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Subject[RFCv3 PATCH 2/6] uacce: add uacce module
Date
From: Kenneth Lee <liguozhu@hisilicon.com>

Uacce is the kernel component to support WarpDrive accelerator
framework. It provides register/unregister interface for device drivers
to expose their hardware resource to the user space. The resource is
taken as "queue" in WarpDrive.

Uacce create a chrdev for every registration, the queue is allocated to
the process when the chrdev is opened. Then the process can access the
hardware resource by interact with the queue file. By mmap the queue
file space to user space, the process can directly put requests to the
hardware without syscall to the kernel space.

Uacce also manages unify addresses between the hardware and user space
of the process. So they can share the same virtual address in the
communication.

Please see Documentation/warpdrive/warpdrive.rst for detail.

Signed-off-by: Kenneth Lee <liguozhu@hisilicon.com>
Signed-off-by: Zaibo Xu <xuzaibo@huawei.com>
Signed-off-by: Zhou Wang <wangzhou1@hisilicon.com>
---
drivers/Kconfig | 2 +
drivers/Makefile | 1 +
drivers/uacce/Kconfig | 11 +
drivers/uacce/Makefile | 2 +
drivers/uacce/uacce.c | 902 +++++++++++++++++++++++++++++++++++++
include/linux/uacce.h | 117 +++++
include/uapi/linux/uacce.h | 33 ++
7 files changed, 1068 insertions(+)
create mode 100644 drivers/uacce/Kconfig
create mode 100644 drivers/uacce/Makefile
create mode 100644 drivers/uacce/uacce.c
create mode 100644 include/linux/uacce.h
create mode 100644 include/uapi/linux/uacce.h

diff --git a/drivers/Kconfig b/drivers/Kconfig
index ab4d43923c4d..b8782be0e7e5 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -219,4 +219,6 @@ source "drivers/siox/Kconfig"

source "drivers/slimbus/Kconfig"

+source "drivers/uacce/Kconfig"
+
endmenu
diff --git a/drivers/Makefile b/drivers/Makefile
index 578f469f72fb..9416c49b7501 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -186,3 +186,4 @@ obj-$(CONFIG_MULTIPLEXER) += mux/
obj-$(CONFIG_UNISYS_VISORBUS) += visorbus/
obj-$(CONFIG_SIOX) += siox/
obj-$(CONFIG_GNSS) += gnss/
+obj-y += uacce/
diff --git a/drivers/uacce/Kconfig b/drivers/uacce/Kconfig
new file mode 100644
index 000000000000..e0e6462f6a42
--- /dev/null
+++ b/drivers/uacce/Kconfig
@@ -0,0 +1,11 @@
+menuconfig UACCE
+ tristate "Accelerator Framework for User Land"
+ depends on IOMMU_API
+ select ANON_INODES
+ help
+ UACCE provides interface for the user process to access the hardware
+ without interaction with the kernel space in data path.
+
+ See Documentation/warpdrive/warpdrive.rst for more details.
+
+ If you don't know what to do here, say N.
diff --git a/drivers/uacce/Makefile b/drivers/uacce/Makefile
new file mode 100644
index 000000000000..5b4374e8b5f2
--- /dev/null
+++ b/drivers/uacce/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+obj-$(CONFIG_UACCE) += uacce.o
diff --git a/drivers/uacce/uacce.c b/drivers/uacce/uacce.c
new file mode 100644
index 000000000000..07e3b9887f28
--- /dev/null
+++ b/drivers/uacce/uacce.c
@@ -0,0 +1,902 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#include <linux/compat.h>
+#include <linux/file.h>
+#include <linux/idr.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/poll.h>
+#include <linux/sched/signal.h>
+#include <linux/slab.h>
+#include <linux/uacce.h>
+#include <linux/wait.h>
+
+static struct class *uacce_class;
+static DEFINE_IDR(uacce_idr);
+static dev_t uacce_devt;
+static DEFINE_MUTEX(uacce_mutex); /* mutex to protect uacce */
