linux/drivers/gpu/drm/via/via_irq.c
Arnd Bergmann 44a2d56429 drm/via: use monotonic time for VIA_WAIT_IRQ
The normal DRM vblank interrupt events started using monotonic times in
commit c61eef726a ("drm: add support for monotonic vblank timestamps"),
which is useful for a number of reasons, including the possible y2038
overflow.

The VIA_WAIT_IRQ ioctl uses the same drm_wait_vblank_reply as
DRM_IOCTL_WAIT_VBLANK, but still uses wall-clock time.

This converts it to using monotonic time as well, which is more
consistent, and avoids problems with the y2038 overflow as well
as synchronization issues when the real time skips.

I could not find the matching user space that calls the VIA_WAIT_IRQ
ioctl to verify that this is safe, but it very likely is. Please
either test or review the user space side before applying this.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20171127111728.1710742-1-arnd@arndb.de
2017-11-27 17:24:52 +01:00

386 lines
11 KiB
C

/* via_irq.c
*
* Copyright 2004 BEAM Ltd.
* Copyright 2002 Tungsten Graphics, Inc.
* Copyright 2005 Thomas Hellstrom.
* 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, sublicense,
* 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 NONINFRINGEMENT. IN NO EVENT SHALL
* BEAM LTD, TUNGSTEN GRAPHICS 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:
* Terry Barnaby <terry1@beam.ltd.uk>
* Keith Whitwell <keith@tungstengraphics.com>
* Thomas Hellstrom <unichrome@shipmail.org>
*
* This code provides standard DRM access to the Via Unichrome / Pro Vertical blank
* interrupt, as well as an infrastructure to handle other interrupts of the chip.
* The refresh rate is also calculated for video playback sync purposes.
*/
#include <drm/drmP.h>
#include <drm/via_drm.h>
#include "via_drv.h"
#define VIA_REG_INTERRUPT 0x200
/* VIA_REG_INTERRUPT */
#define VIA_IRQ_GLOBAL (1 << 31)
#define VIA_IRQ_VBLANK_ENABLE (1 << 19)
#define VIA_IRQ_VBLANK_PENDING (1 << 3)
#define VIA_IRQ_HQV0_ENABLE (1 << 11)
#define VIA_IRQ_HQV1_ENABLE (1 << 25)
#define VIA_IRQ_HQV0_PENDING (1 << 9)
#define VIA_IRQ_HQV1_PENDING (1 << 10)
#define VIA_IRQ_DMA0_DD_ENABLE (1 << 20)
#define VIA_IRQ_DMA0_TD_ENABLE (1 << 21)
#define VIA_IRQ_DMA1_DD_ENABLE (1 << 22)
#define VIA_IRQ_DMA1_TD_ENABLE (1 << 23)
#define VIA_IRQ_DMA0_DD_PENDING (1 << 4)
#define VIA_IRQ_DMA0_TD_PENDING (1 << 5)
#define VIA_IRQ_DMA1_DD_PENDING (1 << 6)
#define VIA_IRQ_DMA1_TD_PENDING (1 << 7)
/*
* Device-specific IRQs go here. This type might need to be extended with
* the register if there are multiple IRQ control registers.
* Currently we activate the HQV interrupts of Unichrome Pro group A.
*/
static maskarray_t via_pro_group_a_irqs[] = {
{VIA_IRQ_HQV0_ENABLE, VIA_IRQ_HQV0_PENDING, 0x000003D0, 0x00008010,
0x00000000 },
{VIA_IRQ_HQV1_ENABLE, VIA_IRQ_HQV1_PENDING, 0x000013D0, 0x00008010,
0x00000000 },
{VIA_IRQ_DMA0_TD_ENABLE, VIA_IRQ_DMA0_TD_PENDING, VIA_PCI_DMA_CSR0,
VIA_DMA_CSR_TA | VIA_DMA_CSR_TD, 0x00000008},
{VIA_IRQ_DMA1_TD_ENABLE, VIA_IRQ_DMA1_TD_PENDING, VIA_PCI_DMA_CSR1,
VIA_DMA_CSR_TA | VIA_DMA_CSR_TD, 0x00000008},
};
static int via_num_pro_group_a = ARRAY_SIZE(via_pro_group_a_irqs);
static int via_irqmap_pro_group_a[] = {0, 1, -1, 2, -1, 3};
static maskarray_t via_unichrome_irqs[] = {
{VIA_IRQ_DMA0_TD_ENABLE, VIA_IRQ_DMA0_TD_PENDING, VIA_PCI_DMA_CSR0,
VIA_DMA_CSR_TA | VIA_DMA_CSR_TD, 0x00000008},
{VIA_IRQ_DMA1_TD_ENABLE, VIA_IRQ_DMA1_TD_PENDING, VIA_PCI_DMA_CSR1,
VIA_DMA_CSR_TA | VIA_DMA_CSR_TD, 0x00000008}
};
