[PATCH v2 05/15] habanalabs: add command buffer module

Oded Gabbay
2019-01-30T23:11:44Z

This patch adds the command buffer (CB) module, which allows the user to
create and destroy CBs and to map them to the user's process
address-space.

A command buffer is a memory blocks that reside in DMA-able address-space
and is physically contiguous so it can be accessed by the device without
MMU translation. The command buffer memory is allocated using the
coherent DMA API.

When creating a new CB, the IOCTL returns a handle of it, and the
user-space process needs to use that handle to mmap the buffer to get a VA
in the user's address-space.

Before destroying (freeing) a CB, the user must unmap the CB's VA using the
CB handle.

Each CB has a reference counter, which tracks its usage in command
submissions and also its mmaps (only a single mmap is allowed).

The driver maintains a pool of pre-allocated CBs in order to reduce
latency during command submissions. In case the pool is empty, the driver
will go to the slow-path of allocating a new CB, i.e. calling
dma_alloc_coherent.

Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
---
Changes in v2:
- Add comment in hl_cb_alloc() about use of GFP_ATOMIC
- Use dev_dbg when printing about empty cb pool
- Simplify return of error code in hl_cb_mmap()
- Remove redundant ioctl numbers check in hl_ioctl()
- Use kzalloc instead of doing memset for kdata in hl_ioctl()

drivers/misc/habanalabs/Makefile | 3 +-
drivers/misc/habanalabs/command_buffer.c | 423 +++++++++++++++++++++
drivers/misc/habanalabs/device.c | 43 ++-
drivers/misc/habanalabs/goya/goya.c | 28 ++
drivers/misc/habanalabs/habanalabs.h | 86 +++++
drivers/misc/habanalabs/habanalabs_drv.c | 2 +
drivers/misc/habanalabs/habanalabs_ioctl.c | 99 +++++
include/uapi/misc/habanalabs.h | 46 +++
8 files changed, 728 insertions(+), 2 deletions(-)
create mode 100644 drivers/misc/habanalabs/command_buffer.c
create mode 100644 drivers/misc/habanalabs/habanalabs_ioctl.c

diff --git a/drivers/misc/habanalabs/Makefile b/drivers/misc/habanalabs/Makefile
index 4944d6ccf8fe..06c886289049 100644
--- a/drivers/misc/habanalabs/Makefile
+++ b/drivers/misc/habanalabs/Makefile
@@ -4,7 +4,8 @@

obj-m := habanalabs.o

-habanalabs-y := habanalabs_drv.o device.o context.o asid.o
+habanalabs-y := habanalabs_drv.o device.o context.o asid.o habanalabs_ioctl.o \
+ command_buffer.o

