drm/amdkfd: Use kfd fd to mmap mmio

TTM doesn't support CPU mapping of sg type bo (under which
mmio bo is created). Switch mmaping of mmio page to kfd
device file.
Signed-off-by: Oak Zeng <Oak.Zeng@amd.com>
Acked-by: Christian Konig <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdkfd/kfd_chardev.c

@@ -1309,6 +1309,14 @@ static int kfd_ioctl_alloc_memory_of_gpu(struct file *filep,
 	args->handle = MAKE_HANDLE(args->gpu_id, idr_handle);
 	args->mmap_offset = offset;
 
+	/* 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;
+	}
+
 	return 0;
 
 err_free:
@@ -1853,6 +1861,39 @@ static long kfd_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
 	return retcode;
 }
 
+static int kfd_mmio_mmap(struct kfd_dev *dev, struct kfd_process *process,
+		      struct vm_area_struct *vma)
+{
+	phys_addr_t address;
+	int ret;
+
+	if (vma->vm_end - vma->vm_start != PAGE_SIZE)
+		return -EINVAL;
+
+	address = amdgpu_amdkfd_get_mmio_remap_phys_addr(dev->kgd);
+
+	vma->vm_flags |= VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_NORESERVE |
+				VM_DONTDUMP | VM_PFNMAP;
+
+	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+
+	pr_debug("Process %d mapping mmio page\n"
+		 "     target user address == 0x%08llX\n"
+		 "     physical address    == 0x%08llX\n"
+		 "     vm_flags            == 0x%04lX\n"
+		 "     size                == 0x%04lX\n",
+		 process->pasid, (unsigned long long) vma->vm_start,
+		 address, vma->vm_flags, PAGE_SIZE);
+
+	ret = io_remap_pfn_range(vma,
+				vma->vm_start,
+				address >> PAGE_SHIFT,
+				PAGE_SIZE,
+				vma->vm_page_prot);
+	return ret;
+}
+
+
 static int kfd_mmap(struct file *filp, struct vm_area_struct *vma)
 {
 	struct kfd_process *process;
@@ -1883,6 +1924,10 @@ static int kfd_mmap(struct file *filp, struct vm_area_struct *vma)
 		if (!dev)
 			return -ENODEV;
 		return kfd_reserved_mem_mmap(dev, process, vma);
+	case KFD_MMAP_TYPE_MMIO:
+		if (!dev)
+			return -ENODEV;
+		return kfd_mmio_mmap(dev, process, vma);
 	}
 
 	return -EFAULT;

drivers/gpu/drm/amd/amdkfd/kfd_priv.h

@@ -59,6 +59,7 @@
 #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_MASK (((1ULL << KFD_GPU_ID_HASH_WIDTH) - 1) \