Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:
 "Apart from some new arm64 features and clean-ups, this also contains
  the core mmu_gather changes for tracking the levels of the page table
  being cleared and a minor update to the generic
  compat_sys_sigaltstack() introducing COMPAT_SIGMINSKSZ.

  Summary:

   - Core mmu_gather changes which allow tracking the levels of
     page-table being cleared together with the arm64 low-level flushing
     routines

   - Support for the new ARMv8.5 PSTATE.SSBS bit which can be used to
     mitigate Spectre-v4 dynamically without trapping to EL3 firmware

   - Introduce COMPAT_SIGMINSTKSZ for use in compat_sys_sigaltstack

   - Optimise emulation of MRS instructions to ID_* registers on ARMv8.4

   - Support for Common Not Private (CnP) translations allowing threads
     of the same CPU to share the TLB entries

   - Accelerated crc32 routines

   - Move swapper_pg_dir to the rodata section

   - Trap WFI instruction executed in user space

   - ARM erratum 1188874 workaround (arch_timer)

   - Miscellaneous fixes and clean-ups"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (78 commits)
  arm64: KVM: Guests can skip __install_bp_hardening_cb()s HYP work
  arm64: cpufeature: Trap CTR_EL0 access only where it is necessary
  arm64: cpufeature: Fix handling of CTR_EL0.IDC field
  arm64: cpufeature: ctr: Fix cpu capability check for late CPUs
  Documentation/arm64: HugeTLB page implementation
  arm64: mm: Use __pa_symbol() for set_swapper_pgd()
  arm64: Add silicon-errata.txt entry for ARM erratum 1188873
  Revert "arm64: uaccess: implement unsafe accessors"
  arm64: mm: Drop the unused cpu parameter
  MAINTAINERS: fix bad sdei paths
  arm64: mm: Use #ifdef for the __PAGETABLE_P?D_FOLDED defines
  arm64: Fix typo in a comment in arch/arm64/mm/kasan_init.c
  arm64: xen: Use existing helper to check interrupt status
  arm64: Use daifflag_restore after bp_hardening
  arm64: daifflags: Use irqflags functions for daifflags
  arm64: arch_timer: avoid unused function warning
  arm64: Trap WFI executed in userspace
  arm64: docs: Document SSBS HWCAP
  arm64: docs: Fix typos in ELF hwcaps
  arm64/kprobes: remove an extra semicolon in arch_prepare_kprobe
  ...

1 files changed, 15 insertions, 0 deletions

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index d8c7f5750cdb..9a7d4dc00b6e 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -319,6 +319,13 @@ static u64 notrace arm64_858921_read_cntvct_el0(void)
 }
 #endif
 
+#ifdef CONFIG_ARM64_ERRATUM_1188873
+static u64 notrace arm64_1188873_read_cntvct_el0(void)
+{
+	return read_sysreg(cntvct_el0);
+}
+#endif
+
 #ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND
 DEFINE_PER_CPU(const struct arch_timer_erratum_workaround *, timer_unstable_counter_workaround);
 EXPORT_SYMBOL_GPL(timer_unstable_counter_workaround);
@@ -408,6 +415,14 @@ static const struct arch_timer_erratum_workaround ool_workarounds[] = {
 		.read_cntvct_el0 = arm64_858921_read_cntvct_el0,
 	},
 #endif
+#ifdef CONFIG_ARM64_ERRATUM_1188873
+	{
+		.match_type = ate_match_local_cap_id,
+		.id = (void *)ARM64_WORKAROUND_1188873,
+		.desc = "ARM erratum 1188873",
+		.read_cntvct_el0 = arm64_1188873_read_cntvct_el0,
+	},
+#endif
 };
 
 typedef bool (*ate_match_fn_t)(const struct arch_timer_erratum_workaround *,