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

Oded Gabbay
2019-01-25T21:47:34Z

On Wed, Jan 23, 2019 at 2:28 PM Mike Rapoport <rppt@linux.ibm.com> wrote:
>
> On Wed, Jan 23, 2019 at 02:00:47AM +0200, Oded Gabbay wrote:
> > This patch adds the CB module, which allows the user to create and
> > destroy CBs and to map them to the user's process address-space.
>
> Can you please spell "command buffer" at least first time it's mentioned?
fixed
>
> > 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>
> > ---
> > drivers/misc/habanalabs/Makefile | 3 +-
> > drivers/misc/habanalabs/command_buffer.c | 414 +++++++++++++++++++++
> > drivers/misc/habanalabs/device.c | 43 ++-
> > drivers/misc/habanalabs/goya/goya.c | 28 ++
> > drivers/misc/habanalabs/habanalabs.h | 95 ++++-
> > drivers/misc/habanalabs/habanalabs_drv.c | 2 +
> > drivers/misc/habanalabs/habanalabs_ioctl.c | 102 +++++
> > include/uapi/misc/habanalabs.h | 62 +++
> > 8 files changed, 746 insertions(+), 3 deletions(-)
> > create mode 100644 drivers/misc/habanalabs/command_buffer.c
> > create mode 100644 drivers/misc/habanalabs/habanalabs_ioctl.c
> > create mode 100644 include/uapi/misc/habanalabs.h
> >
> > diff --git a/drivers/misc/habanalabs/Makefile b/drivers/misc/habanalabs/Makefile
> > index 3ffbadc2ca01..2530c9b78ca4 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..535ed6cc5bda
> > --- /dev/null
> > +++ b/drivers/misc/habanalabs/command_buffer.c
> > @@ -0,0 +1,414 @@
> > +// 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);
>
> As it seems, ASIC specific dma_free_coherent is a shortcut for a generic
> dma_free_coherent. Why not use it directly?
>
As I explained in a previous patch review, there is a different
implementation when I'm working with a simulator.

> > + 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;
> > +
> > + if (ctx_id == HL_KERNEL_ASID_ID)
> > + cb = kzalloc(sizeof(*cb), GFP_ATOMIC);
>
> The GFP_ATOMIC should be used when the caller cannot tolerate reclaim or
> sleep and it does not seem to be the case here.
>
Yes, I can see why this is misleading. The call of this function from
latency-sensitive code comes in a much later patch (command
submission).
In short, due to H/W limitations, I must copy the CB of the user to a
kernel allocated CB (in case of an external queue) and this must be
done during command submission. Hence the GFP_ATOMIC flag in all
memory allocations in this function.
I will add a comment in this patch explaining this.

btw, we solved this problem in future ASICs.

> > + 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);
>
> GFP_KERNEL?
Same explanation as above.
>
> > + 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_warn_once(hdev->dev, "CB pool is empty\n");
>
> Isn't it going to be a false alarm when you allocate the cb for the first
> time?
Why ?
The cb_pool list holds a list of available CBs. See hl_cb_pool_init()
- it adds newly allocated CBs to this pool list.

if (!list_empty(&hdev->cb_pool)) { - this checks whether the
pool is not empty so we can take an available CB from it. If the list
is empty (hence the pool is empty), we print the warning.

>
> > + }
> > + }
> > +
> > + 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);
>
> It seems the ID will remain dangling if the cb is reused.

I'm not sure what you mean by this comment. Reused by whom ? in how
fashion it is reused ?

