new file mode 100644
@@ -0,0 +1,1952 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+/* Copyright (c) 2019-2021, The Linux Foundation. All rights reserved. */
+/* Copyright (c) 2021-2023 Qualcomm Innovation Center, Inc. All rights reserved. */
+
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/dma-buf.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/kref.h>
+#include <linux/list.h>
+#include <linux/mm.h>
+#include <linux/moduleparam.h>
+#include <linux/scatterlist.h>
+#include <linux/spinlock.h>
+#include <linux/srcu.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <linux/wait.h>
+#include <drm/drm_file.h>
+#include <drm/drm_gem.h>
+#include <drm/drm_print.h>
+#include <uapi/drm/qaic_accel.h>
+
+#include "qaic.h"
+
+#define SEM_VAL_MASK GENMASK_ULL(11, 0)
+#define SEM_INDEX_MASK GENMASK_ULL(4, 0)
+#define BULK_XFER BIT(3)
+#define GEN_COMPLETION BIT(4)
+#define INBOUND_XFER 1
+#define OUTBOUND_XFER 2
+#define REQHP_OFF 0x0 /* we read this */
+#define REQTP_OFF 0x4 /* we write this */
+#define RSPHP_OFF 0x8 /* we write this */
+#define RSPTP_OFF 0xc /* we read this */
+
+#define ENCODE_SEM(val, index, sync, cmd, flags) \
+ ((val) | \
+ (index) << 16 | \
+ (sync) << 22 | \
+ (cmd) << 24 | \
+ ((cmd) ? BIT(31) : 0) | \
+ (((flags) & SEM_INSYNCFENCE) ? BIT(30) : 0) | \
+ (((flags) & SEM_OUTSYNCFENCE) ? BIT(29) : 0))
+#define NUM_EVENTS 128
+#define NUM_DELAYS 10
+
+static unsigned int wait_exec_default_timeout = 5000; /* 5 sec default */
+module_param(wait_exec_default_timeout, uint, 0600);
+
+static unsigned int datapath_poll_interval_us = 100; /* 100 usec default */
+module_param(datapath_poll_interval_us, uint, 0600);
+
+struct dbc_req { /* everything must be little endian encoded */
+ /*
+ * A request ID is assigned to each memory handle going in DMA queue.
+ * As a single memory handle can enqueue multiple elements in DMA queue
+ * all of them will have the same request ID.
+ */
+ __le16 req_id;
+ /* Future use */
+ __u8 seq_id;
+ /*
+ * Special encoded variable
+ * 7 0 - Do not force to generate MSI after DMA is completed
+ * 1 - Force to generate MSI after DMA is completed
+ * 6:5 Reserved
+ * 4 1 - Generate completion element in the response queue
+ * 0 - No Completion Code
+ * 3 0 - DMA request is a Link list transfer
+ * 1 - DMA request is a Bulk transfer
+ * 2 Reserved
+ * 1:0 00 - No DMA transfer involved
+ * 01 - DMA transfer is part of inbound transfer
+ * 10 - DMA transfer has outbound transfer
+ * 11 - NA
+ */
+ __u8 cmd;
+ __le32 resv;
+ /* Source address for the transfer */
+ __le64 src_addr;
+ /* Destination address for the transfer */
+ __le64 dest_addr;
+ /* Length of transfer request */
+ __le32 len;
+ __le32 resv2;
+ /* Doorbell address */
+ __le64 db_addr;
+ /*
+ * Special encoded variable
+ * 7 1 - Doorbell(db) write
+ * 0 - No doorbell write
+ * 6:2 Reserved
+ * 1:0 00 - 32 bit access, db address must be aligned to 32bit-boundary
+ * 01 - 16 bit access, db address must be aligned to 16bit-boundary
+ * 10 - 8 bit access, db address must be aligned to 8bit-boundary
+ * 11 - Reserved
+ */
+ __u8 db_len;
+ __u8 resv3;
+ __le16 resv4;
+ /* 32 bit data written to doorbell address */
+ __le32 db_data;
+ /*
+ * Special encoded variable
+ * All the fields of sem_cmdX are passed from user and all are ORed
+ * together to form sem_cmd.
+ * 0:11 Semaphore value
+ * 15:12 Reserved
+ * 20:16 Semaphore index
+ * 21 Reserved
+ * 22 Semaphore Sync
+ * 23 Reserved
+ * 26:24 Semaphore command
+ * 28:27 Reserved
+ * 29 Semaphore DMA out bound sync fence
+ * 30 Semaphore DMA in bound sync fence
+ * 31 Enable semaphore command
+ */
+ __le32 sem_cmd0;
+ __le32 sem_cmd1;
+ __le32 sem_cmd2;
+ __le32 sem_cmd3;
+} __packed;
+
+struct dbc_rsp { /* everything must be little endian encoded */
+ /* Request ID of the memory handle whose DMA transaction is completed */
+ __le16 req_id;
+ /* Status of the DMA transaction. 0 : Success otherwise failure */
+ __le16 status;
+} __packed;
+
+inline int get_dbc_req_elem_size(void)
+{
+ return sizeof(struct dbc_req);
+}
+
+inline int get_dbc_rsp_elem_size(void)
+{
+ return sizeof(struct dbc_rsp);
+}
+
+static int reserve_pages(unsigned long start_pfn, unsigned long nr_pages,
+ bool reserve)
+{
+ unsigned long pfn;
+ unsigned long end_pfn = start_pfn + nr_pages;
+ struct page *page;
+
+ for (pfn = start_pfn; pfn < end_pfn; pfn++) {
+ if (!pfn_valid(pfn))
+ return -EINVAL;
+ page = pfn_to_page(pfn);
+ if (reserve)
+ SetPageReserved(page);
+ else
+ ClearPageReserved(page);
+ }
+ return 0;
+}
+
+static void free_slice(struct kref *kref)
+{
+ struct bo_slice *slice = container_of(kref, struct bo_slice, ref_count);
+
+ list_del(&slice->slice);
+ drm_gem_object_put(&slice->bo->base);
+ sg_free_table(slice->sgt);
+ kfree(slice->sgt);
+ kfree(slice->reqs);
+ kfree(slice);
+}
+
+static int copy_sgt(struct qaic_device *qdev, struct sg_table **sgt_out,
+ struct sg_table *sgt_in, u64 size, u64 offset)
+{
+ int total_len, len, nents, offf = 0, offl = 0;
+ struct scatterlist *sg, *sgn, *sgf, *sgl;
+ struct sg_table *sgt;
+ int ret, j;
+
+ /* find out number of relevant nents needed for this mem */
+ total_len = 0;
+ sgf = NULL;
+ sgl = NULL;
+ nents = 0;
+
+ size = size ? size : PAGE_SIZE;
+ for (sg = sgt_in->sgl; sg; sg = sg_next(sg)) {
+ len = sg_dma_len(sg);
+
+ if (!len)
+ continue;
+ if (offset >= total_len && offset < total_len + len) {
+ sgf = sg;
+ offf = offset - total_len;
+ }
+ if (sgf)
+ nents++;
+ if (offset + size >= total_len &&
+ offset + size <= total_len + len) {
+ sgl = sg;
+ offl = offset + size - total_len;
+ break;
+ }
+ total_len += len;
+ }
+
+ if (!sgf || !sgl) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
+ if (!sgt) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ret = sg_alloc_table(sgt, nents, GFP_KERNEL);
+ if (ret)
+ goto free_sgt;
+
+ /* copy relevant sg node and fix page and length */
+ sgn = sgf;
+ for_each_sgtable_sg(sgt, sg, j) {
+ memcpy(sg, sgn, sizeof(*sg));
+ if (sgn == sgf) {
+ sg_dma_address(sg) += offf;
+ sg_dma_len(sg) -= offf;
+ sg_set_page(sg, sg_page(sgn),
+ sg_dma_len(sg), offf);
+ } else {
+ offf = 0;
+ }
+ if (sgn == sgl) {
+ sg_dma_len(sg) = offl - offf;
+ sg_set_page(sg, sg_page(sgn),
+ offl - offf, offf);
+ sg_mark_end(sg);
+ break;
+ }
+ sgn = sg_next(sgn);
+ }
+
+ *sgt_out = sgt;
+ return ret;
+
+free_sgt:
+ kfree(sgt);
+out:
+ *sgt_out = NULL;
+ return ret;
+}
+
+static int encode_reqs(struct qaic_device *qdev, struct bo_slice *slice,
+ struct qaic_attach_slice_entry *req)
+{
+ __u8 cmd = BULK_XFER;
+ __le64 db_addr = cpu_to_le64(req->db_addr);
+ __u8 db_len;
+ __le32 db_data = cpu_to_le32(req->db_data);
+ struct scatterlist *sg;
+ u64 dev_addr;
+ int presync_sem;
+ int i;
+
+ if (!slice->no_xfer)
+ cmd |= (slice->dir == DMA_TO_DEVICE ? INBOUND_XFER :
+ OUTBOUND_XFER);
+
+ if (req->db_len && !IS_ALIGNED(req->db_addr, req->db_len / 8))
+ return -EINVAL;
+
+ presync_sem = req->sem0.presync + req->sem1.presync +
+ req->sem2.presync + req->sem3.presync;
+ if (presync_sem > 1)
+ return -EINVAL;
+
+ presync_sem = req->sem0.presync << 0 | req->sem1.presync << 1 |
+ req->sem2.presync << 2 | req->sem3.presync << 3;
+
+ switch (req->db_len) {
+ case 32:
+ db_len = BIT(7);
+ break;
+ case 16:
+ db_len = BIT(7) | 1;
+ break;
+ case 8:
+ db_len = BIT(7) | 2;
+ break;
+ case 0:
+ db_len = 0; /* doorbell is not active for this command */
+ break;
+ default:
+ return -EINVAL; /* should never hit this */
+ }
+
+ /*
+ * When we end up splitting up a single request (ie a buf slice) into
+ * multiple DMA requests, we have to manage the sync data carefully.
