drm/amdkfd: implement the dGPU fallback path for apu (v6)

We still have a few iommu issues which need to address, so force raven
as "dgpu" path for the moment.

This is to add the fallback path to bypass IOMMU if IOMMU v2 is disabled
or ACPI CRAT table not correct.

v2: Use ignore_crat parameter to decide whether it will go with IOMMUv2.
v3: Align with existed thunk, don't change the way of raven, only renoir
    will use "dgpu" path by default.
v4: don't update global ignore_crat in the driver, and revise fallback
    function if CRAT is broken.
v5: refine acpi crat good but no iommu support case, and rename the
    title.
v6: fix the issue of dGPU initialized firstly, just modify the report
    value in the node_show().

Signed-off-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 17 insertions, 1 deletions

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c
index 6a250f8fcfb8..3fac06b281ce 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c
@@ -742,6 +742,22 @@ static int kfd_fill_gpu_cache_info(struct kfd_dev *kdev,
 	return 0;
 }
 
+static bool kfd_ignore_crat(void)
+{
+	bool ret;
+
+	if (ignore_crat)
+		return true;
+
+#ifndef KFD_SUPPORT_IOMMU_V2
+	ret = true;
+#else
+	ret = false;
+#endif
+
+	return ret;
+}
+
 /*
  * kfd_create_crat_image_acpi - Allocates memory for CRAT image and
  * copies CRAT from ACPI (if available).
@@ -776,7 +792,7 @@ int kfd_create_crat_image_acpi(void **crat_image, size_t *size)
 		return -EINVAL;
 	}
 
-	if (ignore_crat) {
+	if (kfd_ignore_crat()) {
 		pr_info("CRAT table disabled by module option\n");
 		return -ENODATA;
 	}