+static DEFINE_RWLOCK(uacce_lock); /* lock to protect all queues management */
+
+static const struct file_operations uacce_fops;
+
+static const char *const qfrt_str[] = {
+ "dko",
+ "dus",
+ "ss",
+ "mmio",
+ "invalid"
+};
+
+const char *uacce_qfrt_str(struct uacce_qfile_region *qfr)
+{
+ enum uacce_qfrt type = qfr->type;
+
+ if (type >= UACCE_QFRT_INVALID)
+ type = UACCE_QFRT_INVALID;
+
+ return qfrt_str[type];
+}
+EXPORT_SYMBOL_GPL(uacce_qfrt_str);
+
+/**
+ * uacce_wake_up - Wake up the process who is waiting this queue
+ * @q the accelerator queue to wake up
+ */
+void uacce_wake_up(struct uacce_queue *q)
+{
+ dev_dbg(q->uacce->dev, "wake up\n");
+ wake_up_interruptible(&q->wait);
+}
+EXPORT_SYMBOL_GPL(uacce_wake_up);
+
+static void uacce_cls_release(struct device *dev) { }
+
+static inline int uacce_iommu_map_qfr(struct uacce_queue *q,
+ struct uacce_qfile_region *qfr)
+{
+ struct device *dev = q->uacce->dev;
+ struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
+ int i, j, ret;
+
+ if (!domain)
+ return -ENODEV;
+
+ for (i = 0; i < qfr->nr_pages; i++) {
+ get_page(qfr->pages[i]);
+ ret = iommu_map(domain, qfr->iova + i * PAGE_SIZE,
+ page_to_phys(qfr->pages[i]),
+ PAGE_SIZE, qfr->prot | q->uacce->prot);
+ if (ret) {
+ dev_err(dev, "iommu_map page %i fail %d\n", i, ret);
+ goto err_with_map_pages;
+ }
+ }
+
+ return 0;
+
+err_with_map_pages:
+ for (j = i-1; j >= 0; j--) {
+ iommu_unmap(domain, qfr->iova + j * PAGE_SIZE, PAGE_SIZE);
+ put_page(qfr->pages[j]);
+ }
+ return ret;
+}
+
+static inline void uacce_iommu_unmap_qfr(struct uacce_queue *q,
+ struct uacce_qfile_region *qfr)
+{
+ struct device *dev = q->uacce->dev;
+ struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
+ int i;
+
+ if (!domain || !qfr)
+ return;
+
+ for (i = qfr->nr_pages-1; i >= 0; i--) {
+ iommu_unmap(domain, qfr->iova + i * PAGE_SIZE, PAGE_SIZE);
+ put_page(qfr->pages[i]);
+ }
+}
+
+static int uacce_queue_map_qfr(struct uacce_queue *q,
+ struct uacce_qfile_region *qfr)
+{
+ if (!(qfr->flags & UACCE_QFRF_MAP))
+ return 0;
+
+ dev_dbg(q->uacce->dev, "queue map %s qfr(npage=%d, iova=%lx)\n",
+ uacce_qfrt_str(qfr), qfr->nr_pages, qfr->iova);
+
+ if (q->uacce->ops->flags & UACCE_DEV_NOIOMMU)
+ return q->uacce->ops->map(q, qfr);
+
+ return uacce_iommu_map_qfr(q, qfr);
+}
+
+static void uacce_queue_unmap_qfr(struct uacce_queue *q,
+ struct uacce_qfile_region *qfr)
+{
+ if (!(qfr->flags & UACCE_QFRF_MAP))
+ return;
+
+ if (q->uacce->ops->flags & UACCE_DEV_NOIOMMU)
+ q->uacce->ops->unmap(q, qfr);
+ else
+ uacce_iommu_unmap_qfr(q, qfr);
+}
+
+static vm_fault_t uacce_shm_vm_fault(struct vm_fault *vmf)
+{
+ struct vm_area_struct *vma = vmf->vma;
+ struct uacce_qfile_region *qfr;
+ pgoff_t page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
+ int ret;
+
+ read_lock_irq(&uacce_lock);
+
+ qfr = vma->vm_private_data;
+ if (!qfr) {
+ pr_info("this page is not valid to user space\n");
+ ret = VM_FAULT_SIGBUS;
+ goto out;
+ }
+
+ pr_debug("uacce: fault on %s qfr page %ld/%d\n", uacce_qfrt_str(qfr),
+ page_offset, qfr->nr_pages);
+
+ if (page_offset >= qfr->nr_pages) {
+ ret = VM_FAULT_SIGBUS;
+ goto out;
+ }
+
+ get_page(qfr->pages[page_offset]);
+ vmf->page = qfr->pages[page_offset];
+ ret = 0;
+
+out:
+ read_unlock_irq(&uacce_lock);
+ return ret;
+}
+
+static const struct vm_operations_struct uacce_shm_vm_ops = {
+ .fault = uacce_shm_vm_fault,
+};
+
+static struct uacce_qfile_region *uacce_create_region(struct uacce_queue *q,
+ struct vm_area_struct *vma, enum uacce_qfrt type, int flags)
+{