+ * There can only be one presync sem. That needs to be on every xfer
+ * so that the DMA engine doesn't transfer data before the receiver is
+ * ready. We only do the doorbell and postsync sems after the xfer.
+ * To guarantee previous xfers for the request are complete, we use a
+ * fence.
+ */
+ dev_addr = req->dev_addr;
+ for_each_sgtable_sg(slice->sgt, sg, i) {
+ slice->reqs[i].cmd = cmd;
+ slice->reqs[i].src_addr =
+ cpu_to_le64(slice->dir == DMA_TO_DEVICE ?
+ sg_dma_address(sg) : dev_addr);
+ slice->reqs[i].dest_addr =
+ cpu_to_le64(slice->dir == DMA_TO_DEVICE ?
+ dev_addr : sg_dma_address(sg));
+ /*
+ * sg_dma_len(sg) returns size of a DMA segment, maximum DMA
+ * segment size is set to UINT_MAX by qaic and hence return
+ * values of sg_dma_len(sg) can never exceed u32 range. So,
+ * by down sizing we are not corrupting the value.
+ */
+ slice->reqs[i].len = cpu_to_le32((u32)sg_dma_len(sg));
+ switch (presync_sem) {
+ case BIT(0):
+ slice->reqs[i].sem_cmd0 = cpu_to_le32(ENCODE_SEM(req->sem0.val,
+ req->sem0.index,
+ req->sem0.presync,
+ req->sem0.cmd,
+ req->sem0.flags));
+ break;
+ case BIT(1):
+ slice->reqs[i].sem_cmd1 = cpu_to_le32(ENCODE_SEM(req->sem1.val,
+ req->sem1.index,
+ req->sem1.presync,
+ req->sem1.cmd,
+ req->sem1.flags));
+ break;
+ case BIT(2):
+ slice->reqs[i].sem_cmd2 = cpu_to_le32(ENCODE_SEM(req->sem2.val,
+ req->sem2.index,
+ req->sem2.presync,
+ req->sem2.cmd,
+ req->sem2.flags));
+ break;
+ case BIT(3):
+ slice->reqs[i].sem_cmd3 = cpu_to_le32(ENCODE_SEM(req->sem3.val,
+ req->sem3.index,
+ req->sem3.presync,
+ req->sem3.cmd,
+ req->sem3.flags));
+ break;
+ }
+ dev_addr += sg_dma_len(sg);
+ }
+ /* add post transfer stuff to last segment */
+ i--;
+ slice->reqs[i].cmd |= GEN_COMPLETION;
+ slice->reqs[i].db_addr = db_addr;
+ slice->reqs[i].db_len = db_len;
+ slice->reqs[i].db_data = db_data;
+ /*
+ * Add a fence if we have more than one request going to the hardware
+ * representing the entirety of the user request, and the user request
+ * has no presync condition.
+ * Fences are expensive, so we try to avoid them. We rely on the
+ * hardware behavior to avoid needing one when there is a presync
+ * condition. When a presync exists, all requests for that same
+ * presync will be queued into a fifo. Thus, since we queue the
+ * post xfer activity only on the last request we queue, the hardware
+ * will ensure that the last queued request is processed last, thus
+ * making sure the post xfer activity happens at the right time without
+ * a fence.
+ */
+ if (i && !presync_sem)
+ req->sem0.flags |= (slice->dir == DMA_TO_DEVICE ?
+ SEM_INSYNCFENCE : SEM_OUTSYNCFENCE);
+ slice->reqs[i].sem_cmd0 = cpu_to_le32(ENCODE_SEM(req->sem0.val,
+ req->sem0.index,
+ req->sem0.presync,
+ req->sem0.cmd,
+ req->sem0.flags));
+ slice->reqs[i].sem_cmd1 = cpu_to_le32(ENCODE_SEM(req->sem1.val,
+ req->sem1.index,
+ req->sem1.presync,
+ req->sem1.cmd,
+ req->sem1.flags));
+ slice->reqs[i].sem_cmd2 = cpu_to_le32(ENCODE_SEM(req->sem2.val,
+ req->sem2.index,
+ req->sem2.presync,
+ req->sem2.cmd,
+ req->sem2.flags));
+ slice->reqs[i].sem_cmd3 = cpu_to_le32(ENCODE_SEM(req->sem3.val,
+ req->sem3.index,
+ req->sem3.presync,
+ req->sem3.cmd,
+ req->sem3.flags));
+
+ return 0;
+}
+
+static int qaic_map_one_slice(struct qaic_device *qdev, struct qaic_bo *bo,
+ struct qaic_attach_slice_entry *slice_ent)
+{
+ struct sg_table *sgt = NULL;
+ struct bo_slice *slice;
+ int ret;
+
+ ret = copy_sgt(qdev, &sgt, bo->sgt, slice_ent->size, slice_ent->offset);
+ if (ret)
+ goto out;
+
+ slice = kmalloc(sizeof(*slice), GFP_KERNEL);
+ if (!slice) {
+ ret = -ENOMEM;
+ goto free_sgt;
+ }
+
+ slice->reqs = kcalloc(sgt->nents, sizeof(*slice->reqs), GFP_KERNEL);
+ if (!slice->reqs) {
+ ret = -ENOMEM;
+ goto free_slice;
+ }
+
+ slice->no_xfer = !slice_ent->size;
+ slice->sgt = sgt;
+ slice->nents = sgt->nents;
+ slice->dir = bo->dir;
+ slice->bo = bo;
+ slice->size = slice_ent->size;
+ slice->offset = slice_ent->offset;
+
+ ret = encode_reqs(qdev, slice, slice_ent);
+ if (ret)
+ goto free_req;
+
+ bo->total_slice_nents += sgt->nents;
+ kref_init(&slice->ref_count);
+ drm_gem_object_get(&bo->base);
+ list_add_tail(&slice->slice, &bo->slices);
+
+ return 0;
+
+free_req:
+ kfree(slice->reqs);
+free_slice:
+ kfree(slice);
+free_sgt:
+ sg_free_table(sgt);
+ kfree(sgt);
+out:
+ return ret;
+}
+
+static int create_sgt(struct qaic_device *qdev, struct sg_table **sgt_out,
+ u64 size)
+{
+ struct scatterlist *sg;
+ struct sg_table *sgt;
+ struct page **pages;
+ int *pages_order;
+ int buf_extra;
+ int max_order;
+ int nr_pages;
+ int ret = 0;
+ int i, j, k;
+ int order;
+
+ if (size) {
+ nr_pages = DIV_ROUND_UP(size, PAGE_SIZE);
+ /*
+ * calculate how much extra we are going to allocate, to remove
+ * later
+ */
+ buf_extra = (PAGE_SIZE - size % PAGE_SIZE) % PAGE_SIZE;
+ max_order = min(MAX_ORDER - 1, get_order(size));
+ } else {
+ /* allocate a single page for book keeping */
+ nr_pages = 1;
+ buf_extra = 0;
+ max_order = 0;
+ }
+
+ pages = kvmalloc_array(nr_pages, sizeof(*pages) + sizeof(*pages_order), GFP_KERNEL);
+ if (!pages) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ pages_order = (void *)pages + sizeof(*pages) * nr_pages;
+
+ /*
+ * Allocate requested memory using alloc_pages. It is possible to allocate
+ * the requested memory in multiple chunks by calling alloc_pages
+ * multiple times. Use SG table to handle multiple allocated pages.
