diff options
Diffstat (limited to 'drivers/gpu/drm/rcar-du/rcar_du_plane.c')
| -rw-r--r-- | drivers/gpu/drm/rcar-du/rcar_du_plane.c | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_plane.c b/drivers/gpu/drm/rcar-du/rcar_du_plane.c index 2fa5745fca37..64450ce13526 100644 --- a/drivers/gpu/drm/rcar-du/rcar_du_plane.c +++ b/drivers/gpu/drm/rcar-du/rcar_du_plane.c @@ -12,6 +12,7 @@ */ #include <drm/drmP.h> +#include <drm/drm_atomic.h> #include <drm/drm_atomic_helper.h> #include <drm/drm_crtc.h> #include <drm/drm_crtc_helper.h> @@ -25,6 +26,291 @@ #include "rcar_du_plane.h" #include "rcar_du_regs.h" +/* ----------------------------------------------------------------------------- + * Atomic hardware plane allocator + * + * The hardware plane allocator is solely based on the atomic plane states + * without keeping any external state to avoid races between .atomic_check() + * and .atomic_commit(). + * + * The core idea is to avoid using a free planes bitmask that would need to be + * shared between check and commit handlers with a collective knowledge based on + * the allocated hardware plane(s) for each KMS plane. The allocator then loops + * over all plane states to compute the free planes bitmask, allocates hardware + * planes based on that bitmask, and stores the result back in the plane states. + * + * For this to work we need to access the current state of planes not touched by + * the atomic update. To ensure that it won't be modified, we need to lock all + * planes using drm_atomic_get_plane_state(). This effectively serializes atomic + * updates from .atomic_check() up to completion (when swapping the states if + * the check step has succeeded) or rollback (when freeing the states if the + * check step has failed). + * + * Allocation is performed in the .atomic_check() handler and applied + * automatically when the core swaps the old and new states. + */ + +static bool rcar_du_plane_needs_realloc(struct rcar_du_plane *plane, + struct rcar_du_plane_state *new_state) +{ + struct rcar_du_plane_state *cur_state; + + cur_state = to_rcar_plane_state(plane->plane.state); + + /* Lowering the number of planes doesn't strictly require reallocation + * as the extra hardware plane will be freed when committing, but doing + * so could lead to more fragmentation. + */ + if (!cur_state->format || + cur_state->format->planes != new_state->format->planes) + return true; + + /* Reallocate hardware planes if the source has changed. */ + if (cur_state->source != new_state->source) + return true; + + return false; +} + +static unsigned int rcar_du_plane_hwmask(struct rcar_du_plane_state *state) +{ + unsigned int mask; + + if (state->hwindex == -1) + return 0; + + mask = 1 << state->hwindex; + if (state->format->planes == 2) + mask |= 1 << ((state->hwindex + 1) % 8); + + return mask; +} + +/* + * The R8A7790 DU can source frames directly from the VSP1 devices VSPD0 and + * VSPD1. VSPD0 feeds DU0/1 plane 0, and VSPD1 feeds either DU2 plane 0 or + * DU0/1 plane 1. + * + * Allocate the correct fixed plane when sourcing frames from VSPD0 or VSPD1, + * and allocate planes in reverse index order otherwise to ensure maximum + * availability of planes 0 and 1. + * + * The caller is responsible for ensuring that the requested source is + * compatible with the DU revision. + */ +static int rcar_du_plane_hwalloc(struct rcar_du_plane *plane, + struct rcar_du_plane_state *state, + unsigned int free) +{ + unsigned int num_planes = state->format->planes; + int fixed = -1; + int i; + + if (state->source == RCAR_DU_PLANE_VSPD0) { + /* VSPD0 feeds plane 0 on DU0/1. */ + if (plane->group->index != 0) + return -EINVAL; + + fixed = 0; + } else if (state->source == RCAR_DU_PLANE_VSPD1) { + /* VSPD1 feeds plane 1 on DU0/1 or plane 0 on DU2. */ + fixed = plane->group->index == 0 ? 1 : 0; + } + + if (fixed >= 0) + return free & (1 << fixed) ? fixed : -EBUSY; + + for (i = RCAR_DU_NUM_HW_PLANES - 1; i >= 0; --i) { + if (!(free & (1 << i))) + continue; + + if (num_planes == 1 || free & (1 << ((i + 1) % 8))) + break; + } + + return i < 0 ? -EBUSY : i; +} + +int rcar_du_atomic_check_planes(struct drm_device *dev, + struct drm_atomic_state *state) +{ + struct rcar_du_device *rcdu = dev->dev_private; + unsigned int group_freed_planes[RCAR_DU_MAX_GROUPS] = { 0, }; + unsigned int group_free_planes[RCAR_DU_MAX_GROUPS] = { 0, }; + bool needs_realloc = false; + unsigned int groups = 0; + unsigned int i; + + /* Check if hardware planes need to be reallocated. */ + for (i = 0; i < dev->mode_config.num_total_plane; ++i) { + struct rcar_du_plane_state *plane_state; + struct rcar_du_plane *plane; + unsigned int index; + + if (!state->planes[i]) + continue; + + plane = to_rcar_plane(state->planes[i]); + plane_state = to_rcar_plane_state(state->plane_states[i]); + + dev_dbg(rcdu->dev, "%s: checking