[PATCH 2/2] selftests/mm: va_high_addr_switch: Dynamically initialize testcases to enable LPA2 testing

[Dev Jain]

Post FEAT_LPA2, the Aarch64 Linux kernel extends higher address support
to 4K and 16K translation granules. To support testing this out, we need
to do away with static initialization of page size, while still
maintaining the nice array of testcases; this can be achieved by
initializing and populating the array as a stack variable, and filling
in the page size and hugepage size at runtime.

Suggested-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Dev Jain <dev.jain@xxxxxxx>
---
 .../selftests/mm/va_high_addr_switch.c        | 454 +++++++++---------
 1 file changed, 232 insertions(+), 222 deletions(-)

diff --git a/tools/testing/selftests/mm/va_high_addr_switch.c b/tools/testing/selftests/mm/va_high_addr_switch.c
index cfbc501290d3..fa7eabfaf841 100644
--- a/tools/testing/selftests/mm/va_high_addr_switch.c
+++ b/tools/testing/selftests/mm/va_high_addr_switch.c
@@ -9,26 +9,9 @@
 #include <sys/mman.h>
 #include <string.h>
 
+#include "vm_util.h"
 #include "../kselftest.h"
 
-#ifdef __powerpc64__
-#define PAGE_SIZE	(64 << 10)
-/*
- * This will work with 16M and 2M hugepage size
- */
-#define HUGETLB_SIZE	(16 << 20)
-#elif __aarch64__
-/*
- * The default hugepage size for 64k base pagesize
- * is 512MB.
- */
-#define PAGE_SIZE	(64 << 10)
-#define HUGETLB_SIZE	(512 << 20)
-#else
-#define PAGE_SIZE	(4 << 10)
-#define HUGETLB_SIZE	(2 << 20)
-#endif
-
 /*
  * The hint addr value is used to allocate addresses
  * beyond the high address switch boundary.
@@ -37,18 +20,8 @@
 #define ADDR_MARK_128TB	(1UL << 47)
 #define ADDR_MARK_256TB	(1UL << 48)
 
-#define HIGH_ADDR_128TB	((void *) (1UL << 48))
-#define HIGH_ADDR_256TB	((void *) (1UL << 49))
-
-#define LOW_ADDR	((void *) (1UL << 30))
-
-#ifdef __aarch64__
-#define ADDR_SWITCH_HINT ADDR_MARK_256TB
-#define HIGH_ADDR	 HIGH_ADDR_256TB
-#else
-#define ADDR_SWITCH_HINT ADDR_MARK_128TB
-#define HIGH_ADDR	 HIGH_ADDR_128TB
-#endif
+#define HIGH_ADDR_128TB	(1UL << 48)
+#define HIGH_ADDR_256TB	(1UL << 49)
 
 struct testcase {
 	void *addr;
@@ -59,195 +32,230 @@ struct testcase {
 	unsigned int keep_mapped:1;
 };
 
