--- /dev/null
+/*
+ * Copyright © 2016-2017 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "i915_drv.h"
+#include "intel_guc_ct.h"
+
+enum { CTB_SEND = 0, CTB_RECV = 1 };
+
+enum { CTB_OWNER_HOST = 0 };
+
+void intel_guc_ct_init_early(struct intel_guc_ct *ct)
+{
+ /* we're using static channel owners */
+ ct->host_channel.owner = CTB_OWNER_HOST;
+}
+
+static inline const char *guc_ct_buffer_type_to_str(u32 type)
+{
+ switch (type) {
+ case INTEL_GUC_CT_BUFFER_TYPE_SEND:
+ return "SEND";
+ case INTEL_GUC_CT_BUFFER_TYPE_RECV:
+ return "RECV";
+ default:
+ return "<invalid>";
+ }
+}
+
+static void guc_ct_buffer_desc_init(struct guc_ct_buffer_desc *desc,
+ u32 cmds_addr, u32 size, u32 owner)
+{
+ DRM_DEBUG_DRIVER("CT: desc %p init addr=%#x size=%u owner=%u\n",
+ desc, cmds_addr, size, owner);
+ memset(desc, 0, sizeof(*desc));
+ desc->addr = cmds_addr;
+ desc->size = size;
+ desc->owner = owner;
+}
+
+static void guc_ct_buffer_desc_reset(struct guc_ct_buffer_desc *desc)
+{
+ DRM_DEBUG_DRIVER("CT: desc %p reset head=%u tail=%u\n",
+ desc, desc->head, desc->tail);
+ desc->head = 0;
+ desc->tail = 0;
+ desc->is_in_error = 0;
+}
+
+static int guc_action_register_ct_buffer(struct intel_guc *guc,
+ u32 desc_addr,
+ u32 type)
+{
+ u32 action[] = {
+ INTEL_GUC_ACTION_REGISTER_COMMAND_TRANSPORT_BUFFER,
+ desc_addr,
+ sizeof(struct guc_ct_buffer_desc),
+ type
+ };
+ int err;
+
+ /* Can't use generic send(), CT registration must go over MMIO */
+ err = intel_guc_send_mmio(guc, action, ARRAY_SIZE(action));
+ if (err)
+ DRM_ERROR("CT: register %s buffer failed; err=%d\n",
+ guc_ct_buffer_type_to_str(type), err);
+ return err;
+}
+
+static int guc_action_deregister_ct_buffer(struct intel_guc *guc,
+ u32 owner,
+ u32 type)
+{
+ u32 action[] = {
+ INTEL_GUC_ACTION_DEREGISTER_COMMAND_TRANSPORT_BUFFER,
+ owner,
+ type
+ };
+ int err;
+
+ /* Can't use generic send(), CT deregistration must go over MMIO */
+ err = intel_guc_send_mmio(guc, action, ARRAY_SIZE(action));
+ if (err)
+ DRM_ERROR("CT: deregister %s buffer failed; owner=%d err=%d\n",
+ guc_ct_buffer_type_to_str(type), owner, err);
+ return err;
+}
+
+static bool ctch_is_open(struct intel_guc_ct_channel *ctch)
+{
+ return ctch->vma != NULL;
+}
+
+static int ctch_init(struct intel_guc *guc,
+ struct intel_guc_ct_channel *ctch)
+{
+ struct i915_vma *vma;
+ void *blob;
+ int err;
+ int i;
+
+ GEM_BUG_ON(ctch->vma);
+
+ /* We allocate 1 page to hold both descriptors and both buffers.
+ * ___________.....................
+ * |desc (SEND)| :
+ * |___________| PAGE/4
+ * :___________....................:
+ * |desc (RECV)| :
+ * |___________| PAGE/4
+ * :_______________________________:
+ * |cmds (SEND) |
+ * | PAGE/4
+ * |_______________________________|
+ * |cmds (RECV) |
+ * | PAGE/4
+ * |_______________________________|
+ *
+ * Each message can use a maximum of 32 dwords and we don't expect to
+ * have more than 1 in flight at any time, so we have enough space.
+ * Some logic further ahead will rely on the fact that there is only 1
+ * page and that it is always mapped, so if the size is changed the
+ * other code will need updating as well.
