[PATCH v2 2/3] tools: add more gup configs to hmm_gup selftests

[Alex Sierra <alex.sierra@xxxxxxx>]

Test device pages with get_user_pages and get_user_pages_fast.
The motivation is to test device coherent type pages in the gup and
gup fast paths, after vm_normal_pages was split into LRU and non-LRU
handled.

Signed-off-by: Alex Sierra <alex.sierra@xxxxxxx>
Acked-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>
---
 tools/testing/selftests/vm/hmm-tests.c | 65 +++++++++++++++++---------
 1 file changed, 44 insertions(+), 21 deletions(-)

diff --git a/tools/testing/selftests/vm/hmm-tests.c b/tools/testing/selftests/vm/hmm-tests.c
index 11b83a8084fe..65e30ab6494c 100644
--- a/tools/testing/selftests/vm/hmm-tests.c
+++ b/tools/testing/selftests/vm/hmm-tests.c
@@ -1769,6 +1769,24 @@ TEST_F(hmm, exclusive_cow)
 	hmm_buffer_free(buffer);
 }
 
+static int gup_test_exec(int gup_fd, unsigned long addr,
+			 int cmd, int npages, int size)
+{
+	struct gup_test gup = {
+		.nr_pages_per_call	= npages,
+		.addr			= addr,
+		.gup_flags		= FOLL_WRITE,
+		.size			= size,
+	};
+
+	if (ioctl(gup_fd, cmd, &gup)) {
+		perror("ioctl on error\n");
+		return errno;
+	}
+
+	return 0;
+}
+
 /*
  * Test get user device pages through gup_test. Setting PIN_LONGTERM flag.
  * This should trigger a migration back to system memory for both, private
@@ -1779,7 +1797,6 @@ TEST_F(hmm, exclusive_cow)
 TEST_F(hmm, hmm_gup_test)
 {
 	struct hmm_buffer *buffer;
-	struct gup_test gup;
 	int gup_fd;
 	unsigned long npages;
 	unsigned long size;
@@ -1792,8 +1809,7 @@ TEST_F(hmm, hmm_gup_test)
 	if (gup_fd == -1)
 		SKIP(return, "Skipping test, could not find gup_test driver");
 
-	npages = 4;
-	ASSERT_NE(npages, 0);
+	npages = 3;
 	size = npages << self->page_shift;
 
 	buffer = malloc(sizeof(*buffer));
@@ -1822,28 +1838,35 @@ TEST_F(hmm, hmm_gup_test)
 	for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i)
 		ASSERT_EQ(ptr[i], i);
 
-	gup.nr_pages_per_call = npages;
-	gup.addr = (unsigned long)buffer->ptr;
-	gup.gup_flags = FOLL_WRITE;
-	gup.size = size;
-	/*
-	 * Calling gup_test ioctl. It will try to PIN_LONGTERM these device pages
-	 * causing a migration back to system memory for both, private and coherent
-	 * type pages.
-	 */
-	if (ioctl(gup_fd, PIN_LONGTERM_BENCHMARK, &gup)) {
-		perror("ioctl on PIN_LONGTERM_BENCHMARK\n");
-		goto out_test;
-	}
-
-	/* Take snapshot to make sure pages have been migrated to sys memory */
+	ASSERT_EQ(gup_test_exec(gup_fd,
+				(unsigned long)buffer->ptr,
+				GUP_BASIC_TEST, 1, self->page_size), 0);
+	ASSERT_EQ(gup_test_exec(gup_fd,
+				(unsigned long)buffer->ptr + 1 * self->page_size,
+				GUP_FAST_BENCHMARK, 1, self->page_size), 0);
+	ASSERT_EQ(gup_test_exec(gup_fd,
+				(unsigned long)buffer->ptr + 2 * self->page_size,
+				PIN_LONGTERM_BENCHMARK, 1, self->page_size), 0);
+
+	/* Take snapshot to CPU pagetables */
 	ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_SNAPSHOT, buffer, npages);
 	ASSERT_EQ(ret, 0);
 	ASSERT_EQ(buffer->cpages, npages);
 	m = buffer->mirror;
-	for (i = 0; i < npages; i++)
-		ASSERT_EQ(m[i], HMM_DMIRROR_PROT_WRITE);
-out_test:
+	if (hmm_is_coherent_type(variant->device_number)) {
+		ASSERT_EQ(HMM_DMIRROR_PROT_DEV_COHERENT_LOCAL | HMM_DMIRROR_PROT_WRITE, m[0]);
+		ASSERT_EQ(HMM_DMIRROR_PROT_DEV_COHERENT_LOCAL | HMM_DMIRROR_PROT_WRITE, m[1]);
+	} else {
+		ASSERT_EQ(HMM_DMIRROR_PROT_WRITE, m[0]);
+		ASSERT_EQ(HMM_DMIRROR_PROT_WRITE, m[1]);
+	}
+	ASSERT_EQ(HMM_DMIRROR_PROT_WRITE, m[2]);
+	/* Check again the content on the pages. Make sure there's no
+	 * corrupted data.
+	 */
+	for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
+		ASSERT_EQ(ptr[i], i);
+
 	close(gup_fd);
 	hmm_buffer_free(buffer);
 }
-- 
2.32.0