-static struct testcase testcases[] = {
-	{
-		/*
-		 * If stack is moved, we could possibly allocate
-		 * this at the requested address.
-		 */
-		.addr = ((void *)(ADDR_SWITCH_HINT - PAGE_SIZE)),
-		.size = PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(ADDR_SWITCH_HINT - PAGE_SIZE, PAGE_SIZE)",
-		.low_addr_required = 1,
-	},
-	{
-		/*
-		 * Unless MAP_FIXED is specified, allocation based on hint
-		 * addr is never at requested address or above it, which is
-		 * beyond high address switch boundary in this case. Instead,
-		 * a suitable allocation is found in lower address space.
-		 */
-		.addr = ((void *)(ADDR_SWITCH_HINT - PAGE_SIZE)),
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(ADDR_SWITCH_HINT - PAGE_SIZE, (2 * PAGE_SIZE))",
-		.low_addr_required = 1,
-	},
-	{
-		/*
-		 * Exact mapping at high address switch boundary, should
-		 * be obtained even without MAP_FIXED as area is free.
-		 */
-		.addr = ((void *)(ADDR_SWITCH_HINT)),
-		.size = PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(ADDR_SWITCH_HINT, PAGE_SIZE)",
-		.keep_mapped = 1,
-	},
-	{
-		.addr = (void *)(ADDR_SWITCH_HINT),
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
-		.msg = "mmap(ADDR_SWITCH_HINT, 2 * PAGE_SIZE, MAP_FIXED)",
-	},
-	{
-		.addr = NULL,
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(NULL)",
-		.low_addr_required = 1,
-	},
-	{
-		.addr = LOW_ADDR,
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(LOW_ADDR)",
-		.low_addr_required = 1,
-	},
-	{
-		.addr = HIGH_ADDR,
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(HIGH_ADDR)",
-		.keep_mapped = 1,
-	},
-	{
-		.addr = HIGH_ADDR,
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(HIGH_ADDR) again",
-		.keep_mapped = 1,
-	},
-	{
-		.addr = HIGH_ADDR,
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
-		.msg = "mmap(HIGH_ADDR, MAP_FIXED)",
-	},
-	{
-		.addr = (void *) -1,
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(-1)",
-		.keep_mapped = 1,
-	},
-	{
-		.addr = (void *) -1,
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(-1) again",
-	},
-	{
-		.addr = ((void *)(ADDR_SWITCH_HINT - PAGE_SIZE)),
-		.size = PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(ADDR_SWITCH_HINT - PAGE_SIZE, PAGE_SIZE)",
-		.low_addr_required = 1,
-	},
-	{
-		.addr = (void *)(ADDR_SWITCH_HINT - PAGE_SIZE),
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(ADDR_SWITCH_HINT - PAGE_SIZE, 2 * PAGE_SIZE)",
-		.low_addr_required = 1,
-		.keep_mapped = 1,
-	},
-	{
-		.addr = (void *)(ADDR_SWITCH_HINT - PAGE_SIZE / 2),
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(ADDR_SWITCH_HINT - PAGE_SIZE/2 , 2 * PAGE_SIZE)",
-		.low_addr_required = 1,
-		.keep_mapped = 1,
-	},
-	{
-		.addr = ((void *)(ADDR_SWITCH_HINT)),
-		.size = PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(ADDR_SWITCH_HINT, PAGE_SIZE)",
-	},
-	{
-		.addr = (void *)(ADDR_SWITCH_HINT),
-		.size = 2 * PAGE_SIZE,
-		.flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
-		.msg = "mmap(ADDR_SWITCH_HINT, 2 * PAGE_SIZE, MAP_FIXED)",
-	},
-};
+static struct testcase *testcases;
+static struct testcase *hugetlb_testcases;
+static int sz_testcases, sz_hugetlb_testcases;
+static unsigned long switch_hint;
 