include $(src)/goya/Makefile
habanalabs-y += $(HL_GOYA_FILES)
diff --git a/drivers/misc/habanalabs/command_buffer.c b/drivers/misc/habanalabs/command_buffer.c
new file mode 100644
index 000000000000..f45c3f15e07a
--- /dev/null
+++ b/drivers/misc/habanalabs/command_buffer.c
@@ -0,0 +1,423 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright 2016-2018 HabanaLabs, Ltd.
+ * All Rights Reserved.
+ */
+
+#include <uapi/misc/habanalabs.h>
+#include "habanalabs.h"
+
+#include <linux/dma-mapping.h>
+
+static void cb_fini(struct hl_device *hdev, struct hl_cb *cb)
+{
+ hdev->asic_funcs->dma_free_coherent(hdev, cb->size,
+ (void *) cb->kernel_address, cb->bus_address);
+ kfree(cb);
+}
+
+static void cb_do_release(struct hl_device *hdev, struct hl_cb *cb)
+{
+ if (cb->is_pool) {
+ spin_lock(&hdev->cb_pool_lock);
+ list_add(&cb->pool_list, &hdev->cb_pool);
+ spin_unlock(&hdev->cb_pool_lock);
+ } else {
+ cb_fini(hdev, cb);
+ }
+}
+
+static void cb_release(struct kref *ref)
+{
+ struct hl_device *hdev;
+ struct hl_cb *cb;
+
+ cb = container_of(ref, struct hl_cb, refcount);
+ hdev = cb->hdev;
+
+ cb_do_release(hdev, cb);
+}
+
+static struct hl_cb *hl_cb_alloc(struct hl_device *hdev, u32 cb_size,
+ int ctx_id)
+{
+ struct hl_cb *cb;
+ void *p;
+
+ /*
+ * We use of GFP_ATOMIC here because this function can be called from
+ * the latency-sensitive code path for command submission. Due to H/W
+ * limitations in some of the ASICs, the kernel must copy the user CB
+ * that is designated for an external queue and actually enqueue
+ * the kernel's copy. Hence, we must never sleep in this code section
+ * and must use GFP_ATOMIC for all memory allocations.
+ */
+ if (ctx_id == HL_KERNEL_ASID_ID)
+ cb = kzalloc(sizeof(*cb), GFP_ATOMIC);
+ else
+ cb = kzalloc(sizeof(*cb), GFP_KERNEL);
+
+ if (!cb)
+ return NULL;
+
+ if (ctx_id == HL_KERNEL_ASID_ID)
+ p = hdev->asic_funcs->dma_alloc_coherent(hdev, cb_size,
+ &cb->bus_address, GFP_ATOMIC);
+ else
+ p = hdev->asic_funcs->dma_alloc_coherent(hdev, cb_size,
+ &cb->bus_address,
+ GFP_USER | __GFP_ZERO);
+ if (!p) {
+ dev_err(hdev->dev,
+ "failed to allocate %d of dma memory for CB\n",
+ cb_size);
+ kfree(cb);
+ return NULL;
+ }
+
+ cb->kernel_address = (u64) p;
+ cb->size = cb_size;
+
+ return cb;
+}
+
+int hl_cb_create(struct hl_device *hdev, struct hl_cb_mgr *mgr,
+ u32 cb_size, u64 *handle, int ctx_id)
+{
+ struct hl_cb *cb;
+ bool alloc_new_cb = true;
+ int rc;
+
+ if (hdev->disabled) {
+ dev_warn_ratelimited(hdev->dev,
+ "Device is disabled !!! Can't create new CBs\n");
+ rc = -EBUSY;
+ goto out_err;
+ }
+
+ /* Minimum allocation must be PAGE SIZE */
+ if (cb_size < PAGE_SIZE)
+ cb_size = PAGE_SIZE;
+
+ if (ctx_id == HL_KERNEL_ASID_ID &&
+ cb_size <= hdev->asic_prop.cb_pool_cb_size) {
+
+ spin_lock(&hdev->cb_pool_lock);
+ if (!list_empty(&hdev->cb_pool)) {
+ cb = list_first_entry(&hdev->cb_pool, typeof(*cb),
+ pool_list);
+ list_del(&cb->pool_list);
+ spin_unlock(&hdev->cb_pool_lock);
+ alloc_new_cb = false;
+ } else {
+ spin_unlock(&hdev->cb_pool_lock);
+ dev_dbg(hdev->dev, "CB pool is empty\n");
+ }
+ }
+
+ if (alloc_new_cb) {
+ cb = hl_cb_alloc(hdev, cb_size, ctx_id);
+ if (!cb) {
+ rc = -ENOMEM;
+ goto out_err;
+ }
+ }
+
+ cb->hdev = hdev;
+ cb->ctx_id = ctx_id;
+
+ spin_lock(&mgr->cb_lock);
+ rc = idr_alloc(&mgr->cb_handles, cb, 1, 0, GFP_ATOMIC);
+ spin_unlock(&mgr->cb_lock);
+
+ if (rc < 0) {
+ dev_err(hdev->dev, "Failed to allocate IDR for a new CB\n");
+ goto release_cb;
+ }
+
+ cb->id = rc;
+
+ kref_init(&cb->refcount);
+ spin_lock_init(&cb->lock);
+
+ /*
+ * idr is 32-bit so we can safely OR it with a mask that is above
+ * 32 bit
+ */
+ *handle = cb->id | HL_MMAP_CB_MASK;
+ *handle <<= PAGE_SHIFT;
+
+ return 0;
+
+release_cb:
+ cb_do_release(hdev, cb);
+out_err:
+ *handle = 0;
+
+ return rc;
+}
+
+int hl_cb_destroy(struct hl_device *hdev, struct hl_cb_mgr *mgr, u64 cb_handle)
+{
+ struct hl_cb *cb;
+ u32 handle;
+ int rc = 0;
+
+ /*
+ * handle was given to user to do mmap, I need to shift it back to
+ * how the idr module gave it to me
+ */
+ cb_handle >>= PAGE_SHIFT;
+ handle = (u32) cb_handle;
+
+ spin_lock(&mgr->cb_lock);
+
+ cb = idr_find(&mgr->cb_handles, handle);
+ if (cb) {
+ idr_remove(&mgr->cb_handles, handle);
+ spin_unlock(&mgr->cb_lock);
+ kref_put(&cb->refcount, cb_release);
+ } else {
+ spin_unlock(&mgr->cb_lock);
+ dev_err(hdev->dev,
+ "CB destroy failed, no match to handle 0x%x\n", handle);
+ rc = -EINVAL;
+ }
+
+ return rc;
+}
+
+int hl_cb_ioctl(struct hl_fpriv *hpriv, void *data)
+{
+ union hl_cb_args *args = data;
+ struct hl_device *hdev = hpriv->hdev;
+ u64 handle;
+ int rc;
+
+ switch (args->in.op) {
+ case HL_CB_OP_CREATE:
+ rc = hl_cb_create(hdev, &hpriv->cb_mgr, args->in.cb_size,