+ */
+
+ /* allocate vma */
+ vma = intel_guc_allocate_vma(guc, PAGE_SIZE);
+ if (IS_ERR(vma)) {
+ err = PTR_ERR(vma);
+ goto err_out;
+ }
+ ctch->vma = vma;
+
+ /* map first page */
+ blob = i915_gem_object_pin_map(vma->obj, I915_MAP_WB);
+ if (IS_ERR(blob)) {
+ err = PTR_ERR(blob);
+ goto err_vma;
+ }
+ DRM_DEBUG_DRIVER("CT: vma base=%#x\n", guc_ggtt_offset(ctch->vma));
+
+ /* store pointers to desc and cmds */
+ for (i = 0; i < ARRAY_SIZE(ctch->ctbs); i++) {
+ GEM_BUG_ON((i != CTB_SEND) && (i != CTB_RECV));
+ ctch->ctbs[i].desc = blob + PAGE_SIZE/4 * i;
+ ctch->ctbs[i].cmds = blob + PAGE_SIZE/4 * i + PAGE_SIZE/2;
+ }
+
+ return 0;
+
+err_vma:
+ i915_vma_unpin_and_release(&ctch->vma);
+err_out:
+ DRM_DEBUG_DRIVER("CT: channel %d initialization failed; err=%d\n",
+ ctch->owner, err);
+ return err;
+}
+
+static void ctch_fini(struct intel_guc *guc,
+ struct intel_guc_ct_channel *ctch)
+{
+ GEM_BUG_ON(!ctch->vma);
+
+ i915_gem_object_unpin_map(ctch->vma->obj);
+ i915_vma_unpin_and_release(&ctch->vma);
+}
+
+static int ctch_open(struct intel_guc *guc,
+ struct intel_guc_ct_channel *ctch)
+{
+ u32 base;
+ int err;
+ int i;
+
+ DRM_DEBUG_DRIVER("CT: channel %d reopen=%s\n",
+ ctch->owner, yesno(ctch_is_open(ctch)));
+
+ if (!ctch->vma) {
+ err = ctch_init(guc, ctch);
+ if (unlikely(err))
+ goto err_out;
+ }
+
+ /* vma should be already allocated and map'ed */
+ base = guc_ggtt_offset(ctch->vma);
+
+ /* (re)initialize descriptors
+ * cmds buffers are in the second half of the blob page
+ */
+ for (i = 0; i < ARRAY_SIZE(ctch->ctbs); i++) {
+ GEM_BUG_ON((i != CTB_SEND) && (i != CTB_RECV));
+ guc_ct_buffer_desc_init(ctch->ctbs[i].desc,
+ base + PAGE_SIZE/4 * i + PAGE_SIZE/2,
+ PAGE_SIZE/4,
+ ctch->owner);
+ }
+
+ /* register buffers, starting wirh RECV buffer
+ * descriptors are in first half of the blob
+ */
+ err = guc_action_register_ct_buffer(guc,
+ base + PAGE_SIZE/4 * CTB_RECV,
+ INTEL_GUC_CT_BUFFER_TYPE_RECV);
+ if (unlikely(err))
+ goto err_fini;
+
+ err = guc_action_register_ct_buffer(guc,
+ base + PAGE_SIZE/4 * CTB_SEND,
+ INTEL_GUC_CT_BUFFER_TYPE_SEND);
+ if (unlikely(err))
+ goto err_deregister;
+
+ return 0;
+
+err_deregister:
+ guc_action_deregister_ct_buffer(guc,
+ ctch->owner,
+ INTEL_GUC_CT_BUFFER_TYPE_RECV);
+err_fini:
+ ctch_fini(guc, ctch);
+err_out:
+ DRM_ERROR("CT: can't open channel %d; err=%d\n", ctch->owner, err);
+ return err;
+}
+
+static void ctch_close(struct intel_guc *guc,
+ struct intel_guc_ct_channel *ctch)
+{
+ GEM_BUG_ON(!ctch_is_open(ctch));
+
+ guc_action_deregister_ct_buffer(guc,
+ ctch->owner,
+ INTEL_GUC_CT_BUFFER_TYPE_SEND);
+ guc_action_deregister_ct_buffer(guc,
+ ctch->owner,
+ INTEL_GUC_CT_BUFFER_TYPE_RECV);
+ ctch_fini(guc, ctch);
+}
+
+static u32 ctch_get_next_fence(struct intel_guc_ct_channel *ctch)
+{
+ /* For now it's trivial */
+ return ++ctch->next_fence;
+}
+
+static int ctb_write(struct intel_guc_ct_buffer *ctb,
+ const u32 *action,
+ u32 len /* in dwords */,
+ u32 fence)
+{
+ struct guc_ct_buffer_desc *desc = ctb->desc;
+ u32 head = desc->head / 4; /* in dwords */
+ u32 tail = desc->tail / 4; /* in dwords */
+ u32 size = desc->size / 4; /* in dwords */
+ u32 used; /* in dwords */
+ u32 header;
+ u32 *cmds = ctb->cmds;
+ unsigned int i;
+
+ GEM_BUG_ON(desc->size % 4);
+ GEM_BUG_ON(desc->head % 4);
+ GEM_BUG_ON(desc->tail % 4);
+ GEM_BUG_ON(tail >= size);
+
+ /*
+ * tail == head condition indicates empty. GuC FW does not support
+ * using up the entire buffer to get tail == head meaning full.
