From mboxrd@z Thu Jan  1 00:00:00 1970
From: =?UTF-8?q?Alex=20Benn=C3=A9e?= <alex.bennee@linaro.org>
Subject: [kvm-unit-tests PATCH v5 07/11] new arm/tlbflush-test: TLB torture test
Date: Fri, 31 Jul 2015 16:53:57 +0100
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Cc: qemu-devel@nongnu.org, peter.maydell@linaro.org,
	a.spyridakis@virtualopensystems.com, drjones@redhat.com,
	a.rigo@virtualopensystems.com, claudio.fontana@huawei.com,
	kvm@vger.kernel.org,
	=?UTF-8?q?Alex=20Benn=C3=A9e?= <alex.bennee@linaro.org>
To: mttcg@listserver.greensocs.com, mark.burton@greensocs.com,
	fred.konrad@greensocs.com
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This adds a fairly brain dead torture test for TLB flushes intended for
stressing the MTTCG QEMU build. It takes the usual -smp option for
multiple CPUs.

By default it CPU0 will do a TLBIALL flush after each cycle. You can
pass options via -append to control additional aspects of the test:

  - "page" flush each page in turn (one per function)
  - "self" do the flush after each computation cycle
  - "verbose" report progress on each computation cycle

Signed-off-by: Alex Benn=C3=A9e <alex.bennee@linaro.org>

---
v2
  - rename to tlbflush-test
  - made makefile changes cleaner
  - added self/other flush mode
  - create specific prefix
  - whitespace fixes
---
 arm/tlbflush-test.c          | 194 +++++++++++++++++++++++++++++++++++=
++++++++
 config/config-arm-common.mak |   7 +-
 2 files changed, 198 insertions(+), 3 deletions(-)
 create mode 100644 arm/tlbflush-test.c

