On 2019-05-13 12:03 p.m., Zeng, Oak wrote:
> Hi Felix,
>
> See comments inline [Oak]
>
> Hi Kent, there is one FYI embedded, so be careful when you merge this change
> back to kfd-staging branch.
>
> Regards,
> Oak
>
> -----Original Message-----
> From: Kuehling, Felix <[email protected]>
> Sent: Friday, May 10, 2019 4:28 PM
> To: Zeng, Oak <[email protected]>; [email protected]
> Cc: Keely, Sean <[email protected]>
> Subject: Re: [PATCH 7/8] drm/amdkfd: New IOCTL to allocate queue GWS
>
> On 2019-05-10 12:01 p.m., Zeng, Oak wrote:
>> Add a new kfd ioctl to allocate queue GWS. Queue GWS is released on
>> queue destroy.
>>
>> Change-Id: I60153c26a577992ad873e4292e759e5c3d5bbd15
>> Signed-off-by: Oak Zeng <[email protected]>
>> ---
>> drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 45
>> ++++++++++++++++++++++++++++++++
>> include/uapi/linux/kfd_ioctl.h | 19 +++++++++++++-
>> 2 files changed, 63 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
>> b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
>> index 38ae53f..17dd970 100644
>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
>> @@ -338,6 +338,11 @@ static int kfd_ioctl_destroy_queue(struct file
>> *filp, struct kfd_process *p,
>>
>> mutex_lock(&p->mutex);
>>
>> + if (pqm_get_gws(&p->pqm, args->queue_id)) {
>> + amdgpu_amdkfd_remove_gws_from_process(p->kgd_process_info,
>> + pqm_get_gws(&p->pqm, args->queue_id));
>> + pqm_set_gws(&p->pqm, args->queue_id, NULL);
>> + }
> It would be more robust if this was done inside pqm_destroy_queue. That way
> you'd handle other potential code paths that destroy queues (not sure there
> are any) and you wouldn't need pqm_get_gws exported from PQM.
>
> [Oak] Good idea. Will do it. Even though currently there is no other code
> path destroying a queue using gws, your way is safer for future code change.
>
>
>> retval = pqm_destroy_queue(&p->pqm, args->queue_id);
>>
>> mutex_unlock(&p->mutex);
>> @@ -1559,6 +1564,44 @@ static int kfd_ioctl_unmap_memory_from_gpu(struct
>> file *filep,
>> return err;
>> }
>>
>> +static int kfd_ioctl_alloc_queue_gws(struct file *filep,
>> + struct kfd_process *p, void *data)
>> +{
>> + int retval;
>> + struct kfd_ioctl_alloc_queue_gws_args *args = data;
>> + struct kfd_dev *dev = NULL;
>> + struct kgd_mem *mem;
>> +
>> + if (args->num_gws == 0)
>> + return -EINVAL;
>> +
>> + if (!hws_gws_support ||
>> + dev->dqm->sched_policy == KFD_SCHED_POLICY_NO_HWS)
>> + return -EINVAL;
>> +
>> + dev = kfd_device_by_id(args->gpu_id);
>> + if (!dev) {
>> + pr_debug("Could not find gpu id 0x%x\n", args->gpu_id);
>> + return -EINVAL;
>> + }
>> +
>> + retval = amdgpu_amdkfd_add_gws_to_process(p->kgd_process_info,
>> + dev->gws, &mem);
>> + if (unlikely(retval))
>> + return retval;
>> +
>> + mutex_lock(&p->mutex);
>> + retval = pqm_set_gws(&p->pqm, args->queue_id, mem);
>> + mutex_unlock(&p->mutex);
>> +
>> + if (unlikely(retval))
>> + amdgpu_amdkfd_remove_gws_from_process(p->kgd_process_info, mem);
>> +
>> + /* The gws_array parameter is reserved for future extension*/
>> + args->gws_array[0] = 0;
>> + return retval;
>> +}
>> +
>> static int kfd_ioctl_get_dmabuf_info(struct file *filep,
>> struct kfd_process *p, void *data)
>> {
>> @@ -1761,6 +1804,8 @@ static const struct amdkfd_ioctl_desc amdkfd_ioctls[]
>> = {
>> AMDKFD_IOCTL_DEF(AMDKFD_IOC_IMPORT_DMABUF,
>> kfd_ioctl_import_dmabuf, 0),
>>
