0x00020000 /* Virtual Queue is busy */
#define SetReg2DAGP(nReg, nData) { \
*((uint32_t *)(vb)) = ((nReg) >> 2) | HALCYON_HEADER1; \
*((uint32_t *)(vb) + 1) = (nData); \
vb = ((uint32_t *)vb) + 2; \
dev_priv->dma_low +=8; \
}
#define via_flush_write_combine() DRM_MEMORYBARRIER()
#define VIA_OUT_RING_QW(w1,w2) \
*vb++ = (w1); \
*vb++ = (w2); \
dev_priv->dma_low += 8;
static void via_cmdbuf_start(drm_via_private_t * dev_priv);
static void via_cmdbuf_pause(drm_via_private_t * dev_priv);
static void via_cmdbuf_reset(drm_via_private_t * dev_priv);
static void via_cmdbuf_rewind(drm_via_private_t * dev_priv);
static int via_wait_idle(drm_via_private_t * dev_priv);
static void via_pad_cache(drm_via_private_t * dev_priv, int qwords);
/*
* Free space in command buffer.
*/
static uint32_t via_cmdbuf_space(drm_via_private_t * dev_priv)
{
uint32_t agp_base = dev_priv->dma_offset + (uint32_t) dev_priv->agpAddr;
uint32_t hw_addr = *(dev_priv->hw_addr_ptr) - agp_base;
return ((hw_addr <= dev_priv->dma_low) ?
(dev_priv->dma_high + hw_addr - dev_priv->dma_low) :
(hw_addr - dev_priv->dma_low));
}
/*
* How much does the command regulator lag behind?
*/
static uint32_t via_cmdbuf_lag(drm_via_private_t * dev_priv)
{
uint32_t agp_base = dev_priv->dma_offset + (uint32_t) dev_priv->agpAddr;
uint32_t hw_addr = *(dev_priv->hw_addr_ptr) - agp_base;
return ((hw_addr <= dev_priv->dma_low) ?
(dev_priv->dma_low - hw_addr) :
(dev_priv->dma_wrap + dev_priv->dma_low - hw_addr));
}
/*
* Check that the given size fits in the buffer, otherwise wait.
*/
static inline int
via_cmdbuf_wait(drm_via_private_t * dev_priv, unsigned int size)
{
uint32_t agp_base = dev_priv->dma_offset + (uint32_t) dev_priv->agpAddr;
uint32_t cur_addr, hw_addr, next_addr;
volatile uint32_t *hw_addr_ptr;
uint32_t count;
hw_addr_ptr = dev_priv->hw_addr_ptr;
cur_addr = dev_priv->dma_low;
next_addr = cur_addr + size + 512 * 1024;
count = 1000000;
do {
hw_addr = *hw_addr_ptr - agp_base;
if (count-- == 0) {
DRM_ERROR
("via_cmdbuf_wait timed out hw %x cur_addr %x next_addr %x\n",
hw_addr, cur_addr, next_addr);
return -1;
}
} while ((cur_addr < hw_addr) && (next_addr >= hw_addr));
return 0;
}
/*
* Checks whether buffer head has reach the end. Rewind the ring buffer
* when necessary.
*
* Returns virtual pointer to ring buffer.
