operation.
</para>
</sect2>
- <sect2>
- <title>Locking</title>
- <para>
- Beside some lookup structures with their own locking (which is hidden
- behind the interface functions) most of the modeset state is protected
- by the <code>dev-<mode_config.lock</code> mutex and additionally
- per-crtc locks to allow cursor updates, pageflips and similar operations
- to occur concurrently with background tasks like output detection.
- Operations which cross domains like a full modeset always grab all
- locks. Drivers there need to protect resources shared between crtcs with
- additional locking. They also need to be careful to always grab the
- relevant crtc locks if a modset functions touches crtc state, e.g. for
- load detection (which does only grab the <code>mode_config.lock</code>
- to allow concurrent screen updates on live crtcs).
- </para>
- </sect2>
</sect1>
<!-- Internals: kms initialization and cleanup -->
<para>
Drivers must initialize the vertical blanking handling core with a call to
<function>drm_vblank_init</function> in their
- <methodname>load</methodname> operation. The function will set the struct
- <structname>drm_device</structname>
- <structfield>vblank_disable_allowed</structfield> field to 0. This will
- keep vertical blanking interrupts enabled permanently until the first mode
- set operation, where <structfield>vblank_disable_allowed</structfield> is
- set to 1. The reason behind this is not clear. Drivers can set the field
- to 1 after <function>calling drm_vblank_init</function> to make vertical
- blanking interrupts dynamically managed from the beginning.
+ <methodname>load</methodname> operation.
</para>
<para>
Vertical blanking interrupts can be enabled by the DRM core or by drivers
S: Maintained
F: drivers/gpu/drm/
F: drivers/gpu/vga/
+F: Documentation/devicetree/bindings/display/
+F: Documentation/devicetree/bindings/gpu/
+F: Documentation/devicetree/bindings/video/
F: Documentation/DocBook/gpu.*
F: include/drm/
F: include/uapi/drm/
.get_vblank_counter = drm_vblank_no_hw_counter,
.enable_vblank = hdlcd_enable_vblank,
.disable_vblank = hdlcd_disable_vblank,
- .gem_free_object = drm_gem_cma_free_object,
+ .gem_free_object_unlocked = drm_gem_cma_free_object,
.gem_vm_ops = &drm_gem_cma_vm_ops,
.dumb_create = drm_gem_cma_dumb_create,
.dumb_map_offset = drm_gem_cma_dumb_map_offset,
struct cirrus_crtc *cirrus_crtc = to_cirrus_crtc(crtc);
int i;
- if (size != CIRRUS_LUT_SIZE)
- return;
-
for (i = 0; i < CIRRUS_LUT_SIZE; i++) {
cirrus_crtc->lut_r[i] = red[i];
cirrus_crtc->lut_g[i] = green[i];
for_each_crtc_in_state(state, crtc, crtc_state, i) {
const struct drm_crtc_helper_funcs *funcs;
+ if (!crtc_state->enable)
+ continue;
+
if (!crtc_state->mode_changed &&
!crtc_state->connectors_changed)
continue;
int drm_mode_crtc_set_gamma_size(struct drm_crtc *crtc,
int gamma_size)
{
+ uint16_t *r_base, *g_base, *b_base;
+ int i;
+
crtc->gamma_size = gamma_size;
crtc->gamma_store = kcalloc(gamma_size, sizeof(uint16_t) * 3,
return -ENOMEM;
}
+ r_base = crtc->gamma_store;
+ g_base = r_base + gamma_size;
+ b_base = g_base + gamma_size;
+ for (i = 0; i < gamma_size; i++) {
+ r_base[i] = i << 8;
+ g_base[i] = i << 8;
+ b_base[i] = i << 8;
+ }
+
+
return 0;
}
EXPORT_SYMBOL(drm_mode_crtc_set_gamma_size);
* by commas, search through the list looking for one that
* matches the connector.
*
- * If there's one or more that don't't specify a connector, keep
+ * If there's one or more that doesn't specify a connector, keep
* the last one found one as a fallback.