+ */
+ i = 0;
+ while (nr_pages > 0) {
+ order = min(get_order(nr_pages * PAGE_SIZE), max_order);
+ while (1) {
+ pages[i] = alloc_pages(GFP_KERNEL | GFP_HIGHUSER |
+ __GFP_NOWARN | __GFP_ZERO |
+ (order ? __GFP_NORETRY : __GFP_RETRY_MAYFAIL),
+ order);
+ if (pages[i])
+ break;
+ if (!order--) {
+ ret = -ENOMEM;
+ goto free_partial_alloc;
+ }
+ }
+
+ max_order = order;
+ pages_order[i] = order;
+
+ nr_pages -= 1 << order;
+ if (nr_pages <= 0)
+ /* account for over allocation */
+ buf_extra += abs(nr_pages) * PAGE_SIZE;
+ i++;
+ }
+
+ sgt = kmalloc(sizeof(*sgt), GFP_KERNEL);
+ if (!sgt) {
+ ret = -ENOMEM;
+ goto free_partial_alloc;
+ }
+
+ if (sg_alloc_table(sgt, i, GFP_KERNEL)) {
+ ret = -ENOMEM;
+ goto free_sgt;
+ }
+
+ /* Populate the SG table with the allocated memory pages */
+ sg = sgt->sgl;
+ for (k = 0; k < i; k++, sg = sg_next(sg)) {
+ /* Last entry requires special handling */
+ if (k < i - 1) {
+ sg_set_page(sg, pages[k], PAGE_SIZE << pages_order[k], 0);
+ } else {
+ sg_set_page(sg, pages[k],
+ (PAGE_SIZE << pages_order[k]) - buf_extra, 0);
+ sg_mark_end(sg);
+ }
+
+ ret = reserve_pages(page_to_pfn(pages[k]), DIV_ROUND_UP(sg->length, PAGE_SIZE),
+ true);
+ if (ret)
+ goto clear_pages;
+ }
+
+ kvfree(pages);
+ *sgt_out = sgt;
+ return ret;
+
+clear_pages:
+ for (j = 0; j < k; j++)
+ ret = reserve_pages(page_to_pfn(pages[j]), 1 << pages_order[j],
+ false);
+ sg_free_table(sgt);
+free_sgt:
+ kfree(sgt);
+free_partial_alloc:
+ for (j = 0; j < i; j++)
+ __free_pages(pages[j], pages_order[j]);
+ kvfree(pages);
+out:
+ *sgt_out = NULL;
+ return ret;
+}
+
+static bool invalid_sem(struct qaic_sem *sem)
+{
+ if (sem->val & ~SEM_VAL_MASK || sem->index & ~SEM_INDEX_MASK ||
+ !(sem->presync == 0 || sem->presync == 1) || sem->pad ||
+ sem->flags & ~(SEM_INSYNCFENCE | SEM_OUTSYNCFENCE) ||
+ sem->cmd > SEM_WAIT_GT_0)
+ return true;
+ return false;
+}
+
+static int qaic_validate_req(struct qaic_device *qdev,
+ struct qaic_attach_slice_entry *slice_ent,
+ u32 count, u64 total_size)
+{
+ int i;
+
+ for (i = 0; i < count; i++) {
+ if (!(slice_ent[i].db_len == 32 || slice_ent[i].db_len == 16 ||
+ slice_ent[i].db_len == 8 || slice_ent[i].db_len == 0) ||
+ invalid_sem(&slice_ent[i].sem0) ||
+ invalid_sem(&slice_ent[i].sem1) ||
+ invalid_sem(&slice_ent[i].sem2) ||
+ invalid_sem(&slice_ent[i].sem3))
+ return -EINVAL;
+
+ if (slice_ent[i].offset + slice_ent[i].size > total_size)
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void qaic_free_sgt(struct sg_table *sgt)
+{
+ struct scatterlist *sg;
+
+ for (sg = sgt->sgl; sg; sg = sg_next(sg))
+ if (sg_page(sg)) {
+ reserve_pages(page_to_pfn(sg_page(sg)),
+ DIV_ROUND_UP(sg->length, PAGE_SIZE), false);
+ __free_pages(sg_page(sg), get_order(sg->length));
+ }
+ sg_free_table(sgt);
+ kfree(sgt);
+}
+
+static void qaic_gem_print_info(struct drm_printer *p, unsigned int indent,
+ const struct drm_gem_object *obj)
+{
+ struct qaic_bo *bo = to_qaic_bo(obj);
+
+ drm_printf_indent(p, indent, "user requested size=%llu\n", bo->size);
+}
+
+static const struct vm_operations_struct drm_vm_ops = {
+ .open = drm_gem_vm_open,
+ .close = drm_gem_vm_close,
+};
+
+static int qaic_gem_object_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
+{
+ struct qaic_bo *bo = to_qaic_bo(obj);
+ unsigned long offset = 0;
+ struct scatterlist *sg;
+ int ret;
+
+ if (obj->import_attach)
+ return -EINVAL;
+
+ for (sg = bo->sgt->sgl; sg; sg = sg_next(sg)) {
+ if (sg_page(sg)) {
+ ret = remap_pfn_range(vma, vma->vm_start + offset,
+ page_to_pfn(sg_page(sg)),
+ sg->length, vma->vm_page_prot);
+ if (ret)
+ goto out;
+ offset += sg->length;
+ }
+ }
+
+out:
+ return ret;
+}
+
+static void qaic_free_object(struct drm_gem_object *obj)
+{
+ struct qaic_bo *bo = to_qaic_bo(obj);
+
+ if (obj->import_attach) {
+ /* DMABUF/PRIME Path */
+ dma_buf_detach(obj->import_attach->dmabuf, obj->import_attach);
+ dma_buf_put(obj->import_attach->dmabuf);
+ } else {
+ /* Private buffer allocation path */
+ qaic_free_sgt(bo->sgt);
+ }
+
+ drm_gem_object_release(obj);
+ kfree(bo);
+}
+
+static const struct drm_gem_object_funcs qaic_gem_funcs = {
+ .free = qaic_free_object,
+ .print_info = qaic_gem_print_info,
+ .mmap = qaic_gem_object_mmap,
+ .vm_ops = &drm_vm_ops,
+};
+
+static struct qaic_bo *qaic_alloc_init_bo(void)
+{
+ struct qaic_bo *bo;
+
+ bo = kzalloc(sizeof(*bo), GFP_KERNEL);
+ if (!bo)
+ return ERR_PTR(-ENOMEM);
+
+ INIT_LIST_HEAD(&bo->slices);
+ init_completion(&bo->xfer_done);
+ complete_all(&bo->xfer_done);
+
+ return bo;
+}
+
+int qaic_create_bo_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file_priv)
+{
+ struct qaic_create_bo *args = data;
+ int usr_rcu_id, qdev_rcu_id;
+ struct drm_gem_object *obj;
+ struct qaic_device *qdev;
+ struct qaic_user *usr;
+ struct qaic_bo *bo;
+ size_t size;
+ int ret;
+
+ if (args->pad)
+ return -EINVAL;
+
+ usr = file_priv->driver_priv;
+ usr_rcu_id = srcu_read_lock(&usr->qddev_lock);
+ if (!usr->qddev) {
+ ret = -ENODEV;
+ goto unlock_usr_srcu;
+ }
+
+ qdev = usr->qddev->qdev;
+ qdev_rcu_id = srcu_read_lock(&qdev->dev_lock);
+ if (qdev->in_reset) {
+ ret = -ENODEV;
+ goto unlock_dev_srcu;
+ }
+
+ size = PAGE_ALIGN(args->size);
+ if (size == 0) {
+ ret = -EINVAL;
+ goto unlock_dev_srcu;
+ }
+
+ bo = qaic_alloc_init_bo();
+ if (IS_ERR(bo)) {
+ ret = PTR_ERR(bo);
+ goto unlock_dev_srcu;