*/
static inline uint32_t *via_check_dma(drm_via_private_t * dev_priv,
unsigned int size)
{
if ((dev_priv->dma_low + size + 4 * CMDBUF_ALIGNMENT_SIZE) >
dev_priv->dma_high) {
via_cmdbuf_rewind(dev_priv);
}
if (via_cmdbuf_wait(dev_priv, size) != 0) {
return NULL;
}
return (uint32_t *) (dev_priv->dma_ptr + dev_priv->dma_low);
}
int via_dma_cleanup(drm_device_t * dev)
{
if (dev->dev_private) {
drm_via_private_t *dev_priv =
(drm_via_private_t *) dev->dev_private;
if (dev_priv->ring.virtual_start) {
via_cmdbuf_reset(dev_priv);
drm_core_ioremapfree(&dev_priv->ring.map, dev);
dev_priv->ring.virtual_start = NULL;
}
}
return 0;
}
static int via_initialize(drm_device_t * dev,
drm_via_private_t * dev_priv,
drm_via_dma_init_t * init)
{
if (!dev_priv || !dev_priv->mmio) {
DRM_ERROR("via_dma_init called before via_map_init\n");
return DRM_ERR(EFAULT);
}
if (dev_priv->ring.virtual_start != NULL) {
DRM_ERROR("%s called again without calling cleanup\n",
__FUNCTION__);
return DRM_ERR(EFAULT);
}
if (!dev->agp || !dev->agp->base) {
DRM_ERROR("%s called with no agp memory available\n",
__FUNCTION__);
return DRM_ERR(EFAULT);
}
dev_priv->ring.map.offset = dev->agp->base + init->offset;
dev_priv->ring.map.size = init->size;
dev_priv->ring.map.type = 0;
dev_priv->ring.map.flags = 0;
dev_priv->ring.map.mtrr = 0;
drm_core_ioremap(&dev_priv->ring.map, dev);
if (dev_priv->ring.map.handle == NULL) {
via_dma_cleanup(dev);
DRM_ERROR("can not ioremap virtual address for"
" ring buffer\n");
return DRM_ERR(ENOMEM);
}
dev_priv->ring.virtual_start = dev_priv->ring.map.handle;
dev_priv->dma_ptr = dev_priv->ring.virtual_start;
dev_priv->dma_low = 0;
dev_priv->dma_high = init->size;
dev_priv->dma_wrap = init->size;
dev_priv->dma_offset = init->offset;
dev_priv->last_pause_ptr = NULL;
dev_priv->hw_addr_ptr = dev_priv->mmio->handle + init->reg_pause_addr;
via_cmdbuf_start(dev_priv);
return 0;
}
int via_dma_init(DRM_IOCTL_ARGS)
{
DRM_DEVICE;
drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
drm_via_dma_init_t init;
int retcode = 0;
DRM_COPY_FROM_USER_IOCTL(init, (drm_via_dma_init_t __user *) data,
sizeof(init));
switch (init.func) {
case VIA_INIT_DMA:
if (!capable(CAP_SYS_ADMIN))
retcode = DRM_ERR(EPERM);
else
retcode = via_initialize(dev, dev_priv, &init);
break;
case VIA_CLEANUP_DMA:
if (!capable(CAP_SYS_ADMIN))
retcode = DRM_ERR(EPERM);
else
retcode = via_dma_cleanup(dev);
break;
case VIA_DMA_INITIALIZED:
retcode = (dev_priv->ring.virtual_start != NULL) ?
0 : DRM_ERR(EFAULT);
break;
default:
retcode = DRM_ERR(EINVAL);
break;
}
return retcode;
}
static int via_dispatch_cmdbuffer(drm_device_t * dev, drm_via_cmdbuffer_t * cmd)
{
drm_via_private_t *dev_priv;
uint32_t *vb;
int ret;
dev_priv = (drm_via_private_t *) dev->dev_private;
if (dev_priv->ring.virtual_start == NULL) {
DRM_ERROR("%s called without initializing AGP ring buffer.\n",
__FUNCTION__);
return DRM_ERR(EFAULT);
}
if (cmd->size > VIA_PCI_BUF_SIZE) {
return DRM_ERR(ENOMEM);
}
if (DRM_COPY_FROM_USER(dev_priv->pci_buf, cmd->buf, cmd->size))
return DRM_ERR(EFAULT);
/*
* Running this function on AGP memory is dead slow. Therefore
* we run it on a temporary cacheable system memory buffer and
* copy it to AGP memory when ready.
*/
if ((ret =
via_verify_command_stream((uint32_t *) dev_priv->pci_buf,
cmd->size, dev, 1))) {
return ret;
}
vb = via_check_dma(dev_priv, (cmd->size < 0x100) ? 0x102 : cmd->size);
if (vb == NULL) {
return DRM_ERR(EAGAIN);
}
memcpy(vb, dev_priv->pci_buf, cmd->size);
dev_priv->dma_low += cmd->size;
/*
* Small submissions somehow stalls the CPU. (AGP cache effects?)
