[PATCH v10 5/5] test: add unit test for ptr compression

[Paul Szczepanek <paul.szczepanek@arm.com>]

Test compresses and decompresses pointers with various combinations
of memory regions and alignments and verify the pointers are
recovered correctly.

Signed-off-by: Paul Szczepanek <paul.szczepanek@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Nathan Brown <nathan.brown@arm.com>
---
 MAINTAINERS                  |   1 +
 app/test/meson.build         |   1 +
 app/test/test_ptr_compress.c | 108 +++++++++++++++++++++++++++++++++++
 3 files changed, 110 insertions(+)
 create mode 100644 app/test/test_ptr_compress.c

diff --git a/MAINTAINERS b/MAINTAINERS
index e70f92cdc4..77ab8a2959 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1688,6 +1688,7 @@ F: lib/pci/
 Pointer Compression
 M: Paul Szczepanek <paul.szczepanek@arm.com>
 F: lib/ptr_compress/
+F: app/test/test_ptr_compress.c
 F: doc/guides/prog_guide/ptr_compress_lib.rst

 Power management
diff --git a/app/test/meson.build b/app/test/meson.build
index df8cc00730..e29258e6ec 100644
--- a/app/test/meson.build
+++ b/app/test/meson.build
@@ -144,6 +144,7 @@ source_file_deps = {
     'test_power_intel_uncore.c': ['power'],
     'test_power_kvm_vm.c': ['power'],
     'test_prefetch.c': [],
+    'test_ptr_compress.c': ['ptr_compress'],
     'test_rand_perf.c': [],
     'test_rawdev.c': ['rawdev', 'bus_vdev'],
     'test_rcu_qsbr.c': ['rcu', 'hash'],
diff --git a/app/test/test_ptr_compress.c b/app/test/test_ptr_compress.c
new file mode 100644
index 0000000000..972f832776
--- /dev/null
+++ b/app/test/test_ptr_compress.c
@@ -0,0 +1,108 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2024 Arm Limited
+ */
+
+#include "test.h"
+#include <stdint.h>
+#include <string.h>
+
+#include <rte_ptr_compress.h>
+
+#define MAX_ALIGN_EXPONENT 3
+#define MAX_PTRS 16
+#define NUM_BASES 2
+#define NUM_REGIONS 4
+#define MAX_32BIT_REGION ((uint64_t)UINT32_MAX + 1)
+#define MAX_16BIT_REGION (UINT16_MAX + 1)
+
+static int
+test_ptr_compress_params(
+	void *base,
+	uint64_t mem_sz,
+	unsigned int align_exp,
+	unsigned int num_ptrs,
+	bool use_32_bit)
+{
+	unsigned int i;
+	unsigned int align = 1 << align_exp;
+	void *ptrs[MAX_PTRS] = {0};
+	void *ptrs_out[MAX_PTRS] = {0};
+	uint32_t offsets32[MAX_PTRS] = {0};
+	uint16_t offsets16[MAX_PTRS] = {0};
+
+	for (i = 0; i < num_ptrs; i++) {
+		/* make pointers point at memory in steps of align */
+		/* alternate steps from the start and end of memory region */
+		if ((i & 1) == 1)
+			ptrs[i] = (char *)base + mem_sz - i * align;
+		else
+			ptrs[i] = (char *)base + i * align;
+	}
+
+	if (use_32_bit) {
+		rte_ptr_compress_32(base, ptrs, offsets32, num_ptrs, align_exp);
+		rte_ptr_decompress_32(base, offsets32, ptrs_out, num_ptrs,
+				align_exp);
+	} else {
+		rte_ptr_compress_16(base, ptrs, offsets16, num_ptrs, align_exp);
+		rte_ptr_decompress_16(base, offsets16, ptrs_out, num_ptrs,
+				align_exp);
+	}
+
+	TEST_ASSERT_BUFFERS_ARE_EQUAL(ptrs, ptrs_out, sizeof(void *) * num_ptrs,
+		"Decompressed pointers corrupted\nbase pointer: %p, "
+		"memory region size: %" PRIu64 ", alignment exponent: %u, "
+		"num of pointers: %u, using %s offsets",
+		base, mem_sz, align_exp, num_ptrs,
+		use_32_bit ? "32-bit" : "16-bit");
+
+	return 0;
+}
+
+static int
+test_ptr_compress(void)
+{
+	unsigned int j, k, n;
+	int ret = 0;
+	void * const bases[NUM_BASES] = { (void *)0, (void *)UINT16_MAX };
+	/* maximum size for pointers aligned by consecutive powers of 2 */
+	const uint64_t region_sizes_16[NUM_REGIONS] = {
+		MAX_16BIT_REGION,
+		MAX_16BIT_REGION * 2,
+		MAX_16BIT_REGION * 4,
+		MAX_16BIT_REGION * 8,
+	};
+	const uint64_t region_sizes_32[NUM_REGIONS] = {
+		MAX_32BIT_REGION,
+		MAX_32BIT_REGION * 2,
+		MAX_32BIT_REGION * 4,
+		MAX_32BIT_REGION * 8,
+	};
+
+	for (j = 0; j < NUM_REGIONS; j++) {
+		for (k = 0; k < NUM_BASES; k++) {
+			for (n = 1; n < MAX_PTRS; n++) {
+				ret |= test_ptr_compress_params(
+					bases[k],
+					region_sizes_16[j],
+					j /* exponent of alignment */,
+					n,
+					false
+				);
+				ret |= test_ptr_compress_params(
+					bases[k],
+					region_sizes_32[j],
+					j /* exponent of alignment */,
+					n,
+					true
+				);
+				if (ret != 0)
+					return ret;
+			}
+		}
+	}
+
+	return ret;
+}
+
+REGISTER_FAST_TEST(ptr_compress_autotest, true, true, test_ptr_compress);
--
2.25.1