[PULL 31/45] target/arm: Use the proper TBI settings for linux-user

[Peter Maydell <peter.maydell@linaro.org>]

From: 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>
Message-id: 20210210000223.884088-23-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@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 b251fe44506..112bbb14f07 100644
--- a/target/arm/internals.h
+++ b/target/arm/internals.h
@@ -1425,9 +1425,9 @@ 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 5cf6c056c50..70cfcbc9181 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 9bba0beb639..978652ede3a 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;
 }
-- 
2.20.1