+ struct uacce_qfile_region *qfr;
+ int i, j, ret = -ENOMEM;
+
+ qfr = kzalloc(sizeof(*qfr), GFP_KERNEL | GFP_ATOMIC);
+ if (!qfr)
+ return ERR_PTR(-ENOMEM);
+
+ qfr->type = type;
+ qfr->flags = flags;
+ qfr->iova = vma->vm_start;
+ qfr->nr_pages = vma_pages(vma);
+
+ if (vma->vm_flags & VM_READ)
+ qfr->prot |= IOMMU_READ;
+
+ if (vma->vm_flags & VM_WRITE)
+ qfr->prot |= IOMMU_WRITE;
+
+ qfr->pages = kcalloc(qfr->nr_pages, sizeof(*qfr->pages),
+ GFP_KERNEL | GFP_ATOMIC);
+ if (!qfr->pages)
+ goto err_with_qfr;
+
+ for (i = 0; i < qfr->nr_pages; i++) {
+ qfr->pages[i] = alloc_page(GFP_KERNEL | GFP_ATOMIC |
+ __GFP_ZERO);
+ if (!qfr->pages[i])
+ goto err_with_pages;
+ }
+
+ ret = uacce_queue_map_qfr(q, qfr);
+ if (ret)
+ goto err_with_pages;
+
+ if (flags & UACCE_QFRF_KMAP) {
+ qfr->kaddr = vmap(qfr->pages, qfr->nr_pages, VM_MAP,
+ PAGE_KERNEL);
+ if (!qfr->kaddr) {
+ ret = -ENOMEM;
+ goto err_with_q_map;
+ }
+
+ dev_dbg(q->uacce->dev, "kmap %s qfr to %p\n",
+ uacce_qfrt_str(qfr), qfr->kaddr);
+ }
+
+ if (flags & UACCE_QFRF_MMAP) {
+ vma->vm_private_data = qfr;
+ vma->vm_ops = &uacce_shm_vm_ops;
+ }
+
+ return qfr;
+
+err_with_q_map:
+ uacce_queue_unmap_qfr(q, qfr);
+err_with_pages:
+ for (j = i-1; j >= 0; j--)
+ put_page(qfr->pages[j]);
+
+ kfree(qfr->pages);
+err_with_qfr:
+ kfree(qfr);
+
+ return ERR_PTR(ret);
+}
+
+static void uacce_destroy_region(struct uacce_qfile_region *qfr)
+{
+ int i;
+
+ if (qfr->pages) {
+ for (i = 0; i < qfr->nr_pages; i++)
+ put_page(qfr->pages[i]);
+
+ if (qfr->flags & UACCE_QFRF_KMAP)
+ vunmap(qfr->kaddr);
+
+ kfree(qfr->pages);
+ }
+ kfree(qfr);
+}
+
+static long uacce_cmd_share_qfr(struct uacce_queue *tgt, int fd)
+{
+ struct file *filep = fget(fd);
+ struct uacce_queue *src;
+ int ret;
+
+ if (!filep || filep->f_op != &uacce_fops)
+ return -EINVAL;
+
+ src = (struct uacce_queue *)filep->private_data;
+ if (!src)
+ return -EINVAL;
+
+ /* no ssva is needed if the dev can do fault-from-dev */
+ if (tgt->uacce->ops->flags | UACCE_DEV_FAULT_FROM_DEV)
+ return -EINVAL;
+
+ write_lock(&uacce_lock);
+ if (!src->qfrs[UACCE_QFRT_SS] || tgt->qfrs[UACCE_QFRT_SS]) {
+ ret = -EINVAL;
+ goto out_with_lock;
+ }
+
+ ret = uacce_queue_map_qfr(tgt, src->qfrs[UACCE_QFRT_SS]);
+ if (ret)
+ goto out_with_lock;
+
+ tgt->qfrs[UACCE_QFRT_SS] = src->qfrs[UACCE_QFRT_SS];
+ list_add(&tgt->list, &src->qfrs[UACCE_QFRT_SS]->qs);
+
+out_with_lock:
+ write_unlock(&uacce_lock);
+ return ret;
+}
+
+static long uacce_fops_unl_ioctl(struct file *filep,
+ unsigned int cmd, unsigned long arg)
+{
+ struct uacce_queue *q = (struct uacce_queue *)filep->private_data;
+ struct uacce *uacce = q->uacce;
+
+ switch (cmd) {
+ case UACCE_CMD_SHARE_SVAS:
+ return uacce_cmd_share_qfr(q, arg);
+
+ default:
+ if (uacce->ops->ioctl)
+ return uacce->ops->ioctl(q, cmd, arg);
+
+ dev_err(uacce->dev, "ioctl cmd (%d) is not supported!\n", cmd);
+ return -EINVAL;
+ }
+}
+
+#ifdef CONFIG_COMPAT
+static long uacce_fops_compat_ioctl(struct file *filep,
+ unsigned int cmd, unsigned long arg)
+{
+ arg = (unsigned long)compat_ptr(arg);
+ return uacce_fops_unl_ioctl(filep, cmd, arg);
+}
+#endif
+
+static int uacce_dev_check(struct uacce *uacce)
+{
+ if (uacce->ops->flags & UACCE_DEV_NOIOMMU)
+ return 0;
+
+ /*
+ * The device can be opened once if it dose not support multiple page
+ * table. The better way to check this is count it per iommu_domain,
+ * this is just a temporary solution
+ */
+ if (!(uacce->ops->flags & UACCE_DEV_PASID))
+ if (atomic_cmpxchg(&uacce->state,
+ UACCE_ST_INIT, UACCE_ST_OPENNED))