+ */
+ if (tail < head)
+ used = (size - head) + tail;
+ else
+ used = tail - head;
+
+ /* make sure there is a space including extra dw for the fence */
+ if (unlikely(used + len + 1 >= size))
+ return -ENOSPC;
+
+ /* Write the message. The format is the following:
+ * DW0: header (including action code)
+ * DW1: fence
+ * DW2+: action data
+ */
+ header = (len << GUC_CT_MSG_LEN_SHIFT) |
+ (GUC_CT_MSG_WRITE_FENCE_TO_DESC) |
+ (action[0] << GUC_CT_MSG_ACTION_SHIFT);
+
+ cmds[tail] = header;
+ tail = (tail + 1) % size;
+
+ cmds[tail] = fence;
+ tail = (tail + 1) % size;
+
+ for (i = 1; i < len; i++) {
+ cmds[tail] = action[i];
+ tail = (tail + 1) % size;
+ }
+
+ /* now update desc tail (back in bytes) */
+ desc->tail = tail * 4;
+ GEM_BUG_ON(desc->tail > desc->size);
+
+ return 0;
+}
+
+/* Wait for the response from the GuC.
+ * @fence: response fence
+ * @status: placeholder for status
+ * return: 0 response received (status is valid)
+ * -ETIMEDOUT no response within hardcoded timeout
+ * -EPROTO no response, ct buffer was in error
+ */
+static int wait_for_response(struct guc_ct_buffer_desc *desc,
+ u32 fence,
+ u32 *status)
+{
+ int err;
+
+ /*
+ * Fast commands should complete in less than 10us, so sample quickly
+ * up to that length of time, then switch to a slower sleep-wait loop.
+ * No GuC command should ever take longer than 10ms.
+ */
+#define done (READ_ONCE(desc->fence) == fence)
+ err = wait_for_us(done, 10);
+ if (err)
+ err = wait_for(done, 10);
+#undef done
+
+ if (unlikely(err)) {
+ DRM_ERROR("CT: fence %u failed; reported fence=%u\n",
+ fence, desc->fence);
+
+ if (WARN_ON(desc->is_in_error)) {
+ /* Something went wrong with the messaging, try to reset
+ * the buffer and hope for the best
+ */
+ guc_ct_buffer_desc_reset(desc);
+ err = -EPROTO;
+ }
+ }
+
+ *status = desc->status;
+ return err;
+}
+
+static int ctch_send(struct intel_guc *guc,
+ struct intel_guc_ct_channel *ctch,
+ const u32 *action,
+ u32 len,
+ u32 *status)
+{
+ struct intel_guc_ct_buffer *ctb = &ctch->ctbs[CTB_SEND];
+ struct guc_ct_buffer_desc *desc = ctb->desc;
+ u32 fence;
+ int err;
+
+ GEM_BUG_ON(!ctch_is_open(ctch));
+ GEM_BUG_ON(!len);
+ GEM_BUG_ON(len & ~GUC_CT_MSG_LEN_MASK);
+
+ fence = ctch_get_next_fence(ctch);
+ err = ctb_write(ctb, action, len, fence);
+ if (unlikely(err))
+ return err;
+
+ intel_guc_notify(guc);
+
+ err = wait_for_response(desc, fence, status);
+ if (unlikely(err))
+ return err;
+ if (*status != INTEL_GUC_STATUS_SUCCESS)
+ return -EIO;
+ return 0;
+}
+
+/*
+ * Command Transport (CT) buffer based GuC send function.
