From 9c8870b8587c2de80f8d4981e65dd4cc67c3500f Mon Sep 17 00:00:00 2001 From: Felix Kuehling Date: Thu, 1 Sep 2016 21:11:39 -0400 Subject: [PATCH 1499/4131] drm/amd: Simplify SDMA HQD loading in kernel threads Use the use_mm function to temporarily access a user process context while running in a kernel thread. This avoids the need to lock the mmap_sem, which fixes a circular locking problem observed with user pointers while running without the HW scheduler. Change-Id: I4e74f3b021277e09df55dddf81ae5e070032b599 Signed-off-by: Felix Kuehling --- drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c | 26 ++++++++++++---------- drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c | 24 +++++++++++--------- drivers/gpu/drm/amd/amdkfd/kfd_device.c | 9 +------- .../gpu/drm/amd/amdkfd/kfd_device_queue_manager.c | 4 ---- 4 files changed, 28 insertions(+), 35 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c index 9948b37..22c4b7a 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include "amdgpu.h" #include "amdgpu_amdkfd.h" @@ -528,18 +529,19 @@ static int kgd_hqd_sdma_load(struct kgd_dev *kgd, void *mqd, WREG32(sdma_base_addr + mmSDMA0_RLC0_DOORBELL, m->sdma_rlc_doorbell); WREG32(sdma_base_addr + mmSDMA0_RLC0_RB_RPTR, m->sdma_rlc_rb_rptr); - if (mm && mm == current->mm) - wptr_valid = !get_user(data, wptr); - else if (mm) { - struct vm_area_struct *vma; - - vma = find_vma(mm, (unsigned long)wptr); - if (vma && vma->vm_start <= (unsigned long)wptr && - vma->vm_ops && vma->vm_ops->access) - wptr_valid = (sizeof(data) == vma->vm_ops->access( - vma, (unsigned long)wptr, - &data, sizeof(data), 0)); - } + if (mm) { + if (mm == current->mm) { + /* Running in the correct user process context */ + wptr_valid = !get_user(data, wptr); + } else if (current->mm == NULL) { + /* A kernel thread can temporarily use a user + * process context for AIO + */ + use_mm(mm); + wptr_valid = !get_user(data, wptr); + unuse_mm(mm); + } + if (wptr_valid) WREG32(sdma_base_addr + mmSDMA0_RLC0_RB_WPTR, data); else diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c index 56a88ef..7be32f3 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include "amdgpu.h" #include "amdgpu_amdkfd.h" @@ -524,17 +525,18 @@ static int kgd_hqd_sdma_load(struct kgd_dev *kgd, void *mqd, WREG32(sdma_base_addr + mmSDMA0_RLC0_DOORBELL, m->sdmax_rlcx_doorbell); WREG32(sdma_base_addr + mmSDMA0_RLC0_RB_RPTR, m->sdmax_rlcx_rb_rptr); - if (mm && mm == current->mm) - wptr_valid = !get_user(data, wptr); - else if (mm) { - struct vm_area_struct *vma; - - vma = find_vma(mm, (unsigned long)wptr); - if (vma && vma->vm_start <= (unsigned long)wptr && - vma->vm_ops && vma->vm_ops->access) - wptr_valid = (sizeof(data) == vma->vm_ops->access( - vma, (unsigned long)wptr, - &data, sizeof(data), 0)); + if (mm) { + if (mm == current->mm) { + /* Running in the correct user process context */ + wptr_valid = !get_user(data, wptr); + } else if (current->mm == NULL) { + /* A kernel thread can temporarily use a user + * process context for AIO + */ + use_mm(mm); + wptr_valid = !get_user(data, wptr); + unuse_mm(mm); + } } if (wptr_valid) WREG32(sdma_base_addr + mmSDMA0_RLC0_RB_WPTR, data); diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device.c b/drivers/gpu/drm/amd/amdkfd/kfd_device.c index 69b08a9..a47d7f1 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_device.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device.c @@ -738,16 +738,9 @@ int kgd2kfd_resume_mm(struct kfd_dev *kfd, struct mm_struct *mm) r = -ENODEV; pdd = kfd_get_process_device_data(kfd, p); - if (pdd) { - if (kfd->dqm->sched_policy == KFD_SCHED_POLICY_NO_HWS) - down_read(&mm->mmap_sem); - + if (pdd) r = process_restore_queues(kfd->dqm, &pdd->qpd); - if (kfd->dqm->sched_policy == KFD_SCHED_POLICY_NO_HWS) - up_read(&mm->mmap_sem); - } - kfd_unref_process(p); return r; } diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c index 53fef02..d77c1ad 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c @@ -408,8 +408,6 @@ static int update_queue(struct device_queue_manager *dqm, struct queue *q) BUG_ON(!dqm || !q || !q->mqd); - if (dqm->sched_policy == KFD_SCHED_POLICY_NO_HWS) - down_read(¤t->mm->mmap_sem); mutex_lock(&dqm->lock); pdd = kfd_get_process_device_data(q->device, q->process); @@ -465,8 +463,6 @@ static int update_queue(struct device_queue_manager *dqm, struct queue *q) out_unlock: mutex_unlock(&dqm->lock); - if (dqm->sched_policy == KFD_SCHED_POLICY_NO_HWS) - up_read(¤t->mm->mmap_sem); return retval; } -- 2.7.4