[igt-dev] [RFT v4 6/6] igt/lib: If mappable aperture is missing return 0 size

[Antonio Argenziano]

So far the aperture size has been read directly from the bar,
in this patch we return zero if the mappable aperture is not available
as the value stored in the bar is not accurate. The patch also adds a
'require' when a call to gem_mappable_aperture_size() is made so that
the aperture is guaranteed to exist before checking the size.

Cc: Katarzyna Dec <katarzyna.dec at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld at intel.com>
Signed-off-by: Antonio Argenziano <antonio.argenziano at intel.com>
---
 lib/ioctl_wrappers.c       | 26 ++++++++++++++++++--------
 lib/ioctl_wrappers.h       |  1 +
 tests/i915/gem_cpu_reloc.c | 14 ++++++++++----
 tests/prime_mmap.c         |  7 +++++--
 4 files changed, 34 insertions(+), 14 deletions(-)

diff --git a/lib/ioctl_wrappers.c b/lib/ioctl_wrappers.c
index a66eb4bc..c903d05c 100644
--- a/lib/ioctl_wrappers.c
+++ b/lib/ioctl_wrappers.c
@@ -1089,6 +1089,22 @@ uint64_t gem_aperture_size(int fd)
 	return aperture_size;
 }
 
+static uint64_t __gem_mappable_aperture_size(int fd)
+{
+	struct pci_device *pci_dev = igt_device_get_pci_device(fd);
+	int bar;
+
+	if (!gem_mmap__has_gtt(fd))
+		return 0; /* Aperture not available */
+
+	if (intel_gen(pci_dev->device_id) < 3)
+		bar = 0;
+	else
+		bar = 2;
+
+	return pci_dev->regions[bar].size;
+}
+
 /**
  * gem_mappable_aperture_size:
  *
@@ -1099,15 +1115,9 @@ uint64_t gem_aperture_size(int fd)
  */
 uint64_t gem_mappable_aperture_size(int fd)
 {
-	struct pci_device *pci_dev = igt_device_get_pci_device(fd);
-	int bar;
-
-	if (intel_gen(pci_dev->device_id) < 3)
-		bar = 0;
-	else
-		bar = 2;
+	gem_require_mmap_gtt(fd);
 
-	return pci_dev->regions[bar].size;
+	return __gem_mappable_aperture_size(fd);
 }
 
 /**
diff --git a/lib/ioctl_wrappers.h b/lib/ioctl_wrappers.h
index ad93daff..b3b0313e 100644
--- a/lib/ioctl_wrappers.h
+++ b/lib/ioctl_wrappers.h
@@ -38,6 +38,7 @@
 
 #include "i915/gem_context.h"
 #include "i915/gem_scheduler.h"
+#include "i915/gem_mman.h"
 
 /**
  * igt_ioctl:
diff --git a/tests/i915/gem_cpu_reloc.c b/tests/i915/gem_cpu_reloc.c
index 17c2fe11..58fd4470 100644
--- a/tests/i915/gem_cpu_reloc.c
+++ b/tests/i915/gem_cpu_reloc.c
@@ -283,8 +283,11 @@ igt_main
 		run_test(i915, 1);
 
 	igt_subtest("full") {
-		uint64_t aper_size = gem_mappable_aperture_size(i915);
-		unsigned long count = aper_size / 4096 + 1;
+		uint64_t aper_size;
+		unsigned long count;
+
+		aper_size = gem_mappable_aperture_size(i915);
+		count = aper_size / 4096 + 1;
 
 		intel_require_memory(count, 4096, CHECK_RAM);
 
@@ -292,10 +295,13 @@ igt_main
 	}
 
 	igt_subtest("forked") {
-		uint64_t aper_size = gem_mappable_aperture_size(i915);
-		unsigned long count = aper_size / 4096 + 1;
+		uint64_t aper_size;
+		unsigned long count;
 		int ncpus = sysconf(_SC_NPROCESSORS_ONLN);
 
+		aper_size = gem_mappable_aperture_size(i915);
+		count = aper_size / 4096 + 1;
+
 		intel_require_memory(count, 4096, CHECK_RAM);
 
 		igt_fork(child, ncpus)
diff --git a/tests/prime_mmap.c b/tests/prime_mmap.c
index f28985da..c844effc 100644
--- a/tests/prime_mmap.c
+++ b/tests/prime_mmap.c
@@ -480,8 +480,11 @@ test_aperture_limit(void)
 	char *ptr1, *ptr2;
 	uint32_t handle1, handle2;
 	/* Two buffers the sum of which > mappable aperture */
-	uint64_t size1 = (gem_mappable_aperture_size(fd) * 7) / 8;
-	uint64_t size2 = (gem_mappable_aperture_size(fd) * 3) / 8;
+	uint64_t size1;
+	uint64_t size2;
+
+	size1 = (gem_mappable_aperture_size(fd) * 7) / 8;
+	size2 = (gem_mappable_aperture_size(fd) * 3) / 8;
 
 	handle1 = gem_create(fd, size1);
 	fill_bo(handle1, BO_SIZE);
-- 
2.20.1