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

Deucher, Alexander Alexander.Deucher at amd.com
Wed Sep 13 21:29:20 UTC 2017


> -----Original Message-----
> From: amd-gfx [mailto:amd-gfx-bounces at lists.freedesktop.org] On Behalf
> Of Felix Kuehling
> Sent: Wednesday, September 13, 2017 5:12 PM
> To: Alex Deucher
> Cc: amd-gfx list
> Subject: Re: [PATCH 4/8] drm/amdkfd: Separate doorbell allocation from
> PASID
> 
> 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.

Yeah, that's fine, feel free to keep the original order.

Alex

> 
> 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
> >>
> >> _______________________________________________
> >> amd-gfx mailing list
> >> amd-gfx at lists.freedesktop.org
> >> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
> 
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