Simulate large-BAR system by exporting only visible memory. This
limits the amount of available VRAM to the size of the BAR, but
enables CPU access to VRAM.
Signed-off-by: Felix Kuehling <felix.kuehl...@amd.com>
---
drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 5 +++++
drivers/gpu/drm/amd/amdkfd/kfd_crat.c | 3 +++
drivers/gpu/drm/amd/amdkfd/kfd_module.c | 5 +++++
drivers/gpu/drm/amd/amdkfd/kfd_priv.h | 6 ++++++
4 files changed, 19 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
index ec48010..7c79144 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
@@ -1106,6 +1106,11 @@ bool kfd_dev_is_large_bar(struct kfd_dev *dev)
{
struct kfd_local_mem_info mem_info;
+ if (debug_largebar) {
+ pr_debug("Simulate large-bar allocation on non large-bar
machine\n");
+ return true;
+ }
+
if (dev->device_info->needs_iommu_device)
return false;
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c
b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c
index 7493f47..3c6c4cdd 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c
@@ -1117,6 +1117,9 @@ static int kfd_create_vcrat_image_gpu(void *pcrat_image,
sub_type_hdr = (typeof(sub_type_hdr))((char *)sub_type_hdr +
sub_type_hdr->length);
+ if (debug_largebar)
+ local_mem_info.local_mem_size_private = 0;
+
if (local_mem_info.local_mem_size_private == 0)
ret = kfd_fill_gpu_memory_affinity(&avail_size,
kdev, HSA_MEM_HEAP_TYPE_FB_PUBLIC,
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_module.c
b/drivers/gpu/drm/amd/amdkfd/kfd_module.c
index 65574c6..b0acb06 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_module.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_module.c
@@ -71,6 +71,11 @@ module_param(send_sigterm, int, 0444);
MODULE_PARM_DESC(send_sigterm,
"Send sigterm to HSA process on unhandled exception (0 = disable, 1 =
enable)");
+int debug_largebar;
+module_param(debug_largebar, int, 0444);
+MODULE_PARM_DESC(debug_largebar,
+ "Debug large-bar flag used to simulate large-bar capability on
non-large bar machine (0 = disable, 1 = enable)");
+
int ignore_crat;
module_param(ignore_crat, int, 0444);
MODULE_PARM_DESC(ignore_crat,
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
index afe381f..63e86926 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
@@ -105,6 +105,12 @@ extern int cwsr_enable;
extern int send_sigterm;
/*
+ * This kernel module is used to simulate large bar machine on non-large bar
+ * enabled machines.
+ */
+extern int debug_largebar;
+
+/*
* Ignore CRAT table during KFD initialization, can be used to work around
* broken CRAT tables on some AMD systems
*/
--
2.7.4
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