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Diffstat (limited to 'arch/arm64/mm/context.c')
-rw-r--r--arch/arm64/mm/context.c32
1 files changed, 30 insertions, 2 deletions
diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c
index d89bb22589f6..9b26f9a88724 100644
--- a/arch/arm64/mm/context.c
+++ b/arch/arm64/mm/context.c
@@ -6,6 +6,7 @@
* Copyright (C) 2012 ARM Ltd.
*/
+#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/sched.h>
#include <linux/slab.h>
@@ -254,10 +255,37 @@ switch_mm_fastpath:
/* Errata workaround post TTBRx_EL1 update. */
asmlinkage void post_ttbr_update_workaround(void)
{
+ if (!IS_ENABLED(CONFIG_CAVIUM_ERRATUM_27456))
+ return;
+
asm(ALTERNATIVE("nop; nop; nop",
"ic iallu; dsb nsh; isb",
- ARM64_WORKAROUND_CAVIUM_27456,
- CONFIG_CAVIUM_ERRATUM_27456));
+ ARM64_WORKAROUND_CAVIUM_27456));
+}
+
+void cpu_do_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm)
+{
+ unsigned long ttbr1 = read_sysreg(ttbr1_el1);
+ unsigned long asid = ASID(mm);
+ unsigned long ttbr0 = phys_to_ttbr(pgd_phys);
+
+ /* Skip CNP for the reserved ASID */
+ if (system_supports_cnp() && asid)
+ ttbr0 |= TTBR_CNP_BIT;
+
+ /* SW PAN needs a copy of the ASID in TTBR0 for entry */
+ if (IS_ENABLED(CONFIG_ARM64_SW_TTBR0_PAN))
+ ttbr0 |= FIELD_PREP(TTBR_ASID_MASK, asid);
+
+ /* Set ASID in TTBR1 since TCR.A1 is set */
+ ttbr1 &= ~TTBR_ASID_MASK;
+ ttbr1 |= FIELD_PREP(TTBR_ASID_MASK, asid);
+
+ write_sysreg(ttbr1, ttbr1_el1);
+ isb();
+ write_sysreg(ttbr0, ttbr0_el1);
+ isb();
+ post_ttbr_update_workaround();
}
static int asids_update_limit(void)