+ &handle, hpriv->ctx->asid);
+ memset(args, 0, sizeof(*args));
+ args->out.cb_handle = handle;
+ break;
+ case HL_CB_OP_DESTROY:
+ rc = hl_cb_destroy(hdev, &hpriv->cb_mgr,
+ args->in.cb_handle);
+ memset(args, 0, sizeof(*args));
+ break;
+ default:
+ rc = -EINVAL;
+ break;
+ }
+
+ return rc;
+}
+
+static void cb_vm_close(struct vm_area_struct *vma)
+{
+ struct hl_cb *cb = (struct hl_cb *) vma->vm_private_data;
+
+ hl_cb_put(cb);
+
+ spin_lock(&cb->lock);
+ cb->mmap = false;
+ cb->vm_start = 0;
+ cb->vm_end = 0;
+ spin_unlock(&cb->lock);
+
+ vma->vm_private_data = NULL;
+}
+
+static const struct vm_operations_struct cb_vm_ops = {
+ .close = cb_vm_close
+};
+
+int hl_cb_mmap(struct hl_fpriv *hpriv, struct vm_area_struct *vma)
+{
+ struct hl_device *hdev = hpriv->hdev;
+ struct hl_cb *cb;
+ phys_addr_t address;
+ u32 handle;
+ int rc;
+
+ handle = vma->vm_pgoff;
+
+ /* reference was taken here */
+ cb = hl_cb_get(hdev, &hpriv->cb_mgr, handle);
+ if (!cb) {
+ dev_err(hdev->dev,
+ "CB mmap failed, no match to handle %d\n", handle);
+ return -EINVAL;
+ }
+
+ /* Validation check */
+ if (vma->vm_end - vma->vm_start != cb->size) {
+ dev_err(hdev->dev,
+ "CB mmap failed, mmap size 0x%lx != 0x%x cb size\n",
+ vma->vm_end - vma->vm_start, cb->size);
+ rc = -EINVAL;
+ goto put_cb;
+ }
+
+ spin_lock(&cb->lock);
+
+ if (cb->mmap) {
+ dev_err(hdev->dev,
+ "CB mmap failed, CB already mmaped to user\n");
+ rc = -EINVAL;
+ goto release_lock;
+ }
+
+ cb->mmap = true;
+
+ spin_unlock(&cb->lock);
+
+ vma->vm_ops = &cb_vm_ops;
+
+ /*
+ * Note: We're transferring the cb reference to
+ * vma->vm_private_data here.
+ */
+
+ vma->vm_private_data = cb;
+
+ /* Calculate address for CB */
+ address = virt_to_phys((void *) cb->kernel_address);
+
+ rc = hdev->asic_funcs->cb_mmap(hdev, vma, cb->kernel_address,
+ address, cb->size);
+
+ if (rc) {
+ spin_lock(&cb->lock);
+ cb->mmap = false;
+ goto release_lock;
+ }
+
+ cb->vm_start = vma->vm_start;
+ cb->vm_end = vma->vm_end;
+
+ return 0;
+
+release_lock:
+ spin_unlock(&cb->lock);
+put_cb:
+ hl_cb_put(cb);
+ return rc;
+}
+
+struct hl_cb *hl_cb_get(struct hl_device *hdev, struct hl_cb_mgr *mgr,
+ u32 handle)
+{
+ struct hl_cb *cb;
+
+ spin_lock(&mgr->cb_lock);
+ cb = idr_find(&mgr->cb_handles, handle);
+
+ if (!cb) {
+ spin_unlock(&mgr->cb_lock);
+ dev_warn(hdev->dev,
+ "CB get failed, no match to handle %d\n", handle);
+ return NULL;
+ }
+
+ kref_get(&cb->refcount);
+
+ spin_unlock(&mgr->cb_lock);
+
+ return cb;
+
+}
+
+void hl_cb_put(struct hl_cb *cb)
+{
+ kref_put(&cb->refcount, cb_release);
+}
+
+void hl_cb_mgr_init(struct hl_cb_mgr *mgr)
+{
+ spin_lock_init(&mgr->cb_lock);
+ idr_init(&mgr->cb_handles);
+}
+
+void hl_cb_mgr_fini(struct hl_device *hdev, struct hl_cb_mgr *mgr)
+{
+ struct hl_cb *cb;
+ struct idr *idp;
+ u32 id;
+
+ idp = &mgr->cb_handles;
+
+ idr_for_each_entry(idp, cb, id) {
+ if (kref_put(&cb->refcount, cb_release) != 1)
+ dev_err(hdev->dev,
+ "CB %d for CTX ID %d is still alive\n",
+ id, cb->ctx_id);
+ }
+
+ idr_destroy(&mgr->cb_handles);
+}
+
+struct hl_cb *hl_cb_kernel_create(struct hl_device *hdev, u32 cb_size)
+{
+ u64 cb_handle;
+ struct hl_cb *cb;
+ int rc;
+
+ rc = hl_cb_create(hdev, &hdev->kernel_cb_mgr, cb_size, &cb_handle,
+ HL_KERNEL_ASID_ID);
+ if (rc) {
+ dev_err(hdev->dev, "Failed to allocate CB for KMD %d\n", rc);
+ return NULL;
+ }
+
+ cb_handle >>= PAGE_SHIFT;
+ cb = hl_cb_get(hdev, &hdev->kernel_cb_mgr, (u32) cb_handle);
+ /* hl_cb_get should never fail here so use kernel WARN */
+ WARN(!cb, "Kernel CB handle invalid 0x%x\n", (u32) cb_handle);
+ if (!cb)
+ goto destroy_cb;
+
+ return cb;
+
+destroy_cb:
+ hl_cb_destroy(hdev, &hdev->kernel_cb_mgr, cb_handle << PAGE_SHIFT);
+
+ return NULL;
+}
+
+int hl_cb_pool_init(struct hl_device *hdev)
+{
+ struct hl_cb *cb;
+ int i;
+
+ INIT_LIST_HEAD(&hdev->cb_pool);
+ spin_lock_init(&hdev->cb_pool_lock);
+
+ for (i = 0 ; i < hdev->asic_prop.cb_pool_cb_cnt ; i++) {
+ cb = hl_cb_alloc(hdev, hdev->asic_prop.cb_pool_cb_size,
+ HL_KERNEL_ASID_ID);
+ if (cb) {
+ cb->is_pool = true;
+ list_add(&cb->pool_list, &hdev->cb_pool);
+ } else {
+ hl_cb_pool_fini(hdev);
+ return -ENOMEM;
+ }
+ }
+
+ return 0;
+}
+
+int hl_cb_pool_fini(struct hl_device *hdev)
+{
+ struct hl_cb *cb, *tmp;
+
+ list_for_each_entry_safe(cb, tmp, &hdev->cb_pool, pool_list) {
+ list_del(&cb->pool_list);
+ cb_fini(hdev, cb);
+ }
+
+ return 0;
+}
diff --git a/drivers/misc/habanalabs/device.c b/drivers/misc/habanalabs/device.c
index 81acb1de9c7e..c5296b068aaf 100644
--- a/drivers/misc/habanalabs/device.c
+++ b/drivers/misc/habanalabs/device.c
@@ -53,6 +53,7 @@ static int hl_device_release(struct inode *inode, struct file *filp)
{
struct hl_fpriv *hpriv = filp->private_data;