* pad to greater size.
*/
if (cmd->size < 0x100)
via_pad_cache(dev_priv, (0x100 - cmd->size) >> 3);
via_cmdbuf_pause(dev_priv);
return 0;
}
int via_driver_dma_quiescent(drm_device_t * dev)
{
drm_via_private_t *dev_priv = dev->dev_private;
if (!via_wait_idle(dev_priv)) {
return DRM_ERR(EBUSY);
}
return 0;
}
int via_flush_ioctl(DRM_IOCTL_ARGS)
{
DRM_DEVICE;
LOCK_TEST_WITH_RETURN(dev, filp);
return via_driver_dma_quiescent(dev);
}
int via_cmdbuffer(DRM_IOCTL_ARGS)
{
DRM_DEVICE;
drm_via_cmdbuffer_t cmdbuf;
int ret;
LOCK_TEST_WITH_RETURN(dev, filp);
DRM_COPY_FROM_USER_IOCTL(cmdbuf, (drm_via_cmdbuffer_t __user *) data,
sizeof(cmdbuf));
DRM_DEBUG("via cmdbuffer, buf %p size %lu\n", cmdbuf.buf, cmdbuf.size);
ret = via_dispatch_cmdbuffer(dev, &cmdbuf);
if (ret) {
return ret;
}
return 0;
}
extern int
via_parse_command_stream(drm_device_t * dev, const uint32_t * buf,
unsigned int size);
static int via_dispatch_pci_cmdbuffer(drm_device_t * dev,
drm_via_cmdbuffer_t * cmd)
{
drm_via_private_t *dev_priv = dev->dev_private;
int ret;
if (cmd->size > VIA_PCI_BUF_SIZE) {
return DRM_ERR(ENOMEM);
}
if (DRM_COPY_FROM_USER(dev_priv->pci_buf, cmd->buf, cmd->size))
return DRM_ERR(EFAULT);
if ((ret =
via_verify_command_stream((uint32_t *) dev_priv->pci_buf,
cmd->size, dev, 0))) {
return ret;
}
ret =
via_parse_command_stream(dev, (const uint32_t *)dev_priv->pci_buf,
cmd->size);
return ret;
}
int via_pci_cmdbuffer(DRM_IOCTL_ARGS)
{
DRM_DEVICE;
drm_via_cmdbuffer_t cmdbuf;
int ret;
LOCK_TEST_WITH_RETURN(dev, filp);
DRM_COPY_FROM_USER_IOCTL(cmdbuf, (drm_via_cmdbuffer_t __user *) data,
sizeof(cmdbuf));
DRM_DEBUG("via_pci_cmdbuffer, buf %p size %lu\n", cmdbuf.buf,
cmdbuf.size);
ret = via_dispatch_pci_cmdbuffer(dev, &cmdbuf);
if (ret) {
return ret;
}
return 0;
}
static inline uint32_t *via_align_buffer(drm_via_private_t * dev_priv,
uint32_t * vb, int qw_count)
{
for (; qw_count > 0; --qw_count) {
VIA_OUT_RING_QW(HC_DUMMY, HC_DUMMY);
}
return vb;
}
/*
* This function is used internally by ring buffer mangement code.
*
* Returns virtual pointer to ring buffer.
*/
static inline uint32_t *via_get_dma(drm_via_private_t * dev_priv)
{
return (uint32_t *) (dev_priv->dma_ptr + dev_priv->dma_low);
}
/*
* Hooks a segment of data into the tail of the ring-buffer by
* modifying the pause address stored in the buffer itself. If
* the regulator has already paused, restart it.
*/
static int via_hook_segment(drm_via_private_t * dev_priv,
uint32_t pause_addr_hi, uint32_t pause_addr_lo,
int no_pci_fire)
{
int paused, count;
volatile uint32_t *paused_at = dev_priv->last_pause_ptr;
via_flush_write_combine();
while (!*(via_get_dma(dev_priv) - 1)) ;
*dev_priv->last_pause_ptr = pause_addr_lo;
via_flush_write_combine();
/*
* The below statement is inserted to really force the flush.