static int via_num_unichrome = ARRAY_SIZE(via_unichrome_irqs);
static int via_irqmap_unichrome[] = {-1, -1, -1, 0, -1, 1};
u32 via_get_vblank_counter(struct drm_device *dev, unsigned int pipe)
{
drm_via_private_t *dev_priv = dev->dev_private;
if (pipe != 0)
return 0;
return atomic_read(&dev_priv->vbl_received);
}
irqreturn_t via_driver_irq_handler(int irq, void *arg)
{
struct drm_device *dev = (struct drm_device *) arg;
drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
u32 status;
int handled = 0;
ktime_t cur_vblank;
drm_via_irq_t *cur_irq = dev_priv->via_irqs;
int i;
status = VIA_READ(VIA_REG_INTERRUPT);
if (status & VIA_IRQ_VBLANK_PENDING) {
atomic_inc(&dev_priv->vbl_received);
if (!(atomic_read(&dev_priv->vbl_received) & 0x0F)) {
cur_vblank = ktime_get();
if (dev_priv->last_vblank_valid) {
dev_priv->nsec_per_vblank =
ktime_sub(cur_vblank,
dev_priv->last_vblank) >> 4;
}
dev_priv->last_vblank = cur_vblank;
dev_priv->last_vblank_valid = 1;
}
if (!(atomic_read(&dev_priv->vbl_received) & 0xFF)) {
DRM_DEBUG("nsec per vblank is: %llu\n",
ktime_to_ns(dev_priv->nsec_per_vblank));
}
drm_handle_vblank(dev, 0);
handled = 1;
}
for (i = 0; i < dev_priv->num_irqs; ++i) {
if (status & cur_irq->pending_mask) {
atomic_inc(&cur_irq->irq_received);
wake_up(&cur_irq->irq_queue);
handled = 1;
if (dev_priv->irq_map[drm_via_irq_dma0_td] == i)
via_dmablit_handler(dev, 0, 1);
else if (dev_priv->irq_map[drm_via_irq_dma1_td] == i)
via_dmablit_handler(dev, 1, 1);
}
cur_irq++;
}
/* Acknowledge interrupts */
VIA_WRITE(VIA_REG_INTERRUPT, status);
if (handled)
return IRQ_HANDLED;
else
return IRQ_NONE;
}
static __inline__ void viadrv_acknowledge_irqs(drm_via_private_t *dev_priv)
{
u32 status;
if (dev_priv) {
/* Acknowledge interrupts */
status = VIA_READ(VIA_REG_INTERRUPT);
VIA_WRITE(VIA_REG_INTERRUPT, status |
dev_priv->irq_pending_mask);
}
}
int via_enable_vblank(struct drm_device *dev, unsigned int pipe)
{
drm_via_private_t *dev_priv = dev->dev_private;
u32 status;
if (pipe != 0) {
DRM_ERROR("%s: bad crtc %u\n", __func__, pipe);
return -EINVAL;
}
status = VIA_READ(VIA_REG_INTERRUPT);
VIA_WRITE(VIA_REG_INTERRUPT, status | VIA_IRQ_VBLANK_ENABLE);
VIA_WRITE8(0x83d4, 0x11);
VIA_WRITE8(0x83d5, VIA_READ8(0x83d5) | 0x30);
return 0;
}
void via_disable_vblank(struct drm_device *dev, unsigned int pipe)
{
drm_via_private_t *dev_priv = dev->dev_private;
u32 status;
status = VIA_READ(VIA_REG_INTERRUPT);
VIA_WRITE(VIA_REG_INTERRUPT, status & ~VIA_IRQ_VBLANK_ENABLE);
VIA_WRITE8(0x83d4, 0x11);
VIA_WRITE8(0x83d5, VIA_READ8(0x83d5) & ~0x30);
if (pipe != 0)
DRM_ERROR("%s: bad crtc %u\n", __func__, pipe);
}
static int
via_driver_irq_wait(struct drm_device *dev, unsigned int irq, int force_sequence,
unsigned int *sequence)
{
drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
unsigned int cur_irq_sequence;
drm_via_irq_t *cur_irq;
int ret = 0;
maskarray_t *masks;
int real_irq;
DRM_DEBUG("\n");
if (!dev_priv) {
DRM_ERROR("called with no initialization\n");
return -EINVAL;
}
if (irq >= drm_via_irq_num) {
DRM_ERROR("Trying to wait on unknown irq %d\n", irq);
return -EINVAL;
}
real_irq = dev_priv->irq_map[irq];
if (real_irq < 0) {
DRM_ERROR("Video IRQ %d not available on this hardware.\n",
irq);
return -EINVAL;
}
masks = dev_priv->irq_masks;
cur_irq = dev_priv->via_irqs + real_irq;
if (masks[real_irq][2] && !force_sequence) {
DRM_WAIT_ON(ret, cur_irq->irq_queue, 3 * HZ,
((VIA_READ(masks[irq][2]) & masks[irq][3]) ==
masks[irq][4]));
cur_irq_sequence = atomic_read(&cur_irq->irq_received);
} else {
