arm64: entry: convert el0_sync to C

This is largely a 1-1 conversion of asm to C, with a couple of caveats.

The el0_sync{_compat} switches explicitly handle all the EL0 debug
cases, so el0_dbg doesn't have to try to bail out for unexpected EL1
debug ESR values. This also means that an unexpected vector catch from
AArch32 is routed to el0_inv.

We *could* merge the native and compat switches, which would make the
diffstat negative, but I've tried to stay as close to the existing
assembly as possible for the moment.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
[split out of a bigger series, added nokprobes. removed irq trace
 calls as the C helpers do this. renamed el0_dbg's use of FAR]
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

1 files changed, 222 insertions, 0 deletions

diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c
index e726d1f4b9e9..2c318e41d84b 100644
--- a/arch/arm64/kernel/entry-common.c
+++ b/arch/arm64/kernel/entry-common.c
@@ -96,3 +96,225 @@ asmlinkage void notrace el1_sync_handler(struct pt_regs *regs)
 	};
 }
 NOKPROBE_SYMBOL(el1_sync_handler);
+
+static void notrace el0_da(struct pt_regs *regs, unsigned long esr)
+{
+	unsigned long far = read_sysreg(far_el1);
+
+	user_exit_irqoff();
+	local_daif_restore(DAIF_PROCCTX);
+	far = untagged_addr(far);
+	do_mem_abort(far, esr, regs);
+}
+NOKPROBE_SYMBOL(el0_da);
+
+static void notrace el0_ia(struct pt_regs *regs, unsigned long esr)
+{
+	unsigned long far = read_sysreg(far_el1);
+
+	user_exit_irqoff();
+	local_daif_restore(DAIF_PROCCTX_NOIRQ);
+	do_el0_ia_bp_hardening(far, esr, regs);
+}
+NOKPROBE_SYMBOL(el0_ia);
+
+static void notrace el0_fpsimd_acc(struct pt_regs *regs, unsigned long esr)
+{
+	user_exit_irqoff();
+	local_daif_restore(DAIF_PROCCTX);
+	do_fpsimd_acc(esr, regs);
+}
+NOKPROBE_SYMBOL(el0_fpsimd_acc);
+
+static void notrace el0_sve_acc(struct pt_regs *regs, unsigned long esr)
+{
+	user_exit_irqoff();
+	local_daif_restore(DAIF_PROCCTX);
+	do_sve_acc(esr, regs);
+}
+NOKPROBE_SYMBOL(el0_sve_acc);
+
+static void notrace el0_fpsimd_exc(struct pt_regs *regs, unsigned long esr)
+{
+	user_exit_irqoff();
+	local_daif_restore(DAIF_PROCCTX);
+	do_fpsimd_exc(esr, regs);
+}
+NOKPROBE_SYMBOL(el0_fpsimd_exc);
+
+static void notrace el0_sys(struct pt_regs *regs, unsigned long esr)
+{
+	user_exit_irqoff();
+	local_daif_restore(DAIF_PROCCTX);
+	do_sysinstr(esr, regs);
+}
+NOKPROBE_SYMBOL(el0_sys);
+
+static void notrace el0_pc(struct pt_regs *regs, unsigned long esr)
+{
+	unsigned long far = read_sysreg(far_el1);
+
+	user_exit_irqoff();
+	local_daif_restore(DAIF_PROCCTX_NOIRQ);
+	do_sp_pc_abort(far, esr, regs);
+}
+NOKPROBE_SYMBOL(el0_pc);
+
+static void notrace el0_sp(struct pt_regs *regs, unsigned long esr)
+{
+	user_exit_irqoff();
+	local_daif_restore(DAIF_PROCCTX_NOIRQ);
+	do_sp_pc_abort(regs->sp, esr, regs);
+}
+NOKPROBE_SYMBOL(el0_sp);
+
+static void notrace el0_undef(struct pt_regs *regs)
+{
+	user_exit_irqoff();
+	local_daif_restore(DAIF_PROCCTX);
+	do_undefinstr(regs);
+}
+NOKPROBE_SYMBOL(el0_undef);
+
+static void notrace el0_inv(struct pt_regs *regs, unsigned long esr)
+{
+	user_exit_irqoff();
+	local_daif_restore(DAIF_PROCCTX);
