drm/i915: Add stable memory region names

At the moment memory region names are a bit too varied and too
inconsistent to be used for ABI purposes, like for upcoming fdinfo
memory stats.

System memory can be either system or system-ttm. Local memory has the
instance number appended, others do not. Not only incosistent but thi
kind of implementation detail is uninteresting for intended users of
fdinfo memory stats.

Add a stable name always formed as $type$instance. Could have chosen a
different stable scheme, but I think any consistent and stable scheme
should do just fine.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Aravind Iddamsetty <aravind.iddamsetty@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231107101806.608990-5-tvrtko.ursulin@linux.intel.com

drivers/gpu/drm/i915/intel_memory_region.c

@@ -216,6 +216,22 @@ static int intel_memory_region_memtest(struct intel_memory_region *mem,
 	return err;
 }
 
+static const char *region_type_str(u16 type)
+{
+	switch (type) {
+	case INTEL_MEMORY_SYSTEM:
+		return "system";
+	case INTEL_MEMORY_LOCAL:
+		return "local";
+	case INTEL_MEMORY_STOLEN_LOCAL:
+		return "stolen-local";
+	case INTEL_MEMORY_STOLEN_SYSTEM:
+		return "stolen-system";
+	default:
+		return "unknown";
+	}
+}
+
 struct intel_memory_region *
 intel_memory_region_create(struct drm_i915_private *i915,
 			   resource_size_t start,
@@ -244,6 +260,9 @@ intel_memory_region_create(struct drm_i915_private *i915,
 	mem->type = type;
 	mem->instance = instance;
 
+	snprintf(mem->uabi_name, sizeof(mem->uabi_name), "%s%u",
+		 region_type_str(type), instance);
+
 	mutex_init(&mem->objects.lock);
 	INIT_LIST_HEAD(&mem->objects.list);
 

drivers/gpu/drm/i915/intel_memory_region.h

@@ -80,6 +80,7 @@ struct intel_memory_region {
 	u16 instance;
 	enum intel_region_id id;
 	char name[16];
+	char uabi_name[16];
 	bool private; /* not for userspace */
 
 	struct {