*/
fwstr = kstrdup(edid_firmware, GFP_KERNEL);
{
struct drm_fb_helper *fb_helper = info->par;
struct drm_framebuffer *fb = fb_helper->fb;
- int pindex;
if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
u32 *palette;
!fb_helper->funcs->gamma_get))
return -EINVAL;
- pindex = regno;
+ WARN_ON(fb->bits_per_pixel != 8);
- if (fb->bits_per_pixel == 16) {
- pindex = regno << 3;
+ fb_helper->funcs->gamma_set(crtc, red, green, blue, regno);
- if (fb->depth == 16 && regno > 63)
- return -EINVAL;
- if (fb->depth == 15 && regno > 31)
- return -EINVAL;
-
- if (fb->depth == 16) {
- u16 r, g, b;
- int i;
- if (regno < 32) {
- for (i = 0; i < 8; i++)
- fb_helper->funcs->gamma_set(crtc, red,
- green, blue, pindex + i);
- }
-
- fb_helper->funcs->gamma_get(crtc, &r,
- &g, &b,
- pindex >> 1);
-
- for (i = 0; i < 4; i++)
- fb_helper->funcs->gamma_set(crtc, r,
- green, b,
- (pindex >> 1) + i);
- }
- }
-
- if (fb->depth != 16)
- fb_helper->funcs->gamma_set(crtc, red, green, blue, pindex);
return 0;
}
#include <linux/vgaarb.h>
#include <linux/export.h>
-/* Access macro for slots in vblank timestamp ringbuffer. */
-#define vblanktimestamp(dev, pipe, count) \
- ((dev)->vblank[pipe].time[(count) % DRM_VBLANKTIME_RBSIZE])
-
/* Retry timestamp calculation up to 3 times to satisfy
* drm_timestamp_precision before giving up.
*/
struct timeval *t_vblank, u32 last)
{
struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
- u32 tslot;
assert_spin_locked(&dev->vblank_time_lock);
vblank->last = last;
- /* All writers hold the spinlock, but readers are serialized by
- * the latching of vblank->count below.
- */
- tslot = vblank->count + vblank_count_inc;
- vblanktimestamp(dev, pipe, tslot) = *t_vblank;
-
- /*
- * vblank timestamp updates are protected on the write side with
- * vblank_time_lock, but on the read side done locklessly using a
- * sequence-lock on the vblank counter. Ensure correct ordering using
- * memory barrriers. We need the barrier both before and also after the
- * counter update to synchronize with the next timestamp write.
- * The read-side barriers for this are in drm_vblank_count_and_time.
- */
- smp_wmb();
+ write_seqlock(&vblank->seqlock);
+ vblank->time = *t_vblank;
vblank->count += vblank_count_inc;
- smp_wmb();
+ write_sequnlock(&vblank->seqlock);
}
/**
const struct timeval *t_old;
u64 diff_ns;
- t_old = &vblanktimestamp(dev, pipe, vblank->count);
+ t_old = &vblank->time;
diff_ns = timeval_to_ns(&t_vblank) - timeval_to_ns(t_old);
/*
diff = 1;
}
- /*
- * FIMXE: Need to replace this hack with proper seqlocks.
- *
- * Restrict the bump of the software vblank counter to a safe maximum
- * value of +1 whenever there is the possibility that concurrent readers
- * of vblank timestamps could be active at the moment, as the current
- * implementation of the timestamp caching and updating is not safe
- * against concurrent readers for calls to store_vblank() with a bump
- * of anything but +1. A bump != 1 would very likely return corrupted
- * timestamps to userspace, because the same slot in the cache could
- * be concurrently written by store_vblank() and read by one of those
- * readers without the read-retry logic detecting the collision.
- *
- * Concurrent readers can exist when we are called from the
- * drm_vblank_off() or drm_vblank_on() functions and other non-vblank-
- * irq callers. However, all those calls to us are happening with the
- * vbl_lock locked to prevent drm_vblank_get(), so the vblank refcount
- * can't increase while we are executing. Therefore a zero refcount at
- * this point is safe for arbitrary counter bumps if we are called
- * outside vblank irq, a non-zero count is not 100% safe. Unfortunately
- * we must also accept a refcount of 1, as whenever we are called from
- * drm_vblank_get() -> drm_vblank_enable() the refcount will be 1 and
- * we must let that one pass through in order to not lose vblank counts
- * during vblank irq off - which would completely defeat the whole
- * point of this routine.