+ }
+ obj = &bo->base;
+
+ drm_gem_private_object_init(dev, obj, size);
+
+ obj->funcs = &qaic_gem_funcs;
+ ret = create_sgt(qdev, &bo->sgt, size);
+ if (ret)
+ goto free_bo;
+
+ bo->size = args->size;
+
+ ret = drm_gem_handle_create(file_priv, obj, &args->handle);
+ if (ret)
+ goto free_sgt;
+
+ bo->handle = args->handle;
+ drm_gem_object_put(obj);
+ srcu_read_unlock(&qdev->dev_lock, qdev_rcu_id);
+ srcu_read_unlock(&usr->qddev_lock, usr_rcu_id);
+
+ return 0;
+
+free_sgt:
+ qaic_free_sgt(bo->sgt);
+free_bo:
+ kfree(bo);
+unlock_dev_srcu:
+ srcu_read_unlock(&qdev->dev_lock, qdev_rcu_id);
+unlock_usr_srcu:
+ srcu_read_unlock(&usr->qddev_lock, usr_rcu_id);
+ return ret;
+}
+
+int qaic_mmap_bo_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file_priv)
+{
+ struct qaic_mmap_bo *args = data;
+ int usr_rcu_id, qdev_rcu_id;
+ struct drm_gem_object *obj;
+ struct qaic_device *qdev;
+ struct qaic_user *usr;
+ int ret;
+
+ usr = file_priv->driver_priv;
+ usr_rcu_id = srcu_read_lock(&usr->qddev_lock);
+ if (!usr->qddev) {
+ ret = -ENODEV;
+ goto unlock_usr_srcu;
+ }
+
+ qdev = usr->qddev->qdev;
+ qdev_rcu_id = srcu_read_lock(&qdev->dev_lock);
+ if (qdev->in_reset) {
+ ret = -ENODEV;
+ goto unlock_dev_srcu;
+ }
+
+ obj = drm_gem_object_lookup(file_priv, args->handle);
+ if (!obj) {
+ ret = -ENOENT;
+ goto unlock_dev_srcu;
+ }
+
+ ret = drm_gem_create_mmap_offset(obj);
+ if (ret == 0)
+ args->offset = drm_vma_node_offset_addr(&obj->vma_node);
+
+ drm_gem_object_put(obj);
+
+unlock_dev_srcu:
+ srcu_read_unlock(&qdev->dev_lock, qdev_rcu_id);
+unlock_usr_srcu:
+ srcu_read_unlock(&usr->qddev_lock, usr_rcu_id);
+ return ret;
+}
+
+struct drm_gem_object *qaic_gem_prime_import(struct drm_device *dev,
+ struct dma_buf *dma_buf)
+{
+ struct dma_buf_attachment *attach;
+ struct drm_gem_object *obj;
+ struct qaic_bo *bo;
+ size_t size;
+ int ret;
+
+ bo = qaic_alloc_init_bo();
+ if (IS_ERR(bo)) {
+ ret = PTR_ERR(bo);
+ goto out;
+ }
+
+ obj = &bo->base;
+ get_dma_buf(dma_buf);
+
+ attach = dma_buf_attach(dma_buf, dev->dev);
+ if (IS_ERR(attach)) {
+ ret = PTR_ERR(attach);
+ goto attach_fail;
+ }
+
+ size = PAGE_ALIGN(attach->dmabuf->size);
+ if (size == 0) {
+ ret = -EINVAL;
+ goto size_align_fail;
+ }
+
+ drm_gem_private_object_init(dev, obj, size);
+ /*
+ * skipping dma_buf_map_attachment() as we do not know the direction
+ * just yet. Once the direction is known in the subsequent IOCTL to
+ * attach slicing, we can do it then.
+ */
+
+ obj->funcs = &qaic_gem_funcs;
+ obj->import_attach = attach;
+ obj->resv = dma_buf->resv;
+
+ return obj;
+
+size_align_fail:
+ dma_buf_detach(dma_buf, attach);
+attach_fail:
+ dma_buf_put(dma_buf);
+ kfree(bo);
+out:
+ return ERR_PTR(ret);
+}
+
+static int qaic_prepare_import_bo(struct qaic_bo *bo,
+ struct qaic_attach_slice_hdr *hdr)
+{
+ struct drm_gem_object *obj = &bo->base;
+ struct sg_table *sgt;
+ int ret;
+
+ if (obj->import_attach->dmabuf->size < hdr->size)
+ return -EINVAL;
+
+ sgt = dma_buf_map_attachment(obj->import_attach, hdr->dir);
+ if (IS_ERR(sgt)) {
+ ret = PTR_ERR(sgt);
+ return ret;
+ }
+
+ bo->sgt = sgt;
+ bo->size = hdr->size;
+
+ return 0;
+}
+
+static int qaic_prepare_export_bo(struct qaic_device *qdev, struct qaic_bo *bo,
+ struct qaic_attach_slice_hdr *hdr)
+{
+ int ret;
+
+ if (bo->size != hdr->size)
+ return -EINVAL;
+
+ ret = dma_map_sgtable(&qdev->pdev->dev, bo->sgt, hdr->dir, 0);
+ if (ret)
+ return -EFAULT;
+
+ return 0;
+}
+
+static int qaic_prepare_bo(struct qaic_device *qdev, struct qaic_bo *bo,
+ struct qaic_attach_slice_hdr *hdr)
+{
+ int ret;
+
+ if (bo->base.import_attach)
+ ret = qaic_prepare_import_bo(bo, hdr);
+ else
+ ret = qaic_prepare_export_bo(qdev, bo, hdr);
+
+ if (ret == 0)
+ bo->dir = hdr->dir;
+
+ return ret;
+}
+
+static void qaic_unprepare_import_bo(struct qaic_bo *bo)
+{
+ dma_buf_unmap_attachment(bo->base.import_attach, bo->sgt, bo->dir);
+ bo->sgt = NULL;
+ bo->size = 0;
+}
+
+static void qaic_unprepare_export_bo(struct qaic_device *qdev, struct qaic_bo *bo)
+{
+ dma_unmap_sgtable(&qdev->pdev->dev, bo->sgt, bo->dir, 0);
+}
+
+static void qaic_unprepare_bo(struct qaic_device *qdev, struct qaic_bo *bo)
+{
+ if (bo->base.import_attach)
+ qaic_unprepare_import_bo(bo);
+ else
+ qaic_unprepare_export_bo(qdev, bo);
+
+ bo->dir = 0;
+}
+
+static void qaic_free_slices_bo(struct qaic_bo *bo)
+{
+ struct bo_slice *slice, *temp;
+
+ list_for_each_entry_safe(slice, temp, &bo->slices, slice) {
+ kref_put(&slice->ref_count, free_slice);
+ }
+}
+
+static int qaic_attach_slicing_bo(struct qaic_device *qdev,
+ struct qaic_bo *bo,
+ struct qaic_attach_slice_hdr *hdr,
+ struct qaic_attach_slice_entry *slice_ent)
+{
+ int ret, i;
+
+ for (i = 0; i < hdr->count; i++) {
+ ret = qaic_map_one_slice(qdev, bo, &slice_ent[i]);
+ if (ret) {
+ qaic_free_slices_bo(bo);
+ return ret;
+ }
+ }
+
+ if (bo->total_slice_nents > qdev->dbc[hdr->dbc_id].nelem) {
+ qaic_free_slices_bo(bo);
+ return -ENOSPC;
+ }
+
+ bo->sliced = true;
+ bo->nr_slice = hdr->count;
+ list_add_tail(&bo->bo_list, &qdev->dbc[hdr->dbc_id].bo_lists);
+
+ return 0;
+}
+
+int qaic_attach_slice_bo_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file_priv)
+{
+ struct qaic_attach_slice_entry *slice_ent;
+ struct qaic_attach_slice *args = data;
+ struct dma_bridge_chan *dbc;
+ int usr_rcu_id, qdev_rcu_id;
