[PATCH] drm/amdkfd: Simplify the mmap offset related bit operations

[Zhao, Yong]

True. Thank you for spotting that. MMAP-related code was added after I inititally drafted this change earlier this year.

Regards,
Yong
________________________________
From: Kuehling, Felix <Felix.Kuehling at amd.com>
Sent: Thursday, November 7, 2019 12:05 AM
To: Zhao, Yong <Yong.Zhao at amd.com>; amd-gfx at lists.freedesktop.org <amd-gfx at lists.freedesktop.org>
Subject: Re: [PATCH] drm/amdkfd: Simplify the mmap offset related bit operations

On 2019-11-05 18:18, Zhao, Yong wrote:
> The new code uses straightforward bit shifts and thus has better
> readability.

You're missing the MMAP-related code for mmio remapping. In
kfd_ioctl_alloc_memory_of_gpu:

         /* MMIO is mapped through kfd device
          * Generate a kfd mmap offset
          */
         if (flags & KFD_IOC_ALLOC_MEM_FLAGS_MMIO_REMAP) {
                 args->mmap_offset = KFD_MMAP_TYPE_MMIO |
KFD_MMAP_GPU_ID(args->gpu_id);
                 args->mmap_offset <<= PAGE_SHIFT;
         }

Regards,
   Felix

>
> Change-Id: I0c1f7cca7e24ddb7b4ffe1cb0fa71943828ae373
> Signed-off-by: Yong Zhao <Yong.Zhao at amd.com>
> ---
> drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 10 ++++------
> drivers/gpu/drm/amd/amdkfd/kfd_events.c | 1 -
> drivers/gpu/drm/amd/amdkfd/kfd_priv.h | 9 +++------
> drivers/gpu/drm/amd/amdkfd/kfd_process.c | 3 +--
> 4 files changed, 8 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> index b91993753b82..34078df36621 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> @@ -298,7 +298,6 @@ static int kfd_ioctl_create_queue(struct file
> *filep, struct kfd_process *p,
> /* Return gpu_id as doorbell offset for mmap usage */
> args->doorbell_offset = KFD_MMAP_TYPE_DOORBELL;
> args->doorbell_offset |= KFD_MMAP_GPU_ID(args->gpu_id);
> - args->doorbell_offset <<= PAGE_SHIFT;
> if (KFD_IS_SOC15(dev->device_info->asic_family))
> /* On SOC15 ASICs, include the doorbell offset within the
> * process doorbell frame, which could be 1 page or 2 pages.
> @@ -1938,20 +1937,19 @@ static int kfd_mmap(struct file *filp, struct
> vm_area_struct *vma)
> {
> struct kfd_process *process;
> struct kfd_dev *dev = NULL;
> - unsigned long vm_pgoff;
> + unsigned long mmap_offset;
> unsigned int gpu_id;
> process = kfd_get_process(current);
> if (IS_ERR(process))
> return PTR_ERR(process);
> - vm_pgoff = vma->vm_pgoff;
> - vma->vm_pgoff = KFD_MMAP_OFFSET_VALUE_GET(vm_pgoff);
> - gpu_id = KFD_MMAP_GPU_ID_GET(vm_pgoff);
> + mmap_offset = vma->vm_pgoff << PAGE_SHIFT;
> + gpu_id = KFD_MMAP_GET_GPU_ID(mmap_offset);
> if (gpu_id)
> dev = kfd_device_by_id(gpu_id);
> - switch (vm_pgoff & KFD_MMAP_TYPE_MASK) {
> + switch (mmap_offset & KFD_MMAP_TYPE_MASK) {
> case KFD_MMAP_TYPE_DOORBELL:
> if (!dev)
> return -ENODEV;
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_events.c
> b/drivers/gpu/drm/amd/amdkfd/kfd_events.c
> index 908081c85de1..1f8365575b12 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_events.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_events.c
> @@ -346,7 +346,6 @@ int kfd_event_create(struct file *devkfd, struct
> kfd_process *p,
> ret = create_signal_event(devkfd, p, ev);
> if (!ret) {
> *event_page_offset = KFD_MMAP_TYPE_EVENTS;
> - *event_page_offset <<= PAGE_SHIFT;
> *event_slot_index = ev->event_id;
> }
> break;
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
> b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
> index 66bae8f2dad1..8eecd2cd1fd2 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
> @@ -59,24 +59,21 @@
> * NOTE: struct vm_area_struct.vm_pgoff uses offset in pages. Hence, these
> * defines are w.r.t to PAGE_SIZE
> */
> -#define KFD_MMAP_TYPE_SHIFT (62 - PAGE_SHIFT)
> +#define KFD_MMAP_TYPE_SHIFT (62)
> #define KFD_MMAP_TYPE_MASK (0x3ULL << KFD_MMAP_TYPE_SHIFT)
> #define KFD_MMAP_TYPE_DOORBELL (0x3ULL << KFD_MMAP_TYPE_SHIFT)
> #define KFD_MMAP_TYPE_EVENTS (0x2ULL << KFD_MMAP_TYPE_SHIFT)
> #define KFD_MMAP_TYPE_RESERVED_MEM (0x1ULL << KFD_MMAP_TYPE_SHIFT)
> #define KFD_MMAP_TYPE_MMIO (0x0ULL << KFD_MMAP_TYPE_SHIFT)
> -#define KFD_MMAP_GPU_ID_SHIFT (46 - PAGE_SHIFT)
> +#define KFD_MMAP_GPU_ID_SHIFT (46)
> #define KFD_MMAP_GPU_ID_MASK (((1ULL << KFD_GPU_ID_HASH_WIDTH) - 1) \
> << KFD_MMAP_GPU_ID_SHIFT)
> #define KFD_MMAP_GPU_ID(gpu_id) ((((uint64_t)gpu_id) <<
> KFD_MMAP_GPU_ID_SHIFT)\
> & KFD_MMAP_GPU_ID_MASK)
> -#define KFD_MMAP_GPU_ID_GET(offset) ((offset & KFD_MMAP_GPU_ID_MASK) \
> +#define KFD_MMAP_GET_GPU_ID(offset) ((offset & KFD_MMAP_GPU_ID_MASK) \
> >> KFD_MMAP_GPU_ID_SHIFT)
> -#define KFD_MMAP_OFFSET_VALUE_MASK (0x3FFFFFFFFFFFULL >> PAGE_SHIFT)
> -#define KFD_MMAP_OFFSET_VALUE_GET(offset) (offset &
> KFD_MMAP_OFFSET_VALUE_MASK)
> -
> /*
> * When working with cp scheduler we should assign the HIQ manually or via
> * the amdgpu driver to a fixed hqd slot, here are the fixed HIQ hqd slot
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> index 6abfb77ae540..39dc49b8fd85 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> @@ -554,8 +554,7 @@ static int kfd_process_init_cwsr_apu(struct
> kfd_process *p, struct file *filep)
> if (!dev->cwsr_enabled || qpd->cwsr_kaddr || qpd->cwsr_base)
> continue;
> - offset = (KFD_MMAP_TYPE_RESERVED_MEM | KFD_MMAP_GPU_ID(dev->id))
> - << PAGE_SHIFT;
> + offset = KFD_MMAP_TYPE_RESERVED_MEM | KFD_MMAP_GPU_ID(dev->id);
> qpd->tba_addr = (int64_t)vm_mmap(filep, 0,
> KFD_CWSR_TBA_TMA_SIZE, PROT_READ | PROT_EXEC,
> MAP_SHARED, offset);
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