diff options
Diffstat (limited to 'drivers/gpu/drm/i915/display/intel_dsb.c')
-rw-r--r-- | drivers/gpu/drm/i915/display/intel_dsb.c | 332 |
1 files changed, 332 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_dsb.c b/drivers/gpu/drm/i915/display/intel_dsb.c new file mode 100644 index 000000000000..bb5a0e91b370 --- /dev/null +++ b/drivers/gpu/drm/i915/display/intel_dsb.c @@ -0,0 +1,332 @@ +// SPDX-License-Identifier: MIT +/* + * Copyright © 2019 Intel Corporation + * + */ + +#include "i915_drv.h" +#include "intel_display_types.h" + +#define DSB_BUF_SIZE (2 * PAGE_SIZE) + +/** + * DOC: DSB + * + * A DSB (Display State Buffer) is a queue of MMIO instructions in the memory + * which can be offloaded to DSB HW in Display Controller. DSB HW is a DMA + * engine that can be programmed to download the DSB from memory. + * It allows driver to batch submit display HW programming. This helps to + * reduce loading time and CPU activity, thereby making the context switch + * faster. DSB Support added from Gen12 Intel graphics based platform. + * + * DSB's can access only the pipe, plane, and transcoder Data Island Packet + * registers. + * + * DSB HW can support only register writes (both indexed and direct MMIO + * writes). There are no registers reads possible with DSB HW engine. + */ + +/* DSB opcodes. */ +#define DSB_OPCODE_SHIFT 24 +#define DSB_OPCODE_MMIO_WRITE 0x1 +#define DSB_OPCODE_INDEXED_WRITE 0x9 +#define DSB_BYTE_EN 0xF +#define DSB_BYTE_EN_SHIFT 20 +#define DSB_REG_VALUE_MASK 0xfffff + +static inline bool is_dsb_busy(struct intel_dsb *dsb) +{ + struct intel_crtc *crtc = container_of(dsb, typeof(*crtc), dsb); + struct drm_i915_private *dev_priv = to_i915(crtc->base.dev); + enum pipe pipe = crtc->pipe; + + return DSB_STATUS & I915_READ(DSB_CTRL(pipe, dsb->id)); +} + +static inline bool intel_dsb_enable_engine(struct intel_dsb *dsb) +{ + struct intel_crtc *crtc = container_of(dsb, typeof(*crtc), dsb); + struct drm_i915_private *dev_priv = to_i915(crtc->base.dev); + enum pipe pipe = crtc->pipe; + u32 dsb_ctrl; + + dsb_ctrl = I915_READ(DSB_CTRL(pipe, dsb->id)); + if (DSB_STATUS & dsb_ctrl) { + DRM_DEBUG_KMS("DSB engine is busy.\n"); + return false; + } + + dsb_ctrl |= DSB_ENABLE; + I915_WRITE(DSB_CTRL(pipe, dsb->id), dsb_ctrl); + + POSTING_READ(DSB_CTRL(pipe, dsb->id)); + return true; +} + +static inline bool intel_dsb_disable_engine(struct intel_dsb *dsb) +{ + struct intel_crtc *crtc = container_of(dsb, typeof(*crtc), dsb); + struct drm_i915_private *dev_priv = to_i915(crtc->base.dev); + enum pipe pipe = crtc->pipe; + u32 dsb_ctrl; + + dsb_ctrl = I915_READ(DSB_CTRL(pipe, dsb->id)); + if (DSB_STATUS & dsb_ctrl) { + DRM_DEBUG_KMS("DSB engine is busy.\n"); + return false; + } + + dsb_ctrl &= ~DSB_ENABLE; + I915_WRITE(DSB_CTRL(pipe, dsb->id), dsb_ctrl); + + POSTING_READ(DSB_CTRL(pipe, dsb->id)); + return true; +} + +/** + * intel_dsb_get() - Allocate DSB context and return a DSB instance. + * @crtc: intel_crtc structure to get pipe info. + * + * This function provides handle of a DSB instance, for the further DSB + * operations. + * + * Returns: address of Intel_dsb instance requested for. + * Failure: Returns the same DSB instance, but without a command buffer. + */ + +struct intel_dsb * +intel_dsb_get(struct intel_crtc *crtc) +{ + struct drm_device *dev = crtc->base.dev; + struct drm_i915_private *i915 = to_i915(dev); + struct intel_dsb *dsb = &crtc->dsb; + struct drm_i915_gem_object *obj; + struct i915_vma *vma; + intel_wakeref_t wakeref; + + if (!HAS_DSB(i915)) + return dsb; + + if (atomic_add_return(1, &dsb->refcount) != 1) + return dsb; + + dsb->id = DSB1; + wakeref = intel_runtime_pm_get(&i915->runtime_pm); + + obj = i915_gem_object_create_internal(i915, DSB_BUF_SIZE); + if (IS_ERR(obj)) { + DRM_ERROR("Gem object creation failed\n"); + goto err; + } + + vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, PIN_MAPPABLE); + if (IS_ERR(vma)) { + DRM_ERROR("Vma creation failed\n"); + i915_gem_object_put(obj); + atomic_dec(&dsb->refcount); + goto err; + } + + dsb->cmd_buf = i915_gem_object_pin_map(vma->obj, I915_MAP_WC); + if (IS_ERR(dsb->cmd_buf)) { + DRM_ERROR("Command buffer creation failed\n"); + i915_vma_unpin_and_release(&vma, 0); + dsb->cmd_buf = NULL; + atomic_dec(&dsb->refcount); + goto err; + } + dsb->vma = vma; + +err: + intel_runtime_pm_put(&i915->runtime_pm, wakeref); + return dsb; +} + +/** + * intel_dsb_put() - To destroy DSB context. + * @dsb: intel_dsb structure. + * + * This function destroys the DSB context allocated by a dsb_get(), by + * unpinning and releasing the VMA object associated with it. + */ + +void intel_dsb_put(struct intel_dsb *dsb) +{ + struct intel_crtc *crtc = container_of(dsb, typeof(*crtc), dsb); + struct drm_i915_private *i915 = to_i915(crtc->base.dev); + + if (!HAS_DSB(i915)) + return; + + if (WARN_ON(atomic_read(&dsb->refcount) == 0)) + return; + + if (atomic_dec_and_test(&dsb->refcount)) { + i915_vma_unpin_and_release(&dsb->vma, I915_VMA_RELEASE_MAP); + dsb->cmd_buf = NULL; + dsb->free_pos = 0; + dsb->ins_start_offset = 0; + } +} + +/** + * intel_dsb_indexed_reg_write() -Write to the DSB context for auto + * increment register. + * @dsb: intel_dsb structure. + * @reg: register address. + * @val: value. + * + * This function is used for writing register-value pair in command + * buffer of DSB for auto-increment register. During command buffer overflow, + * a warning is thrown and rest all erroneous condition register programming + * is done through mmio write. + */ + +void intel_dsb_indexed_reg_write(struct intel_dsb *dsb, i915_reg_t reg, + u32 val) +{ + struct intel_crtc *crtc = container_of(dsb, typeof(*crtc), dsb); + struct drm_i915_private *dev_priv = to_i915(crtc->base.dev); + u32 *buf = dsb->cmd_buf; + u32 reg_val; + + if (!buf) { + I915_WRITE(reg, val); + return; + } + + if (WARN_ON(dsb->free_pos >= DSB_BUF_SIZE)) { + DRM_DEBUG_KMS("DSB buffer overflow\n"); + return; + } + + /* + * For example the buffer will look like below for 3 dwords for auto + * increment register: + * +--------------------------------------------------------+ + * | size = 3 | offset &| value1 | value2 | value3 | zero | + * | | opcode | | | | | + * +--------------------------------------------------------+ + * + + + + + + + + * 0 4 8 12 16 20 24 + * Byte + * + * As every instruction is 8 byte aligned the index of dsb instruction + * will start always from even number while dealing with u32 array. If + * we are writing odd no of dwords, Zeros will be