+ return -EBUSY;
+
+ return 0;
+}
+
+static int uacce_start_queue(struct uacce_queue *q)
+{
+ int ret;
+
+ ret = q->uacce->ops->start_queue(q);
+ if (ret)
+ return ret;
+
+ dev_dbg(q->uacce->dev, "queue started\n");
+ atomic_set(&q->uacce->state, UACCE_ST_STARTED);
+ return 0;
+}
+
+static int uacce_fops_open(struct inode *inode, struct file *filep)
+{
+ struct uacce_queue *q;
+ struct uacce *uacce;
+ int ret;
+ int pasid = 0;
+
+ uacce = idr_find(&uacce_idr, iminor(inode));
+ if (!uacce)
+ return -ENODEV;
+
+ if (!uacce->ops->get_queue)
+ return -EINVAL;
+
+ ret = uacce_dev_check(uacce);
+
+#ifdef CONFIG_IOMMU_SVA
+ if (uacce->ops->flags & UACCE_DEV_PASID)
+ ret = __iommu_sva_bind_device(uacce->dev, current->mm, &pasid,
+ IOMMU_SVA_FEAT_IOPF, NULL);
+#endif
+
+ if (ret)
+ return ret;
+
+ ret = uacce->ops->get_queue(uacce, pasid, &q);
+ if (ret < 0)
+ return ret;
+
+ q->uacce = uacce;
+ q->mm = current->mm;
+ init_waitqueue_head(&q->wait);
+ filep->private_data = q;
+
+ /* if DKO or DSU is set, the q is started when they are ready */
+ if (uacce->ops->qf_pg_start[UACCE_QFRT_DKO] == UACCE_QFR_NA &&
+ uacce->ops->qf_pg_start[UACCE_QFRT_DUS] == UACCE_QFR_NA) {
+ ret = uacce_start_queue(q);
+ if (ret)
+ goto err_with_queue;
+ }
+
+ __module_get(uacce->ops->owner);
+
+ return 0;
+
+err_with_queue:
+ if (uacce->ops->put_queue)
+ uacce->ops->put_queue(q);
+ atomic_set(&uacce->state, UACCE_ST_INIT);
+ return ret;
+}
+
+static int uacce_fops_release(struct inode *inode, struct file *filep)
+{
+ struct uacce_queue *q = (struct uacce_queue *)filep->private_data;
+ struct uacce *uacce;
+ int i;
+ bool is_to_free_region;
+ int free_pages = 0;
+
+ uacce = q->uacce;
+
+ if (atomic_read(&uacce->state) == UACCE_ST_STARTED &&
+ uacce->ops->stop_queue)
+ uacce->ops->stop_queue(q);
+
+ write_lock_irq(&uacce_lock);
+
+ for (i = 0; i < UACCE_QFRT_MAX; i++) {
+ is_to_free_region = false;
+ if (q->qfrs[i]) {
+ uacce_queue_unmap_qfr(q, q->qfrs[i]);
+ if (i == UACCE_QFRT_SS) {
+ list_del(&q->list);
+ if (list_empty(&q->qfrs[i]->qs))
+ is_to_free_region = true;
+ } else
+ is_to_free_region = true;
+ }
+
+ if (is_to_free_region) {
+ free_pages += q->qfrs[i]->nr_pages;
+ uacce_destroy_region(q->qfrs[i]);
+ }
+
+ q->qfrs[i] = NULL;
+ }
+
+ write_unlock_irq(&uacce_lock);
+
+ down_write(&q->mm->mmap_sem);
+ q->mm->data_vm -= free_pages;
+ up_write(&q->mm->mmap_sem);
+
+#ifdef CONFIG_IOMMU_SVA
+ if (uacce->ops->flags & UACCE_DEV_SVA)
+ iommu_sva_unbind_device(uacce->dev, q->pasid);
+#endif
+
+ if (uacce->ops->put_queue)
+ uacce->ops->put_queue(q);
+
+ module_put(uacce->ops->owner);
+ atomic_set(&uacce->state, UACCE_ST_INIT);
+
+ return 0;
+}
+
+static enum uacce_qfrt uacce_get_region_type(struct uacce *uacce,
+ struct vm_area_struct *vma)
+{
+ enum uacce_qfrt type = UACCE_QFRT_MAX;
+ int i;
+ size_t next_size = UACCE_QFR_NA;
+
+ for (i = UACCE_QFRT_MAX - 1; i >= 0; i--) {
+ if (vma->vm_pgoff >= uacce->ops->qf_pg_start[i]) {
+ type = i;
+ break;
+ }
+ }
+
+ switch (type) {
+ case UACCE_QFRT_MMIO:
+ if (!uacce->ops->mmap) {
+ dev_err(uacce->dev, "no driver mmap!\n");
+ return UACCE_QFRT_INVALID;
+ }
+ break;
+
+ case UACCE_QFRT_DKO:
+ if (uacce->ops->flags & UACCE_DEV_PASID)
+ return UACCE_QFRT_INVALID;
+ break;
+
+ case UACCE_QFRT_DUS:
+ if (uacce->ops->flags & UACCE_DEV_FAULT_FROM_DEV)
+ return UACCE_QFRT_INVALID;
+ break;
+
+ case UACCE_QFRT_SS:
+ if (uacce->ops->flags & UACCE_DEV_FAULT_FROM_DEV)
+ return UACCE_QFRT_INVALID;
+ break;
+
+ default:
+ dev_err(uacce->dev, "uacce bug (%d)!\n", type);
