[PATCH 4/8] drm/amdkfd: Separate doorbell allocation from PASID

Felix Kuehling felix.kuehling at amd.com
Wed Sep 13 21:11:58 UTC 2017


On 2017-09-13 03:40 PM, Alex Deucher wrote:
> On Tue, Sep 12, 2017 at 7:05 PM, Felix Kuehling <Felix.Kuehling at amd.com> wrote:
>> PASID management is moving into KGD. Limiting the PASID range to the
>> number of doorbell pages is no longer practical.
>>
>> Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com>
> Maybe you want this before patches 2 and 3?
> Acked-by: Alex Deucher <alexander.deucher at amd.com>

Thanks for the reviews. I'll wait to give Oded a chance to review as well.

I can change the order of commits. However, I prefer to keep the two KFD
commits next to each other. This one is preparation for the next one.
Patches 2 and 3 don't depend on this one.

Regards,
  Felix

>
>> ---
>>  drivers/gpu/drm/amd/amdkfd/kfd_device.c   |  7 -----
>>  drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c | 50 +++++++++++++++++++++----------
>>  drivers/gpu/drm/amd/amdkfd/kfd_priv.h     | 10 +++----
>>  drivers/gpu/drm/amd/amdkfd/kfd_process.c  |  6 ++++
>>  4 files changed, 45 insertions(+), 28 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device.c b/drivers/gpu/drm/amd/amdkfd/kfd_device.c
>> index 61fff25..5df12b2 100644
>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_device.c
>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device.c
>> @@ -168,13 +168,6 @@ static bool device_iommu_pasid_init(struct kfd_dev *kfd)
>>         pasid_limit = min_t(unsigned int,
>>                         (unsigned int)(1 << kfd->device_info->max_pasid_bits),
>>                         iommu_info.max_pasids);
>> -       /*
>> -        * last pasid is used for kernel queues doorbells
>> -        * in the future the last pasid might be used for a kernel thread.
>> -        */
>> -       pasid_limit = min_t(unsigned int,
>> -                               pasid_limit,
>> -                               kfd->doorbell_process_limit - 1);
>>
>>         err = amd_iommu_init_device(kfd->pdev, pasid_limit);
>>         if (err < 0) {
>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c b/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c
>> index acf4d2a..feb76c2 100644
>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c
>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c
>> @@ -24,16 +24,15 @@
>>  #include <linux/mman.h>
>>  #include <linux/slab.h>
>>  #include <linux/io.h>
>> +#include <linux/idr.h>
>>
>>  /*
>> - * This extension supports a kernel level doorbells management for
>> - * the kernel queues.
>> - * Basically the last doorbells page is devoted to kernel queues
>> - * and that's assures that any user process won't get access to the
>> - * kernel doorbells page
>> + * This extension supports a kernel level doorbells management for the
>> + * kernel queues using the first doorbell page reserved for the kernel.
>>   */
>>
>> -#define KERNEL_DOORBELL_PASID 1
>> +static DEFINE_IDA(doorbell_ida);
>> +static unsigned int max_doorbell_slices;
>>  #define KFD_SIZE_OF_DOORBELL_IN_BYTES 4
>>
>>  /*
>> @@ -84,13 +83,16 @@ int kfd_doorbell_init(struct kfd_dev *kfd)
>>                         (doorbell_aperture_size - doorbell_start_offset) /
>>                                                 doorbell_process_allocation();
>>         else
>> -               doorbell_process_limit = 0;
>> +               return -ENOSPC;
>> +
>> +       if (!max_doorbell_slices ||
>> +           doorbell_process_limit < max_doorbell_slices)
>> +               max_doorbell_slices = doorbell_process_limit;
>>
>>         kfd->doorbell_base = kfd->shared_resources.doorbell_physical_address +
>>                                 doorbell_start_offset;
>>
>>         kfd->doorbell_id_offset = doorbell_start_offset / sizeof(u32);
>> -       kfd->doorbell_process_limit = doorbell_process_limit - 1;
>>
>>         kfd->doorbell_kernel_ptr = ioremap(kfd->doorbell_base,
>>                                                 doorbell_process_allocation());
>> @@ -185,11 +187,10 @@ u32 __iomem *kfd_get_kernel_doorbell(struct kfd_dev *kfd,
>>                 return NULL;
>>
>>         /*
>> -        * Calculating the kernel doorbell offset using "faked" kernel
>> -        * pasid that allocated for kernel queues only
>> +        * Calculating the kernel doorbell offset using the first
>> +        * doorbell page.
>>          */
>> -       *doorbell_off = KERNEL_DOORBELL_PASID * (doorbell_process_allocation() /
>> -                                                       sizeof(u32)) + inx;
>> +       *doorbell_off = kfd->doorbell_id_offset + inx;
>>
>>         pr_debug("Get kernel queue doorbell\n"
>>                          "     doorbell offset   == 0x%08X\n"
