[PATCH V6 2/2] drm/vkms: Add support for virtual hardware mode
Sumera Priyadarsini
sylphrenadin at gmail.com
Wed Sep 1 16:42:42 UTC 2021
Add a virtual hardware or vblank-less mode as a module
to enable VKMS to emulate virtual hardware drivers. This means
no vertical blanking events occur and pageflips are completed
arbitrarily and when required for updating the frame.
Add a new drm_crtc_funcs struct, vkms_vblankless_crtc_funcs and a
drm_crtc_helper_funcs struct, vkms_vblankless_crtc_helper_funcs()
which hold the atomic helpers for virtual hardware mode.
The existing vkms_crtc_funcs struct and vkms_crtc_helper_funcs
struct hold atomic helpers for the default vblank mode.
This makes the code flow clearer and testing
virtual hardware mode easier.
Add a function vkms_crtc_composer() which calls the helper function,
vkms_composer_common() for plane composition in vblank-less mode.
vkms_crtc_composer() is directly called in the atomic hook in
vkms_crtc_atomic_begin().
However, some crc captures still use vblanks which causes the crc-based
igt tests to crash. So, no CRC functions are called in vblankless mode
for now and will be implemented in a later patch.
This patchset has been tested with the igt tests- kms_writeback, kms_atomic
, kms_lease, kms_flip, kms_pipe_get_crc and preserves results except for
subtests related to crc reads and vertical blanking, in which case,
tests are skipped.
The patch is based on Rodrigo Siqueira's
patch(https://patchwork.freedesktop.org/patch/316851/?series=48469&rev=3)
and the ensuing review.
Signed-off-by: Sumera Priyadarsini <sylphrenadin at gmail.com>
---
Changes in V6:
- Skip CRC functions in vblankless mode
- Refactor helper function names(Melissa)
Changes in V5:
- Move vkms_crtc_composer() to this patch(Melissa)
- Add more clarification for "vblank-less" mode(Pekka)
- Replace kzalloc() with kvmalloc() in compose_active_planes()
to fix memory allocation error for output frame
- Fix checkpatch warnings (Melissa)
Changes in V3:
- Refactor patchset(Melissa)
Changes in V2:
- Add atomic helper functions in a separate struct for virtual hardware
mode (Daniel)
- Remove spinlock across 'vkms_output->lock' in vkms_crtc.c(Daniel)
- Add vkms_composer_common() (Daniel)
---
drivers/gpu/drm/vkms/vkms_composer.c | 21 +++++++++++--
drivers/gpu/drm/vkms/vkms_crtc.c | 43 +++++++++++++++++++++++++--
drivers/gpu/drm/vkms/vkms_drv.c | 16 +++++++---
drivers/gpu/drm/vkms/vkms_drv.h | 2 ++
drivers/gpu/drm/vkms/vkms_writeback.c | 3 +-
5 files changed, 74 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c
index bca746fb5b53..a009589b2c3a 100644
--- a/drivers/gpu/drm/vkms/vkms_composer.c
+++ b/drivers/gpu/drm/vkms/vkms_composer.c
@@ -176,11 +176,12 @@ static int compose_active_planes(void **vaddr_out,
{
struct drm_framebuffer *fb = &primary_composer->fb;
struct drm_gem_object *gem_obj = drm_gem_fb_get_obj(fb, 0);
+
const void *vaddr;
int i;
if (!*vaddr_out) {
- *vaddr_out = kzalloc(gem_obj->size, GFP_KERNEL);
+ *vaddr_out = kvmalloc(gem_obj->size, GFP_KERNEL);
if (!*vaddr_out) {
DRM_ERROR("Cannot allocate memory for output frame.");
return -ENOMEM;
@@ -229,7 +230,7 @@ int vkms_composer_common(struct vkms_crtc_state *crtc_state,
if (ret) {
if ((ret == -EINVAL || ret == -ENOMEM) && !wb_pending)
