kselftest/arm64: Add SME2 coverage to syscall-abi

Verify that ZT0 is preserved over syscalls when it is present and
PSTATE.ZA is set.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20221208-arm64-sme2-v4-19-f2fa0aef982f@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/tools/testing/selftests/arm64/abi/syscall-abi-asm.S b/tools/testing/selftests/arm64/abi/syscall-abi-asm.S
index acd5e9f3bc0b424b4dddbfb5de88913d2f49056b..6ddf392329c9e7e40776b285b9313f533879b622 100644 (file)
--- a/tools/testing/selftests/arm64/abi/syscall-abi-asm.S
+++ b/tools/testing/selftests/arm64/abi/syscall-abi-asm.S
@@ -23,6 +23,9 @@
 
 .arch_extension sve
 
+#define ID_AA64SMFR0_EL1_SMEver_SHIFT           56
+#define ID_AA64SMFR0_EL1_SMEver_WIDTH           4
+
 /*
  * LDR (vector to ZA array):
  *     LDR ZA[\nw, #\offset], [X\nxbase, #\offset, MUL VL]
@@ -45,6 +48,26 @@
                | ((\offset) & 7)
 .endm
 
+/*
+ * LDR (ZT0)
+ *
+ *     LDR ZT0, nx
+ */
+.macro _ldr_zt nx
+       .inst   0xe11f8000                      \
+               | (((\nx) & 0x1f) << 5)
+.endm
+
+/*
+ * STR (ZT0)
+ *
+ *     STR ZT0, nx
+ */
+.macro _str_zt nx
+       .inst   0xe13f8000                      \
+               | (((\nx) & 0x1f) << 5)
+.endm
+
 .globl do_syscall
 do_syscall:
        // Store callee saved registers x19-x29 (80 bytes) plus x0 and x1
@@ -64,7 +87,7 @@ do_syscall:
        msr     S3_3_C4_C2_2, x2
 1:
 
-       // Load ZA if it's enabled - uses x12 as scratch due to SME LDR
+       // Load ZA and ZT0 if enabled - uses x12 as scratch due to SME LDR
        tbz     x2, #SVCR_ZA_SHIFT, 1f
        mov     w12, #0
        ldr     x2, =za_in
@@ -73,6 +96,15 @@ do_syscall:
        add     x12, x12, #1
        cmp     x1, x12
        bne     2b
+
+       // ZT0
+       mrs     x2, S3_0_C0_C4_5        // ID_AA64SMFR0_EL1
+       ubfx    x2, x2, #ID_AA64SMFR0_EL1_SMEver_SHIFT, \
+                        #ID_AA64SMFR0_EL1_SMEver_WIDTH
+       cbz     x2, 1f
+       adrp    x2, zt_in
+       add     x2, x2, :lo12:zt_in
+       _ldr_zt 2
 1:
 
        // Load GPRs x8-x28, and save our SP/FP for later comparison
@@ -235,6 +267,15 @@ do_syscall:
        add     x12, x12, #1
        cmp     x1, x12
        bne     2b
+
+       // ZT0
+       mrs     x2, S3_0_C0_C4_5        // ID_AA64SMFR0_EL1
+       ubfx    x2, x2, #ID_AA64SMFR0_EL1_SMEver_SHIFT, \
+                       #ID_AA64SMFR0_EL1_SMEver_WIDTH
+       cbz     x2, 1f
+       adrp    x2, zt_out
+       add     x2, x2, :lo12:zt_out
+       _str_zt 2
 1:
 
        // Save the SVE state if we have some

diff --git a/tools/testing/selftests/arm64/abi/syscall-abi.c b/tools/testing/selftests/arm64/abi/syscall-abi.c
index dd7ebe536d05faec4cc7053ee10c9e39bf31e094..9800f9dc6b35faceb6bc785b0c5e5beeb612efac 100644 (file)
--- a/tools/testing/selftests/arm64/abi/syscall-abi.c
+++ b/tools/testing/selftests/arm64/abi/syscall-abi.c
@@ -311,6 +311,35 @@ static int check_za(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
        return errors;
 }
 
+uint8_t zt_in[ZT_SIG_REG_BYTES] __attribute__((aligned(16)));
+uint8_t zt_out[ZT_SIG_REG_BYTES] __attribute__((aligned(16)));
+
+static void setup_zt(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
+                    uint64_t svcr)
+{
+       fill_random(zt_in, sizeof(zt_in));
+       memset(zt_out, 0, sizeof(zt_out));
+}
+
+static int check_zt(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
+                   uint64_t svcr)
+{
+       int errors = 0;
+
+       if (!(getauxval(AT_HWCAP2) & HWCAP2_SME2))
+               return 0;
+
+       if (!(svcr & SVCR_ZA_MASK))
+               return 0;
+
+       if (memcmp(zt_in, zt_out, sizeof(zt_in)) != 0) {
+               ksft_print_msg("SME VL %d ZT does not match\n", sme_vl);
+               errors++;
+       }
+
+       return errors;
+}
+
 typedef void (*setup_fn)(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
                         uint64_t svcr);
 typedef int (*check_fn)(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
@@ -334,6 +363,7 @@ static struct {
        { setup_ffr, check_ffr },
        { setup_svcr, check_svcr },
        { setup_za, check_za },
+       { setup_zt, check_zt },
 };
 
 static bool do_test(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
@@ -474,6 +504,7 @@ int main(void)
 {
        int i;
        int tests = 1;  /* FPSIMD */
+       int sme_ver;
 
        srandom(getpid());
 
@@ -482,10 +513,15 @@ int main(void)
        tests += (sve_count_vls() * sme_count_vls()) * 3;
        ksft_set_plan(ARRAY_SIZE(syscalls) * tests);
 
+       if (getauxval(AT_HWCAP2) & HWCAP2_SME2)
+               sme_ver = 2;
+       else
+               sme_ver = 1;
+
        if (getauxval(AT_HWCAP2) & HWCAP2_SME_FA64)
-               ksft_print_msg("SME with FA64\n");
+               ksft_print_msg("SME%d with FA64\n", sme_ver);
        else if (getauxval(AT_HWCAP2) & HWCAP2_SME)
-               ksft_print_msg("SME without FA64\n");
+               ksft_print_msg("SME%d without FA64\n", sme_ver);
 
        for (i = 0; i < ARRAY_SIZE(syscalls); i++)
                test_one_syscall(&syscalls[i]);