[PATCH v6 22/31] target/arm: Use the proper TBI settings for linux-user

[Richard Henderson <richard.henderson@linaro.org>]

We were fudging TBI1 enabled to speed up the generated code.
Now that we've improved the code generation, remove this.
Also, tidy the comment to reflect the current code.

The pauth test was testing a kernel address (-1) and making
incorrect assumptions about TBI1; stick to userland addresses.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/internals.h      |  4 ++--
 target/arm/cpu.c            | 10 +++-------
 tests/tcg/aarch64/pauth-2.c |  1 -
 3 files changed, 5 insertions(+), 10 deletions(-)

diff --git a/target/arm/internals.h b/target/arm/internals.h
index 448982dd2f..1f7f81f10e 100644
--- a/target/arm/internals.h
+++ b/target/arm/internals.h
@@ -1419,9 +1419,9 @@ static inline bool tcma_check(uint32_t desc, int bit55, int ptr_tag)
  */
 static inline uint64_t useronly_clean_ptr(uint64_t ptr)
 {
-    /* TBI is known to be enabled. */
 #ifdef CONFIG_USER_ONLY
-    ptr = sextract64(ptr, 0, 56);
+    /* TBI0 is known to be enabled, while TBI1 is disabled. */
+    ptr &= sextract64(ptr, 0, 56);
 #endif
     return ptr;
 }
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 8ddb2556f8..761f0c61bd 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -205,14 +205,10 @@ static void arm_cpu_reset(DeviceState *dev)
             env->vfp.zcr_el[1] = MIN(cpu->sve_max_vq - 1, 3);
         }
         /*
-         * Enable TBI0 and TBI1.  While the real kernel only enables TBI0,
-         * turning on both here will produce smaller code and otherwise
-         * make no difference to the user-level emulation.
-         *
-         * In sve_probe_page, we assume that this is set.
-         * Do not modify this without other changes.
+         * Enable TBI0 but not TBI1.
+         * Note that this must match useronly_clean_ptr.
          */
-        env->cp15.tcr_el[1].raw_tcr = (3ULL << 37);
+        env->cp15.tcr_el[1].raw_tcr = (1ULL << 37);
 #else
         /* Reset into the highest available EL */
         if (arm_feature(env, ARM_FEATURE_EL3)) {
diff --git a/tests/tcg/aarch64/pauth-2.c b/tests/tcg/aarch64/pauth-2.c
index 9bba0beb63..978652ede3 100644
--- a/tests/tcg/aarch64/pauth-2.c
+++ b/tests/tcg/aarch64/pauth-2.c
@@ -53,7 +53,6 @@ void do_test(uint64_t value)
 int main()
 {
     do_test(0);
-    do_test(-1);
     do_test(0xda004acedeadbeefull);
     return 0;
 }
-- 
2.25.1