plane (%u,%u)\n", __func__, + plane->group->index, plane - plane->group->planes); + + /* If the plane is being disabled we don't need to go through + * the full reallocation procedure. Just mark the hardware + * plane(s) as freed. + */ + if (!plane_state->format) { + dev_dbg(rcdu->dev, "%s: plane is being disabled\n", + __func__); + index = plane - plane->group->planes; + group_freed_planes[plane->group->index] |= 1 << index; + plane_state->hwindex = -1; + continue; + } + + /* If the plane needs to be reallocated mark it as such, and + * mark the hardware plane(s) as free. + */ + if (rcar_du_plane_needs_realloc(plane, plane_state)) { + dev_dbg(rcdu->dev, "%s: plane needs reallocation\n", + __func__); + groups |= 1 << plane->group->index; + needs_realloc = true; + + index = plane - plane->group->planes; + group_freed_planes[plane->group->index] |= 1 << index; + plane_state->hwindex = -1; + } + } + + if (!needs_realloc) + return 0; + + /* Grab all plane states for the groups that need reallocation to ensure + * locking and avoid racy updates. This serializes the update operation, + * but there's not much we can do about it as that's the hardware + * design. + * + * Compute the used planes mask for each group at the same time to avoid + * looping over the planes separately later. + */ + while (groups) { + unsigned int index = ffs(groups) - 1; + struct rcar_du_group *group = &rcdu->groups[index]; + unsigned int used_planes = 0; + + dev_dbg(rcdu->dev, "%s: finding free planes for group %u\n", + __func__, index); + + for (i = 0; i < group->num_planes; ++i) { + struct rcar_du_plane *plane = &group->planes[i]; + struct rcar_du_plane_state *plane_state; + struct drm_plane_state *s; + + s = drm_atomic_get_plane_state(state, &plane->plane); + if (IS_ERR(s)) + return PTR_ERR(s); + + /* If the plane has been freed in the above loop its + * hardware planes must not be added to the used planes + * bitmask. However, the current state doesn't reflect + * the free state yet, as we've modified the new state + * above. Use the local freed planes list to check for + * that condition instead. + */ + if (group_freed_planes[index] & (1 << i)) { + dev_dbg(rcdu->dev, + "%s: plane (%u,%u) has been freed, skipping\n", + __func__, plane->group->index, + plane - plane->group->planes); + continue; + } + + plane_state = to_rcar_plane_state(plane->plane.state); + used_planes |= rcar_du_plane_hwmask(plane_state); + + dev_dbg(rcdu->dev, + "%s: plane (%u,%u) uses %u hwplanes (index %d)\n", + __func__, plane->group->index, + plane - plane->group->planes, + plane_state->format ? + plane_state->format->planes : 0, + plane_state->hwindex); + } + + group_free_planes[index] = 0xff & ~used_planes; + groups &= ~(1 << index); + + dev_dbg(rcdu->dev, "%s: group %u free planes mask 0x%02x\n", + __func__, index, group_free_planes[index]); + } + + /* Reallocate hardware planes for each plane that needs it. */ + for (i = 0; i < dev->mode_config.num_total_plane; ++i) { + struct rcar_du_plane_state *plane_state; + struct rcar_du_plane *plane; + unsigned int crtc_planes; + unsigned int free; + int idx; + + if (!state->planes[i]) + continue; + + plane = to_rcar_plane(state->planes[i]); + plane_state = to_rcar_plane_state(state->plane_states[i]); + + dev_dbg(rcdu->dev, "%s: allocating plane (%u,%u)\n", __func__, + plane->group->index, plane - plane->group->planes); + + /* Skip planes that are being disabled or don't need to be + * reallocated. + */ + if (!plane_state->format || + !rcar_du_plane_needs_realloc(plane, plane_state)) + continue; + + /* Try to allocate the plane from the free planes currently + * associated with the target CRTC to avoid restarting the CRTC + * group and thus minimize flicker. If it fails fall back to + * allocating from all free planes. + */ + crtc_planes = to_rcar_crtc(plane_state->state.crtc)->index % 2 + ? plane->group->dptsr_planes + : ~plane->group->dptsr_planes; + free = group_free_planes[plane->group->index]; + + idx = rcar_du_plane_hwalloc(plane, plane_state, + free & crtc_planes); + if (idx < 0) + idx = rcar_du_plane_hwalloc(plane, plane_state, + free); + if (idx < 0) { + dev_dbg(rcdu->dev, "%s: no available hardware plane\n", + __func__); + return idx; + } + + dev_dbg(rcdu->dev, "%s: allocated %u hwplanes (index %u)\n", + __func__, plane_state->format->planes, idx); + + plane_state->hwindex = idx; + + group_free_planes[plane->group->index] &= + ~rcar_du_plane_hwmask(plane_state); + + dev_dbg(rcdu->dev, "%s: group %u free planes mask 0x%02x\n", + __func__, plane->group->index, + group_free_planes[plane->group->index]); + } + + return 0; +} + +/* ----------------------------------------------------------------------------- + * Plane Setup + */ + #define RCAR_DU_COLORKEY_NONE (0 << 24) #define RCAR_DU_COLORKEY_SOURCE (1 << 24) #define RCAR_DU_COLORKEY_MASK (1 << 24) |