+ */
+static int intel_guc_send_ct(struct intel_guc *guc, const u32 *action, u32 len)
+{
+ struct intel_guc_ct_channel *ctch = &guc->ct.host_channel;
+ u32 status = ~0; /* undefined */
+ int err;
+
+ mutex_lock(&guc->send_mutex);
+
+ err = ctch_send(guc, ctch, action, len, &status);
+ if (unlikely(err)) {
+ DRM_ERROR("CT: send action %#X failed; err=%d status=%#X\n",
+ action[0], err, status);
+ }
+
+ mutex_unlock(&guc->send_mutex);
+ return err;
+}
+
+/**
+ * Enable buffer based command transport
+ * Shall only be called for platforms with HAS_GUC_CT.
+ * @guc: the guc
+ * return: 0 on success
+ * non-zero on failure
+ */
+int intel_guc_enable_ct(struct intel_guc *guc)
+{
+ struct drm_i915_private *dev_priv = guc_to_i915(guc);
+ struct intel_guc_ct_channel *ctch = &guc->ct.host_channel;
+ int err;
+
+ GEM_BUG_ON(!HAS_GUC_CT(dev_priv));
+
+ err = ctch_open(guc, ctch);
+ if (unlikely(err))
+ return err;
+
+ /* Switch into cmd transport buffer based send() */
+ guc->send = intel_guc_send_ct;
+ DRM_INFO("CT: %s\n", enableddisabled(true));
+ return 0;
+}
+
+/**
+ * Disable buffer based command transport.
+ * Shall only be called for platforms with HAS_GUC_CT.
+ * @guc: the guc
+ */
+void intel_guc_disable_ct(struct intel_guc *guc)
+{
+ struct drm_i915_private *dev_priv = guc_to_i915(guc);
+ struct intel_guc_ct_channel *ctch = &guc->ct.host_channel;
+
+ GEM_BUG_ON(!HAS_GUC_CT(dev_priv));
+
+ if (!ctch_is_open(ctch))
+ return;
+
+ ctch_close(guc, ctch);
+
+ /* Disable send */
+ guc->send = intel_guc_send_nop;
+ DRM_INFO("CT: %s\n", enableddisabled(false));
+}
--- /dev/null
+/*
+ * Copyright © 2016-2017 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#ifndef _INTEL_GUC_CT_H_
+#define _INTEL_GUC_CT_H_
+
+struct intel_guc;
+struct i915_vma;
+
+#include "intel_guc_fwif.h"
+
+/**
+ * DOC: Command Transport (CT).
+ *
+ * Buffer based command transport is a replacement for MMIO based mechanism.
+ * It can be used to perform both host-2-guc and guc-to-host communication.
+ */
+
+/** Represents single command transport buffer.
+ *
+ * A single command transport buffer consists of two parts, the header
+ * record (command transport buffer descriptor) and the actual buffer which
+ * holds the commands.
+ *
+ * @desc: pointer to the buffer descriptor
+ * @cmds: pointer to the commands buffer
+ */
+struct intel_guc_ct_buffer {
+ struct guc_ct_buffer_desc *desc;
+ u32 *cmds;
+};
+
+/** Represents pair of command transport buffers.
+ *
+ * Buffers go in pairs to allow bi-directional communication.
+ * To simplify the code we place both of them in the same vma.
+ * Buffers from the same pair must share unique owner id.
+ *
+ * @vma: pointer to the vma with pair of CT buffers
+ * @ctbs: buffers for sending(0) and receiving(1) commands
+ * @owner: unique identifier
+ * @next_fence: fence to be used with next send command
+ */
+struct intel_guc_ct_channel {
+ struct i915_vma *vma;
+ struct intel_guc_ct_buffer ctbs[2];
+ u32 owner;
+ u32 next_fence;
+};
+
+/** Holds all command transport channels.
+ *
+ * @host_channel: main channel used by the host
+ */
+struct intel_guc_ct {
+ struct intel_guc_ct_channel host_channel;
+ /* other channels are tbd */
+};
+
+void intel_guc_ct_init_early(struct intel_guc_ct *ct);
+
+/* XXX: move to intel_uc.h ? don't fit there either */
+int intel_guc_enable_ct(struct intel_guc *guc);
+void intel_guc_disable_ct(struct intel_guc *guc);
+
+#endif /* _INTEL_GUC_CT_H_ */