DRM_WAIT_ON(ret, cur_irq->irq_queue, 3 * HZ,
(((cur_irq_sequence =
atomic_read(&cur_irq->irq_received)) -
*sequence) <= (1 << 23)));
}
*sequence = cur_irq_sequence;
return ret;
}
/*
* drm_dma.h hooks
*/
void via_driver_irq_preinstall(struct drm_device *dev)
{
drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
u32 status;
drm_via_irq_t *cur_irq;
int i;
DRM_DEBUG("dev_priv: %p\n", dev_priv);
if (dev_priv) {
cur_irq = dev_priv->via_irqs;
dev_priv->irq_enable_mask = VIA_IRQ_VBLANK_ENABLE;
dev_priv->irq_pending_mask = VIA_IRQ_VBLANK_PENDING;
if (dev_priv->chipset == VIA_PRO_GROUP_A ||
dev_priv->chipset == VIA_DX9_0) {
dev_priv->irq_masks = via_pro_group_a_irqs;
dev_priv->num_irqs = via_num_pro_group_a;
dev_priv->irq_map = via_irqmap_pro_group_a;
} else {
dev_priv->irq_masks = via_unichrome_irqs;
dev_priv->num_irqs = via_num_unichrome;
dev_priv->irq_map = via_irqmap_unichrome;
}
for (i = 0; i < dev_priv->num_irqs; ++i) {
atomic_set(&cur_irq->irq_received, 0);
cur_irq->enable_mask = dev_priv->irq_masks[i][0];
cur_irq->pending_mask = dev_priv->irq_masks[i][1];
init_waitqueue_head(&cur_irq->irq_queue);
dev_priv->irq_enable_mask |= cur_irq->enable_mask;
dev_priv->irq_pending_mask |= cur_irq->pending_mask;
cur_irq++;
DRM_DEBUG("Initializing IRQ %d\n", i);
}
dev_priv->last_vblank_valid = 0;
/* Clear VSync interrupt regs */
status = VIA_READ(VIA_REG_INTERRUPT);
VIA_WRITE(VIA_REG_INTERRUPT, status &
~(dev_priv->irq_enable_mask));
/* Clear bits if they're already high */
viadrv_acknowledge_irqs(dev_priv);
}
}
int via_driver_irq_postinstall(struct drm_device *dev)
{
drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
u32 status;
DRM_DEBUG("via_driver_irq_postinstall\n");
if (!dev_priv)
return -EINVAL;
status = VIA_READ(VIA_REG_INTERRUPT);
VIA_WRITE(VIA_REG_INTERRUPT, status | VIA_IRQ_GLOBAL
| dev_priv->irq_enable_mask);
/* Some magic, oh for some data sheets ! */
VIA_WRITE8(0x83d4, 0x11);
VIA_WRITE8(0x83d5, VIA_READ8(0x83d5) | 0x30);
return 0;
}
void via_driver_irq_uninstall(struct drm_device *dev)
{
drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
u32 status;
DRM_DEBUG("\n");
if (dev_priv) {
/* Some more magic, oh for some data sheets ! */
VIA_WRITE8(0x83d4, 0x11);
VIA_WRITE8(0x83d5, VIA_READ8(0x83d5) & ~0x30);
status = VIA_READ(VIA_REG_INTERRUPT);
VIA_WRITE(VIA_REG_INTERRUPT, status &
~(VIA_IRQ_VBLANK_ENABLE | dev_priv->irq_enable_mask));
}
}
int via_wait_irq(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
drm_via_irqwait_t *irqwait = data;
struct timespec64 now;
int ret = 0;
drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
drm_via_irq_t *cur_irq = dev_priv->via_irqs;
int force_sequence;
if (irqwait->request.irq >= dev_priv->num_irqs) {
DRM_ERROR("Trying to wait on unknown irq %d\n",
irqwait->request.irq);
return -EINVAL;
}
cur_irq += irqwait->request.irq;
switch (irqwait->request.type & ~VIA_IRQ_FLAGS_MASK) {
case VIA_IRQ_RELATIVE:
irqwait->request.sequence +=
atomic_read(&cur_irq->irq_received);
irqwait->request.type &= ~_DRM_VBLANK_RELATIVE;
case VIA_IRQ_ABSOLUTE:
break;
default:
return -EINVAL;
}
if (irqwait->request.type & VIA_IRQ_SIGNAL) {
DRM_ERROR("Signals on Via IRQs not implemented yet.\n");
return -EINVAL;
}
force_sequence = (irqwait->request.type & VIA_IRQ_FORCE_SEQUENCE);
ret = via_driver_irq_wait(dev, irqwait->request.irq, force_sequence,
&irqwait->request.sequence);
ktime_get_ts64(&now);
irqwait->reply.tval_sec = now.tv_sec;
irqwait->reply.tval_usec = now.tv_nsec / NSEC_PER_USEC;
return ret;
}