+ struct drm_gem_object *obj;
+ struct qaic_device *qdev;
+ unsigned long arg_size;
+ struct qaic_user *usr;
+ u8 __user *user_data;
+ struct qaic_bo *bo;
+ int ret;
+
+ usr = file_priv->driver_priv;
+ usr_rcu_id = srcu_read_lock(&usr->qddev_lock);
+ if (!usr->qddev) {
+ ret = -ENODEV;
+ goto unlock_usr_srcu;
+ }
+
+ qdev = usr->qddev->qdev;
+ qdev_rcu_id = srcu_read_lock(&qdev->dev_lock);
+ if (qdev->in_reset) {
+ ret = -ENODEV;
+ goto unlock_dev_srcu;
+ }
+
+ if (args->hdr.count == 0) {
+ ret = -EINVAL;
+ goto unlock_dev_srcu;
+ }
+
+ arg_size = args->hdr.count * sizeof(*slice_ent);
+ if (arg_size / args->hdr.count != sizeof(*slice_ent)) {
+ ret = -EINVAL;
+ goto unlock_dev_srcu;
+ }
+
+ if (args->hdr.dbc_id >= qdev->num_dbc) {
+ ret = -EINVAL;
+ goto unlock_dev_srcu;
+ }
+
+ if (args->hdr.size == 0) {
+ ret = -EINVAL;
+ goto unlock_dev_srcu;
+ }
+
+ if (!(args->hdr.dir == DMA_TO_DEVICE ||
+ args->hdr.dir == DMA_FROM_DEVICE)) {
+ ret = -EINVAL;
+ goto unlock_dev_srcu;
+ }
+
+ dbc = &qdev->dbc[args->hdr.dbc_id];
+ if (dbc->usr != usr) {
+ ret = -EINVAL;
+ goto unlock_dev_srcu;
+ }
+
+ if (args->data == 0) {
+ ret = -EINVAL;
+ goto unlock_dev_srcu;
+ }
+
+ user_data = u64_to_user_ptr(args->data);
+
+ slice_ent = kzalloc(arg_size, GFP_KERNEL);
+ if (!slice_ent) {
+ ret = -EINVAL;
+ goto unlock_dev_srcu;
+ }
+
+ ret = copy_from_user(slice_ent, user_data, arg_size);
+ if (ret) {
+ ret = -EFAULT;
+ goto free_slice_ent;
+ }
+
+ ret = qaic_validate_req(qdev, slice_ent, args->hdr.count, args->hdr.size);
+ if (ret)
+ goto free_slice_ent;
+
+ obj = drm_gem_object_lookup(file_priv, args->hdr.handle);
+ if (!obj) {
+ ret = -ENOENT;
+ goto free_slice_ent;
+ }
+
+ bo = to_qaic_bo(obj);
+
+ ret = qaic_prepare_bo(qdev, bo, &args->hdr);
+ if (ret)
+ goto put_bo;
+
+ ret = qaic_attach_slicing_bo(qdev, bo, &args->hdr, slice_ent);
+ if (ret)
+ goto unprepare_bo;
+
+ if (args->hdr.dir == DMA_TO_DEVICE)
+ dma_sync_sgtable_for_cpu(&qdev->pdev->dev, bo->sgt, args->hdr.dir);
+
+ bo->dbc = dbc;
+ drm_gem_object_put(obj);
+ srcu_read_unlock(&qdev->dev_lock, qdev_rcu_id);
+ srcu_read_unlock(&usr->qddev_lock, usr_rcu_id);
+
+ return 0;
+
+unprepare_bo:
+ qaic_unprepare_bo(qdev, bo);
+put_bo:
+ drm_gem_object_put(obj);
+free_slice_ent:
+ kfree(slice_ent);
+unlock_dev_srcu:
+ srcu_read_unlock(&qdev->dev_lock, qdev_rcu_id);
+unlock_usr_srcu:
+ srcu_read_unlock(&usr->qddev_lock, usr_rcu_id);
+ return ret;
+}
+
+static inline int copy_exec_reqs(struct qaic_device *qdev,
+ struct bo_slice *slice, u32 dbc_id, u32 head,
+ u32 *ptail)
+{
+ struct dma_bridge_chan *dbc = &qdev->dbc[dbc_id];
+ struct dbc_req *reqs = slice->reqs;
+ u32 tail = *ptail;
+ u32 avail;
+
+ avail = head - tail;
+ if (head <= tail)
+ avail += dbc->nelem;
+
+ --avail;
+
+ if (avail < slice->nents)
+ return -EAGAIN;
+
+ if (tail + slice->nents > dbc->nelem) {
+ avail = dbc->nelem - tail;
+ avail = min_t(u32, avail, slice->nents);
+ memcpy(dbc->req_q_base + tail * get_dbc_req_elem_size(),
+ reqs, sizeof(*reqs) * avail);
+ reqs += avail;
+ avail = slice->nents - avail;
+ if (avail)
+ memcpy(dbc->req_q_base, reqs, sizeof(*reqs) * avail);
+ } else {
+ memcpy(dbc->req_q_base + tail * get_dbc_req_elem_size(),
+ reqs, sizeof(*reqs) * slice->nents);
+ }
+
+ *ptail = (tail + slice->nents) % dbc->nelem;
+
+ return 0;
+}
+
+/*
+ * Based on the value of resize we may only need to transmit first_n
+ * entries and the last entry, with last_bytes to send from the last entry.
+ * Note that first_n could be 0.
+ */
+static inline int copy_partial_exec_reqs(struct qaic_device *qdev,
+ struct bo_slice *slice,
+ u64 resize, u32 dbc_id,
+ u32 head, u32 *ptail)
+{
+ struct dma_bridge_chan *dbc = &qdev->dbc[dbc_id];
+ struct dbc_req *reqs = slice->reqs;
+ struct dbc_req *last_req;
+ u32 tail = *ptail;
+ u64 total_bytes;
+ u64 last_bytes;
+ u32 first_n;
+ u32 avail;
+ int ret;
+ int i;
+
+ avail = head - tail;
+ if (head <= tail)
+ avail += dbc->nelem;
+
+ --avail;
+
+ total_bytes = 0;
+ for (i = 0; i < slice->nents; i++) {
+ total_bytes += le32_to_cpu(reqs[i].len);
+ if (total_bytes >= resize)
+ break;
+ }
+
+ if (total_bytes < resize) {
+ /* User space should have used the full buffer path. */
+ ret = -EINVAL;
+ return ret;
+ }
+
+ first_n = i;
+ last_bytes = i ? resize + le32_to_cpu(reqs[i].len) - total_bytes : resize;
+
+ if (avail < (first_n + 1))
+ return -EAGAIN;
+
+ if (first_n) {
+ if (tail + first_n > dbc->nelem) {
+ avail = dbc->nelem - tail;
+ avail = min_t(u32, avail, first_n);
+ memcpy(dbc->req_q_base + tail * get_dbc_req_elem_size(),
+ reqs, sizeof(*reqs) * avail);
+ last_req = reqs + avail;
+ avail = first_n - avail;
+ if (avail)
+ memcpy(dbc->req_q_base, last_req,
+ sizeof(*reqs) * avail);
+ } else {
+ memcpy(dbc->req_q_base + tail * get_dbc_req_elem_size(),
+ reqs, sizeof(*reqs) * first_n);
+ }
+ }
+
+ /* Copy over the last entry. Here we need to adjust len to the left over
+ * size, and set src and dst to the entry it is copied to.
+ */
+ last_req = dbc->req_q_base +
+ (tail + first_n) % dbc->nelem * get_dbc_req_elem_size();
+ memcpy(last_req, reqs + slice->nents - 1, sizeof(*reqs));
+
+ /*
+ * last_bytes holds size of a DMA segment, maximum DMA segment size is
+ * set to UINT_MAX by qaic and hence last_bytes can never exceed u32
+ * range. So, by down sizing we are not corrupting the value.