* Not sure it is needed.
*/
while (!*dev_priv->last_pause_ptr) ;
dev_priv->last_pause_ptr = via_get_dma(dev_priv) - 1;
while (!*dev_priv->last_pause_ptr) ;
paused = 0;
count = 20;
while (!(paused = (VIA_READ(0x41c) & 0x80000000)) && count--) ;
if ((count <= 8) && (count >= 0)) {
uint32_t rgtr, ptr;
rgtr = *(dev_priv->hw_addr_ptr);
ptr = ((char *)dev_priv->last_pause_ptr - dev_priv->dma_ptr) +
dev_priv->dma_offset + (uint32_t) dev_priv->agpAddr + 4 -
CMDBUF_ALIGNMENT_SIZE;
if (rgtr <= ptr) {
DRM_ERROR
("Command regulator\npaused at count %d, address %x, "
"while current pause address is %x.\n"
"Please mail this message to "
"<unichrome-devel@lists.sourceforge.net>\n", count,
rgtr, ptr);
}
}
if (paused && !no_pci_fire) {
uint32_t rgtr, ptr;
uint32_t ptr_low;
count = 1000000;
while ((VIA_READ(VIA_REG_STATUS) & VIA_CMD_RGTR_BUSY)
&& count--) ;
rgtr = *(dev_priv->hw_addr_ptr);
ptr = ((char *)paused_at - dev_priv->dma_ptr) +
dev_priv->dma_offset + (uint32_t) dev_priv->agpAddr + 4;
ptr_low = (ptr > 3 * CMDBUF_ALIGNMENT_SIZE) ?
ptr - 3 * CMDBUF_ALIGNMENT_SIZE : 0;
if (rgtr <= ptr && rgtr >= ptr_low) {
VIA_WRITE(VIA_REG_TRANSET, (HC_ParaType_PreCR << 16));
VIA_WRITE(VIA_REG_TRANSPACE, pause_addr_hi);
VIA_WRITE(VIA_REG_TRANSPACE, pause_addr_lo);
}
}
return paused;
}
static int via_wait_idle(drm_via_private_t * dev_priv)
{
int count = 10000000;
while (count-- && (VIA_READ(VIA_REG_STATUS) &
(VIA_CMD_RGTR_BUSY | VIA_2D_ENG_BUSY |
VIA_3D_ENG_BUSY))) ;
return count;
}
static uint32_t *via_align_cmd(drm_via_private_t * dev_priv, uint32_t cmd_type,
uint32_t addr, uint32_t * cmd_addr_hi,
uint32_t * cmd_addr_lo, int skip_wait)
{
uint32_t agp_base;
uint32_t cmd_addr, addr_lo, addr_hi;
uint32_t *vb;
uint32_t qw_pad_count;
if (!skip_wait)
via_cmdbuf_wait(dev_priv, 2 * CMDBUF_ALIGNMENT_SIZE);
vb = via_get_dma(dev_priv);
VIA_OUT_RING_QW(HC_HEADER2 | ((VIA_REG_TRANSET >> 2) << 12) |
(VIA_REG_TRANSPACE >> 2), HC_ParaType_PreCR << 16);
agp_base = dev_priv->dma_offset + (uint32_t) dev_priv->agpAddr;
qw_pad_count = (CMDBUF_ALIGNMENT_SIZE >> 3) -
((dev_priv->dma_low & CMDBUF_ALIGNMENT_MASK) >> 3);
cmd_addr = (addr) ? addr :
agp_base + dev_priv->dma_low - 8 + (qw_pad_count << 3);
addr_lo = ((HC_SubA_HAGPBpL << 24) | (cmd_type & HC_HAGPBpID_MASK) |
(cmd_addr & HC_HAGPBpL_MASK));
addr_hi = ((HC_SubA_HAGPBpH << 24) | (cmd_addr >> 24));
vb = via_align_buffer(dev_priv, vb, qw_pad_count - 1);
VIA_OUT_RING_QW(*cmd_addr_hi = addr_hi, *cmd_addr_lo = addr_lo);
return vb;
}
static void via_cmdbuf_start(drm_via_private_t * dev_priv)
{
uint32_t pause_addr_lo, pause_addr_hi;
uint32_t start_addr, start_addr_lo;
