[PATCH 3/9] drm/radeon: Add PASID manager for KFD

[Felix.Kuehling@xxxxxxx (Felix Kuehling)]

Change-Id: I101a5ac8e0ebf0dbbe6dbd1f61cd8236d499c5b8
Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com>
---
 drivers/gpu/drm/radeon/radeon_kfd.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/drivers/gpu/drm/radeon/radeon_kfd.c b/drivers/gpu/drm/radeon/radeon_kfd.c
index 81fb94b..acfe34e 100644
--- a/drivers/gpu/drm/radeon/radeon_kfd.c
+++ b/drivers/gpu/drm/radeon/radeon_kfd.c
@@ -79,6 +79,9 @@ static uint64_t get_gpu_clock_counter(struct kgd_dev *kgd);
 
 static uint32_t get_max_engine_clock_in_mhz(struct kgd_dev *kgd);
 
+static int alloc_pasid(unsigned int bits);
+static void free_pasid(unsigned int pasid);
+
 static int create_process_vm(struct kgd_dev *kgd, void **vm, void **info);
 static void destroy_process_vm(struct kgd_dev *kgd, void *vm);
 
@@ -161,6 +164,8 @@ static const struct kfd2kgd_calls kfd2kgd = {
 	.get_local_mem_info = get_local_mem_info,
 	.get_gpu_clock_counter = get_gpu_clock_counter,
 	.get_max_engine_clock_in_mhz = get_max_engine_clock_in_mhz,
+	.alloc_pasid = alloc_pasid,
+	.free_pasid = free_pasid,
 	.create_process_vm = create_process_vm,
 	.destroy_process_vm = destroy_process_vm,
 	.get_process_page_dir = get_process_page_dir,
@@ -415,6 +420,31 @@ static uint32_t get_max_engine_clock_in_mhz(struct kgd_dev *kgd)
 }
 
 /*
+ * PASID manager
+ */
+static DEFINE_IDA(pasid_ida);
+
+int alloc_pasid(unsigned int bits)
+{
+	int pasid = -EINVAL;
+
+	for (bits = min(bits, 31U); bits > 0; bits--) {
+		pasid = ida_simple_get(&pasid_ida,
+				       1U << (bits - 1), 1U << bits,
+				       GFP_KERNEL);
+		if (pasid != -ENOSPC)
+			break;
+	}
+
+	return pasid;
+}
+
+void free_pasid(unsigned int pasid)
+{
+	ida_simple_remove(&pasid_ida, pasid);
+}
+
+/*
  * Creates a VM context for HSA process
  */
 static int create_process_vm(struct kgd_dev *kgd, void **vm, void **info)
-- 
2.7.4