>> + AMDKFD_IOCTL_DEF(AMDKFD_IOC_ALLOC_QUEUE_GWS,
>> + kfd_ioctl_alloc_queue_gws, 0),
>> };
>>
>> #define AMDKFD_CORE_IOCTL_COUNT ARRAY_SIZE(amdkfd_ioctls)
>> diff --git a/include/uapi/linux/kfd_ioctl.h
>> b/include/uapi/linux/kfd_ioctl.h index 20917c5..1964ab2 100644
>> --- a/include/uapi/linux/kfd_ioctl.h
>> +++ b/include/uapi/linux/kfd_ioctl.h
>> @@ -410,6 +410,20 @@ struct kfd_ioctl_unmap_memory_from_gpu_args {
>> __u32 n_success; /* to/from KFD */
>> };
>>
>> +/* Allocate GWS for specific queue
>> + *
>> + * @gpu_id: device identifier
>> + * @queue_id: queue's id that GWS is allocated for
>> + * @num_gws: how many GWS to allocate
>> + * @gws_array: used to return the allocated gws
>> + */
>> +struct kfd_ioctl_alloc_queue_gws_args {
>> + __u32 gpu_id; /* to KFD */
>> + __u32 queue_id; /* to KFD */
>> + __u32 num_gws; /* to KFD */
>> + __u32 *gws_array; /* from KFD */
> Don't use pointers in ioctl structures. Use uint64_t. Accessing user mode
> pointers requires copy_to/from_user or similar.
>
> Also prefer to move 64-bit elements to the first element to ensure proper
> alignment, and pad the structure to 64-bit for ABI compatibility.
>
> I'm not sure what your plan is for that gws_array. If it's a pointer to a
> user mode array, then that array needs be allocated by user mode. And user
> mode should probably pass down the size of the array it allocated in another
> parameter.
>
> That said, I think what we want is not an array, but just the index of the
> first GWS entry that was allocated for the queue, which is currently always
> 0. So I'm not sure why you're calling this an "array".
>
> [Oak] For the current design, one queue always get all 64 GWS, so returning
> the index of the first GWS (0) is not a problem. In the future, is it
> possible queue can only allocate a few none-contiguous GWS, for example GWS3
> and GWS56? If this is the case, we will have to copy an array of gws back to
> user space.
Current HW only support contiguous allocations of GWS. I don't foresee
that changing. I think we can acknowledge that in the API.
>
>> +};
>> +
>> struct kfd_ioctl_get_dmabuf_info_args {
>> __u64 size; /* from KFD */
>> __u64 metadata_ptr; /* to KFD */
>> @@ -529,7 +543,10 @@ enum kfd_mmio_remap {
>> #define AMDKFD_IOC_IMPORT_DMABUF \
>> AMDKFD_IOWR(0x1D, struct kfd_ioctl_import_dmabuf_args)
>>
>> +#define AMDKFD_IOC_ALLOC_QUEUE_GWS \
>> + AMDKFD_IOWR(0x1E, struct kfd_ioctl_alloc_queue_gws_args)
>> +
> This will force us to move some ioctl numbers in amd-kfd-staging and the DKMS
> branch, which will break the ABI of our ROCm releases. Not sure there is a
> good way to avoid that other than leaving a whole in the upstream ioctl
> space. I got push-back on that kind of thing when I originally upstreamed
> KFD. So this is just an FYI.
> [Oak] Yes, when we merge this changes back to amd-kfd-staging branch, we have
> to change the ioctl number for GWS allocation to 0x22, to accommodate extra
> kfd ioctls on kfd-staging branch. @Russell, Kent FYI
No, the other way around. With APIs that are upstream we should have
amd-kfd-staging match the upstream ABI. That means we have to move the
other non-upstream ioctl numbers.
Regards,
Felix
>
> Regards,
> Felix
>
>> #define AMDKFD_COMMAND_START 0x01
>> -#define AMDKFD_COMMAND_END 0x1E
>> +#define AMDKFD_COMMAND_END 0x1F
>>
>> #endif
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