[Intel-gfx] [PATCH 12/13] drm/i915: Add a CMD_PARSER_VERSION getparam

[bradley.d.volkin at intel.com]

From: Brad Volkin <bradley.d.volkin at intel.com>

So userspace can query the kernel for command parser support.

v2: Add i915_cmd_parser_get_version(), history log, and kerneldoc

OTC-Tracker: AXIA-4631
Change-Id: I58af650db9f6753c2dcac9c54ab432fd31db302f
Signed-off-by: Brad Volkin <bradley.d.volkin at intel.com>
---
 drivers/gpu/drm/i915/i915_cmd_parser.c | 19 +++++++++++++++++++
 drivers/gpu/drm/i915/i915_dma.c        |  3 +++
 drivers/gpu/drm/i915/i915_drv.h        |  1 +
 include/uapi/drm/i915_drm.h            |  1 +
 4 files changed, 24 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c
index f9aa01a..23c8174 100644
--- a/drivers/gpu/drm/i915/i915_cmd_parser.c
+++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
@@ -897,3 +897,22 @@ int i915_parse_cmds(struct intel_ring_buffer *ring,
 
 	return ret;
 }
+
+/**
+ * i915_cmd_parser_get_version() - get the cmd parser version number
+ *
+ * The cmd parser maintains a simple increasing integer version number suitable
+ * for passing to userspace clients to determine what operations are permitted.
+ *
+ * Return: the current version number of the cmd parser
+ */
+int i915_cmd_parser_get_version(void)
+{
+	/*
+	 * Command parser version history
+	 *
+	 * 1. Initial version. Checks batches and reports violations, but leaves
+	 *    hardware parsing enabled (so does not allow new use cases).
+	 */
+	return 1;
+}
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 7688abc..14875f5 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1017,6 +1017,9 @@ static int i915_getparam(struct drm_device *dev, void *data,
 	case I915_PARAM_HAS_EXEC_HANDLE_LUT:
 		value = 1;
 		break;
+	case I915_PARAM_CMD_PARSER_VERSION:
+		value = i915_cmd_parser_get_version();
+		break;
 	default:
 		DRM_DEBUG("Unknown parameter %d\n", param->param);
 		return -EINVAL;
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 27a48d9..6294d61 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2582,6 +2582,7 @@ void i915_get_extra_instdone(struct drm_device *dev, uint32_t *instdone);
 const char *i915_cache_level_str(int type);
 
 /* i915_cmd_parser.c */
+int i915_cmd_parser_get_version(void);
 void i915_cmd_parser_init_ring(struct intel_ring_buffer *ring);
 bool i915_needs_cmd_parser(struct intel_ring_buffer *ring);
 int i915_parse_cmds(struct intel_ring_buffer *ring,
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 126bfaa..8a3e4ef00 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -337,6 +337,7 @@ typedef struct drm_i915_irq_wait {
 #define I915_PARAM_HAS_EXEC_NO_RELOC	 25
 #define I915_PARAM_HAS_EXEC_HANDLE_LUT   26
 #define I915_PARAM_HAS_WT     	 	 27
+#define I915_PARAM_CMD_PARSER_VERSION	 28
 
 typedef struct drm_i915_getparam {
 	int param;
-- 
1.8.3.2