+ break;
+ }
+
+ if (type < UACCE_QFRT_SS) {
+ for (i = type + 1; i < UACCE_QFRT_MAX; i++)
+ if (uacce->ops->qf_pg_start[i] != UACCE_QFR_NA) {
+ next_size = uacce->ops->qf_pg_start[i];
+ break;
+ }
+
+ if (next_size == UACCE_QFR_NA) {
+ dev_err(uacce->dev, "uacce config error. \
+ make sure setting SS offset properly\n");
+ return UACCE_QFRT_INVALID;
+ }
+
+ if (vma_pages(vma) !=
+ next_size - uacce->ops->qf_pg_start[type]) {
+ dev_err(uacce->dev,
+ "invalid mmap size (%ld page) for region %s.\n",
+ vma_pages(vma), qfrt_str[type]);
+ return UACCE_QFRT_INVALID;
+ }
+ }
+
+ return type;
+}
+
+static int uacce_fops_mmap(struct file *filep, struct vm_area_struct *vma)
+{
+ struct uacce_queue *q = (struct uacce_queue *)filep->private_data;
+ struct uacce *uacce = q->uacce;
+ enum uacce_qfrt type = uacce_get_region_type(uacce, vma);
+ struct uacce_qfile_region *qfr;
+ int flags, ret;
+ bool to_start = false;
+
+ dev_dbg(uacce->dev, "mmap q file(t=%s, off=%lx, start=%lx, end=%lx)\n",
+ qfrt_str[type], vma->vm_pgoff, vma->vm_start, vma->vm_end);
+
+ if (type == UACCE_QFRT_INVALID)
+ return -EINVAL;
+
+ vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND;
+
+ write_lock_irq(&uacce_lock);
+
+ if (q->mm->data_vm + vma_pages(vma) >
+ rlimit(RLIMIT_DATA) >> PAGE_SHIFT) {
+ ret = -ENOMEM;
+ goto out_with_lock;
+ }
+
+ if (type == UACCE_QFRT_MMIO) {
+ ret = uacce->ops->mmap(q, vma);
+ goto out_with_lock;
+ }
+
+ if (q->qfrs[type]) {
+ ret = -EBUSY;
+ goto out_with_lock;
+ }
+
+ switch (type) {
+ case UACCE_QFRT_SS:
+ if ((q->uacce->ops->flags & UACCE_DEV_FAULT_FROM_DEV) ||
+ (atomic_read(&uacce->state) != UACCE_ST_STARTED)) {
+ ret = -EINVAL;
+ goto out_with_lock;
+ }
+
+ flags = UACCE_QFRF_MAP | UACCE_QFRF_MMAP;
+ break;
+
+ case UACCE_QFRT_DKO:
+ flags = UACCE_QFRF_MAP | UACCE_QFRF_KMAP;
+ break;
+
+ case UACCE_QFRT_DUS:
+ flags = UACCE_QFRF_MAP | UACCE_QFRF_MMAP;
+ if (q->uacce->ops->flags & UACCE_DEV_KMAP_DUS)
+ flags |= UACCE_QFRF_KMAP;
+ break;
+
+ default:
+ dev_err(uacce->dev, "bug\n");
+ break;
+ }
+
+ qfr = q->qfrs[type] = uacce_create_region(q, vma, type, flags);
+ if (IS_ERR(qfr)) {
+ ret = PTR_ERR(qfr);
+ goto out_with_lock;
+ }
+
+ switch (type) {
+ case UACCE_QFRT_SS:
+ INIT_LIST_HEAD(&qfr->qs);
+ list_add(&q->list, &q->qfrs[type]->qs);
+ break;
+
+ case UACCE_QFRT_DKO:
+ case UACCE_QFRT_DUS:
+ if (q->uacce->ops->qf_pg_start[UACCE_QFRT_DUS] == UACCE_QFR_NA
+ &&
+ q->uacce->ops->qf_pg_start[UACCE_QFRT_DKO] == UACCE_QFR_NA)
+ break;
+
+ if ((q->uacce->ops->qf_pg_start[UACCE_QFRT_DUS] == UACCE_QFR_NA
+ || q->qfrs[UACCE_QFRT_DUS]) &&
+ (q->uacce->ops->qf_pg_start[UACCE_QFRT_DKO] == UACCE_QFR_NA
+ || q->qfrs[UACCE_QFRT_DKO]))
+ to_start = true;
+
+ break;
+
+ default:
+ break;
+ }
+
+ write_unlock_irq(&uacce_lock);
+
+ if (to_start) {
+ ret = uacce_start_queue(q);
+ if (ret) {
+ write_lock_irq(&uacce_lock);
+ goto err_with_region;
+ }
+ }
+
+ q->mm->data_vm += qfr->nr_pages;
+ return 0;
+
+err_with_region:
+ uacce_destroy_region(q->qfrs[type]);
+ q->qfrs[type] = NULL;
+out_with_lock:
+ write_unlock_irq(&uacce_lock);
+ return ret;
+}
+
+static __poll_t uacce_fops_poll(struct file *file, poll_table *wait)
+{
+ struct uacce_queue *q = (struct uacce_queue *)file->private_data;
+ struct uacce *uacce = q->uacce;
+
+ poll_wait(file, &q->wait, wait);
+ if (uacce->ops->is_q_updated && uacce->ops->is_q_updated(q))
+ return EPOLLIN | EPOLLRDNORM;
+ else
+ return 0;
+}
+
+static const struct file_operations uacce_fops = {
+ .owner = THIS_MODULE,
+ .open = uacce_fops_open,
