[PATCH v5 15/24] amdkfd: Add module parameter of scheduling policy

Oded Gabbay
2014-11-08T18:43:57Z

From: Ben Goz <ben.goz@amd.com>

This patch adds a new parameter to the amdkfd driver. This parameter enables
the user to select the scheduling policy of the CP. The choices are:

* CP Scheduling with support for over-subscription
* CP Scheduling without support for over-subscription
* Without CP Scheduling

Note that the third option (Without CP scheduling) is only for debug purposes
and bringup of new H/W. As such, it is _not_ guaranteed to work at all times on
all H/W versions.

v3: Fixed description of parameter, changed the permissions to read_only, added
a verification of the value and added documentation

v5: Set default sched_policy to HWS as it is now supported by firmware

Signed-off-by: Ben Goz <ben.goz@amd.com>
Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
---
drivers/gpu/drm/amd/amdkfd/kfd_module.c | 18 +++++++++++++++---
drivers/gpu/drm/amd/amdkfd/kfd_priv.h | 30 ++++++++++++++++++++++++++++++
2 files changed, 45 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_module.c b/drivers/gpu/drm/amd/amdkfd/kfd_module.c
index 56a71d8..0858dce 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_module.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_module.c
@@ -29,10 +29,10 @@
#define KFD_DRIVER_AUTHOR "AMD Inc. and others"

#define KFD_DRIVER_DESC "Standalone HSA driver for AMD's GPUs"
-#define KFD_DRIVER_DATE "20140804"
+#define KFD_DRIVER_DATE "20140807"
#define KFD_DRIVER_MAJOR 0
-#define KFD_DRIVER_MINOR 6
-#define KFD_DRIVER_PATCHLEVEL 4
+#define KFD_DRIVER_MINOR 8
+#define KFD_DRIVER_PATCHLEVEL 0

const struct kfd2kgd_calls *kfd2kgd;
static const struct kgd2kfd_calls kgd2kfd = {
@@ -45,6 +45,11 @@ static const struct kgd2kfd_calls kgd2kfd = {
.resume = kgd2kfd_resume,
};

+int sched_policy = KFD_SCHED_POLICY_HWS;
+module_param(sched_policy, int, 0444);
+MODULE_PARM_DESC(sched_policy,
+ "Kernel cmdline parameter that defines the amdkfd scheduling policy");
+
int max_num_of_processes = KFD_MAX_NUM_OF_PROCESSES_DEFAULT;
module_param(max_num_of_processes, int, 0444);
MODULE_PARM_DESC(max_num_of_processes,
@@ -88,6 +93,13 @@ static int __init kfd_module_init(void)
kfd2kgd = NULL;

/* Verify module parameters */
+ if ((sched_policy < KFD_SCHED_POLICY_HWS) ||
+ (sched_policy > KFD_SCHED_POLICY_NO_HWS)) {
+ pr_err("kfd: sched_policy has invalid value\n");
+ return -1;
+ }
+
+ /* Verify module parameters */
if ((max_num_of_processes < 0) ||
(max_num_of_processes > KFD_MAX_NUM_OF_PROCESSES)) {
pr_err("kfd: max_num_of_processes must be between 0 to KFD_MAX_NUM_OF_PROCESSES\n");
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
index bba3c2a..32bca8a 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
@@ -69,6 +69,36 @@ extern int max_num_of_queues_per_process;

#define KFD_KERNEL_QUEUE_SIZE 2048

+/* Kernel module parameter to specify the scheduling policy */
+extern int sched_policy;
+
+/**
+ * enum kfd_sched_policy
+ *
+ * @KFD_SCHED_POLICY_HWS: H/W scheduling policy known as command processor (cp)
+ * scheduling. In this scheduling mode we're using the firmware code to
+ * schedule the user mode queues and kernel queues such as HIQ and DIQ.
+ * the HIQ queue is used as a special queue that dispatches the configuration
+ * to the cp and the user mode queues list that are currently running.
+ * the DIQ queue is a debugging queue that dispatches debugging commands to the
+ * firmware.
+ * in this scheduling mode user mode queues over subscription feature is
+ * enabled.
+ *
+ * @KFD_SCHED_POLICY_HWS_NO_OVERSUBSCRIPTION: The same as above but the over
+ * subscription feature disabled.
+ *
+ * @KFD_SCHED_POLICY_NO_HWS: no H/W scheduling policy is a mode which directly
+ * set the command processor registers and sets the queues "manually". This
+ * mode is used *ONLY* for debugging proposes.
+ *
+ */
+enum kfd_sched_policy {
+ KFD_SCHED_POLICY_HWS = 0,
+ KFD_SCHED_POLICY_HWS_NO_OVERSUBSCRIPTION,
+ KFD_SCHED_POLICY_NO_HWS
+};
+
enum cache_policy {
cache_policy_coherent,
cache_policy_noncoherent
--
2.1.0