+ hl_cb_mgr_fini(hpriv->hdev, &hpriv->cb_mgr);
hl_ctx_mgr_fini(hpriv->hdev, &hpriv->ctx_mgr);

filp->private_data = NULL;
@@ -62,10 +63,34 @@ static int hl_device_release(struct inode *inode, struct file *filp)
return 0;
}

+/*
+ * hl_mmap - mmap function for habanalabs device
+ *
+ * @*filp: pointer to file structure
+ * @*vma: pointer to vm_area_struct of the process
+ *
+ * Called when process does an mmap on habanalabs device. Call the device's mmap
+ * function at the end of the common code.
+ */
+static int hl_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+ struct hl_fpriv *hpriv = filp->private_data;
+
+ if ((vma->vm_pgoff & HL_MMAP_CB_MASK) == HL_MMAP_CB_MASK) {
+ vma->vm_pgoff ^= HL_MMAP_CB_MASK;
+ return hl_cb_mmap(hpriv, vma);
+ }
+
+ return hpriv->hdev->asic_funcs->mmap(hpriv, vma);
+}
+
static const struct file_operations hl_ops = {
.owner = THIS_MODULE,
.open = hl_device_open,
- .release = hl_device_release
+ .release = hl_device_release,
+ .mmap = hl_mmap,
+ .unlocked_ioctl = hl_ioctl,
+ .compat_ioctl = hl_ioctl
};

/*
@@ -150,6 +175,8 @@ static int device_early_init(struct hl_device *hdev)
if (rc)
goto early_fini;

+ hl_cb_mgr_init(&hdev->kernel_cb_mgr);
+
mutex_init(&hdev->fd_open_cnt_lock);
atomic_set(&hdev->fd_open_cnt, 0);