- kfree(vaddr_out);
+ kvfree(vaddr_out);
return ret;
}
@@ -241,7 +242,7 @@ int vkms_composer_common(struct vkms_crtc_state *crtc_state,
crtc_state->wb_pending = false;
spin_unlock_irq(&out->composer_lock);
} else {
- kfree(vaddr_out);
+ kvfree(vaddr_out);
}
return 0;
@@ -296,6 +297,20 @@ void vkms_composer_worker(struct work_struct *work)
drm_crtc_add_crc_entry(crtc, true, frame_start++, &crc32);
}
+void vkms_crtc_composer(struct vkms_crtc_state *crtc_state)
+{
+ struct drm_crtc *crtc = crtc_state->base.crtc;
+ struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
+ u32 crc32 = 0;
+ int ret;
+
+ ret = vkms_composer_common(crtc_state, out, crtc_state->wb_pending, &crc32);
+ if (ret == -EINVAL)
+ return;
+
+ drm_crtc_add_crc_entry(crtc, true, 0, &crc32);
+}
+
static const char * const pipe_crc_sources[] = {"auto"};
const char *const *vkms_get_crc_sources(struct drm_crtc *crtc,
diff --git a/drivers/gpu/drm/vkms/vkms_crtc.c b/drivers/gpu/drm/vkms/vkms_crtc.c
index 57bbd32e9beb..4a933553e0e4 100644
--- a/drivers/gpu/drm/vkms/vkms_crtc.c
+++ b/drivers/gpu/drm/vkms/vkms_crtc.c
@@ -174,6 +174,15 @@ static const struct drm_crtc_funcs vkms_crtc_funcs = {
.verify_crc_source = vkms_verify_crc_source,
};
+static const struct drm_crtc_funcs vkms_vblankless_crtc_funcs = {
+ .set_config = drm_atomic_helper_set_config,
+ .destroy = drm_crtc_cleanup,
+ .page_flip = drm_atomic_helper_page_flip,
+ .reset = vkms_atomic_crtc_reset,
+ .atomic_duplicate_state = vkms_atomic_crtc_duplicate_state,
+ .atomic_destroy_state = vkms_atomic_crtc_destroy_state,
+};
+
static int vkms_crtc_atomic_check(struct drm_crtc *crtc,
struct drm_atomic_state *state)
{
@@ -268,6 +277,20 @@ static void vkms_crtc_atomic_flush(struct drm_crtc *crtc,
spin_unlock_irq(&vkms_output->lock);
}
+/*
+ * Crtc functions for virtual hardware/vblankless mode
+ */
+static void vkms_vblankless_crtc_atomic_flush(struct drm_crtc *crtc,
+ struct drm_atomic_state *state)
+{
+ struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
+ struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(crtc->state);
+
+ vkms_crtc_composer(vkms_state);
+
+ vkms_output->composer_state = to_vkms_crtc_state(crtc->state);
+}
+
static const struct drm_crtc_helper_funcs vkms_crtc_helper_funcs = {
.atomic_check = vkms_crtc_atomic_check,
.atomic_begin = vkms_crtc_atomic_begin,
@@ -276,20 +299,34 @@ static const struct drm_crtc_helper_funcs vkms_crtc_helper_funcs = {
.atomic_disable = vkms_crtc_atomic_disable,
};
+static const struct drm_crtc_helper_funcs vkms_vblankless_crtc_helper_funcs = {
+ .atomic_check = vkms_crtc_atomic_check,
+ .atomic_flush = vkms_vblankless_crtc_atomic_flush,
+};
+
int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
struct drm_plane *primary, struct drm_plane *cursor)
{
struct vkms_output *vkms_out = drm_crtc_to_vkms_output(crtc);
+ struct vkms_device *vkmsdev = drm_device_to_vkms_device(dev);
int ret;
- ret = drm_crtc_init_with_planes(dev, crtc, primary, cursor,
- &vkms_crtc_funcs, NULL);
+ if (vkmsdev->config->virtual_hw)
+ ret = drm_crtc_init_with_planes(dev, crtc, primary, cursor,
+ &vkms_vblankless_crtc_funcs, NULL);
+ else
+ ret = drm_crtc_init_with_planes(dev, crtc, primary, cursor,
+ &vkms_crtc_funcs, NULL);
+
if (ret) {
DRM_ERROR("Failed to init CRTC\n");
return ret;