-static struct testcase hugetlb_testcases[] = {
-	{
-		.addr = NULL,
-		.size = HUGETLB_SIZE,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(NULL, MAP_HUGETLB)",
-		.low_addr_required = 1,
-	},
-	{
-		.addr = LOW_ADDR,
-		.size = HUGETLB_SIZE,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(LOW_ADDR, MAP_HUGETLB)",
-		.low_addr_required = 1,
-	},
-	{
-		.addr = HIGH_ADDR,
-		.size = HUGETLB_SIZE,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(HIGH_ADDR, MAP_HUGETLB)",
-		.keep_mapped = 1,
-	},
-	{
-		.addr = HIGH_ADDR,
-		.size = HUGETLB_SIZE,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(HIGH_ADDR, MAP_HUGETLB) again",
-		.keep_mapped = 1,
-	},
-	{
-		.addr = HIGH_ADDR,
-		.size = HUGETLB_SIZE,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
-		.msg = "mmap(HIGH_ADDR, MAP_FIXED | MAP_HUGETLB)",
-	},
-	{
-		.addr = (void *) -1,
-		.size = HUGETLB_SIZE,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(-1, MAP_HUGETLB)",
-		.keep_mapped = 1,
-	},
-	{
-		.addr = (void *) -1,
-		.size = HUGETLB_SIZE,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(-1, MAP_HUGETLB) again",
-	},
-	{
-		.addr = (void *)(ADDR_SWITCH_HINT - PAGE_SIZE),
-		.size = 2 * HUGETLB_SIZE,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
-		.msg = "mmap(ADDR_SWITCH_HINT - PAGE_SIZE, 2*HUGETLB_SIZE, MAP_HUGETLB)",
-		.low_addr_required = 1,
-		.keep_mapped = 1,
-	},
-	{
-		.addr = (void *)(ADDR_SWITCH_HINT),
-		.size = 2 * HUGETLB_SIZE,
-		.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
-		.msg = "mmap(ADDR_SWITCH_HINT , 2*HUGETLB_SIZE, MAP_FIXED | MAP_HUGETLB)",
-	},
-};
+/* Initialize testcases inside a function to compute parameters at runtime */
+void testcases_init(void)
+{
+	unsigned long pagesize = getpagesize();
+	unsigned long hugepagesize = default_huge_page_size();
+	unsigned long low_addr = (1UL << 30);
+	unsigned long addr_switch_hint = ADDR_MARK_128TB;
+	unsigned long high_addr = HIGH_ADDR_128TB;
+
+#ifdef __aarch64__
+
+	/* Post LPA2, the lower userspace VA on a 16K pagesize is 47 bits. */
+	if (pagesize != (16UL << 10)) {
+		addr_switch_hint = ADDR_MARK_256TB;
+		high_addr = HIGH_ADDR_256TB;
+	}
+#endif
+
+	struct testcase t[] = {
+		{
+			/*
+			 * If stack is moved, we could possibly allocate
+			 * this at the requested address.
+			 */
+			.addr = ((void *)(addr_switch_hint - pagesize)),
+			.size = pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(addr_switch_hint - pagesize, pagesize)",
+			.low_addr_required = 1,
+		},
+		{
+			/*
+			 * Unless MAP_FIXED is specified, allocation based on hint
+			 * addr is never at requested address or above it, which is
+			 * beyond high address switch boundary in this case. Instead,
+			 * a suitable allocation is found in lower address space.
+			 */
+			.addr = ((void *)(addr_switch_hint - pagesize)),
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(addr_switch_hint - pagesize, (2 * pagesize))",
+			.low_addr_required = 1,
+		},
+		{
+			/*
+			 * Exact mapping at high address switch boundary, should
+			 * be obtained even without MAP_FIXED as area is free.
+			 */
+			.addr = ((void *)(addr_switch_hint)),
+			.size = pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(addr_switch_hint, pagesize)",
+			.keep_mapped = 1,
+		},
+		{
+			.addr = (void *)(addr_switch_hint),
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
+			.msg = "mmap(addr_switch_hint, 2 * pagesize, MAP_FIXED)",
+		},
+		{
+			.addr = NULL,
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(NULL)",
+			.low_addr_required = 1,
+		},
+		{
+			.addr = (void *)low_addr,
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(low_addr)",
+			.low_addr_required = 1,
+		},
+		{
+			.addr = (void *)high_addr,
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(high_addr)",
+			.keep_mapped = 1,
+		},
+		{
+			.addr = (void *)high_addr,
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(high_addr) again",
+			.keep_mapped = 1,
+		},
+		{
+			.addr = (void *)high_addr,
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
+			.msg = "mmap(high_addr, MAP_FIXED)",
+		},
+		{
+			.addr = (void *) -1,
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(-1)",
+			.keep_mapped = 1,
+		},
+		{
+			.addr = (void *) -1,
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(-1) again",
+		},
+		{
+			.addr = ((void *)(addr_switch_hint - pagesize)),
+			.size = pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(addr_switch_hint - pagesize, pagesize)",
+			.low_addr_required = 1,
+		},
+		{
+			.addr = (void *)(addr_switch_hint - pagesize),
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(addr_switch_hint - pagesize, 2 * pagesize)",
+			.low_addr_required = 1,
+			.keep_mapped = 1,
+		},
+		{
+			.addr = (void *)(addr_switch_hint - pagesize / 2),
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(addr_switch_hint - pagesize/2 , 2 * pagesize)",
+			.low_addr_required = 1,
+			.keep_mapped = 1,
+		},
+		{
+			.addr = ((void *)(addr_switch_hint)),
+			.size = pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(addr_switch_hint, pagesize)",
+		},
+		{
+			.addr = (void *)(addr_switch_hint),
+			.size = 2 * pagesize,
+			.flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
+			.msg = "mmap(addr_switch_hint, 2 * pagesize, MAP_FIXED)",
+		},
+	};
+
+	struct testcase ht[] = {
+		{
+			.addr = NULL,
+			.size = hugepagesize,
+			.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(NULL, MAP_HUGETLB)",
+			.low_addr_required = 1,
+		},
+		{
+			.addr = (void *)low_addr,
+			.size = hugepagesize,
+			.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(low_addr, MAP_HUGETLB)",
+			.low_addr_required = 1,
+		},
+		{
+			.addr = (void *)high_addr,
+			.size = hugepagesize,
+			.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(high_addr, MAP_HUGETLB)",
+			.keep_mapped = 1,
+		},
+		{
+			.addr = (void *)high_addr,
+			.size = hugepagesize,
+			.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(high_addr, MAP_HUGETLB) again",
+			.keep_mapped = 1,
+		},
+		{
+			.addr = (void *)high_addr,
+			.size = hugepagesize,
+			.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
+			.msg = "mmap(high_addr, MAP_FIXED | MAP_HUGETLB)",
+		},
+		{
+			.addr = (void *) -1,
+			.size = hugepagesize,
+			.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(-1, MAP_HUGETLB)",
+			.keep_mapped = 1,
+		},
+		{
+			.addr = (void *) -1,
+			.size = hugepagesize,
+			.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(-1, MAP_HUGETLB) again",
+		},
+		{
+			.addr = (void *)(addr_switch_hint - pagesize),
+			.size = 2 * hugepagesize,
+			.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS,
+			.msg = "mmap(addr_switch_hint - pagesize, 2*hugepagesize, MAP_HUGETLB)",
+			.low_addr_required = 1,
+			.keep_mapped = 1,
+		},
+		{
+			.addr = (void *)(addr_switch_hint),
+			.size = 2 * hugepagesize,
+			.flags = MAP_HUGETLB | MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
+			.msg = "mmap(addr_switch_hint , 2*hugepagesize, MAP_FIXED | MAP_HUGETLB)",
+		},
+	};
+
+	testcases = malloc(sizeof(t));
+	hugetlb_testcases = malloc(sizeof(ht));
+
+	/* Copy into global arrays */
+	memcpy(testcases, t, sizeof(t));
+	memcpy(hugetlb_testcases, ht, sizeof(ht));
+
+	sz_testcases = ARRAY_SIZE(t);
+	sz_hugetlb_testcases = ARRAY_SIZE(ht);
+	switch_hint = addr_switch_hint;
+}
 
