Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20210217' into staging

target-arm queue:
 * Support ARMv8.5-MemTag for linux-user
 * ncpm7xx: Support SMBus
 * MAINTAINERS: add section for Clock framework

# gpg: Signature made Wed 17 Feb 2021 11:01:45 GMT
# gpg:                using RSA key E1A5C593CD419DE28E8315CF3C2525ED14360CDE
# gpg:                issuer "peter.maydell@linaro.org"
# gpg: Good signature from "Peter Maydell <peter.maydell@linaro.org>" [ultimate]
# gpg:                 aka "Peter Maydell <pmaydell@gmail.com>" [ultimate]
# gpg:                 aka "Peter Maydell <pmaydell@chiark.greenend.org.uk>" [ultimate]
# Primary key fingerprint: E1A5 C593 CD41 9DE2 8E83  15CF 3C25 25ED 1436 0CDE

* remotes/pmaydell/tags/pull-target-arm-20210217: (37 commits)
  MAINTAINERS: add myself maintainer for the clock framework
  hw/i2c: Implement NPCM7XX SMBus Module FIFO Mode
  hw/i2c: Add a QTest for NPCM7XX SMBus Device
  hw/arm: Add I2C sensors and EEPROM for GSJ machine
  hw/arm: Add I2C sensors for NPCM750 eval board
  hw/i2c: Implement NPCM7XX SMBus Module Single Mode
  tests/tcg/aarch64: Add mte smoke tests
  target/arm: Enable MTE for user-only
  target/arm: Add allocation tag storage for user mode
  linux-user/aarch64: Signal SEGV_MTEAERR for async tag check error
  linux-user/aarch64: Signal SEGV_MTESERR for sync tag check fault
  linux-user/aarch64: Pass syndrome to EXC_*_ABORT
  target/arm: Split out syndrome.h from internals.h
  linux-user/aarch64: Implement PROT_MTE
  linux-user/aarch64: Implement PR_MTE_TCF and PR_MTE_TAG
  target/arm: Use the proper TBI settings for linux-user
  target/arm: Improve gen_top_byte_ignore
  linux-user/aarch64: Implement PR_TAGGED_ADDR_ENABLE
  linux-user: Handle tags in lock_user/unlock_user
  linux-user: Fix types in uaccess.c
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 18 insertions, 7 deletions

diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 5cf6c056c5..b8bc89e71f 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -205,14 +205,25 @@ 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);
+
+        /* Enable MTE */
+        if (cpu_isar_feature(aa64_mte, cpu)) {
+            /* Enable tag access, but leave TCF0 as No Effect (0). */
+            env->cp15.sctlr_el[1] |= SCTLR_ATA0;
+            /*
+             * Exclude all tags, so that tag 0 is always used.
+             * This corresponds to Linux current->thread.gcr_incl = 0.
+             *
+             * Set RRND, so that helper_irg() will generate a seed later.
+             * Here in cpu_reset(), the crypto subsystem has not yet been
+             * initialized.
+             */
+            env->cp15.gcr_el1 = 0x1ffff;
+        }
 #else
         /* Reset into the highest available EL */
         if (arm_feature(env, ARM_FEATURE_EL3)) {