>
> > + 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);
> > + goto err_out;
>
> why no simply return -EINVAL?
>
fixed
> > + }
> > +
> > + /* 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);
> > + goto put_cb;
> > + }
> > +
> > + spin_lock(&cb->lock);
> > +
> > + if (cb->mmap) {
> > + dev_err(hdev->dev,
> > + "CB mmap failed, CB already mmaped to user\n");
> > + 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);
> > +err_out:
> > + return -EINVAL;
> > +}
> > +
> > +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 84ce9fcb52da..0bd86a7d34db 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
> > };
> >
> > /**
> > @@ -145,6 +170,8 @@ 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->device_open);
> > atomic_set(&hdev->fd_open_cnt, 0);
> >
> > @@ -166,6 +193,8 @@ 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)
> > @@ -280,11 +309,21 @@ 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:
> > @@ -321,6 +360,8 @@ 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 b2952296b890..341ac085af82 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;
> > }
> >
> > /**
> > @@ -598,6 +603,27 @@ 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)
> > {
> > @@ -617,6 +643,8 @@ 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 d003a6af2131..6ad476df65b0 100644
> > --- a/drivers/misc/habanalabs/habanalabs.h
> > +++ b/drivers/misc/habanalabs/habanalabs.h
> > @@ -21,10 +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;
> >
> >
> >
> > @@ -53,6 +55,8 @@ 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 {
> > @@ -73,11 +77,68 @@ 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
> >
> >
> > @@ -109,6 +170,8 @@ 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: DMA allocate coherent memory.
> > * @dma_free_coherent: free DMA allocation.
> > */
> > @@ -119,6 +182,9 @@ 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,
> > @@ -175,6 +241,7 @@ 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 {
> > @@ -183,6 +250,7 @@ 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;
> > };
> >
> > @@ -239,6 +307,7 @@ 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.
> > @@ -249,6 +318,8 @@ 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 context executing.
> > * @major: habanalabs KMD major.
> > @@ -264,6 +335,7 @@ 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;
> > @@ -275,6 +347,10 @@ 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: The following fields should be moved for multi-context */
> > struct hl_ctx *user_ctx;
> > atomic_t fd_open_cnt;
> > @@ -345,6 +421,23 @@ 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 0646da83eb53..5c312dd3aa50 100644
> > --- a/drivers/misc/habanalabs/habanalabs_drv.c
> > +++ b/drivers/misc/habanalabs/habanalabs_drv.c
> > @@ -123,6 +123,7 @@ 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);
> > @@ -138,6 +139,7 @@ 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..fa2287569e0e
> > --- /dev/null
> > +++ b/drivers/misc/habanalabs/habanalabs_ioctl.c
> > @@ -0,0 +1,102 @@
> > +// 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];
> > + char *kdata = NULL;
> > + unsigned int usize, asize;
> > + int retcode = -EINVAL;
> > +
> > + if (nr >= HL_CORE_IOCTL_COUNT)
>
> nr > HL_CORE_IOCTL_COUNT, isn't it?
>
> > + goto err_i1;
>
> err_i1 is not very meaningfull. Maybe invalid_ioctl?
Changed to out_err as this is used from other places in this function
>
> > +
> > + if ((nr >= HL_COMMAND_START) && (nr < HL_COMMAND_END)) {
>
> The HL_COMMAND_{START,END} do not seem to be defined.
They are defined in uapi/misc/habanalabs.h

> Besides, this check seem to be overlapped with
>
> if (nr > HL_CORE_IOCTL_COUNT)

Correct, removed the first if (HL_CORE_IOCTL_COUNT)
>
> > + 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 {
> > + goto err_i1;
> > + }
> > +
> > + /* Do not trust userspace, use our own definition */
> > + func = ioctl->func;
> > +
> > + if (unlikely(!func)) {
> > + dev_dbg(hdev->dev, "no function\n");
> > + retcode = -EINVAL;
> > + goto err_i1;
> > + }
> > +
> > + if (cmd & (IOC_IN | IOC_OUT)) {
> > + if (asize <= sizeof(stack_kdata)) {
> > + kdata = stack_kdata;
> > + } else {
> > + kdata = kmalloc(asize, GFP_KERNEL);
> > + if (!kdata) {
> > + retcode = -ENOMEM;
> > + goto err_i1;
> > + }
> > + }
> > + if (asize > usize)
> > + memset(kdata + usize, 0, asize - usize);
>
> Just init stack_kdata to 0 and use kzalloc instead of malloc.
fixed
>
> > + }
> > +
> > + if (cmd & IOC_IN) {
> > + if (copy_from_user(kdata, (void __user *)arg, usize)) {
> > + retcode = -EFAULT;
> > + goto err_i1;
> > + }
> > + } 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;
> > +
> > +err_i1:
> > + if (!ioctl)
> > + dev_dbg(hdev->dev,
> > + "invalid ioctl: pid=%d, cmd=0x%02x, nr=0x%02x\n",
> > + task_pid_nr(current), cmd, nr);
>
> I think this can move right after the 'nr' sanity check and there you can
> simple return -EINVAL after dev_dbg().
But you reach here from many different places and I want to print the
ioctl information for each case.
I think the real mistake here is if(!ioctl). This should actually be
if (ioctl) because only then it is relevant for most of the places in
this function that has an error.
And I'll add a dedicated print if the nr is not correct.
>
> > +
> > + if (kdata != stack_kdata)
> > + kfree(kdata);
> > +
> > + return retcode;
> > +}
> > diff --git a/include/uapi/misc/habanalabs.h b/include/uapi/misc/habanalabs.h
> > new file mode 100644
> > index 000000000000..b3f9213d4709
> > --- /dev/null
> > +++ b/include/uapi/misc/habanalabs.h
> > @@ -0,0 +1,62 @@
> > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note
> > + *
> > + * Copyright 2016-2018 HabanaLabs, Ltd.
> > + * All Rights Reserved.
> > + *
> > + * Author: Oded Gabbay <oded.gabbay@gmail.com>
> > + *
> > + */
> > +
> > +#ifndef HABANALABS_H_
> > +#define HABANALABS_H_
> > +
> > +#include <linux/types.h>
> > +#include <linux/ioctl.h>
> > +
> > +/* 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
> >
>
> --
> Sincerely yours,
> Mike.
>