@@ -171,6 +198,8 @@ static int device_early_init(struct hl_device *hdev)
static void device_early_fini(struct hl_device *hdev)
{

+ hl_cb_mgr_fini(hdev, &hdev->kernel_cb_mgr);
+
hl_asid_fini(hdev);

if (hdev->asic_funcs->early_fini)
@@ -285,11 +314,21 @@ int hl_device_init(struct hl_device *hdev, struct class *hclass)
goto free_ctx;
}

+ rc = hl_cb_pool_init(hdev);
+ if (rc) {
+ dev_err(hdev->dev, "failed to initialize CB pool\n");
+ goto release_ctx;
+ }
+
dev_notice(hdev->dev,
"Successfully added device to habanalabs driver\n");

return 0;

+release_ctx:
+ if (hl_ctx_put(hdev->kernel_ctx) != 1)
+ dev_err(hdev->dev,
+ "kernel ctx is still alive on initialization failure\n");
free_ctx:
kfree(hdev->kernel_ctx);
sw_fini:
@@ -326,6 +365,8 @@ void hl_device_fini(struct hl_device *hdev)
/* Mark device as disabled */
hdev->disabled = true;

+ hl_cb_pool_fini(hdev);
+
/* Release kernel context */
if ((hdev->kernel_ctx) && (hl_ctx_put(hdev->kernel_ctx) != 1))
dev_err(hdev->dev, "kernel ctx is still alive\n");
diff --git a/drivers/misc/habanalabs/goya/goya.c b/drivers/misc/habanalabs/goya/goya.c
index 47e7472b7472..6626dead7231 100644
--- a/drivers/misc/habanalabs/goya/goya.c
+++ b/drivers/misc/habanalabs/goya/goya.c
@@ -92,6 +92,9 @@

#define GOYA_MAX_INITIATORS 20

+#define GOYA_CB_POOL_CB_CNT 512
+#define GOYA_CB_POOL_CB_SIZE 0x20000 /* 128KB */
+
static void goya_get_fixed_properties(struct hl_device *hdev)
{
struct asic_fixed_properties *prop = &hdev->asic_prop;
@@ -119,6 +122,8 @@ static void goya_get_fixed_properties(struct hl_device *hdev)
prop->tpc_enabled_mask = TPC_ENABLED_MASK;

prop->high_pll = PLL_HIGH_DEFAULT;
+ prop->cb_pool_cb_cnt = GOYA_CB_POOL_CB_CNT;
+ prop->cb_pool_cb_size = GOYA_CB_POOL_CB_SIZE;
}

/*
@@ -604,6 +609,27 @@ int goya_resume(struct hl_device *hdev)
return 0;
}

+int goya_mmap(struct hl_fpriv *hpriv, struct vm_area_struct *vma)
+{
+ return -EINVAL;
+}
+
+int goya_cb_mmap(struct hl_device *hdev, struct vm_area_struct *vma,
+ u64 kaddress, phys_addr_t paddress, u32 size)
+{
+ int rc;
+
+ vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP |
+ VM_DONTCOPY | VM_NORESERVE;
+
+ rc = remap_pfn_range(vma, vma->vm_start, paddress >> PAGE_SHIFT,
+ size, vma->vm_page_prot);
+ if (rc)
+ dev_err(hdev->dev, "remap_pfn_range error %d", rc);
+
+ return rc;
+}
+
void *goya_dma_alloc_coherent(struct hl_device *hdev, size_t size,
dma_addr_t *dma_handle, gfp_t flags)
{
@@ -623,6 +649,8 @@ static const struct hl_asic_funcs goya_funcs = {
.sw_fini = goya_sw_fini,
.suspend = goya_suspend,
.resume = goya_resume,
+ .mmap = goya_mmap,
+ .cb_mmap = goya_cb_mmap,
.dma_alloc_coherent = goya_dma_alloc_coherent,
.dma_free_coherent = goya_dma_free_coherent,
};
diff --git a/drivers/misc/habanalabs/habanalabs.h b/drivers/misc/habanalabs/habanalabs.h
index 9f76373b3e2c..0ca174a8dad9 100644
--- a/drivers/misc/habanalabs/habanalabs.h
+++ b/drivers/misc/habanalabs/habanalabs.h
@@ -21,9 +21,12 @@

#define HL_NAME "habanalabs"

+#define HL_MMAP_CB_MASK (0x8000000000000000ull >> PAGE_SHIFT)
+
#define HL_MAX_QUEUES 128

struct hl_device;
+struct hl_fpriv;