>> @@ -228,11 +229,12 @@ unsigned int kfd_queue_id_to_doorbell(struct kfd_dev *kfd,
>>  {
>>         /*
>>          * doorbell_id_offset accounts for doorbells taken by KGD.
>> -        * pasid * doorbell_process_allocation/sizeof(u32) adjusts
>> -        * to the process's doorbells
>> +        * index * doorbell_process_allocation/sizeof(u32) adjusts to
>> +        * the process's doorbells.
>>          */
>>         return kfd->doorbell_id_offset +
>> -               process->pasid * (doorbell_process_allocation()/sizeof(u32)) +
>> +               process->doorbell_index
>> +               * doorbell_process_allocation() / sizeof(u32) +
>>                 queue_id;
>>  }
>>
>> @@ -250,5 +252,21 @@ phys_addr_t kfd_get_process_doorbells(struct kfd_dev *dev,
>>                                         struct kfd_process *process)
>>  {
>>         return dev->doorbell_base +
>> -               process->pasid * doorbell_process_allocation();
>> +               process->doorbell_index * doorbell_process_allocation();
>> +}
>> +
>> +int kfd_alloc_process_doorbells(struct kfd_process *process)
>> +{
>> +       int r = ida_simple_get(&doorbell_ida, 1, max_doorbell_slices,
>> +                               GFP_KERNEL);
>> +       if (r > 0)
>> +               process->doorbell_index = r;
>> +
>> +       return r;
>> +}
>> +
>> +void kfd_free_process_doorbells(struct kfd_process *process)
>> +{
>> +       if (process->doorbell_index)
>> +               ida_simple_remove(&doorbell_ida, process->doorbell_index);
>>  }
>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
>> index b397ec7..4cb90f5 100644
>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
>> @@ -157,9 +157,6 @@ struct kfd_dev {
>>                                          * to HW doorbell, GFX reserved some
>>                                          * at the start)
>>                                          */
>> -       size_t doorbell_process_limit;  /* Number of processes we have doorbell
>> -                                        * space for.
>> -                                        */
>>         u32 __iomem *doorbell_kernel_ptr; /* This is a pointer for a doorbells
>>                                            * page used by kernel queue
>>                                            */
>> @@ -495,6 +492,7 @@ struct kfd_process {
>>         struct rcu_head rcu;
>>
>>         unsigned int pasid;
>> +       unsigned int doorbell_index;
>>
>>         /*
>>          * List of kfd_process_device structures,
>> @@ -583,6 +581,10 @@ void write_kernel_doorbell(u32 __iomem *db, u32 value);
>>  unsigned int kfd_queue_id_to_doorbell(struct kfd_dev *kfd,
>>                                         struct kfd_process *process,
>>                                         unsigned int queue_id);
>> +phys_addr_t kfd_get_process_doorbells(struct kfd_dev *dev,
>> +                                       struct kfd_process *process);
>> +int kfd_alloc_process_doorbells(struct kfd_process *process);
>> +void kfd_free_process_doorbells(struct kfd_process *process);
>>
>>  /* GTT Sub-Allocator */
>>
>> @@ -694,8 +696,6 @@ int pm_send_unmap_queue(struct packet_manager *pm, enum kfd_queue_type type,
>>  void pm_release_ib(struct packet_manager *pm);
>>
>>  uint64_t kfd_get_number_elems(struct kfd_dev *kfd);
>> -phys_addr_t kfd_get_process_doorbells(struct kfd_dev *dev,
>> -                                       struct kfd_process *process);
>>
>>  /* Events */
>>  extern const struct kfd_event_interrupt_class event_interrupt_class_cik;
>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
>> index c74cf22..9e65ce3 100644
>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
>> @@ -183,6 +183,7 @@ static void kfd_process_wq_release(struct work_struct *work)
>>         kfd_event_free_process(p);
>>
>>         kfd_pasid_free(p->pasid);
>> +       kfd_free_process_doorbells(p);
>>
>>         mutex_unlock(&p->mutex);
>>
>> @@ -288,6 +289,9 @@ static struct kfd_process *create_process(const struct task_struct *thread)
>>         if (process->pasid == 0)
>>                 goto err_alloc_pasid;
>>
>> +       if (kfd_alloc_process_doorbells(process) < 0)
>> +               goto err_alloc_doorbells;
>> +
>>         mutex_init(&process->mutex);
>>
>>         process->mm = thread->mm;
>> @@ -329,6 +333,8 @@ static struct kfd_process *create_process(const struct task_struct *thread)
>>         mmu_notifier_unregister_no_release(&process->mmu_notifier, process->mm);
>>  err_mmu_notifier:
>>         mutex_destroy(&process->mutex);
>> +       kfd_free_process_doorbells(process);
>> +err_alloc_doorbells:
>>         kfd_pasid_free(process->pasid);
>>  err_alloc_pasid:
>>         kfree(process->queues);
>> --
>> 2.7.4
>>
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