// SPDX-License-Identifier: MIT /* * Copyright © 2014-2019 Intel Corporation */ #include "gem/i915_gem_lmem.h" #include "gt/intel_gt.h" #include "gt/intel_gt_irq.h" #include "gt/intel_gt_pm_irq.h" #include "intel_guc.h" #include "intel_guc_slpc.h" #include "intel_guc_ads.h" #include "intel_guc_submission.h" #include "i915_drv.h" /** * DOC: GuC * * The GuC is a microcontroller inside the GT HW, introduced in gen9. The GuC is * designed to offload some of the functionality usually performed by the host * driver; currently the main operations it can take care of are: * * - Authentication of the HuC, which is required to fully enable HuC usage. * - Low latency graphics context scheduling (a.k.a. GuC submission). * - GT Power management. * * The enable_guc module parameter can be used to select which of those * operations to enable within GuC. Note that not all the operations are * supported on all gen9+ platforms. * * Enabling the GuC is not mandatory and therefore the firmware is only loaded * if at least one of the operations is selected. However, not loading the GuC * might result in the loss of some features that do require the GuC (currently * just the HuC, but more are expected to land in the future). */ void intel_guc_notify(struct intel_guc *guc) { struct intel_gt *gt = guc_to_gt(guc); /* * On Gen11+, the value written to the register is passes as a payload * to the FW. However, the FW currently treats all values the same way * (H2G interrupt), so we can just write the value that the HW expects * on older gens. */ intel_uncore_write(gt->uncore, guc->notify_reg, GUC_SEND_TRIGGER); } static inline i915_reg_t guc_send_reg(struct intel_guc *guc, u32 i) { GEM_BUG_ON(!guc->send_regs.base); GEM_BUG_ON(!guc->send_regs.count); GEM_BUG_ON(i >= guc->send_regs.count); return _MMIO(guc->send_regs.base + 4 * i); } void intel_guc_init_send_regs(struct intel_guc *guc) { struct intel_gt *gt = guc_to_gt(guc); enum forcewake_domains fw_domains = 0; unsigned int i; GEM_BUG_ON(!guc->send_regs.base); GEM_BUG_ON(!guc->send_regs.count); for (i = 0; i < guc->send_regs.count; i++) { fw_domains |= intel_uncore_forcewake_for_reg(gt->uncore, guc_send_reg(guc, i), FW_REG_READ | FW_REG_WRITE); } guc->send_regs.fw_domains = fw_domains; } static void gen9_reset_guc_interrupts(struct intel_guc *guc) { struct intel_gt *gt = guc_to_gt(guc); assert_rpm_wakelock_held(>->i915->runtime_pm); spin_lock_irq(>->irq_lock); gen6_gt_pm_reset_iir(gt, gt->pm_guc_events); spin_unlock_irq(>->irq_lock); } static void gen9_enable_guc_interrupts(struct intel_guc *guc) { struct intel_gt *gt = guc_to_gt(guc); assert_rpm_wakelock_held(>->i915->runtime_pm); spin_lock_irq(>->irq_lock); WARN_ON_ONCE(intel_uncore_read(gt->uncore, GEN8_GT_IIR(2)) & gt->pm_guc_events); gen6_gt_pm_enable_irq(gt, gt->pm_guc_events); spin_unlock_irq(>->irq_lock); } static void gen9_disable_guc_interrupts(struct intel_guc *guc) { struct intel_gt *gt = guc_to_gt(guc); assert_rpm_wakelock_held(>->i915->runtime_pm); spin_lock_irq(>->irq_lock); gen6_gt_pm_disable_irq(gt, gt->pm_guc_events); spin_unlock_irq(>->irq_lock); intel_synchronize_irq(gt->i915); gen9_reset_guc_interrupts(guc); } static void gen11_reset_guc_interrupts(struct intel_guc *guc) { struct intel_gt *gt = guc_to_gt(guc); spin_lock_irq(>->irq_lock); gen11_gt_reset_one_iir(gt, 0, GEN11_GUC); spin_unlock_irq(>->irq_lock); } static void gen11_enable_guc_interrupts(struct intel_guc *guc) { struct intel_gt *gt = guc_to_gt(guc); u32 events = REG_FIELD_PREP(ENGINE1_MASK, GUC_INTR_GUC2HOST); spin_lock_irq(>->irq_lock); WARN_ON_ONCE(gen11_gt_reset_one_iir(gt, 0, GEN11_GUC)); intel_uncore_write(gt->uncore, GEN11_GUC_SG_INTR_ENABLE, events); intel_uncore_write(gt->uncore, GEN11_GUC_SG_INTR_MASK, ~events); spin_unlock_irq(>->irq_lock); } static void gen11_disable_guc_interrupts(struct intel_guc *guc) { struct intel_gt *gt = guc_to_gt(guc); spin_lock_irq(>->irq_lock); intel_uncore_write(gt->uncore, GEN11_GUC_SG_INTR_MASK, ~0); intel_uncore_write(gt->uncore, GEN11_GUC_SG_INTR_ENABLE, 0); spin_unlock_irq(>->irq_lock); intel_synchronize_irq(gt->i915); gen11_reset_guc_interrupts(guc); } void intel_guc_init_early(struct intel_guc *guc) { struct drm_i915_private *i915 = guc_to_gt(guc)->i915; intel_uc_fw_init_early(&guc->fw, INTEL_UC_FW_TYPE_GUC); intel_guc_ct_init_early(&guc->ct); intel_guc_log_init_early(&guc->log); intel_guc_submission_init_early(guc); intel_guc_slpc_init_early(&guc->slpc); intel_guc_rc_init_early(guc); mutex_init(&guc->send_mutex); spin_lock_init(&guc->irq_lock); if (GRAPHICS_VER(i915) >= 11) { guc->notify_reg = GEN11_GUC_HOST_INTERRUPT; guc->interrupts.reset = gen11_reset_guc_interrupts; guc->interrupts.enable = gen11_enable_guc_interrupts; guc->interrupts.disable = gen11_disable_guc_interrupts; guc->send_regs.base = i915_mmio_reg_offset(GEN11_SOFT_SCRATCH(0)); guc->send_regs.count = GEN11_SOFT_SCRATCH_COUNT; } else { guc->notify_reg = GUC_SEND_INTERRUPT; guc->interrupts.reset = gen9_reset_guc_interrupts; guc->interrupts.enable = gen9_enable_guc_interrupts; guc->interrupts.disable = gen9_disable_guc_interrupts; guc->send_regs.base = i915_mmio_reg_offset(SOFT_SCRATCH(0)); guc->send_regs.count = GUC_MAX_MMIO_MSG_LEN; BUILD_BUG_ON(GUC_MAX_MMIO_MSG_LEN > SOFT_SCRATCH_COUNT); } } void intel_guc_init_late(struct intel_guc *guc) { intel_guc_ads_init_late(guc); } static u32 guc_ctl_debug_flags(struct intel_guc *guc) { u32 level = intel_guc_log_get_level(&guc->log); u32 flags = 0; if (!GUC_LOG_LEVEL_IS_VERBOSE(level)) flags |= GUC_LOG_DISABLED; else flags |= GUC_LOG_LEVEL_TO_VERBOSITY(level) << GUC_LOG_VERBOSITY_SHIFT; return flags; } static u32 guc_ctl_feature_flags(struct intel_guc *guc) { u32 flags = 0; if (!intel_guc_submission_is_used(guc)) flags |= GUC_CTL_DISABLE_SCHEDULER; if (intel_guc_slpc_is_used(guc)) flags |= GUC_CTL_ENABLE_SLPC; return flags; } static u32 guc_ctl_log_params_flags(struct intel_guc *guc) { u32 offset = intel_guc_ggtt_offset(guc, guc->log.vma) >> PAGE_SHIFT; u32 flags; #if (((CRASH_BUFFER_SIZE) % SZ_1M) == 0) #define UNIT SZ_1M #define FLAG GUC_LOG_ALLOC_IN_MEGABYTE #else #define UNIT SZ_4K #define FLAG 0 #endif BUILD_BUG_ON(!CRASH_BUFFER_SIZE); BUILD_BUG_ON(!IS_ALIGNED(CRASH_BUFFER_SIZE, UNIT)); BUILD_BUG_ON(!DEBUG_BUFFER_SIZE); BUILD_BUG_ON(!IS_ALIGNED(DEBUG_BUFFER_SIZE, UNIT)); BUILD_BUG_ON((CRASH_BUFFER_SIZE / UNIT - 1) > (GUC_LOG_CRASH_MASK >> GUC_LOG_CRASH_SHIFT)); BUILD_BUG_ON((DEBUG_BUFFER_SIZE / UNIT - 1) > (GUC_LOG_DEBUG_MASK >> GUC_LOG_DEBUG_SHIFT)); flags = GUC_LOG_VALID | GUC_LOG_NOTIFY_ON_HALF_FULL | FLAG | ((CRASH_BUFFER_SIZE / UNIT - 1) << GUC_LOG_CRASH_SHIFT) | ((DEBUG_BUFFER_SIZE / UNIT - 1) << GUC_LOG_DEBUG_SHIFT) | (offset << GUC_LOG_BUF_ADDR_SHIFT); #undef UNIT #undef FLAG return flags; } static u32 guc_ctl_ads_flags(struct intel_guc *guc) { u32 ads = intel_guc_ggtt_offset(guc, guc->ads_vma) >> PAGE_SHIFT; u32 