/**
@@ -51,6 +54,8 @@ struct hl_device;
* @max_asid: maximum number of open contexts (ASIDs).
* @completion_queues_count: number of completion queues.
* @high_pll: high PLL frequency used by the device.
+ * @cb_pool_cb_cnt: number of CBs in the CB pool.
+ * @cb_pool_cb_size: size of each CB in the CB pool.
* @tpc_enabled_mask: which TPCs are enabled.
*/
struct asic_fixed_properties {
@@ -71,11 +76,60 @@ struct asic_fixed_properties {
u32 sram_size;
u32 max_asid;
u32 high_pll;
+ u32 cb_pool_cb_cnt;
+ u32 cb_pool_cb_size;
u8 completion_queues_count;
u8 tpc_enabled_mask;
};

+/*
+ * Command Buffers
+ */
+
+/**
+ * struct hl_cb_mgr - describes a Command Buffer Manager.
+ * @cb_lock: protects cb_handles.
+ * @cb_handles: an idr to hold all command buffer handles.
+ */
+struct hl_cb_mgr {
+ spinlock_t cb_lock;
+ struct idr cb_handles; /* protected by cb_lock */
+};
+
+/**
+ * struct hl_cb - describes a Command Buffer.
+ * @refcount: reference counter for usage of the CB.
+ * @hdev: pointer to device this CB belongs to.
+ * @lock: spinlock to protect mmap/cs flows.
+ * @pool_list: node in pool list of command buffers.
+ * @kernel_address: Holds the CB's kernel virtual address.
+ * @bus_address: Holds the CB's DMA address.
+ * @vm_start: Holds the CB's user start virtual address (when mmaped).
+ * @vm_end: Holds the CB's user end virtual address (when mmaped).
+ * @size: holds the CB's size.
+ * @id: the CB's ID.
+ * @ctx_id: holds the ID of the owner's context.
+ * @mmap: true if the CB is currently mmaped to user.
+ * @is_pool: true if CB was acquired from the pool, false otherwise.
+ */
+struct hl_cb {
+ struct kref refcount;
+ struct hl_device *hdev;
+ spinlock_t lock;
+ struct list_head pool_list;
+ u64 kernel_address;
+ dma_addr_t bus_address;
+ u64 vm_start;
+ u64 vm_end;
+ u32 size;
+ u32 id;
+ u32 ctx_id;
+ u8 mmap;
+ u8 is_pool;
+};
+
+
#define HL_QUEUE_LENGTH 256

@@ -104,6 +158,8 @@ enum hl_asic_type {
* @sw_fini: tears down driver state, does not configure H/W.
* @suspend: handles IP specific H/W or SW changes for suspend.
* @resume: handles IP specific H/W or SW changes for resume.
+ * @mmap: mmap function, does nothing.
+ * @cb_mmap: maps a CB.
* @dma_alloc_coherent: Allocate coherent DMA memory by calling
* dma_alloc_coherent(). This is ASIC function because its
* implementation is not trivial when the driver is loaded
@@ -120,6 +176,9 @@ struct hl_asic_funcs {
int (*sw_fini)(struct hl_device *hdev);
int (*suspend)(struct hl_device *hdev);
int (*resume)(struct hl_device *hdev);
+ int (*mmap)(struct hl_fpriv *hpriv, struct vm_area_struct *vma);
+ int (*cb_mmap)(struct hl_device *hdev, struct vm_area_struct *vma,
+ u64 kaddress, phys_addr_t paddress, u32 size);
void* (*dma_alloc_coherent)(struct hl_device *hdev, size_t size,
dma_addr_t *dma_handle, gfp_t flag);
void (*dma_free_coherent)(struct hl_device *hdev, size_t size,
@@ -170,6 +229,7 @@ struct hl_ctx_mgr {
* @taskpid: current process ID.
* @ctx: current executing context.
* @ctx_mgr: context manager to handle multiple context for this FD.
+ * @cb_mgr: command buffer manager to handle multiple buffers for this FD.
* @refcount: number of related contexts.
*/
struct hl_fpriv {
@@ -178,6 +238,7 @@ struct hl_fpriv {
struct pid *taskpid;
struct hl_ctx *ctx; /* TODO: remove for multiple ctx */
struct hl_ctx_mgr ctx_mgr;
+ struct hl_cb_mgr cb_mgr;
struct kref refcount;
};