- *
- * Whenever we are called from vblank irq, we have to assume concurrent
- * readers exist or can show up any time during our execution, even if
- * the refcount is currently zero, as vblank irqs are usually only
- * enabled due to the presence of readers, and because when we are called
- * from vblank irq we can't hold the vbl_lock to protect us from sudden
- * bumps in vblank refcount. Therefore also restrict bumps to +1 when
- * called from vblank irq.
- */
- if ((diff > 1) && (atomic_read(&vblank->refcount) > 1 ||
- (flags & DRM_CALLED_FROM_VBLIRQ))) {
- DRM_DEBUG_VBL("clamping vblank bump to 1 on crtc %u: diffr=%u "
- "refcount %u, vblirq %u\n", pipe, diff,
- atomic_read(&vblank->refcount),
- (flags & DRM_CALLED_FROM_VBLIRQ) != 0);
- diff = 1;
- }
-
DRM_DEBUG_VBL("updating vblank count on crtc %u:"
" current=%u, diff=%u, hw=%u hw_last=%u\n",
pipe, vblank->count, diff, cur_vblank, vblank->last);
init_waitqueue_head(&vblank->queue);
setup_timer(&vblank->disable_timer, vblank_disable_fn,
(unsigned long)vblank);
+ seqlock_init(&vblank->seqlock);
}
DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
struct timeval *vblanktime)
{
struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
- int count = DRM_TIMESTAMP_MAXRETRIES;
- u32 cur_vblank;
+ u32 vblank_count;
+ unsigned int seq;
if (WARN_ON(pipe >= dev->num_crtcs))
return 0;
- /*
- * Vblank timestamps are read lockless. To ensure consistency the vblank
- * counter is rechecked and ordering is ensured using memory barriers.
- * This works like a seqlock. The write-side barriers are in store_vblank.
- */
do {
- cur_vblank = vblank->count;
- smp_rmb();
- *vblanktime = vblanktimestamp(dev, pipe, cur_vblank);
- smp_rmb();
- } while (cur_vblank != vblank->count && --count > 0);
+ seq = read_seqbegin(&vblank->seqlock);
+ vblank_count = vblank->count;
+ *vblanktime = vblank->time;
+ } while (read_seqretry(&vblank->seqlock, seq));
- return cur_vblank;
+ return vblank_count;
}
EXPORT_SYMBOL(drm_vblank_count_and_time);
int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node)
{
struct drm_mm_node *hole;
- u64 end = node->start + node->size;
+ u64 end;
u64 hole_start;
u64 hole_end;
BUG_ON(node == NULL);
+ end = node->start + node->size;
+
/* Find the relevant hole to add our node to */
drm_mm_for_each_hole(hole, mm, hole_start, hole_end) {
if (hole_start > node->start || hole_end < end)
*
* As KMS moves toward more fine grained locking, and atomic ioctl where
* userspace can indirectly control locking order, it becomes necessary
- * to use ww_mutex and acquire-contexts to avoid deadlocks. But because
+ * to use &ww_mutex and acquire-contexts to avoid deadlocks. But because
* the locking is more distributed around the driver code, we want a bit
* of extra utility/tracking out of our acquire-ctx. This is provided
* by drm_modeset_lock / drm_modeset_acquire_ctx.
*
- * For basic principles of ww_mutex, see: Documentation/locking/ww-mutex-design.txt
+ * For basic principles of &ww_mutex, see: Documentation/locking/ww-mutex-design.txt
*
* The basic usage pattern is to:
*
* ... do stuff ...
* drm_modeset_drop_locks(&ctx);
* drm_modeset_acquire_fini(&ctx);
+ *
+ * On top of of these per-object locks using &ww_mutex there's also an overall
+ * dev->mode_config.lock, for protecting everything else. Mostly this means
+ * probe state of connectors, and preventing hotplug add/removal of connectors.
+ *
+ * Finally there's a bunch of dedicated locks to protect drm core internal
+ * lists and lookup data structures.