uint32_t end_addr, end_addr_lo;
uint32_t command;
uint32_t agp_base;
dev_priv->dma_low = 0;
agp_base = dev_priv->dma_offset + (uint32_t) dev_priv->agpAddr;
start_addr = agp_base;
end_addr = agp_base + dev_priv->dma_high;
start_addr_lo = ((HC_SubA_HAGPBstL << 24) | (start_addr & 0xFFFFFF));
end_addr_lo = ((HC_SubA_HAGPBendL << 24) | (end_addr & 0xFFFFFF));
command = ((HC_SubA_HAGPCMNT << 24) | (start_addr >> 24) |
((end_addr & 0xff000000) >> 16));
dev_priv->last_pause_ptr =
via_align_cmd(dev_priv, HC_HAGPBpID_PAUSE, 0,
&pause_addr_hi, &pause_addr_lo, 1) - 1;
via_flush_write_combine();
while (!*dev_priv->last_pause_ptr) ;
VIA_WRITE(VIA_REG_TRANSET, (HC_ParaType_PreCR << 16));
VIA_WRITE(VIA_REG_TRANSPACE, command);
VIA_WRITE(VIA_REG_TRANSPACE, start_addr_lo);
VIA_WRITE(VIA_REG_TRANSPACE, end_addr_lo);
VIA_WRITE(VIA_REG_TRANSPACE, pause_addr_hi);
VIA_WRITE(VIA_REG_TRANSPACE, pause_addr_lo);
VIA_WRITE(VIA_REG_TRANSPACE, command | HC_HAGPCMNT_MASK);
}
static void via_pad_cache(drm_via_private_t * dev_priv, int qwords)
{
uint32_t *vb;
via_cmdbuf_wait(dev_priv, qwords + 2);
vb = via_get_dma(dev_priv);
VIA_OUT_RING_QW(HC_HEADER2, HC_ParaType_NotTex << 16);
via_align_buffer(dev_priv, vb, qwords);
}
static inline void via_dummy_bitblt(drm_via_private_t * dev_priv)
{
uint32_t *vb = via_get_dma(dev_priv);
SetReg2DAGP(0x0C, (0 | (0 << 16)));
SetReg2DAGP(0x10, 0 | (0 << 16));
SetReg2DAGP(0x0, 0x1 | 0x2000 | 0xAA000000);
}
static void via_cmdbuf_jump(drm_via_private_t * dev_priv)
{
uint32_t agp_base;
uint32_t pause_addr_lo, pause_addr_hi;
uint32_t jump_addr_lo, jump_addr_hi;
volatile uint32_t *last_pause_ptr;
uint32_t dma_low_save1, dma_low_save2;
agp_base = dev_priv->dma_offset + (uint32_t) dev_priv->agpAddr;
via_align_cmd(dev_priv, HC_HAGPBpID_JUMP, 0, &jump_addr_hi,
&jump_addr_lo, 0);
dev_priv->dma_wrap = dev_priv->dma_low;
/*
* Wrap command buffer to the beginning.
*/
dev_priv->dma_low = 0;
if (via_cmdbuf_wait(dev_priv, CMDBUF_ALIGNMENT_SIZE) != 0) {
DRM_ERROR("via_cmdbuf_jump failed\n");
}
via_dummy_bitblt(dev_priv);
via_dummy_bitblt(dev_priv);
last_pause_ptr =
via_align_cmd(dev_priv, HC_HAGPBpID_PAUSE, 0, &pause_addr_hi,
&pause_addr_lo, 0) - 1;
via_align_cmd(dev_priv, HC_HAGPBpID_PAUSE, 0, &pause_addr_hi,
&pause_addr_lo, 0);
*last_pause_ptr = pause_addr_lo;
dma_low_save1 = dev_priv->dma_low;
/*
* Now, set a trap that will pause the regulator if it tries to rerun the old
* command buffer. (Which may happen if via_hook_segment detecs a command regulator pause
* and reissues the jump command over PCI, while the regulator has already taken the jump
* and actually paused at the current buffer end).