+ .release = uacce_fops_release,
+ .unlocked_ioctl = uacce_fops_unl_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = uacce_fops_compat_ioctl,
+#endif
+ .mmap = uacce_fops_mmap,
+ .poll = uacce_fops_poll,
+};
+
+static int uacce_create_chrdev(struct uacce *uacce)
+{
+ int ret;
+
+ ret = idr_alloc(&uacce_idr, uacce, 0, 0, GFP_KERNEL);
+ if (ret < 0)
+ return ret;
+
+ uacce->dev_id = ret;
+ uacce->cdev = cdev_alloc();
+ if (!uacce->cdev) {
+ ret = -ENOMEM;
+ goto err_with_idr;
+ }
+
+ uacce->cdev->ops = &uacce_fops;
+ uacce->cdev->owner = uacce->ops->owner;
+ ret = cdev_add(uacce->cdev, MKDEV(MAJOR(uacce_devt), uacce->dev_id), 1);
+ if (ret)
+ goto err_with_cdev;
+
+ dev_dbg(uacce->dev, "create uacce minior=%d\n", uacce->dev_id);
+ return 0;
+
+err_with_cdev:
+ cdev_del(uacce->cdev);
+err_with_idr:
+ idr_remove(&uacce_idr, uacce->dev_id);
+ return ret;
+}
+
+static void uacce_destroy_chrdev(struct uacce *uacce)
+{
+ cdev_del(uacce->cdev);
+ idr_remove(&uacce_idr, uacce->dev_id);
+}
+
+static int uacce_default_map(struct uacce_queue *q,
+ struct uacce_qfile_region *qfr)
+{
+ dev_dbg(q->uacce->dev, "fake map %s qfr(npage=%d, iova=%lx)\n",
+ uacce_qfrt_str(qfr), qfr->nr_pages, qfr->iova);
+ return -ENODEV;
+}
+
+static int uacce_default_start_queue(struct uacce_queue *q)
+{
+ dev_dbg(q->uacce->dev, "fake start queue");
+ return 0;
+}
+
+static void uacce_default_unmap(struct uacce_queue *q,
+ struct uacce_qfile_region *qfr)
+{
+ dev_dbg(q->uacce->dev, "fake unmap %s qfr(npage=%d, iova=%lx)\n",
+ uacce_qfrt_str(qfr), qfr->nr_pages, qfr->iova);
+}
+
+static int uacce_dev_match(struct device *dev, void *data)
+{
+ if (dev->parent == data)
+ return -EBUSY;
+
+ return 0;
+}
+
+static int uacce_set_iommu_domain(struct uacce *uacce)
+{
+ struct iommu_domain *domain;
+ int ret;
+
+ if (uacce->ops->flags & UACCE_DEV_NOIOMMU)
+ return 0;
+
+ /*
+ * We don't support multiple register for the same dev in RFC version ,
+ * will add it in formal version
+ */
+ ret = class_for_each_device(uacce_class, NULL, uacce->dev,
+ uacce_dev_match);
+ if (ret)
+ return ret;
+
+ /* allocate and attach a unmanged domain */
+ domain = iommu_domain_alloc(uacce->dev->bus);
+ if (!domain)
+ return -ENODEV;
+
+ ret = iommu_attach_device(domain, uacce->dev);
+ if (ret)
+ goto err_with_domain;
+
+ if (iommu_capable(uacce->dev->bus, IOMMU_CAP_CACHE_COHERENCY)) {
+ uacce->prot |= IOMMU_CACHE;
+ dev_dbg(uacce->dev, "Enable uacce with c-coherent capa\n");
+ } else {
+ dev_dbg(uacce->dev, "Enable uacce without c-coherent cap\n");
+ }
+
+ return 0;
+
+err_with_domain:
+ iommu_domain_free(domain);
+ return ret;
+}
+
+void uacce_unset_iommu_domain(struct uacce *uacce)
+{
+ struct iommu_domain *domain;
+
+ domain = iommu_get_domain_for_dev(uacce->dev);
+ if (domain) {
+ iommu_detach_device(domain, uacce->dev);
+ iommu_domain_free(domain);
+ } else
+ dev_err(uacce->dev, "bug: no domain attached to device\n");
+}
+
+/**
+ * uacce_register - register an accelerator
+ * @uacce: the accelerator structure
+ */
+int uacce_register(struct uacce *uacce)
+{
+ int ret;
+
+ if (!uacce->dev)
+ return -ENODEV;
+
+ /* if dev support fault-from-dev, it should support pasid */
+ if ((uacce->ops->flags & UACCE_DEV_FAULT_FROM_DEV) &&
+ !(uacce->ops->flags & UACCE_DEV_PASID)) {
+ dev_warn(uacce->dev, "SVM/SAV device should support PASID\n");
+ return -EINVAL;
+ }
+
+ if (!uacce->ops->map)
+ uacce->ops->map = uacce_default_map;
+
+ if (!uacce->ops->unmap)
+ uacce->ops->unmap = uacce_default_unmap;
+