}
- drm_crtc_helper_add(crtc, &vkms_crtc_helper_funcs);
+ if (vkmsdev->config->virtual_hw)
+ drm_crtc_helper_add(crtc, &vkms_vblankless_crtc_helper_funcs);
+ else
+ drm_crtc_helper_add(crtc, &vkms_crtc_helper_funcs);
spin_lock_init(&vkms_out->lock);
spin_lock_init(&vkms_out->composer_lock);
diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c
index 0ffe5f0e33f7..ee78f5eef653 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.c
+++ b/drivers/gpu/drm/vkms/vkms_drv.c
@@ -51,6 +51,10 @@ static bool enable_overlay;
module_param_named(enable_overlay, enable_overlay, bool, 0444);
MODULE_PARM_DESC(enable_overlay, "Enable/Disable overlay support");
+static bool enable_virtual_hw;
+module_param_named(enable_virtual_hw, enable_virtual_hw, bool, 0444);
+MODULE_PARM_DESC(enable_virtual_hw, "Enable/Disable virtual hardware mode(vblank-less mode)");
+
DEFINE_DRM_GEM_FOPS(vkms_driver_fops);
static void vkms_release(struct drm_device *dev)
@@ -98,6 +102,7 @@ static int vkms_config_show(struct seq_file *m, void *data)
seq_printf(m, "writeback=%d\n", vkmsdev->config->writeback);
seq_printf(m, "cursor=%d\n", vkmsdev->config->cursor);
seq_printf(m, "overlay=%d\n", vkmsdev->config->overlay);
+ seq_printf(m, "virtual_hw=%d\n", vkmsdev->config->virtual_hw);
return 0;
}
@@ -191,10 +196,12 @@ static int vkms_create(struct vkms_config *config)
goto out_devres;
}
- ret = drm_vblank_init(&vkms_device->drm, 1);
- if (ret) {
- DRM_ERROR("Failed to vblank\n");
- goto out_devres;
+ if (!vkms_device->config->virtual_hw) {
+ ret = drm_vblank_init(&vkms_device->drm, 1);
+ if (ret) {
+ DRM_ERROR("Failed to vblank\n");
+ goto out_devres;
+ }
}
ret = vkms_modeset_init(vkms_device);
@@ -229,6 +236,7 @@ static int __init vkms_init(void)
config->cursor = enable_cursor;
config->writeback = enable_writeback;
config->overlay = enable_overlay;
+ config->virtual_hw = enable_virtual_hw;
return vkms_create(config);
}
diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
index 6f5f63591c20..d64554f21838 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.h
+++ b/drivers/gpu/drm/vkms/vkms_drv.h
@@ -97,6 +97,7 @@ struct vkms_config {
bool writeback;
bool cursor;
bool overlay;
+ bool virtual_hw;
/* only set when instantiated */
struct vkms_device *dev;
};
@@ -141,6 +142,7 @@ int vkms_composer_common(struct vkms_crtc_state *crtc_state, struct vkms_output
bool wb_pending, uint32_t *crcs);
void vkms_composer_worker(struct work_struct *work);
void vkms_set_composer(struct vkms_output *out, bool enabled);
+void vkms_crtc_composer(struct vkms_crtc_state *crtc_state);
/* Writeback */
int vkms_enable_writeback_connector(struct vkms_device *vkmsdev);
diff --git a/drivers/gpu/drm/vkms/vkms_writeback.c b/drivers/gpu/drm/vkms/vkms_writeback.c
index 8694227f555f..6082cacbca1e 100644
--- a/drivers/gpu/drm/vkms/vkms_writeback.c
+++ b/drivers/gpu/drm/vkms/vkms_writeback.c
@@ -120,7 +120,8 @@ static void vkms_wb_atomic_commit(struct drm_connector *conn,
if (!conn_state)
return;
- vkms_set_composer(&vkmsdev->output, true);
+ if (!vkmsdev->config->virtual_hw)
+ vkms_set_composer(&vkmsdev->output, true);
spin_lock_irq(&output->composer_lock);
crtc_state->active_writeback = conn_state->writeback_job->priv;
--
2.31.1
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