added in the end for + * padding. + */ + reg_val = buf[dsb->ins_start_offset + 1] & DSB_REG_VALUE_MASK; + if (reg_val != i915_mmio_reg_offset(reg)) { + /* Every instruction should be 8 byte aligned. */ + dsb->free_pos = ALIGN(dsb->free_pos, 2); + + dsb->ins_start_offset = dsb->free_pos; + + /* Update the size. */ + buf[dsb->free_pos++] = 1; + + /* Update the opcode and reg. */ + buf[dsb->free_pos++] = (DSB_OPCODE_INDEXED_WRITE << + DSB_OPCODE_SHIFT) | + i915_mmio_reg_offset(reg); + + /* Update the value. */ + buf[dsb->free_pos++] = val; + } else { + /* Update the new value. */ + buf[dsb->free_pos++] = val; + + /* Update the size. */ + buf[dsb->ins_start_offset]++; + } + + /* if number of data words is odd, then the last dword should be 0.*/ + if (dsb->free_pos & 0x1) + buf[dsb->free_pos] = 0; +} + +/** + * intel_dsb_reg_write() -Write to the DSB context for normal + * register. + * @dsb: intel_dsb structure. + * @reg: register address. + * @val: value. + * + * This function is used for writing register-value pair in command + * buffer of DSB. During command buffer overflow, a warning is thrown + * and rest all erroneous condition register programming is done + * through mmio write. + */ +void intel_dsb_reg_write(struct intel_dsb *dsb, i915_reg_t reg, u32 val) +{ + struct intel_crtc *crtc = container_of(dsb, typeof(*crtc), dsb); + struct drm_i915_private *dev_priv = to_i915(crtc->base.dev); + u32 *buf = dsb->cmd_buf; + + if (!buf) { + I915_WRITE(reg, val); + return; + } + + if (WARN_ON(dsb->free_pos >= DSB_BUF_SIZE)) { + DRM_DEBUG_KMS("DSB buffer overflow\n"); + return; + } + + dsb->ins_start_offset = dsb->free_pos; + buf[dsb->free_pos++] = val; + buf[dsb->free_pos++] = (DSB_OPCODE_MMIO_WRITE << DSB_OPCODE_SHIFT) | + (DSB_BYTE_EN << DSB_BYTE_EN_SHIFT) | + i915_mmio_reg_offset(reg); +} + +/** + * intel_dsb_commit() - Trigger workload execution of DSB. + * @dsb: intel_dsb structure. + * + * This function is used to do actual write to hardware using DSB. + * On errors, fall back to MMIO. Also this function help to reset the context. + */ +void intel_dsb_commit(struct intel_dsb *dsb) +{ + struct intel_crtc *crtc = container_of(dsb, typeof(*crtc), dsb); + struct drm_device *dev = crtc->base.dev; + struct drm_i915_private *dev_priv = to_i915(dev); + enum pipe pipe = crtc->pipe; + u32 tail; + + if (!dsb->free_pos) + return; + + if (!intel_dsb_enable_engine(dsb)) + goto reset; + + if (is_dsb_busy(dsb)) { + DRM_ERROR("HEAD_PTR write failed - dsb engine is busy.\n"); + goto reset; + } + I915_WRITE(DSB_HEAD(pipe, dsb->id), i915_ggtt_offset(dsb->vma)); + + tail = ALIGN(dsb->free_pos * 4, CACHELINE_BYTES); + if (tail > dsb->free_pos * 4) + memset(&dsb->cmd_buf[dsb->free_pos], 0, + (tail - dsb->free_pos * 4)); + + if (is_dsb_busy(dsb)) { + DRM_ERROR("TAIL_PTR write failed - dsb engine is busy.\n"); + goto reset; + } + DRM_DEBUG_KMS("DSB execution started - head 0x%x, tail 0x%x\n", + i915_ggtt_offset(dsb->vma), tail); + I915_WRITE(DSB_TAIL(pipe, dsb->id), i915_ggtt_offset(dsb->vma) + tail); + if (wait_for(!is_dsb_busy(dsb), 1)) { + DRM_ERROR("Timed out waiting for DSB workload completion.\n"); + goto reset; + } + +reset: + dsb->free_pos = 0; + dsb->ins_start_offset = 0; + intel_dsb_disable_engine(dsb); +} |