+ if (!uacce->ops->start_queue)
+ uacce->ops->start_queue = uacce_default_start_queue;
+
+ ret = uacce_set_iommu_domain(uacce);
+ if (ret)
+ return ret;
+
+ mutex_lock(&uacce_mutex);
+
+ ret = uacce_create_chrdev(uacce);
+ if (ret)
+ goto err_with_lock;
+
+ uacce->cls_dev.parent = uacce->dev;
+ uacce->cls_dev.class = uacce_class;
+ uacce->cls_dev.release = uacce_cls_release;
+ dev_set_name(&uacce->cls_dev, "%s", dev_name(uacce->dev));
+ ret = device_register(&uacce->cls_dev);
+ if (ret)
+ goto err_with_chrdev;
+
+#ifdef CONFIG_IOMMU_SVA
+ ret = iommu_sva_init_device(uacce->dev, IOMMU_SVA_FEAT_IOPF, 0, 0,
+ NULL);
+ if (ret) {
+ device_unregister(&uacce->cls_dev);
+ goto err_with_chrdev;
+ }
+#else
+ if (uacce->ops->flags & UACCE_DEV_PASID)
+ uacce->ops->flags &=
+ ~(UACCE_DEV_FAULT_FROM_DEV | UACCE_DEV_PASID);
+#endif
+
+ atomic_set(&uacce->state, UACCE_ST_INIT);
+ mutex_unlock(&uacce_mutex);
+ return 0;
+
+err_with_chrdev:
+ uacce_destroy_chrdev(uacce);
+err_with_lock:
+ mutex_unlock(&uacce_mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(uacce_register);
+
+/**
+ * uacce_unregister - unregisters a uacce
+ * @uacce: the accelerator to unregister
+ *
+ * Unregister an accelerator that wat previously successully registered with
+ * uacce_register().
+ */
+void uacce_unregister(struct uacce *uacce)
+{
+ mutex_lock(&uacce_mutex);
+
+#ifdef CONFIG_IOMMU_SVA
+ iommu_sva_shutdown_device(uacce->dev);
+#endif
+ device_unregister(&uacce->cls_dev);
+ uacce_destroy_chrdev(uacce);
+ uacce_unset_iommu_domain(uacce);
+
+ mutex_unlock(&uacce_mutex);
+}
+EXPORT_SYMBOL_GPL(uacce_unregister);
+
+static int __init uacce_init(void)
+{
+ int ret;
+
+ uacce_class = class_create(THIS_MODULE, UACCE_CLASS_NAME);
+ if (IS_ERR(uacce_class)) {
+ ret = PTR_ERR(uacce_class);
+ goto err;
+ }
+
+ ret = alloc_chrdev_region(&uacce_devt, 0, MINORMASK, "uacce");
+ if (ret)
+ goto err_with_class;
+
+ pr_info("uacce init with major number:%d\n", MAJOR(uacce_devt));
+
+ return 0;
+
+err_with_class:
+ class_destroy(uacce_class);
+err:
+ return ret;
+}
+
+static __exit void uacce_exit(void)
+{
+ unregister_chrdev_region(uacce_devt, MINORMASK);
+ class_destroy(uacce_class);
+ idr_destroy(&uacce_idr);
+}
+
+subsys_initcall(uacce_init);
+module_exit(uacce_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Hisilicon Tech. Co., Ltd.");
+MODULE_DESCRIPTION("Accelerator interface for Userland applications");
diff --git a/include/linux/uacce.h b/include/linux/uacce.h
new file mode 100644
index 000000000000..7b7bc5821811
--- /dev/null
+++ b/include/linux/uacce.h
@@ -0,0 +1,117 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef __UACCE_H
+#define __UACCE_H
+
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/iommu.h>
+#include <uapi/linux/uacce.h>
+
+struct uacce_queue;
+struct uacce;
+
+#define UACCE_QFRF_MAP (1<<0) /* map to current queue */
+#define UACCE_QFRF_MMAP (1<<1) /* map to user space */
+#define UACCE_QFRF_KMAP (1<<2) /* map to kernel space */
+
+#define UACCE_QFR_NA ((unsigned long)-1)
+enum uacce_qfrt {
+ UACCE_QFRT_DKO = 0, /* device kernel-only */
+ UACCE_QFRT_DUS, /* device user share */
+ UACCE_QFRT_SS, /* static share memory */
+ UACCE_QFRT_MAX, /* used also for IO region */
+ UACCE_QFRT_INVALID
+};
+#define UACCE_QFRT_MMIO (UACCE_QFRT_MAX)
+
+struct uacce_qfile_region {
+ enum uacce_qfrt type;
+ unsigned long iova;
+ struct page **pages;
+ int nr_pages;
+ unsigned long prot;
+ int flags;
+ union {
+ struct list_head qs; /* qs sharing the same region, for ss */
+ void *kaddr; /* kernel addr, for dko */