@@ -232,6 +293,7 @@ void hl_wreg(struct hl_device *hdev, u32 reg, u32 val);
* @asic_name: ASIC specific nmae.
* @asic_type: ASIC specific type.
* @kernel_ctx: KMD context structure.
+ * @kernel_cb_mgr: command buffer manager for creating/destroying/handling CGs.
* @dma_pool: DMA pool for small allocations.
* @cpu_accessible_dma_mem: KMD <-> ArmCP shared memory CPU address.
* @cpu_accessible_dma_address: KMD <-> ArmCP shared memory DMA address.
@@ -247,6 +309,8 @@ void hl_wreg(struct hl_device *hdev, u32 reg, u32 val);
* @asic_prop: ASIC specific immutable properties.
* @asic_funcs: ASIC specific functions.
* @asic_specific: ASIC specific information to use only from ASIC files.
+ * @cb_pool: list of preallocated CBs.
+ * @cb_pool_lock: protects the CB pool.
* @user_ctx: current user context executing.
* @fd_open_cnt: number of open user processes.
* @major: habanalabs KMD major.
@@ -262,6 +326,7 @@ struct hl_device {
char asic_name[16];
enum hl_asic_type asic_type;
struct hl_ctx *kernel_ctx;
+ struct hl_cb_mgr kernel_cb_mgr;
struct dma_pool *dma_pool;
void *cpu_accessible_dma_mem;
dma_addr_t cpu_accessible_dma_address;
@@ -273,6 +338,10 @@ struct hl_device {
struct asic_fixed_properties asic_prop;
const struct hl_asic_funcs *asic_funcs;
void *asic_specific;
+
+ struct list_head cb_pool;
+ spinlock_t cb_pool_lock;
+
/* TODO: remove user_ctx for multiple process support */
struct hl_ctx *user_ctx;
atomic_t fd_open_cnt;
@@ -341,6 +410,23 @@ int hl_device_resume(struct hl_device *hdev);
void hl_hpriv_get(struct hl_fpriv *hpriv);
void hl_hpriv_put(struct hl_fpriv *hpriv);

+int hl_cb_create(struct hl_device *hdev, struct hl_cb_mgr *mgr, u32 cb_size,
+ u64 *handle, int ctx_id);
+int hl_cb_destroy(struct hl_device *hdev, struct hl_cb_mgr *mgr, u64 cb_handle);
+int hl_cb_mmap(struct hl_fpriv *hpriv, struct vm_area_struct *vma);
+struct hl_cb *hl_cb_get(struct hl_device *hdev, struct hl_cb_mgr *mgr,
+ u32 handle);
+void hl_cb_put(struct hl_cb *cb);
+void hl_cb_mgr_init(struct hl_cb_mgr *mgr);
+void hl_cb_mgr_fini(struct hl_device *hdev, struct hl_cb_mgr *mgr);
+struct hl_cb *hl_cb_kernel_create(struct hl_device *hdev, u32 cb_size);
+int hl_cb_pool_init(struct hl_device *hdev);
+int hl_cb_pool_fini(struct hl_device *hdev);
+
void goya_set_asic_funcs(struct hl_device *hdev);

+/* IOCTLs */
+long hl_ioctl(struct file *filep, unsigned int cmd, unsigned long arg);
+int hl_cb_ioctl(struct hl_fpriv *hpriv, void *data);
+
#endif /* HABANALABSP_H_ */
diff --git a/drivers/misc/habanalabs/habanalabs_drv.c b/drivers/misc/habanalabs/habanalabs_drv.c
index 8ecb51fbb133..b07979c599e2 100644
--- a/drivers/misc/habanalabs/habanalabs_drv.c
+++ b/drivers/misc/habanalabs/habanalabs_drv.c
@@ -120,6 +120,7 @@ int hl_device_open(struct inode *inode, struct file *filp)
kref_init(&hpriv->refcount);
nonseekable_open(inode, filp);

+ hl_cb_mgr_init(&hpriv->cb_mgr);
hl_ctx_mgr_init(&hpriv->ctx_mgr);

rc = hl_ctx_create(hdev, hpriv);
@@ -135,6 +136,7 @@ int hl_device_open(struct inode *inode, struct file *filp)
out_err:
filp->private_data = NULL;
hl_ctx_mgr_fini(hpriv->hdev, &hpriv->ctx_mgr);
+ hl_cb_mgr_fini(hpriv->hdev, &hpriv->cb_mgr);
kfree(hpriv);