flags = ads << GUC_ADS_ADDR_SHIFT; return flags; } /* * Initialise the GuC parameter block before starting the firmware * transfer. These parameters are read by the firmware on startup * and cannot be changed thereafter. */ static void guc_init_params(struct intel_guc *guc) { u32 *params = guc->params; int i; BUILD_BUG_ON(sizeof(guc->params) != GUC_CTL_MAX_DWORDS * sizeof(u32)); params[GUC_CTL_LOG_PARAMS] = guc_ctl_log_params_flags(guc); params[GUC_CTL_FEATURE] = guc_ctl_feature_flags(guc); params[GUC_CTL_DEBUG] = guc_ctl_debug_flags(guc); params[GUC_CTL_ADS] = guc_ctl_ads_flags(guc); for (i = 0; i < GUC_CTL_MAX_DWORDS; i++) DRM_DEBUG_DRIVER("param[%2d] = %#x\n", i, params[i]); } /* * Initialise the GuC parameter block before starting the firmware * transfer. These parameters are read by the firmware on startup * and cannot be changed thereafter. */ void intel_guc_write_params(struct intel_guc *guc) { struct intel_uncore *uncore = guc_to_gt(guc)->uncore; int i; /* * All SOFT_SCRATCH registers are in FORCEWAKE_GT domain and * they are power context saved so it's ok to release forcewake * when we are done here and take it again at xfer time. */ intel_uncore_forcewake_get(uncore, FORCEWAKE_GT); intel_uncore_write(uncore, SOFT_SCRATCH(0), 0); for (i = 0; i < GUC_CTL_MAX_DWORDS; i++) intel_uncore_write(uncore, SOFT_SCRATCH(1 + i), guc->params[i]); intel_uncore_forcewake_put(uncore, FORCEWAKE_GT); } int intel_guc_init(struct intel_guc *guc) { struct intel_gt *gt = guc_to_gt(guc); int ret; ret = intel_uc_fw_init(&guc->fw); if (ret) goto out; ret = intel_guc_log_create(&guc->log); if (ret) goto err_fw; ret = intel_guc_ads_create(guc); if (ret) goto err_log; GEM_BUG_ON(!guc->ads_vma); ret = intel_guc_ct_init(&guc->ct); if (ret) goto err_ads; if (intel_guc_submission_is_used(guc)) { /* * This is stuff we need to have available at fw load time * if we are planning to enable submission later */ ret = intel_guc_submission_init(guc); if (ret) goto err_ct; } if (intel_guc_slpc_is_used(guc)) { ret = intel_guc_slpc_init(&guc->slpc); if (ret) goto err_submission; } /* now that everything is perma-pinned, initialize the parameters */ guc_init_params(guc); /* We need to notify the guc whenever we change the GGTT */ i915_ggtt_enable_guc(gt->ggtt); intel_uc_fw_change_status(&guc->fw, INTEL_UC_FIRMWARE_LOADABLE); return 0; err_submission: intel_guc_submission_fini(guc); err_ct: intel_guc_ct_fini(&guc->ct); err_ads: intel_guc_ads_destroy(guc); err_log: intel_guc_log_destroy(&guc->log); err_fw: intel_uc_fw_fini(&guc->fw); out: i915_probe_error(gt->i915, "failed with %d\n", ret); return ret; } void intel_guc_fini(struct intel_guc *guc) { struct intel_gt *gt = guc_to_gt(guc); if (!intel_uc_fw_is_loadable(&guc->fw)) return; i915_ggtt_disable_guc(gt->ggtt); if (intel_guc_slpc_is_used(guc)) intel_guc_slpc_fini(&guc->slpc); if (intel_guc_submission_is_used(guc)) intel_guc_submission_fini(guc); intel_guc_ct_fini(&guc->ct); intel_guc_ads_destroy(guc); intel_guc_log_destroy(&guc->log); intel_uc_fw_fini(&guc->fw); } /* * This function implements the MMIO based host to GuC interface. */ int intel_guc_send_mmio(struct intel_guc *guc, const u32 *request, u32 len, u32 *response_buf, u32 response_buf_size) { struct drm_i915_private *i915 = guc_to_gt(guc)->i915; struct intel_uncore *uncore = guc_to_gt(guc)->uncore; u32 header; int i; int ret; GEM_BUG_ON(!len); GEM_BUG_ON(len > guc->send_regs.count); GEM_BUG_ON(FIELD_GET(GUC_HXG_MSG_0_ORIGIN, request[0]) != GUC_HXG_ORIGIN_HOST); GEM_BUG_ON(FIELD_GET(GUC_HXG_MSG_0_TYPE, request[0]) != GUC_HXG_TYPE_REQUEST); mutex_lock(&guc->send_mutex); intel_uncore_forcewake_get(uncore, guc->send_regs.fw_domains); retry: for (i = 0; i < len; i++) intel_uncore_write(uncore, guc_send_reg(guc, i), request[i]); intel_uncore_posting_read(uncore, guc_send_reg(guc, i - 1)); intel_guc_notify(guc); /* * No GuC command should ever take longer than 10ms. * Fast commands should still complete in 10us. */ ret = __intel_wait_for_register_fw(uncore, guc_send_reg(guc, 0), GUC_HXG_MSG_0_ORIGIN, FIELD_PREP(GUC_HXG_MSG_0_ORIGIN, GUC_HXG_ORIGIN_GUC), 10, 10, &header); if (unlikely(ret)) { timeout: drm_err(&i915->drm, "mmio request %#x: no reply %x\n", request[0], header); goto out; } if (FIELD_GET(GUC_HXG_MSG_0_TYPE, header) == GUC_HXG_TYPE_NO_RESPONSE_BUSY) { #define done ({ header = intel_uncore_read(uncore, guc_send_reg(guc, 0)); \ FIELD_GET(GUC_HXG_MSG_0_ORIGIN, header) != GUC_HXG_ORIGIN_GUC || \ FIELD_GET(GUC_HXG_MSG_0_TYPE, header) != GUC_HXG_TYPE_NO_RESPONSE_BUSY; }) ret = wait_for(done, 1000); if (unlikely(ret)) goto timeout; if (unlikely(FIELD_GET(GUC_HXG_MSG_0_ORIGIN, header) != GUC_HXG_ORIGIN_GUC)) goto proto; #undef done } if (FIELD_GET(GUC_HXG_MSG_0_TYPE, header) == GUC_HXG_TYPE_NO_RESPONSE_RETRY) { u32 reason = FIELD_GET(GUC_HXG_RETRY_MSG_0_REASON, header); drm_dbg(&i915->drm, "mmio request %#x: retrying, reason %u\n", request[0], reason); goto retry; } if (FIELD_GET(GUC_HXG_MSG_0_TYPE, header) == GUC_HXG_TYPE_RESPONSE_FAILURE) { u32 hint = FIELD_GET(GUC_HXG_FAILURE_MSG_0_HINT, header); u32 error = FIELD_GET(GUC_HXG_FAILURE_MSG_0_ERROR, header); drm_err(&i915->drm, "mmio request %#x: failure %x/%u\n", request[0], error, hint); ret = -ENXIO; goto out; } if (FIELD_GET(GUC_HXG_MSG_0_TYPE, header) != GUC_HXG_TYPE_RESPONSE_SUCCESS) { proto: drm_err(&i915->drm, "mmio request %#x: unexpected reply %#x\n", request[0], header); ret = -EPROTO; goto out; } if (response_buf) { int count = min(response_buf_size, guc->send_regs.count); GEM_BUG_ON(!count); response_buf[0] = header; for (i = 1; i < count; i++) response_buf[i] = intel_uncore_read(uncore, guc_send_reg(guc, i)); /* Use number of copied dwords as our return value */ ret = count; } else { /* Use data from the GuC response as our return value */ ret = FIELD_GET(GUC_HXG_RESPONSE_MSG_0_DATA0, header); } out: intel_uncore_forcewake_put(uncore, guc->send_regs.fw_domains); mutex_unlock(&guc->send_mutex); return ret; } int intel_guc_to_host_process_recv_msg(struct intel_guc *guc, const u32 *payload, u32 len) { u32 msg; if (unlikely(!len)) return -EPROTO; /* Make sure to handle only enabled messages */ msg = payload[0] & guc->msg_enabled_mask; if (msg & (INTEL_GUC_RECV_MSG_FLUSH_LOG_BUFFER | INTEL_GUC_RECV_MSG_CRASH_DUMP_POSTED)) intel_guc_log_handle_flush_event(&guc->log); return 0; } /** * intel_guc_auth_huc() - Send action to GuC to authenticate HuC ucode * @guc: intel_guc structure * @rsa_offset: rsa offset w.r.t ggtt base of huc vma * * Triggers a HuC firmware authentication request to the GuC via intel_guc_send * INTEL_GUC_ACTION_AUTHENTICATE_HUC interface. This function is invoked by * intel_huc_auth(). * * Return: non-zero code on error */ int intel_guc_auth_huc(struct intel_guc *guc, u32 rsa_offset) { u32 action[] = { INTEL_GUC_ACTION_AUTHENTICATE_HUC, rsa_offset }; return intel_guc_send(guc, action, ARRAY_SIZE(action)); } /** * intel_guc_suspend() - notify GuC entering suspend state * @guc: the guc */ int intel_guc_suspend(struct intel_guc *guc) { int ret; u32 action[] = { INTEL_GUC_ACTION_RESET_CLIENT, }; if (!intel_guc_is_ready(guc)) return 0; if (intel_guc_submission_is_used(guc)) { /* * This H2G MMIO command tears down the GuC in two steps. First it will * generate a G2H CTB for every active context indicating a reset. In * practice the i915 shouldn't ever get a G2H as suspend should only be * called when the GPU is idle. Next, it tears down the CTBs and this * H2G MMIO command completes. * * Don't abort on a failure code from the GuC. Keep going and do the * clean up in santize() and re-initialisation on resume and hopefully * the error here won't be problematic. */ ret = intel_guc_send_mmio(guc, action, ARRAY_SIZE(action), NULL, 0); if (ret) DRM_ERROR("GuC suspend: RESET_CLIENT action failed with error %d!\n", ret); } /* Signal that the GuC isn't running. */ intel_guc_sanitize(guc); return 0; } /** * intel_guc_resume() - notify GuC resuming from suspend state * @guc: the guc */ int intel_guc_resume(struct intel_guc *guc) { /* * NB: This function can still be called even if GuC submission is * disabled, e.g. if GuC is enabled for HuC authentication only. Thus, * if any code is later added here, it must be support doing nothing * if submission is disabled (as per intel_guc_suspend). */ return 0; } /** * DOC: GuC Memory Management * * GuC can't allocate any memory for its own usage, so all the allocations must * be handled by the host driver. GuC accesses the memory via the GGTT, with the * exception of the top and bottom parts of the 4GB address space, which are * instead re-mapped by the GuC HW to memory location of the FW itself (WOPCM) * or other parts of the HW. The driver must take care not to place objects that * the GuC is going to access in these reserved ranges. The layout of the GuC * address space is shown below: * * :: * * +===========> +====================+ <== FFFF_FFFF * ^ | Reserved | * | +====================+ <== GUC_GGTT_TOP * | | | * | | DRAM | * GuC | | * Address +===> +====================+ <== GuC ggtt_pin_bias * Space ^ | | * | | | | * | GuC | GuC | * | WOPCM | WOPCM | * | Size | | * | | | | * v v | | * +=======+===> +====================+ <== 0000_0000 * * The lower part of GuC Address Space [0, ggtt_pin_bias) is mapped to GuC WOPCM * while upper part of GuC Address Space [ggtt_pin_bias, GUC_GGTT_TOP) is mapped * to DRAM. The value of the GuC ggtt_pin_bias is the GuC WOPCM size. */ /** * intel_guc_allocate_vma() - Allocate a GGTT VMA for GuC usage * @guc: the guc * @size: size of area to allocate (both virtual space and memory) * * This is a wrapper to create an object for use with the GuC. In order to * use it inside the GuC, an object needs to be pinned lifetime, so we allocate * both some backing storage and a range inside the Global GTT. We must pin * it in the GGTT somewhere other than than [0, GUC ggtt_pin_bias) because that * range is reserved inside GuC. * * Return: A i915_vma if successful, otherwise an ERR_PTR. */ struct i915_vma *intel_guc_allocate_vma(struct intel_guc *guc, u32 size) { struct intel_gt *gt = guc_to_gt(guc); struct drm_i915_gem_object *obj; struct i915_vma *vma; u64 flags; int ret; if (HAS_LMEM(gt->i915)) obj = i915_gem_object_create_lmem(gt->i915, size, I915_BO_ALLOC_CPU_CLEAR | I915_BO_ALLOC_CONTIGUOUS | I915_BO_ALLOC_PM_EARLY); else obj = i915_gem_object_create_shmem(gt->i915, size); if (IS_ERR(obj)) return ERR_CAST(obj); vma = i915_vma_instance(obj, >->ggtt->vm, NULL); if (IS_ERR(vma)) goto err; flags = PIN_OFFSET_BIAS | i915_ggtt_pin_bias(vma); ret = i915_ggtt_pin(vma, NULL, 0, flags); if (ret) { vma = ERR_PTR(ret); goto err; } return i915_vma_make_unshrinkable(vma); err: i915_gem_object_put(obj); return vma; } /** * intel_guc_allocate_and_map_vma() - Allocate and map VMA for GuC usage * @guc: the guc * @size: size of area to allocate (both virtual space and memory) * @out_vma: return variable for the allocated vma pointer * @out_vaddr: return variable for the obj mapping * * This wrapper calls intel_guc_allocate_vma() and then maps the allocated * object with I915_MAP_WB. * * Return: 0 if successful, a negative errno code otherwise. */ int intel_guc_allocate_and_map_vma(struct intel_guc *guc, u32 size, struct i915_vma **out_vma, void **out_vaddr) { struct i915_vma *vma; void *vaddr; vma = intel_guc_allocate_vma(guc, size); if (IS_ERR(vma)) return PTR_ERR(vma); vaddr = i915_gem_object_pin_map_unlocked(vma->obj, i915_coherent_map_type(guc_to_gt(guc)->i915, vma->obj, true)); if (IS_ERR(vaddr)) { i915_vma_unpin_and_release(&vma, 0); return PTR_ERR(vaddr); } *out_vma = vma; *out_vaddr = vaddr; return 0; } /** * intel_guc_load_status - dump information about GuC load status * @guc: the GuC * @p: the &drm_printer * * Pretty printer for GuC load status. */ void intel_guc_load_status(struct intel_guc *guc, struct drm_printer *p) { struct intel_gt *gt = guc_to_gt(guc); struct intel_uncore *uncore = gt->uncore; intel_wakeref_t wakeref; if (!intel_guc_is_supported(guc)) { drm_printf(p, "GuC not supported\n"); return; } if (!intel_guc_is_wanted(guc)) { drm_printf(p, "GuC disabled\n"); return; } intel_uc_fw_dump(&guc->fw, p); with_intel_runtime_pm(uncore->rpm, wakeref) { u32 status = intel_uncore_read(uncore, GUC_STATUS); u32 i; drm_printf(p, "\nGuC status 0x%08x:\n", status); drm_printf(p, "\tBootrom status = 0x%x\n", (status & GS_BOOTROM_MASK) >> GS_BOOTROM_SHIFT); drm_printf(p, "\tuKernel status = 0x%x\n", (status & GS_UKERNEL_MASK) >> GS_UKERNEL_SHIFT); drm_printf(p, "\tMIA Core status = 0x%x\n", (status & GS_MIA_MASK) >> GS_MIA_SHIFT); drm_puts(p, "\nScratch registers:\n"); for (i = 0; i < 16; i++) { drm_printf(p, "\t%2d: \t0x%x\n", i, intel_uncore_read(uncore, SOFT_SCRATCH(i))); } } } void intel_guc_write_barrier(struct intel_guc *guc) { struct intel_gt *gt = guc_to_gt(guc); if (i915_gem_object_is_lmem(guc->ct.vma->obj)) { /* * Ensure intel_uncore_write_fw can be used rather than * intel_uncore_write. */ GEM_BUG_ON(guc->send_regs.fw_domains); /* * This register is used by the i915 and GuC for MMIO based * communication. Once we are in this code CTBs are the only * method the i915 uses to communicate with the GuC so it is * safe to write to this register (a value of 0 is NOP for MMIO * communication). If we ever start mixing CTBs and MMIOs a new * register will have to be chosen. This function is also used * to enforce ordering of a work queue item write and an update * to the process descriptor. When a work queue is being used, * CTBs are also the only mechanism of communication. */ intel_uncore_write_fw(gt->uncore, GEN11_SOFT_SCRATCH(0), 0); } else { /* wmb() sufficient for a barrier if in smem */ wmb(); } }