*/
/**
struct drm_psb_private *dev_priv = dev->dev_private;
struct gma_crtc *gma_crtc;
int i;
- uint16_t *r_base, *g_base, *b_base;
/* We allocate a extra array of drm_connector pointers
* for fbdev after the crtc */
gma_crtc->pipe = pipe;
gma_crtc->plane = pipe;
- r_base = gma_crtc->base.gamma_store;
- g_base = r_base + 256;
- b_base = g_base + 256;
for (i = 0; i < 256; i++) {
gma_crtc->lut_r[i] = i;
gma_crtc->lut_g[i] = i;
gma_crtc->lut_b[i] = i;
- r_base[i] = i << 8;
- g_base[i] = i << 8;
- b_base[i] = i << 8;
gma_crtc->lut_adj[i] = 0;
}
.fops = &kirin_drm_fops,
.set_busid = drm_platform_set_busid,
- .gem_free_object = drm_gem_cma_free_object,
+ .gem_free_object_unlocked = drm_gem_cma_free_object,
.gem_vm_ops = &drm_gem_cma_vm_ops,
.dumb_create = kirin_gem_cma_dumb_create,
.dumb_map_offset = drm_gem_cma_dumb_map_offset,
#include "i915_trace.h"
#include "intel_drv.h"
-#include <linux/apple-gmux.h>
#include <linux/console.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>
-#include <linux/vgaarb.h>
#include <linux/vga_switcheroo.h>
#include <drm/drm_crtc_helper.h>
if (PCI_FUNC(pdev->devfn))
return -ENODEV;
- /*
- * apple-gmux is needed on dual GPU MacBook Pro
- * to probe the panel if we're the inactive GPU.
- */
- if (IS_ENABLED(CONFIG_VGA_ARB) && IS_ENABLED(CONFIG_VGA_SWITCHEROO) &&
- apple_gmux_present() && pdev != vga_default_device() &&
- !vga_switcheroo_handler_flags())
+ if (vga_switcheroo_client_probe_defer(pdev))
return -EPROBE_DEFER;
return drm_get_pci_dev(pdev, ent, &driver);
.enable_vblank = mtk_drm_crtc_enable_vblank,
.disable_vblank = mtk_drm_crtc_disable_vblank,
- .gem_free_object = mtk_drm_gem_free_object,
+ .gem_free_object_unlocked = mtk_drm_gem_free_object,
.gem_vm_ops = &drm_gem_cma_vm_ops,
.dumb_create = mtk_drm_gem_dumb_create,
.dumb_map_offset = mtk_drm_gem_dumb_map_offset,
return ret;
}
-static void msm_crtc_fb_gamma_set(struct drm_crtc *crtc,
- u16 red, u16 green, u16 blue, int regno)
-{
- DBG("fbdev: set gamma");
-}
-
-static void msm_crtc_fb_gamma_get(struct drm_crtc *crtc,
- u16 *red, u16 *green, u16 *blue, int regno)
-{
- DBG("fbdev: get gamma");
-}
-
static const struct drm_fb_helper_funcs msm_fb_helper_funcs = {
- .gamma_set = msm_crtc_fb_gamma_set,
- .gamma_get = msm_crtc_fb_gamma_get,
.fb_probe = msm_fbdev_create,
};
* Authors: Ben Skeggs
*/
-#include <linux/apple-gmux.h>
#include <linux/console.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/pm_runtime.h>
-#include <linux/vgaarb.h>
#include <linux/vga_switcheroo.h>
#include "drmP.h"
bool boot = false;
int ret;
- /*
- * apple-gmux is needed on dual GPU MacBook Pro
- * to probe the panel if we're the inactive GPU.