 static int run_test(struct testcase *test, int count)
 {
@@ -267,7 +275,7 @@ static int run_test(struct testcase *test, int count)
 			continue;
 		}
 
-		if (t->low_addr_required && p >= (void *)(ADDR_SWITCH_HINT)) {
+		if (t->low_addr_required && p >= (void *)(switch_hint)) {
 			printf("FAILED\n");
 			ret = KSFT_FAIL;
 		} else {
@@ -292,7 +300,7 @@ static int supported_arch(void)
 #elif defined(__x86_64__)
 	return 1;
 #elif defined(__aarch64__)
-	return getpagesize() == PAGE_SIZE;
+	return 1;
 #else
 	return 0;
 #endif
@@ -305,8 +313,10 @@ int main(int argc, char **argv)
 	if (!supported_arch())
 		return KSFT_SKIP;
 
-	ret = run_test(testcases, ARRAY_SIZE(testcases));
+	testcases_init();
+
+	ret = run_test(testcases, sz_testcases);
 	if (argc == 2 && !strcmp(argv[1], "--run-hugetlb"))
-		ret = run_test(hugetlb_testcases, ARRAY_SIZE(hugetlb_testcases));
+		ret = run_test(hugetlb_testcases, sz_hugetlb_testcases);
 	return ret;
 }
-- 
2.34.1