+ */
+ last_req->len = cpu_to_le32((u32)last_bytes);
+ last_req->src_addr = reqs[first_n].src_addr;
+ last_req->dest_addr = reqs[first_n].dest_addr;
+
+ *ptail = (tail + first_n + 1) % dbc->nelem;
+
+ return 0;
+}
+
+static int __qaic_execute_bo_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file_priv, bool is_partial)
+{
+ struct qaic_partial_execute_entry *pexec;
+ struct qaic_execute *args = data;
+ struct qaic_execute_entry *exec;
+ struct dma_bridge_chan *dbc;
+ int usr_rcu_id, qdev_rcu_id;
+ struct drm_gem_object *obj;
+ struct qaic_device *qdev;
+ struct bo_slice *slice;
+ struct qaic_user *usr;
+ u8 __user *user_data;
+ unsigned long flags;
+ u64 received_ts = 0;
+ u32 queue_level = 0;
+ struct qaic_bo *bo;
+ u64 submit_ts = 0;
+ unsigned long n;
+ bool queued;
+ int ret = 0;
+ int dbc_id;
+ int rcu_id;
+ u32 head;
+ u32 tail;
+ u64 size;
+ int i, j;
+
+ received_ts = ktime_get_ns();
+
+ usr = file_priv->driver_priv;
+ usr_rcu_id = srcu_read_lock(&usr->qddev_lock);
+ if (!usr->qddev) {
+ ret = -ENODEV;
+ goto unlock_usr_srcu;
+ }
+
+ qdev = usr->qddev->qdev;
+ qdev_rcu_id = srcu_read_lock(&qdev->dev_lock);
+ if (qdev->in_reset) {
+ ret = -ENODEV;
+ goto unlock_dev_srcu;
+ }
+
+ if (args->hdr.dbc_id >= qdev->num_dbc) {
+ ret = -EINVAL;
+ goto unlock_dev_srcu;
+ }
+
+ dbc_id = args->hdr.dbc_id;
+ dbc = &qdev->dbc[dbc_id];
+
+ size = is_partial ? sizeof(*pexec) : sizeof(*exec);
+
+ n = (unsigned long)size * args->hdr.count;
+ if (args->hdr.count == 0 || n / args->hdr.count != size) {
+ ret = -EINVAL;
+ goto unlock_dev_srcu;
+ }
+
+ user_data = u64_to_user_ptr(args->data);
+
+ exec = kcalloc(args->hdr.count, size, GFP_KERNEL);
+ pexec = (struct qaic_partial_execute_entry *)exec;
+ if (!exec) {
+ ret = -ENOMEM;
+ goto unlock_dev_srcu;
+ }
+
+ if (copy_from_user(exec, user_data, n)) {
+ ret = -EFAULT;
+ goto free_exec;
+ }
+
+ rcu_id = srcu_read_lock(&dbc->ch_lock);
+ if (!dbc->usr || dbc->usr->handle != usr->handle) {
+ ret = -EPERM;
+ goto release_ch_rcu;
+ }
+
+ head = readl(dbc->dbc_base + REQHP_OFF);
+ tail = readl(dbc->dbc_base + REQTP_OFF);
+
+ if (head == U32_MAX || tail == U32_MAX) {
+ /* PCI link error */
+ ret = -ENODEV;
+ goto release_ch_rcu;
+ }
+
+ queue_level = head <= tail ? tail - head : dbc->nelem - (head - tail);
+
+ for (i = 0; i < args->hdr.count; i++) {
+ /*
+ * ref count will be decremented when the transfer of this
+ * buffer is complete. It is inside dbc_irq_threaded_fn().
+ */
+ obj = drm_gem_object_lookup(file_priv,
+ is_partial ? pexec[i].handle : exec[i].handle);
+ if (!obj) {
+ ret = -ENOENT;
+ goto sync_to_cpu;
+ }
+
+ bo = to_qaic_bo(obj);
+
+ if (!bo->sliced) {
+ ret = -EINVAL;
+ goto sync_to_cpu;
+ }
+
+ if (is_partial && pexec[i].resize > bo->size) {
+ ret = -EINVAL;
+ goto sync_to_cpu;
+ }
+
+ spin_lock_irqsave(&dbc->xfer_lock, flags);
+ queued = bo->queued;
+ bo->queued = true;
+ if (queued) {
+ spin_unlock_irqrestore(&dbc->xfer_lock, flags);
+ ret = -EINVAL;
+ goto sync_to_cpu;
+ }
+
+ bo->req_id = dbc->next_req_id++;
+
+ list_for_each_entry(slice, &bo->slices, slice) {
+ /*
+ * If this slice does not fall under the given
+ * resize then skip this slice and continue the loop
+ */
+ if (is_partial && pexec[i].resize &&
+ pexec[i].resize <= slice->offset)
+ continue;
+
+ for (j = 0; j < slice->nents; j++)
+ slice->reqs[j].req_id = cpu_to_le16(bo->req_id);
+
+ /*
+ * If it is a partial execute ioctl call then check if
+ * resize has cut this slice short then do a partial copy
+ * else do complete copy
+ */
+ if (is_partial && pexec[i].resize &&
+ pexec[i].resize < slice->offset + slice->size)
+ ret = copy_partial_exec_reqs(qdev, slice,
+ pexec[i].resize - slice->offset,
+ dbc_id, head, &tail);
+ else
+ ret = copy_exec_reqs(qdev, slice, dbc_id, head, &tail);
+ if (ret) {
+ bo->queued = false;
+ spin_unlock_irqrestore(&dbc->xfer_lock, flags);
+ goto sync_to_cpu;
+ }
+ }
+ reinit_completion(&bo->xfer_done);
+ list_add_tail(&bo->xfer_list, &dbc->xfer_list);
+ spin_unlock_irqrestore(&dbc->xfer_lock, flags);
+ dma_sync_sgtable_for_device(&qdev->pdev->dev, bo->sgt, bo->dir);
+ }
+
+ submit_ts = ktime_get_ns();
+ writel(tail, dbc->dbc_base + REQTP_OFF);
+
+ /* Collect kernel Profiling data */
+ for (i = 0; i < args->hdr.count; i++) {
+ /*
+ * Since we already committed the BO to hardware, the only way
+ * this should fail is a pending signal. We can't cancel the
+ * submit to hardware, so we have to just skip the profiling
+ * data. In case the signal is not fatal to the process, we
+ * return success so that the user doesn't try to resubmit.
+ */
+ obj = drm_gem_object_lookup(file_priv,
+ is_partial ? pexec[i].handle : exec[i].handle);
+ if (!obj)
+ break;
+ bo = to_qaic_bo(obj);
+ bo->perf_stats.req_received_ts = received_ts;
+ bo->perf_stats.req_submit_ts = submit_ts;
+ bo->perf_stats.queue_level_before = queue_level;
+ queue_level += bo->total_slice_nents;
+ drm_gem_object_put(obj);
+ }
+
+ if (poll_datapath)
+ schedule_work(&dbc->poll_work);
+
+ goto release_ch_rcu;
+
+sync_to_cpu:
+ if (likely(obj))
+ drm_gem_object_put(obj);
+ for (j = 0; j < i; j++) {
+ spin_lock_irqsave(&dbc->xfer_lock, flags);
+ bo = list_last_entry(&dbc->xfer_list, struct qaic_bo,
+ xfer_list);
+ obj = &bo->base;
+ bo->queued = false;
+ list_del(&bo->xfer_list);
+ spin_unlock_irqrestore(&dbc->xfer_lock, flags);
+ dma_sync_sgtable_for_cpu(&qdev->pdev->dev, bo->sgt, bo->dir);
+ /* Release ref to BO */
+ drm_gem_object_put(obj);
+ }
+release_ch_rcu:
+ srcu_read_unlock(&dbc->ch_lock, rcu_id);
+free_exec:
+ kfree(exec);
+unlock_dev_srcu:
+ srcu_read_unlock(&qdev->dev_lock, qdev_rcu_id);
+unlock_usr_srcu:
+ srcu_read_unlock(&usr->qddev_lock, usr_rcu_id);
+ return ret;
+}
+
+int qaic_execute_bo_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file_priv)
+{
+ return __qaic_execute_bo_ioctl(dev, data, file_priv, false);
+}
+
+int qaic_partial_execute_bo_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file_priv)
+{
+ return __qaic_execute_bo_ioctl(dev, data, file_priv, true);
+}
+
+/*
+ * Our interrupt handling is a bit more complicated than a simple ideal, but
+ * sadly necessary.
+ *
+ * Each dbc has a completion queue. Entries in the queue correspond to DMA
+ * requests which the device has processed. The hardware already has a built
+ * in irq mitigation. When the device puts an entry into the queue, it will
+ * only trigger an interrupt if the queue was empty. Therefore, when adding
+ * the Nth event to a non-empty queue, the hardware doesn't trigger an
+ * interrupt. This means the host doesn't get additional interrupts signaling
+ * the same thing - the queue has something to process.
+ * This behavior can be overridden in the DMA request.
+ * This means that when the host receives an interrupt, it is required to
+ * drain the queue.
+ *
+ * This behavior is what NAPI attempts to accomplish, although we can't use
+ * NAPI as we don't have a netdev. We use threaded irqs instead.
+ *
+ * However, there is a situation where the host drains the queue fast enough
+ * that every event causes an interrupt. Typically this is not a problem as
+ * the rate of events would be low. However, that is not the case with
+ * lprnet for example. On an Intel Xeon D-2191 where we run 8 instances of
+ * lprnet, the host receives roughly 80k interrupts per second from the device
+ * (per /proc/interrupts). While NAPI documentation indicates the host should
+ * just chug along, sadly that behavior causes instability in some hosts.
+ *
+ * Therefore, we implement an interrupt disable scheme similar to NAPI. The
+ * key difference is that we will delay after draining the queue for a small
+ * time to allow additional events to come in via polling. Using the above
+ * lprnet workload, this reduces the number of interrupts processed from
+ * ~80k/sec to about 64 in 5 minutes and appears to solve the system
+ * instability.