+	bad_el0_sync(regs, 0, esr);
+}
+NOKPROBE_SYMBOL(el0_inv);
+
+static void notrace el0_dbg(struct pt_regs *regs, unsigned long esr)
+{
+	/* Only watchpoints write FAR_EL1, otherwise its UNKNOWN */
+	unsigned long far = read_sysreg(far_el1);
+
+	if (system_uses_irq_prio_masking())
+		gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET);
+
+	user_exit_irqoff();
+	do_debug_exception(far, esr, regs);
+	local_daif_restore(DAIF_PROCCTX_NOIRQ);
+}
+NOKPROBE_SYMBOL(el0_dbg);
+
+static void notrace el0_svc(struct pt_regs *regs)
+{
+	if (system_uses_irq_prio_masking())
+		gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET);
+
+	el0_svc_handler(regs);
+}
+NOKPROBE_SYMBOL(el0_svc);
+
+asmlinkage void notrace el0_sync_handler(struct pt_regs *regs)
+{
+	unsigned long esr = read_sysreg(esr_el1);
+
+	switch (ESR_ELx_EC(esr)) {
+	case ESR_ELx_EC_SVC64:
+		el0_svc(regs);
+		break;
+	case ESR_ELx_EC_DABT_LOW:
+		el0_da(regs, esr);
+		break;
+	case ESR_ELx_EC_IABT_LOW:
+		el0_ia(regs, esr);
+		break;
+	case ESR_ELx_EC_FP_ASIMD:
+		el0_fpsimd_acc(regs, esr);
+		break;
+	case ESR_ELx_EC_SVE:
+		el0_sve_acc(regs, esr);
+		break;
+	case ESR_ELx_EC_FP_EXC64:
+		el0_fpsimd_exc(regs, esr);
+		break;
+	case ESR_ELx_EC_SYS64:
+	case ESR_ELx_EC_WFx:
+		el0_sys(regs, esr);
+		break;
+	case ESR_ELx_EC_SP_ALIGN:
+		el0_sp(regs, esr);
+		break;
+	case ESR_ELx_EC_PC_ALIGN:
+		el0_pc(regs, esr);
+		break;
+	case ESR_ELx_EC_UNKNOWN:
+		el0_undef(regs);
+		break;
+	case ESR_ELx_EC_BREAKPT_LOW:
+	case ESR_ELx_EC_SOFTSTP_LOW:
+	case ESR_ELx_EC_WATCHPT_LOW:
+	case ESR_ELx_EC_BRK64:
+		el0_dbg(regs, esr);
+		break;
+	default:
+		el0_inv(regs, esr);
+	}
+}
+NOKPROBE_SYMBOL(el0_sync_handler);
+
+#ifdef CONFIG_COMPAT
+static void notrace el0_cp15(struct pt_regs *regs, unsigned long esr)
+{
+	user_exit_irqoff();
+	local_daif_restore(DAIF_PROCCTX);
+	do_cp15instr(esr, regs);
+}
+NOKPROBE_SYMBOL(el0_cp15);
+
+static void notrace el0_svc_compat(struct pt_regs *regs)
+{
+	if (system_uses_irq_prio_masking())
+		gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET);
+
+	el0_svc_compat_handler(regs);
+}
+NOKPROBE_SYMBOL(el0_svc_compat);
+
+asmlinkage void notrace el0_sync_compat_handler(struct pt_regs *regs)
+{
+	unsigned long esr = read_sysreg(esr_el1);
+
+	switch (ESR_ELx_EC(esr)) {
+	case ESR_ELx_EC_SVC32:
+		el0_svc_compat(regs);
+		break;
+	case ESR_ELx_EC_DABT_LOW:
+		el0_da(regs, esr);
+		break;
+	case ESR_ELx_EC_IABT_LOW:
+		el0_ia(regs, esr);
+		break;
+	case ESR_ELx_EC_FP_ASIMD:
+		el0_fpsimd_acc(regs, esr);
+		break;
+	case ESR_ELx_EC_FP_EXC32:
+		el0_fpsimd_exc(regs, esr);
+		break;
+	case ESR_ELx_EC_PC_ALIGN:
+		el0_pc(regs, esr);
+		break;
+	case ESR_ELx_EC_UNKNOWN:
+	case ESR_ELx_EC_CP14_MR:
+	case ESR_ELx_EC_CP14_LS:
+	case ESR_ELx_EC_CP14_64:
+		el0_undef(regs);
+		break;
+	case ESR_ELx_EC_CP15_32:
+	case ESR_ELx_EC_CP15_64:
+		el0_cp15(regs, esr);
+		break;
+	case ESR_ELx_EC_BREAKPT_LOW:
+	case ESR_ELx_EC_SOFTSTP_LOW:
+	case ESR_ELx_EC_WATCHPT_LOW:
+	case ESR_ELx_EC_BKPT32:
+		el0_dbg(regs, esr);
+		break;
+	default:
+		el0_inv(regs, esr);
+	}
+}
+NOKPROBE_SYMBOL(el0_sync_compat_handler);
+#endif /* CONFIG_COMPAT */