[igt-dev] [PATCH i-g-t 1/1] lib/intel_allocator: Query exact gtt size

[Jonathan Cavitt <jonathan.cavitt@intel.com>]

Use the gem_context_get_param functionality to query the exact gtt size
for each vm in the intel_allocator.  This replaces the fixed declaration
using the GEN8_GTT_ADDRESS_WIDTH.

Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Suggested-by: Chris Wilson <chris.p.wilson@linux.intel.com>
---
 lib/intel_allocator.h        | 11 +++++++++++
 lib/intel_allocator_simple.c | 10 +++++-----
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/lib/intel_allocator.h b/lib/intel_allocator.h
index f9ff7f1cc9..cfe20bf8aa 100644
--- a/lib/intel_allocator.h
+++ b/lib/intel_allocator.h
@@ -12,6 +12,7 @@
 #include <stdint.h>
 #include <stdatomic.h>
 #include "i915/gem_submission.h"
+#include "i915/gem_context.h"
 #include "intel_reg.h"
 
 /**
@@ -275,6 +276,16 @@ static inline uint64_t get_offset(uint64_t ahnd, uint32_t handle,
 	return intel_allocator_alloc(ahnd, handle, size, alignment);
 }
 
+static inline uint64_t get_gtt_size(int fd)
+{
+	struct drm_i915_gem_context_param p = {
+		.param = I915_CONTEXT_PARAM_GTT_SIZE
+	};
+
+	gem_context_get_param(fd, &p);
+	return p.value;
+}
+
 static inline bool put_offset(uint64_t ahnd, uint32_t handle)
 {
 	if (!ahnd)
diff --git a/lib/intel_allocator_simple.c b/lib/intel_allocator_simple.c
index 3d5e45870e..137885a88b 100644
--- a/lib/intel_allocator_simple.c
+++ b/lib/intel_allocator_simple.c
@@ -459,9 +459,9 @@ static bool intel_allocator_simple_is_allocated(struct intel_allocator *ial,
 	return same;
 }
 
-static uint64_t get_size(uint64_t start, uint64_t end)
+static uint64_t get_size(int fd, uint64_t start, uint64_t end)
 {
-	end = end ? end : 1ull << GEN8_GTT_ADDRESS_WIDTH;
+	end = end ? end : get_gtt_size(fd);
 
 	return end - start;
 }
@@ -485,7 +485,7 @@ static bool intel_allocator_simple_reserve(struct intel_allocator *ial,
 	start = DECANONICAL(start);
 	end = DECANONICAL(end);
 	igt_assert(end > start || end == 0);
-	size = get_size(start, end);
+	size = get_size(ial->fd, start, end);
 	igt_assert(start + size <= ials->end);
 	igt_assert(start >= ials->start);
 
@@ -526,7 +526,7 @@ static bool intel_allocator_simple_unreserve(struct intel_allocator *ial,
 	start = DECANONICAL(start);
 	end = DECANONICAL(end);
 	igt_assert(end > start || end == 0);
-	size = get_size(start, end);
+	size = get_size(ial->fd, start, end);
 
 	entry = igt_map_search_entry(ials->reserved, &start);
 
@@ -574,7 +574,7 @@ static bool intel_allocator_simple_is_reserved(struct intel_allocator *ial,
 	start = DECANONICAL(start);
 	end = DECANONICAL(end);
 	igt_assert(end > start || end == 0);
-	size = get_size(start, end);
+	size = get_size(ial->fd, start, end);
 
 	rec = igt_map_search(ials->reserved, &start);
 
-- 
2.25.1