+ };
+};
+
+/**
+ * struct uacce_ops - WD device operations
+ * @get_queue: get a queue from the device according to algorithm
+ * @put_queue: free a queue to the device
+ * @start_queue: make the queue start work after get_queue
+ * @stop_queue: make the queue stop work before put_queue
+ * @is_q_updated: check whether the task is finished
+ * @mask_notify: mask the task irq of queue
+ * @mmap: mmap addresses of queue to user space
+ * @map: map queue to device (for NOIOMMU device)
+ * @unmap: unmap queue to device (for NOIOMMU device)
+ * @reset: reset the WD device
+ * @reset_queue: reset the queue
+ * @ioctl: ioctl for user space users of the queue
+ */
+struct uacce_ops {
+ struct module *owner;
+ const char *api_ver;
+ int flags;
+ unsigned long qf_pg_start[UACCE_QFRT_MAX];
+
+ int (*get_queue)(struct uacce *uacce, unsigned long arg,
+ struct uacce_queue **q);
+ void (*put_queue)(struct uacce_queue *q);
+ int (*start_queue)(struct uacce_queue *q);
+ void (*stop_queue)(struct uacce_queue *q);
+ int (*is_q_updated)(struct uacce_queue *q);
+ void (*mask_notify)(struct uacce_queue *q, int event_mask);
+ int (*mmap)(struct uacce_queue *q, struct vm_area_struct *vma);
+ int (*map)(struct uacce_queue *q, struct uacce_qfile_region *qfr);
+ void (*unmap)(struct uacce_queue *q, struct uacce_qfile_region *qfr);
+ int (*reset)(struct uacce *uacce);
+ int (*reset_queue)(struct uacce_queue *q);
+ long (*ioctl)(struct uacce_queue *q, unsigned int cmd,
+ unsigned long arg);
+};
+
+struct uacce_queue {
+ struct uacce *uacce;
+ __u32 flags;
+ void *priv;
+ wait_queue_head_t wait;
+
+#ifdef CONFIG_IOMMU_SVA
+ int pasid;
+#endif
+ struct list_head list; /* as list for as->qs */
+
+ struct mm_struct *mm;
+
+ struct uacce_qfile_region *qfrs[UACCE_QFRT_MAX];
+};
+
+#define UACCE_ST_INIT 0
+#define UACCE_ST_OPENNED 1
+#define UACCE_ST_STARTED 2
+
+struct uacce {
+ const char *name;
+ int status;
+ struct uacce_ops *ops;
+ struct device *dev;
+ struct device cls_dev;
+ bool is_vf;
+ u32 dev_id;
+ struct cdev *cdev;
+ void *priv;
+ atomic_t state;
+ int prot;
+};
+
+int uacce_register(struct uacce *uacce);
+void uacce_unregister(struct uacce *uacce);
+void uacce_wake_up(struct uacce_queue *q);
+const char *uacce_qfrt_str(struct uacce_qfile_region *qfr);
+
+#endif
diff --git a/include/uapi/linux/uacce.h b/include/uapi/linux/uacce.h
new file mode 100644
index 000000000000..b30fd92dc07e
--- /dev/null
+++ b/include/uapi/linux/uacce.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _UAPIUUACCE_H
+#define _UAPIUUACCE_H
+
+#include <linux/types.h>
+#include <linux/ioctl.h>
+
+#define UACCE_CLASS_NAME "uacce"
+
+#define UACCE_CMD_SHARE_SVAS _IO('W', 0)
+
+/**
+ * UACCE Device Attributes:
+ *
+ * NOIOMMU: the device has no IOMMU support
+ * can do ssva, but no map to the dev
+ * PASID: the device has IOMMU which support PASID setting
+ * can do ssva, mapped to dev per process
+ * FAULT_FROM_DEV: the device has IOMMU which can do page fault request
+ * no need for ssva, should be used with PASID
+ * KMAP_DUS: map the Device user-shared space to kernel
+ * SVA: full function device
+ * SHARE_DOMAIN: no PASID, can do ssva only for one process and the kernel
+ */
+#define UACCE_DEV_NOIOMMU (1<<0)
+#define UACCE_DEV_PASID (1<<1)
+#define UACCE_DEV_FAULT_FROM_DEV (1<<2)
+#define UACCE_DEV_KMAP_DUS (1<<3)
+
+#define UACCE_DEV_SVA (UACCE_DEV_PASID | UACCE_DEV_FAULT_FROM_DEV)
+#define UACCE_DEV_SHARE_DOMAIN (0)
+
+#endif
--
2.17.1
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