- */
- if (IS_ENABLED(CONFIG_VGA_ARB) && IS_ENABLED(CONFIG_VGA_SWITCHEROO) &&
- apple_gmux_present() && pdev != vga_default_device() &&
- !vga_switcheroo_handler_flags())
+ if (vga_switcheroo_client_probe_defer(pdev))
return -EPROBE_DEFER;
/* remove conflicting drivers (vesafb, efifb etc) */
drm_crtc_init(dev, &qxl_crtc->base, &qxl_crtc_funcs);
qxl_crtc->index = crtc_id;
- drm_mode_crtc_set_gamma_size(&qxl_crtc->base, 256);
drm_crtc_helper_add(&qxl_crtc->base, &qxl_crtc_helper_funcs);
return 0;
}
#include "radeon_drv.h"
#include <drm/drm_pciids.h>
-#include <linux/apple-gmux.h>
#include <linux/console.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>
-#include <linux/vgaarb.h>
#include <linux/vga_switcheroo.h>
#include <drm/drm_gem.h>
if (ret == -EPROBE_DEFER)
return ret;
- /*
- * apple-gmux is needed on dual GPU MacBook Pro
- * to probe the panel if we're the inactive GPU.
- */
- if (IS_ENABLED(CONFIG_VGA_ARB) && IS_ENABLED(CONFIG_VGA_SWITCHEROO) &&
- apple_gmux_present() && pdev != vga_default_device() &&
- !vga_switcheroo_handler_flags())
+ if (vga_switcheroo_client_probe_defer(pdev))
return -EPROBE_DEFER;
/* Get rid of things like offb */
/* Called on the last userspace/kernel unreference of the BO. Returns
* it to the BO cache if possible, otherwise frees it.
- *
- * Note that this is called with the struct_mutex held.
*/
void vc4_free_object(struct drm_gem_object *gem_bo)
{
#endif
.gem_create_object = vc4_create_object,
- .gem_free_object = vc4_free_object,
+ .gem_free_object_unlocked = vc4_free_object,
.gem_vm_ops = &drm_gem_cma_vm_ops,
.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
{
unsigned int i;
- mutex_lock(&dev->struct_mutex);
for (i = 0; i < state->user_state.bo_count; i++)
- drm_gem_object_unreference(state->bo[i]);
- mutex_unlock(&dev->struct_mutex);
+ drm_gem_object_unreference_unlocked(state->bo[i]);
kfree(state);
}
struct vc4_dev *vc4 = to_vc4_dev(dev);
unsigned i;
- /* Need the struct lock for drm_gem_object_unreference(). */
- mutex_lock(&dev->struct_mutex);
if (exec->bo) {
for (i = 0; i < exec->bo_count; i++)
- drm_gem_object_unreference(&exec->bo[i]->base);
+ drm_gem_object_unreference_unlocked(&exec->bo[i]->base);
kfree(exec->bo);
}
struct vc4_bo *bo = list_first_entry(&exec->unref_list,
struct vc4_bo, unref_head);
list_del(&bo->unref_head);
- drm_gem_object_unreference(&bo->base.base);
+ drm_gem_object_unreference_unlocked(&bo->base.base);
}
- mutex_unlock(&dev->struct_mutex);
mutex_lock(&vc4->power_lock);
if (--vc4->power_refcount == 0)
static struct drm_driver vgem_driver = {
.driver_features = DRIVER_GEM,
- .gem_free_object = vgem_gem_free_object,
+ .gem_free_object_unlocked = vgem_gem_free_object,
.gem_vm_ops = &vgem_gem_vm_ops,
.ioctls = vgem_ioctls,
.fops = &vgem_driver_fops,
{
struct drm_device *dev = plane->dev;
struct virtio_gpu_device *vgdev = dev->dev_private;
- struct virtio_gpu_output *output = drm_crtc_to_virtio_gpu_output(plane->crtc);
+ struct virtio_gpu_output *output = NULL;
struct virtio_gpu_framebuffer *vgfb;
struct virtio_gpu_object *bo;
uint32_t handle;
+ if (plane->state->crtc)
+ output = drm_crtc_to_virtio_gpu_output(plane->state->crtc);
+ if (old_state->crtc)
+ output = drm_crtc_to_virtio_gpu_output(old_state->crtc);
+ WARN_ON(!output);
+
if (plane->state->fb) {
vgfb = to_virtio_gpu_framebuffer(plane->state->fb);
bo = gem_to_virtio_gpu_obj(vgfb->obj);
#define pr_fmt(fmt) "vga_switcheroo: " fmt
+#include <linux/apple-gmux.h>
#include <linux/console.h>
#include <linux/debugfs.h>
#include <linux/fb.h>
*
* Register vga client (GPU). Enable vga_switcheroo if another GPU and a
* handler have already registered. The power state of the client is assumed
- * to be ON.