+ */
+irqreturn_t dbc_irq_handler(int irq, void *data)
+{
+ struct dma_bridge_chan *dbc = data;
+ int rcu_id;
+ u32 head;
+ u32 tail;
+
+ rcu_id = srcu_read_lock(&dbc->ch_lock);
+
+ if (!dbc->usr) {
+ srcu_read_unlock(&dbc->ch_lock, rcu_id);
+ return IRQ_HANDLED;
+ }
+
+ head = readl(dbc->dbc_base + RSPHP_OFF);
+ if (head == U32_MAX) { /* PCI link error */
+ srcu_read_unlock(&dbc->ch_lock, rcu_id);
+ return IRQ_NONE;
+ }
+
+ tail = readl(dbc->dbc_base + RSPTP_OFF);
+ if (tail == U32_MAX) { /* PCI link error */
+ srcu_read_unlock(&dbc->ch_lock, rcu_id);
+ return IRQ_NONE;
+ }
+
+ if (head == tail) { /* queue empty */
+ srcu_read_unlock(&dbc->ch_lock, rcu_id);
+ return IRQ_NONE;
+ }
+
+ disable_irq_nosync(irq);
+ srcu_read_unlock(&dbc->ch_lock, rcu_id);
+ return IRQ_WAKE_THREAD;
+}
+
+void irq_polling_work(struct work_struct *work)
+{
+ struct dma_bridge_chan *dbc = container_of(work,
+ struct dma_bridge_chan,
+ poll_work);
+ unsigned long flags;
+ int rcu_id;
+ u32 head;
+ u32 tail;
+
+ rcu_id = srcu_read_lock(&dbc->ch_lock);
+
+ while (1) {
+ if (dbc->qdev->in_reset) {
+ srcu_read_unlock(&dbc->ch_lock, rcu_id);
+ return;
+ }
+ if (!dbc->usr) {
+ srcu_read_unlock(&dbc->ch_lock, rcu_id);
+ return;
+ }
+ spin_lock_irqsave(&dbc->xfer_lock, flags);
+ if (list_empty(&dbc->xfer_list)) {
+ spin_unlock_irqrestore(&dbc->xfer_lock, flags);
+ srcu_read_unlock(&dbc->ch_lock, rcu_id);
+ return;
+ }
+ spin_unlock_irqrestore(&dbc->xfer_lock, flags);
+
+ head = readl(dbc->dbc_base + RSPHP_OFF);
+ if (head == U32_MAX) { /* PCI link error */
+ srcu_read_unlock(&dbc->ch_lock, rcu_id);
+ return;
+ }
+
+ tail = readl(dbc->dbc_base + RSPTP_OFF);
+ if (tail == U32_MAX) { /* PCI link error */
+ srcu_read_unlock(&dbc->ch_lock, rcu_id);
+ return;
+ }
+
+ if (head != tail) {
+ irq_wake_thread(dbc->irq, dbc);
+ srcu_read_unlock(&dbc->ch_lock, rcu_id);
+ return;
+ }
+
+ cond_resched();
+ usleep_range(datapath_poll_interval_us,
+ 2 * datapath_poll_interval_us);
+ }
+}
+
+irqreturn_t dbc_irq_threaded_fn(int irq, void *data)
+{
+ struct dma_bridge_chan *dbc = data;
+ int event_count = NUM_EVENTS;
+ int delay_count = NUM_DELAYS;
+ struct qaic_device *qdev;
+ struct qaic_bo *bo, *i;
+ struct dbc_rsp *rsp;
+ unsigned long flags;
+ int rcu_id;
+ u16 status;
+ u16 req_id;
+ u32 head;
+ u32 tail;
+
+ rcu_id = srcu_read_lock(&dbc->ch_lock);
+
+ head = readl(dbc->dbc_base + RSPHP_OFF);
+ if (head == U32_MAX) /* PCI link error */
+ goto error_out;
+
+ qdev = dbc->qdev;
+read_fifo:
+
+ if (!event_count) {
+ event_count = NUM_EVENTS;
+ cond_resched();
+ }
+
+ /*
+ * if this channel isn't assigned or gets unassigned during processing
+ * we have nothing further to do
+ */
+ if (!dbc->usr)
+ goto error_out;
+
+ tail = readl(dbc->dbc_base + RSPTP_OFF);
+ if (tail == U32_MAX) /* PCI link error */
+ goto error_out;
+
+ if (head == tail) { /* queue empty */
+ if (delay_count) {
+ --delay_count;
+ usleep_range(100, 200);
+ goto read_fifo; /* check for a new event */
+ }
+ goto normal_out;
+ }
+
+ delay_count = NUM_DELAYS;
+ while (head != tail) {
+ if (!event_count)
+ break;
+ --event_count;
+ rsp = dbc->rsp_q_base + head * sizeof(*rsp);
+ req_id = le16_to_cpu(rsp->req_id);
+ status = le16_to_cpu(rsp->status);
+ if (status)
+ pci_dbg(qdev->pdev, "req_id %d failed with status %d\n",
+ req_id, status);
+ spin_lock_irqsave(&dbc->xfer_lock, flags);
+ /*
+ * A BO can receive multiple interrupts, since a BO can be
+ * divided into multiple slices and a buffer receives as many
+ * interrupts as slices. So until it receives interrupts for
+ * all the slices we cannot mark that buffer complete.
+ */
+ list_for_each_entry_safe(bo, i, &dbc->xfer_list, xfer_list) {
+ if (bo->req_id == req_id)
+ bo->nr_slice_xfer_done++;
+ else
+ continue;
+
+ if (bo->nr_slice_xfer_done < bo->nr_slice)
+ break;
+
+ /*
+ * At this point we have received all the interrupts for
+ * BO, which means BO execution is complete.
+ */
+ dma_sync_sgtable_for_cpu(&qdev->pdev->dev, bo->sgt, bo->dir);
+ bo->nr_slice_xfer_done = 0;
+ bo->queued = false;
+ list_del(&bo->xfer_list);
+ bo->perf_stats.req_processed_ts = ktime_get_ns();
+ complete_all(&bo->xfer_done);
+ drm_gem_object_put(&bo->base);
+ break;
+ }
+ spin_unlock_irqrestore(&dbc->xfer_lock, flags);
+ head = (head + 1) % dbc->nelem;
+ }
+
+ /*
+ * Update the head pointer of response queue and let the device know
+ * that we have consumed elements from the queue.
