From: Alex Deucher alexander.deucher@amd.com
We don't get the right offset in that case. The GPU has an unused 4K area of the register BAR space into which you can remap registers. We remap the HDP flush registers into this space to allow userspace (CPU or GPU) to flush the HDP when it updates VRAM. However, on systems with >4K pages, we end up exposing PAGE_SIZE of MMIO space.
Fixes: d8e408a82704 ("drm/amdkfd: Expose HDP registers to user space") Reviewed-by: Felix Kuehling felix.kuehling@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org (cherry picked from commit 24e82654e98e96cece5d8b919c522054456eeec6) Signed-off-by: Felix Kuehling felix.kuehling@amd.com --- drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c index 88f9e1aa51f8..34c466e8eee9 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c @@ -1290,7 +1290,7 @@ static int kfd_ioctl_alloc_memory_of_gpu(struct file *filep, goto err_unlock; } offset = amdgpu_amdkfd_get_mmio_remap_phys_addr(dev->kgd); - if (!offset) { + if (!offset || (PAGE_SIZE > 4096)) { err = -ENOMEM; goto err_unlock; } @@ -2029,6 +2029,9 @@ static int kfd_mmio_mmap(struct kfd_dev *dev, struct kfd_process *process, if (vma->vm_end - vma->vm_start != PAGE_SIZE) return -EINVAL;
+ if (PAGE_SIZE > 4096) + return -EINVAL; + address = amdgpu_amdkfd_get_mmio_remap_phys_addr(dev->kgd);
vma->vm_flags |= VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_NORESERVE |