arm64: mte: change ASYNC and SYNC TCF settings into bitfields

[linux-2.6-microblaze.git] / arch / arm64 / kernel / mte.c

diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c
index a526955..3b6b685 100644 (file)
--- a/arch/arm64/kernel/mte.c
+++ b/arch/arm64/kernel/mte.c
@@ -193,14 +193,19 @@ void mte_check_tfsr_el1(void)
 }
 #endif
 
-static void set_gcr_el1_excl(u64 excl)
+static void mte_update_sctlr_user(struct task_struct *task)
 {
-       current->thread.mte_ctrl = excl;
+       unsigned long sctlr = task->thread.sctlr_user;
+       unsigned long pref = MTE_CTRL_TCF_ASYNC;
+       unsigned long mte_ctrl = task->thread.mte_ctrl;
+       unsigned long resolved_mte_tcf = (mte_ctrl & pref) ? pref : mte_ctrl;
 
-       /*
-        * SYS_GCR_EL1 will be set to current->thread.gcr_user_excl value
-        * by mte_set_user_gcr() in kernel_exit,
-        */
+       sctlr &= ~SCTLR_EL1_TCF0_MASK;
+       if (resolved_mte_tcf & MTE_CTRL_TCF_ASYNC)
+               sctlr |= SCTLR_EL1_TCF0_ASYNC;
+       else if (resolved_mte_tcf & MTE_CTRL_TCF_SYNC)
+               sctlr |= SCTLR_EL1_TCF0_SYNC;
+       task->thread.sctlr_user = sctlr;
 }
 
 void mte_thread_init_user(void)
@@ -212,15 +217,16 @@ void mte_thread_init_user(void)
        dsb(ish);
        write_sysreg_s(0, SYS_TFSRE0_EL1);
        clear_thread_flag(TIF_MTE_ASYNC_FAULT);
-       /* disable tag checking */
-       set_task_sctlr_el1((current->thread.sctlr_user & ~SCTLR_EL1_TCF0_MASK) |
-                          SCTLR_EL1_TCF0_NONE);
-       /* reset tag generation mask */
-       set_gcr_el1_excl(SYS_GCR_EL1_EXCL_MASK);
+       /* disable tag checking and reset tag generation mask */
+       current->thread.mte_ctrl = MTE_CTRL_GCR_USER_EXCL_MASK;
+       mte_update_sctlr_user(current);
+       set_task_sctlr_el1(current->thread.sctlr_user);
 }
 
 void mte_thread_switch(struct task_struct *next)
 {
+       mte_update_sctlr_user(next);
+
        /*
         * Check if an async tag exception occurred at EL1.
         *
@@ -259,33 +265,21 @@ void mte_suspend_exit(void)
 
 long set_mte_ctrl(struct task_struct *task, unsigned long arg)
 {
-       u64 sctlr = task->thread.sctlr_user & ~SCTLR_EL1_TCF0_MASK;
        u64 mte_ctrl = (~((arg & PR_MTE_TAG_MASK) >> PR_MTE_TAG_SHIFT) &
                        SYS_GCR_EL1_EXCL_MASK) << MTE_CTRL_GCR_USER_EXCL_SHIFT;
 
        if (!system_supports_mte())
                return 0;
 
-       switch (arg & PR_MTE_TCF_MASK) {
-       case PR_MTE_TCF_NONE:
-               sctlr |= SCTLR_EL1_TCF0_NONE;
-               break;
-       case PR_MTE_TCF_SYNC:
-               sctlr |= SCTLR_EL1_TCF0_SYNC;
-               break;
-       case PR_MTE_TCF_ASYNC:
-               sctlr |= SCTLR_EL1_TCF0_ASYNC;
-               break;
-       default:
-               return -EINVAL;
-       }
+       if (arg & PR_MTE_TCF_ASYNC)
+               mte_ctrl |= MTE_CTRL_TCF_ASYNC;
+       if (arg & PR_MTE_TCF_SYNC)
+               mte_ctrl |= MTE_CTRL_TCF_SYNC;
 
-       if (task != current) {
-               task->thread.sctlr_user = sctlr;
-               task->thread.mte_ctrl = mte_ctrl;
-       } else {
-               set_task_sctlr_el1(sctlr);
-               set_gcr_el1_excl(mte_ctrl);
+       task->thread.mte_ctrl = mte_ctrl;
+       if (task == current) {
+               mte_update_sctlr_user(task);
+               set_task_sctlr_el1(task->thread.sctlr_user);
        }
 
        return 0;
@@ -302,18 +296,10 @@ long get_mte_ctrl(struct task_struct *task)
                return 0;
 
        ret = incl << PR_MTE_TAG_SHIFT;
-
-       switch (task->thread.sctlr_user & SCTLR_EL1_TCF0_MASK) {
-       case SCTLR_EL1_TCF0_NONE:
-               ret |= PR_MTE_TCF_NONE;
-               break;
-       case SCTLR_EL1_TCF0_SYNC:
-               ret |= PR_MTE_TCF_SYNC;
-               break;
-       case SCTLR_EL1_TCF0_ASYNC:
+       if (mte_ctrl & MTE_CTRL_TCF_ASYNC)
                ret |= PR_MTE_TCF_ASYNC;
-               break;
-       }
+       if (mte_ctrl & MTE_CTRL_TCF_SYNC)
+               ret |= PR_MTE_TCF_SYNC;
 
        return ret;
 }