+ */
+ writel(head, dbc->dbc_base + RSPHP_OFF);
+
+ /* elements might have been put in the queue while we were processing */
+ goto read_fifo;
+
+normal_out:
+ if (likely(!poll_datapath))
+ enable_irq(irq);
+ else
+ schedule_work(&dbc->poll_work);
+ /* checking the fifo and enabling irqs is a race, missed event check */
+ tail = readl(dbc->dbc_base + RSPTP_OFF);
+ if (tail != U32_MAX && head != tail) {
+ if (likely(!poll_datapath))
+ disable_irq_nosync(irq);
+ goto read_fifo;
+ }
+ srcu_read_unlock(&dbc->ch_lock, rcu_id);
+ return IRQ_HANDLED;
+
+error_out:
+ srcu_read_unlock(&dbc->ch_lock, rcu_id);
+ if (likely(!poll_datapath))
+ enable_irq(irq);
+ else
+ schedule_work(&dbc->poll_work);
+
+ return IRQ_HANDLED;
+}
+
+int qaic_wait_bo_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file_priv)
+{
+ struct qaic_wait *args = data;
+ int usr_rcu_id, qdev_rcu_id;
+ struct dma_bridge_chan *dbc;
+ struct drm_gem_object *obj;
+ struct qaic_device *qdev;
+ unsigned long timeout;
+ struct qaic_user *usr;
+ struct qaic_bo *bo;
+ int rcu_id;
+ int ret;
+
+ usr = file_priv->driver_priv;
+ usr_rcu_id = srcu_read_lock(&usr->qddev_lock);
+ if (!usr->qddev) {
+ ret = -ENODEV;
+ goto unlock_usr_srcu;
+ }
+
+ qdev = usr->qddev->qdev;
+ qdev_rcu_id = srcu_read_lock(&qdev->dev_lock);
+ if (qdev->in_reset) {
+ ret = -ENODEV;
+ goto unlock_dev_srcu;
+ }
+
+ if (args->pad != 0) {
+ ret = -EINVAL;
+ goto unlock_dev_srcu;
+ }
+
+ if (args->dbc_id >= qdev->num_dbc) {
+ ret = -EINVAL;
+ goto unlock_dev_srcu;
+ }
+
+ dbc = &qdev->dbc[args->dbc_id];
+
+ rcu_id = srcu_read_lock(&dbc->ch_lock);
+ if (dbc->usr != usr) {
+ ret = -EPERM;
+ goto unlock_ch_srcu;
+ }
+
+ obj = drm_gem_object_lookup(file_priv, args->handle);
+ if (!obj) {
+ ret = -ENOENT;
+ goto unlock_ch_srcu;
+ }
+
+ bo = to_qaic_bo(obj);
+ timeout = args->timeout ? args->timeout : wait_exec_default_timeout;
+ timeout = msecs_to_jiffies(timeout);
+ ret = wait_for_completion_interruptible_timeout(&bo->xfer_done, timeout);
+ if (!ret) {
+ ret = -ETIMEDOUT;
+ goto put_obj;
+ }
+ if (ret > 0)
+ ret = 0;
+
+ if (!dbc->usr)
+ ret = -EPERM;
+
+put_obj:
+ drm_gem_object_put(obj);
+unlock_ch_srcu:
+ srcu_read_unlock(&dbc->ch_lock, rcu_id);
+unlock_dev_srcu:
+ srcu_read_unlock(&qdev->dev_lock, qdev_rcu_id);
+unlock_usr_srcu:
+ srcu_read_unlock(&usr->qddev_lock, usr_rcu_id);
+ return ret;
+}
+
+int qaic_perf_stats_bo_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file_priv)
+{
+ struct qaic_perf_stats_entry *ent = NULL;
+ struct qaic_perf_stats *args = data;
+ int usr_rcu_id, qdev_rcu_id;
+ struct drm_gem_object *obj;
+ struct qaic_device *qdev;
+ struct qaic_user *usr;
+ struct qaic_bo *bo;
+ int ret, i;
+
+ usr = file_priv->driver_priv;
+ usr_rcu_id = srcu_read_lock(&usr->qddev_lock);
+ if (!usr->qddev) {
+ ret = -ENODEV;
+ goto unlock_usr_srcu;
+ }
+
+ qdev = usr->qddev->qdev;
+ qdev_rcu_id = srcu_read_lock(&qdev->dev_lock);
+ if (qdev->in_reset) {
+ ret = -ENODEV;
+ goto unlock_dev_srcu;
+ }
+
+ if (args->hdr.dbc_id >= qdev->num_dbc) {
+ ret = -EINVAL;
+ goto unlock_dev_srcu;
+ }
+
+ ent = kcalloc(args->hdr.count, sizeof(*ent), GFP_KERNEL);
+ if (!ent) {
+ ret = -EINVAL;
+ goto unlock_dev_srcu;
+ }
+
+ ret = copy_from_user(ent, u64_to_user_ptr(args->data),
+ args->hdr.count * sizeof(*ent));
+ if (ret) {
+ ret = -EFAULT;
+ goto free_ent;
+ }
+
+ for (i = 0; i < args->hdr.count; i++) {
+ obj = drm_gem_object_lookup(file_priv, ent[i].handle);
+ if (!obj) {
+ ret = -ENOENT;
+ goto free_ent;
+ }
+ bo = to_qaic_bo(obj);
+ /*
+ * perf stats ioctl is called before wait ioctl is complete then
+ * the latency information is invalid.
+ */
+ if (bo->perf_stats.req_processed_ts < bo->perf_stats.req_submit_ts) {
+ ent[i].device_latency_us = 0;
+ } else {
+ ent[i].device_latency_us = (bo->perf_stats.req_processed_ts -
+ bo->perf_stats.req_submit_ts) / 1000;
+ }
+ ent[i].submit_latency_us = (bo->perf_stats.req_submit_ts -
+ bo->perf_stats.req_received_ts) / 1000;
+ ent[i].queue_level_before = bo->perf_stats.queue_level_before;
+ ent[i].num_queue_element = bo->total_slice_nents;
+ drm_gem_object_put(obj);
+ }
+
+ if (copy_to_user(u64_to_user_ptr(args->data), ent,
+ args->hdr.count * sizeof(*ent)))
+ ret = -EFAULT;
+
+free_ent:
+ kfree(ent);
+unlock_dev_srcu:
+ srcu_read_unlock(&qdev->dev_lock, qdev_rcu_id);
+unlock_usr_srcu:
+ srcu_read_unlock(&usr->qddev_lock, usr_rcu_id);
+ return ret;
+}
+
+static void empty_xfer_list(struct qaic_device *qdev, struct dma_bridge_chan *dbc)
+{
+ unsigned long flags;
+ struct qaic_bo *bo;
+
+ spin_lock_irqsave(&dbc->xfer_lock, flags);
+ while (!list_empty(&dbc->xfer_list)) {
+ bo = list_first_entry(&dbc->xfer_list, typeof(*bo), xfer_list);
+ bo->queued = false;
+ list_del(&bo->xfer_list);
+ spin_unlock_irqrestore(&dbc->xfer_lock, flags);
+ dma_sync_sgtable_for_cpu(&qdev->pdev->dev, bo->sgt, bo->dir);
+ complete_all(&bo->xfer_done);
+ drm_gem_object_put(&bo->base);
+ spin_lock_irqsave(&dbc->xfer_lock, flags);
+ }
+ spin_unlock_irqrestore(&dbc->xfer_lock, flags);
+}
+
+int disable_dbc(struct qaic_device *qdev, u32 dbc_id, struct qaic_user *usr)
+{
+ if (!qdev->dbc[dbc_id].usr ||
+ qdev->dbc[dbc_id].usr->handle != usr->handle)
+ return -EPERM;
+
+ qdev->dbc[dbc_id].usr = NULL;
+ synchronize_srcu(&qdev->dbc[dbc_id].ch_lock);
+ return 0;
+}
+
+/**
+ * enable_dbc - Enable the DBC. DBCs are disabled by removing the context of
+ * user. Add user context back to DBC to enable it. This function trusts the
+ * DBC ID passed and expects the DBC to be disabled.
+ * @qdev: Qranium device handle
+ * @dbc_id: ID of the DBC
+ * @usr: User context
+ */
+void enable_dbc(struct qaic_device *qdev, u32 dbc_id, struct qaic_user *usr)
+{
+ qdev->dbc[dbc_id].usr = usr;
+}
+
+void wakeup_dbc(struct qaic_device *qdev, u32 dbc_id)
+{
+ struct dma_bridge_chan *dbc = &qdev->dbc[dbc_id];
+
+ dbc->usr = NULL;
+ empty_xfer_list(qdev, dbc);
+ synchronize_srcu(&dbc->ch_lock);
+}
+
+void release_dbc(struct qaic_device *qdev, u32 dbc_id)
+{
+ struct bo_slice *slice, *slice_temp;
+ struct qaic_bo *bo, *bo_temp;
+ struct dma_bridge_chan *dbc;
+
+ dbc = &qdev->dbc[dbc_id];
+ if (!dbc->in_use)
+ return;
+
+ wakeup_dbc(qdev, dbc_id);
+
+ dma_free_coherent(&qdev->pdev->dev, dbc->total_size, dbc->req_q_base,
+ dbc->dma_addr);
+ dbc->total_size = 0;
+ dbc->req_q_base = NULL;
+ dbc->dma_addr = 0;
+ dbc->nelem = 0;
+ dbc->usr = NULL;
+
+ list_for_each_entry_safe(bo, bo_temp, &dbc->bo_lists, bo_list) {
+ list_for_each_entry_safe(slice, slice_temp, &bo->slices, slice)
+ kref_put(&slice->ref_count, free_slice);
+ bo->sliced = false;
+ INIT_LIST_HEAD(&bo->slices);
+ bo->total_slice_nents = 0;
+ bo->dir = 0;
+ bo->dbc = NULL;
+ bo->nr_slice = 0;
+ bo->nr_slice_xfer_done = 0;
+ bo->queued = false;
+ bo->req_id = 0;
+ init_completion(&bo->xfer_done);
+ complete_all(&bo->xfer_done);
+ list_del(&bo->bo_list);
+ bo->perf_stats.req_received_ts = 0;
+ bo->perf_stats.req_submit_ts = 0;
+ bo->perf_stats.req_processed_ts = 0;
+ bo->perf_stats.queue_level_before = 0;
+ }
+
+ dbc->in_use = false;
+ wake_up(&dbc->dbc_release);
+}