+ * to be ON. Beforehand, vga_switcheroo_client_probe_defer() shall be called
+ * to ensure that all prerequisites are met.
*
* Return: 0 on success, -ENOMEM on memory allocation error.
*/
* @id: client identifier
*
* Register audio client (audio device on a GPU). The power state of the
- * client is assumed to be ON.
+ * client is assumed to be ON. Beforehand, vga_switcheroo_client_probe_defer()
+ * shall be called to ensure that all prerequisites are met.
*
* Return: 0 on success, -ENOMEM on memory allocation error.
*/
return NULL;
}
+/**
+ * vga_switcheroo_client_probe_defer() - whether to defer probing a given client
+ * @pdev: client pci device
+ *
+ * Determine whether any prerequisites are not fulfilled to probe a given
+ * client. Drivers shall invoke this early on in their ->probe callback
+ * and return %-EPROBE_DEFER if it evaluates to %true. Thou shalt not
+ * register the client ere thou hast called this.
+ *
+ * Return: %true if probing should be deferred, otherwise %false.
+ */
+bool vga_switcheroo_client_probe_defer(struct pci_dev *pdev)
+{
+ if ((pdev->class >> 16) == PCI_BASE_CLASS_DISPLAY) {
+ /*
+ * apple-gmux is needed on pre-retina MacBook Pro
+ * to probe the panel if pdev is the inactive GPU.
+ */
+ if (apple_gmux_present() && pdev != vga_default_device() &&
+ !vgasr_priv.handler_flags)
+ return true;
+ }
+
+ return false;
+}
+EXPORT_SYMBOL(vga_switcheroo_client_probe_defer);
+
/**
* vga_switcheroo_get_client_state() - obtain power state of a given client
* @pdev: client pci device
#include <linux/poll.h>
#include <linux/ratelimit.h>
#include <linux/sched.h>
+#include <linux/seqlock.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/vmalloc.h>
void *driver_priv;
};
-/* Size of ringbuffer for vblank timestamps. Just double-buffer
- * in initial implementation.
- */
-#define DRM_VBLANKTIME_RBSIZE 2
-
/* Flags and return codes for get_vblank_timestamp() driver function. */
#define DRM_CALLED_FROM_VBLIRQ 1
#define DRM_VBLANKTIME_SCANOUTPOS_METHOD (1 << 0)
wait_queue_head_t queue; /**< VBLANK wait queue */
struct timer_list disable_timer; /* delayed disable timer */
- /* vblank counter, protected by dev->vblank_time_lock for writes */
- u32 count;
- /* vblank timestamps, protected by dev->vblank_time_lock for writes */
- struct timeval time[DRM_VBLANKTIME_RBSIZE];
+ seqlock_t seqlock; /* protects vblank count and time */
+
+ u32 count; /* vblank counter */
+ struct timeval time; /* vblank timestamp */
atomic_t refcount; /* number of users of vblank interruptsper crtc */
u32 last; /* protected by dev->vbl_lock, used */
int vga_switcheroo_process_delayed_switch(void);
+bool vga_switcheroo_client_probe_defer(struct pci_dev *pdev);
enum vga_switcheroo_state vga_switcheroo_get_client_state(struct pci_dev *dev);
void vga_switcheroo_set_dynamic_switch(struct pci_dev *pdev, enum vga_switcheroo_state dynamic);
static inline int vga_switcheroo_lock_ddc(struct pci_dev *pdev) { return -ENODEV; }
static inline int vga_switcheroo_unlock_ddc(struct pci_dev *pdev) { return -ENODEV; }
static inline int vga_switcheroo_process_delayed_switch(void) { return 0; }
+static inline bool vga_switcheroo_client_probe_defer(struct pci_dev *pdev) { return false; }
static inline enum vga_switcheroo_state vga_switcheroo_get_client_state(struct pci_dev *dev) { return VGA_SWITCHEROO_ON; }
static inline void vga_switcheroo_set_dynamic_switch(struct pci_dev *pdev, enum vga_switcheroo_state dynamic) {}
projects / cascardo / linux.git / commitdiff