* There appears to be no other way to detect this condition, since the hw_addr_pointer
* does not seem to get updated immediately when a jump occurs.
*/
last_pause_ptr =
via_align_cmd(dev_priv, HC_HAGPBpID_PAUSE, 0, &pause_addr_hi,
&pause_addr_lo, 0) - 1;
via_align_cmd(dev_priv, HC_HAGPBpID_PAUSE, 0, &pause_addr_hi,
&pause_addr_lo, 0);
*last_pause_ptr = pause_addr_lo;
dma_low_save2 = dev_priv->dma_low;
dev_priv->dma_low = dma_low_save1;
via_hook_segment(dev_priv, jump_addr_hi, jump_addr_lo, 0);
dev_priv->dma_low = dma_low_save2;
via_hook_segment(dev_priv, pause_addr_hi, pause_addr_lo, 0);
}
static void via_cmdbuf_rewind(drm_via_private_t * dev_priv)
{
via_cmdbuf_jump(dev_priv);
}
static void via_cmdbuf_flush(drm_via_private_t * dev_priv, uint32_t cmd_type)
{
uint32_t pause_addr_lo, pause_addr_hi;
via_align_cmd(dev_priv, cmd_type, 0, &pause_addr_hi, &pause_addr_lo, 0);
via_hook_segment(dev_priv, pause_addr_hi, pause_addr_lo, 0);
}
static void via_cmdbuf_pause(drm_via_private_t * dev_priv)
{
via_cmdbuf_flush(dev_priv, HC_HAGPBpID_PAUSE);
}
static void via_cmdbuf_reset(drm_via_private_t * dev_priv)
{
via_cmdbuf_flush(dev_priv, HC_HAGPBpID_STOP);
via_wait_idle(dev_priv);
}
/*
* User interface to the space and lag functions.
*/
int via_cmdbuf_size(DRM_IOCTL_ARGS)
{
DRM_DEVICE;
drm_via_cmdbuf_size_t d_siz;
int ret = 0;
uint32_t tmp_size, count;
drm_via_private_t *dev_priv;
DRM_DEBUG("via cmdbuf_size\n");
LOCK_TEST_WITH_RETURN(dev, filp);
dev_priv = (drm_via_private_t *) dev->dev_private;
if (dev_priv->ring.virtual_start == NULL) {
DRM_ERROR("%s called without initializing AGP ring buffer.\n",
__FUNCTION__);
return DRM_ERR(EFAULT);
}
DRM_COPY_FROM_USER_IOCTL(d_siz, (drm_via_cmdbuf_size_t __user *) data,
sizeof(d_siz));
count = 1000000;
tmp_size = d_siz.size;
switch (d_siz.func) {
case VIA_CMDBUF_SPACE:
while (((tmp_size = via_cmdbuf_space(dev_priv)) < d_siz.size)
&& count--) {
if (!d_siz.wait) {
break;
}
}
if (!count) {
DRM_ERROR("VIA_CMDBUF_SPACE timed out.\n");
ret = DRM_ERR(EAGAIN);
}
break;
case VIA_CMDBUF_LAG:
while (((tmp_size = via_cmdbuf_lag(dev_priv)) > d_siz.size)
&& count--) {
if (!d_siz.wait) {
break;
}
}
if (!count) {
DRM_ERROR("VIA_CMDBUF_LAG timed out.\n");
ret = DRM_ERR(EAGAIN);
}
break;
default:
ret = DRM_ERR(EFAULT);
}
d_siz.size = tmp_size;
DRM_COPY_TO_USER_IOCTL((drm_via_cmdbuf_size_t __user *) data, d_siz,
sizeof(d_siz));
return ret;
}