diff --git a/arm/tlbflush-test.c b/arm/tlbflush-test.c
new file mode 100644
index 0000000..0375ad9
--- /dev/null
+++ b/arm/tlbflush-test.c
@@ -0,0 +1,194 @@
+#include <libcflat.h>
+#include <asm/smp.h>
+#include <asm/cpumask.h>
+#include <asm/barrier.h>
+#include <asm/mmu.h>
+
+#define SEQ_LENGTH 10
+#define SEQ_HASH 0x7cd707fe
+
+static cpumask_t smp_test_complete;
+static int flush_count =3D 1000000;
+static int flush_self =3D 0;
+static int flush_page =3D 0;
+static int flush_verbose =3D 0;
+
+/* Work functions
+ *
+ * These work functions need to be:
+ *
+ *  - page aligned, so we can flush one function at a time
+ *  - have branches, so QEMU TCG generates multiple basic blocks
+ *  - call across pages, so we exercise the TCG basic block slow path
+ */
+
+/* Adler32 */
+__attribute__((aligned(PAGE_SIZE))) uint32_t hash_array(const void *bu=
f,
+							size_t buflen)
+{
+	const uint8_t *data =3D (uint8_t *) buf;
+	uint32_t s1 =3D 1;
+	uint32_t s2 =3D 0;
+
+	for (size_t n =3D 0; n < buflen; n++) {
+		s1 =3D (s1 + data[n]) % 65521;
+		s2 =3D (s2 + s1) % 65521;
+	}
+	return (s2 << 16) | s1;
+}
+
+__attribute__((aligned(PAGE_SIZE))) void create_fib_sequence(int lengt=
h,
+							unsigned int *array)
+{
+	int i;
+
+	/* first two values */
+	array[0] =3D 0;
+	array[1] =3D 1;
+	for (i=3D2; i<length; i++) {
+		array[i] =3D array[i-2] + array[i-1];
+	}
+}
+
+__attribute__((aligned(PAGE_SIZE))) unsigned long long factorial(unsig=
ned int n)
+{
+	unsigned int i;
+	unsigned long long fac =3D 1;
+	for (i=3D1; i<=3Dn; i++)
+	{
+		fac =3D fac * i;
+	}
+	return fac;
+}
+
+__attribute__((aligned(PAGE_SIZE))) void factorial_array
+(unsigned int n, unsigned int *input, unsigned long long *output)
+{
+	unsigned int i;
+	for (i=3D0; i<n; i++) {
+		output[i] =3D factorial(input[i]);
+	}
+}
+
+__attribute__((aligned(PAGE_SIZE))) unsigned int do_computation(void)
+{
+	unsigned int fib_array[SEQ_LENGTH];
+	unsigned long long facfib_array[SEQ_LENGTH];
+	uint32_t fib_hash, facfib_hash;
+
+	create_fib_sequence(SEQ_LENGTH, &fib_array[0]);
+	fib_hash =3D hash_array(&fib_array[0], sizeof(fib_array));
+	factorial_array(SEQ_LENGTH, &fib_array[0], &facfib_array[0]);
+	facfib_hash =3D hash_array(&facfib_array[0], sizeof(facfib_array));
+
+	return (fib_hash ^ facfib_hash);
+}
+
+/* This provides a table of the work functions so we can flush each
+ * page individually
+ */
+static void * pages[] =3D {&hash_array, &create_fib_sequence, &factori=
al,
+			 &factorial_array, &do_computation};
+
+static void do_flush(int i)
+{
+	if (flush_page) {
+		flush_tlb_page((unsigned long)pages[i % ARRAY_SIZE(pages)]);
+	} else {
+		flush_tlb_all();
+	}
+}
+
+
+static void just_compute(void)
+{
+	int i, errors =3D 0;
+	int cpu =3D smp_processor_id();
+
+	uint32_t result;
+
+	printf("CPU%d online\n", cpu);
+
+	for (i=3D0; i < flush_count; i++) {
+		result =3D do_computation();
+
+		if (result !=3D SEQ_HASH) {
+			errors++;
+			printf("CPU%d: seq%d 0x%x!=3D0x%x\n",
+				cpu, i, result, SEQ_HASH);
+		}
+
+		if (flush_verbose && (i % 1000) =3D=3D 0) {
+			printf("CPU%d: seq%d\n", cpu, i);
+		}
+
+		if (flush_self) {
+			do_flush(i);
+		}
+	}
+
+	report("CPU%d: Done - Errors: %d\n", errors =3D=3D 0, cpu, errors);
+
+	cpumask_set_cpu(cpu, &smp_test_complete);
+	if (cpu !=3D 0)
+		halt();
+}
+
+static void just_flush(void)
+{
+	int cpu =3D smp_processor_id();
+	int i =3D 0;
+
+	/* set our CPU as done, keep flushing until everyone else
+	   finished */
+	cpumask_set_cpu(cpu, &smp_test_complete);
+
+	while (!cpumask_full(&smp_test_complete)) {
+		do_flush(i++);
+	}
+
+	report("CPU%d: Done - Triggered %d flushes\n", true, cpu, i);
+}
+
+int main(int argc, char **argv)
+{
+	int cpu, i;
+	char prefix[100];
+
+	for (i=3D0; i<argc; i++) {
+		char *arg =3D argv[i];
+
+		if (strcmp(arg, "page") =3D=3D 0) {
+			flush_page =3D 1;
+                }
+
+                if (strcmp(arg, "self") =3D=3D 0) {
+			flush_self =3D 1;
+                }
+
+		if (strcmp(arg, "verbose") =3D=3D 0) {
+			flush_verbose =3D 1;
+                }
+	}
+
+	snprintf(prefix, sizeof(prefix), "tlbflush_%s_%s",
+		flush_page?"page":"all",
+		flush_self?"self":"other");
+	report_prefix_push(prefix);
+
+	for_each_present_cpu(cpu) {
+		if (cpu =3D=3D 0)
+			continue;
+		smp_boot_secondary(cpu, just_compute);
+	}
+
+	if (flush_self)
+		just_compute();
+	else
+		just_flush();
+
+	while (!cpumask_full(&smp_test_complete))
+		cpu_relax();
+
+	return report_summary();
+}
diff --git a/config/config-arm-common.mak b/config/config-arm-common.ma=
k
index 0674daa..164199b 100644
--- a/config/config-arm-common.mak
+++ b/config/config-arm-common.mak
@@ -9,9 +9,9 @@ ifeq ($(LOADADDR),)
 	LOADADDR =3D 0x40000000
 endif
=20
-tests-common =3D \
-	$(TEST_DIR)/selftest.flat \
-	$(TEST_DIR)/spinlock-test.flat
+tests-common =3D $(TEST_DIR)/selftest.flat
+tests-common +=3D $(TEST_DIR)/spinlock-test.flat
+tests-common +=3D $(TEST_DIR)/tlbflush-test.flat
=20
 all: test_cases
=20
@@ -72,3 +72,4 @@ test_cases: $(generated_files) $(tests-common) $(test=
s)
=20
 $(TEST_DIR)/selftest.elf: $(cstart.o) $(TEST_DIR)/selftest.o
 $(TEST_DIR)/spinlock-test.elf: $(cstart.o) $(TEST_DIR)/spinlock-test.o
+$(TEST_DIR)/tlbflush-test.elf: $(cstart.o) $(TEST_DIR)/tlbflush-test.o
--=20
2.5.0