arm64: cpu: Move errata and feature enable callbacks closer to callers

mainline inclusion
from mainline-v4.20-rc1
commit b8925ee2
category: feature
bugzilla: 20806
CVE: NA

-------------------------------------------------

The cpu errata and feature enable callbacks are only called via their
respective arm64_cpu_capabilities structure and therefore shouldn't
exist in the global namespace.

Move the PAN, RAS and cache maintenance emulation enable callbacks into
the same files as their corresponding arm64_cpu_capabilities structures,
making them static in the process.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Conflicts:
  arch/arm64/kernel/cpu_errata.c
  arch/arm64/kernel/cpufeature.c
[yyl: adjust context]
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Reviewed-by: NXuefeng Wang <wxf.wang@hisilicon.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

arch/arm64/include/asm/processor.h

@@ -262,10 +262,6 @@ static inline void spin_lock_prefetch(const void *ptr)
 
 #endif
 
-void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused);
-void cpu_enable_cache_maint_trap(const struct arm64_cpu_capabilities *__unused);
-void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused);
-
 extern unsigned long __ro_after_init signal_minsigstksz; /* sigframe size */
 extern void __init minsigstksz_setup(void);
 

arch/arm64/kernel/cpu_errata.c

@@ -467,6 +467,12 @@ static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry,
 }
 #endif	/* CONFIG_ARM64_SSBD */
 
+static void __maybe_unused
+cpu_enable_cache_maint_trap(const struct arm64_cpu_capabilities *__unused)
+{
+	sysreg_clear_set(sctlr_el1, SCTLR_EL1_UCI, 0);
+}
+
 #ifdef CONFIG_ARM64_ERRATUM_1463225
 DEFINE_PER_CPU(int, __in_cortex_a76_erratum_1463225_wa);
 

arch/arm64/kernel/cpufeature.c

@@ -1116,6 +1116,28 @@ static void cpu_enable_ssbs(const struct arm64_cpu_capabilities *__unused)
 }
 #endif /* CONFIG_ARM64_SSBD */
 
+#ifdef CONFIG_ARM64_PAN
+static void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused)
+{
+	/*
+	 * We modify PSTATE. This won't work from irq context as the PSTATE
+	 * is discarded once we return from the exception.
+	 */
+	WARN_ON_ONCE(in_interrupt());
+
+	sysreg_clear_set(sctlr_el1, SCTLR_EL1_SPAN, 0);
+	asm(SET_PSTATE_PAN(1));
+}
+#endif /* CONFIG_ARM64_PAN */
+
+#ifdef CONFIG_ARM64_RAS_EXTN
+static void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused)
+{
+	/* Firmware may have left a deferred SError in this register. */
+	write_sysreg_s(0, SYS_DISR_EL1);
+}
+#endif /* CONFIG_ARM64_RAS_EXTN */
+
 #ifdef CONFIG_ARM64_PSEUDO_NMI
 static bool enable_pseudo_nmi;
 
@@ -1906,9 +1928,3 @@ static int __init enable_mrs_emulation(void)
 }
 
 core_initcall(enable_mrs_emulation);
-
-void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused)
-{
-	/* Firmware may have left a deferred SError in this register. */
-	write_sysreg_s(0, SYS_DISR_EL1);
-}

arch/arm64/kernel/traps.c

@@ -418,11 +418,6 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
 	force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc);
 }
 
-void cpu_enable_cache_maint_trap(const struct arm64_cpu_capabilities *__unused)
-{
-	sysreg_clear_set(sctlr_el1, SCTLR_EL1_UCI, 0);
-}
-
 #define __user_cache_maint(insn, address, res)			\
 	if (address >= user_addr_max()) {			\
 		res = -EFAULT;					\

arch/arm64/mm/fault.c

@@ -908,17 +908,3 @@ asmlinkage int __exception do_debug_exception(unsigned long addr_if_watchpoint,
 	return rv;
 }
 NOKPROBE_SYMBOL(do_debug_exception);
-
-#ifdef CONFIG_ARM64_PAN
-void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused)
-{
-	/*
-	 * We modify PSTATE. This won't work from irq context as the PSTATE
-	 * is discarded once we return from the exception.
-	 */
-	WARN_ON_ONCE(in_interrupt());
-
-	sysreg_clear_set(sctlr_el1, SCTLR_EL1_SPAN, 0);
-	asm(SET_PSTATE_PAN(1));
-}
-#endif /* CONFIG_ARM64_PAN */