close_device:
diff --git a/drivers/misc/habanalabs/habanalabs_ioctl.c b/drivers/misc/habanalabs/habanalabs_ioctl.c
new file mode 100644
index 000000000000..ac3069dd4b19
--- /dev/null
+++ b/drivers/misc/habanalabs/habanalabs_ioctl.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright 2016-2018 HabanaLabs, Ltd.
+ * All Rights Reserved.
+ */
+
+#include <uapi/misc/habanalabs.h>
+#include "habanalabs.h"
+
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+#include <linux/cred.h>
+
+#define HL_IOCTL_DEF(ioctl, _func) \
+ [_IOC_NR(ioctl)] = {.cmd = ioctl, .func = _func}
+
+static const struct hl_ioctl_desc hl_ioctls[] = {
+ HL_IOCTL_DEF(HL_IOCTL_CB, hl_cb_ioctl)
+};
+
+#define HL_CORE_IOCTL_COUNT ARRAY_SIZE(hl_ioctls)
+
+long hl_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
+{
+ struct hl_fpriv *hpriv = filep->private_data;
+ struct hl_device *hdev = hpriv->hdev;
+ hl_ioctl_t *func;
+ const struct hl_ioctl_desc *ioctl = NULL;
+ unsigned int nr = _IOC_NR(cmd);
+ char stack_kdata[128] = {0};
+ char *kdata = NULL;
+ unsigned int usize, asize;
+ int retcode;
+
+ if ((nr >= HL_COMMAND_START) && (nr < HL_COMMAND_END)) {
+ u32 hl_size;
+
+ ioctl = &hl_ioctls[nr];
+
+ hl_size = _IOC_SIZE(ioctl->cmd);
+ usize = asize = _IOC_SIZE(cmd);
+ if (hl_size > asize)
+ asize = hl_size;
+
+ cmd = ioctl->cmd;
+ } else {
+ dev_err(hdev->dev, "invalid ioctl: pid=%d, nr=0x%02x\n",
+ task_pid_nr(current), nr);
+ return -EINVAL;
+ }
+
+ /* Do not trust userspace, use our own definition */
+ func = ioctl->func;
+
+ if (unlikely(!func)) {
+ dev_dbg(hdev->dev, "no function\n");
+ retcode = -EINVAL;
+ goto out_err;
+ }
+
+ if (cmd & (IOC_IN | IOC_OUT)) {
+ if (asize <= sizeof(stack_kdata)) {
+ kdata = stack_kdata;
+ } else {
+ kdata = kzalloc(asize, GFP_KERNEL);
+ if (!kdata) {
+ retcode = -ENOMEM;
+ goto out_err;
+ }
+ }
+ }
+
+ if (cmd & IOC_IN) {
+ if (copy_from_user(kdata, (void __user *)arg, usize)) {
+ retcode = -EFAULT;
+ goto out_err;
+ }
+ } else if (cmd & IOC_OUT) {
+ memset(kdata, 0, usize);
+ }
+
+ retcode = func(hpriv, kdata);
+
+ if (cmd & IOC_OUT)
+ if (copy_to_user((void __user *)arg, kdata, usize))
+ retcode = -EFAULT;
+
+out_err:
+ if (ioctl)
+ dev_dbg(hdev->dev,
+ "error in ioctl: pid=%d, cmd=0x%02x, nr=0x%02x\n",
+ task_pid_nr(current), cmd, nr);
+
+ if (kdata != stack_kdata)
+ kfree(kdata);
+
+ return retcode;
+}
diff --git a/include/uapi/misc/habanalabs.h b/include/uapi/misc/habanalabs.h
index a0ec23adf8f5..a8edfd3e9c95 100644
--- a/include/uapi/misc/habanalabs.h
+++ b/include/uapi/misc/habanalabs.h
@@ -17,4 +17,50 @@
*/
#define GOYA_KMD_SRAM_RESERVED_SIZE_FROM_START 0x8000 /* 32KB */

+/* Opcode to create a new command buffer */
+#define HL_CB_OP_CREATE 0
+/* Opcode to destroy previously created command buffer */
+#define HL_CB_OP_DESTROY 1
+
+struct hl_cb_in {
+ /* Handle of CB or 0 if we want to create one */
+ __u64 cb_handle;
+ /* HL_CB_OP_* */
+ __u32 op;
+ /* Size of CB. Minimum requested size must be PAGE_SIZE */
+ __u32 cb_size;
+ /* Context ID - Currently not in use */
+ __u32 ctx_id;
+ __u32 pad;
+};
+
+struct hl_cb_out {
+ /* Handle of CB */
+ __u64 cb_handle;
+};
+
+union hl_cb_args {
+ struct hl_cb_in in;
+ struct hl_cb_out out;
+};
+
+/*
+ * Command Buffer
+ * - Request a Command Buffer
+ * - Destroy a Command Buffer
+ *
+ * The command buffers are memory blocks that reside in DMA-able address
+ * space and are physically contiguous so they can be accessed by the device
+ * directly. They are allocated using the coherent DMA API.
+ *
+ * When creating a new CB, the IOCTL returns a handle of it, and the user-space
+ * process needs to use that handle to mmap the buffer so it can access them.
+ *
+ */
+#define HL_IOCTL_CB \
+ _IOWR('H', 0x02, union hl_cb_args)
+
+#define HL_COMMAND_START 0x02
+#define HL_COMMAND_END 0x03
+
#endif /* HABANALABS_H_ */
--
2.17.1