Merge changes Ibdb1fd76,I6005a6e9,Ie5a9a93f,I0705f47c into mnc-dr-dev-qcom-lego

* changes:
  clocksource: arch_timer: make virtual counter access configurable
  arm64: issue isb when trapping CNTVCT_EL0 access
  BACKPORT: arm64: Add CNTFRQ_EL0 trap handler
  BACKPORT: arm64: Add CNTVCT_EL0 trap handler

arch/arm64/include/asm/esr.h

@@ -54,4 +54,44 @@
 #define ESR_EL1_EC_BKPT32	(0x38)
 #define ESR_EL1_EC_BRK64	(0x3C)
 
+/* ISS field definitions for System instruction traps */
+#define ESR_ELx_SYS64_ISS_RES0_SHIFT	22
+#define ESR_ELx_SYS64_ISS_RES0_MASK	(UL(0x7) << ESR_ELx_SYS64_ISS_RES0_SHIFT)
+#define ESR_ELx_SYS64_ISS_DIR_MASK	0x1
+#define ESR_ELx_SYS64_ISS_DIR_READ	0x1
+#define ESR_ELx_SYS64_ISS_DIR_WRITE	0x0
+
+#define ESR_ELx_SYS64_ISS_RT_SHIFT	5
+#define ESR_ELx_SYS64_ISS_RT_MASK	(UL(0x1f) << ESR_ELx_SYS64_ISS_RT_SHIFT)
+#define ESR_ELx_SYS64_ISS_CRM_SHIFT	1
+#define ESR_ELx_SYS64_ISS_CRM_MASK	(UL(0xf) << ESR_ELx_SYS64_ISS_CRM_SHIFT)
+#define ESR_ELx_SYS64_ISS_CRN_SHIFT	10
+#define ESR_ELx_SYS64_ISS_CRN_MASK	(UL(0xf) << ESR_ELx_SYS64_ISS_CRN_SHIFT)
+#define ESR_ELx_SYS64_ISS_OP1_SHIFT	14
+#define ESR_ELx_SYS64_ISS_OP1_MASK	(UL(0x7) << ESR_ELx_SYS64_ISS_OP1_SHIFT)
+#define ESR_ELx_SYS64_ISS_OP2_SHIFT	17
+#define ESR_ELx_SYS64_ISS_OP2_MASK	(UL(0x7) << ESR_ELx_SYS64_ISS_OP2_SHIFT)
+#define ESR_ELx_SYS64_ISS_OP0_SHIFT	20
+#define ESR_ELx_SYS64_ISS_OP0_MASK	(UL(0x3) << ESR_ELx_SYS64_ISS_OP0_SHIFT)
+#define ESR_ELx_SYS64_ISS_SYS_MASK	(ESR_ELx_SYS64_ISS_OP0_MASK | \
+					 ESR_ELx_SYS64_ISS_OP1_MASK | \
+					 ESR_ELx_SYS64_ISS_OP2_MASK | \
+					 ESR_ELx_SYS64_ISS_CRN_MASK | \
+					 ESR_ELx_SYS64_ISS_CRM_MASK)
+#define ESR_ELx_SYS64_ISS_SYS_VAL(op0, op1, op2, crn, crm) \
+					(((op0) << ESR_ELx_SYS64_ISS_OP0_SHIFT) | \
+					 ((op1) << ESR_ELx_SYS64_ISS_OP1_SHIFT) | \
+					 ((op2) << ESR_ELx_SYS64_ISS_OP2_SHIFT) | \
+					 ((crn) << ESR_ELx_SYS64_ISS_CRN_SHIFT) | \
+					 ((crm) << ESR_ELx_SYS64_ISS_CRM_SHIFT))
+
+#define ESR_ELx_SYS64_ISS_SYS_OP_MASK	(ESR_ELx_SYS64_ISS_SYS_MASK | \
+					 ESR_ELx_SYS64_ISS_DIR_MASK)
+
+#define ESR_ELx_SYS64_ISS_SYS_CNTVCT	(ESR_ELx_SYS64_ISS_SYS_VAL(3, 3, 2, 14, 0) | \
+					 ESR_ELx_SYS64_ISS_DIR_READ)
+
+#define ESR_ELx_SYS64_ISS_SYS_CNTFRQ	(ESR_ELx_SYS64_ISS_SYS_VAL(3, 3, 0, 14, 0) | \
+					 ESR_ELx_SYS64_ISS_DIR_READ)
+
 #endif /* __ASM_ESR_H */

arch/arm64/kernel/entry.S

@@ -378,7 +378,7 @@ el0_sync:
 	cmp	x24, #ESR_EL1_EC_FP_EXC64	// FP/ASIMD exception
 	b.eq	el0_fpsimd_exc
 	cmp	x24, #ESR_EL1_EC_SYS64		// configurable trap
-	b.eq	el0_undef
+	b.eq	el0_sys
 	cmp	x24, #ESR_EL1_EC_SP_ALIGN	// stack alignment exception
 	b.eq	el0_sp_pc
 	cmp	x24, #ESR_EL1_EC_PC_ALIGN	// pc alignment exception
@@ -491,6 +491,15 @@ el0_undef:
 	enable_dbg_and_irq
 	mov	x0, sp
 	b	do_undefinstr
+el0_sys:
+	/*
+	 * System instructions, for trapped cache maintenance instructions
+	 */
+	enable_dbg
+	enable_irq
+	mov	x0, x25
+	mov	x1, sp
+	b	do_sysinstr
 el0_dbg:
 	/*
 	 * Debug exception handling

arch/arm64/kernel/traps.c

@@ -32,8 +32,11 @@
 #include <linux/sched.h>
 #include <linux/syscalls.h>
 
+#include <asm/arch_timer.h>
 #include <asm/atomic.h>
+#include <asm/barrier.h>
 #include <asm/debug-monitors.h>
+#include <asm/esr.h>
 #include <asm/traps.h>
 #include <asm/stacktrace.h>
 #include <asm/exception.h>
@@ -381,6 +384,38 @@ die_sig:
 	arm64_notify_die("Oops - undefined instruction", regs, &info, 0);
 }
 
+static void cntvct_read_handler(unsigned int esr, struct pt_regs *regs)
+{
+	int rt = (esr & ESR_ELx_SYS64_ISS_RT_MASK) >> ESR_ELx_SYS64_ISS_RT_SHIFT;
+
+	isb();
+	if (rt != 31)
+		regs->regs[rt] = arch_counter_get_cntvct();
+	regs->pc += 4;
+}
+
+static void cntfrq_read_handler(unsigned int esr, struct pt_regs *regs)
+{
+	int rt = (esr & ESR_ELx_SYS64_ISS_RT_MASK) >> ESR_ELx_SYS64_ISS_RT_SHIFT;
+
+	if (rt != 31)
+		asm volatile("mrs %0, cntfrq_el0" : "=r" (regs->regs[rt]));
+	regs->pc += 4;
+}
+
+asmlinkage void __exception do_sysinstr(unsigned int esr, struct pt_regs *regs)
+{
+	if ((esr & ESR_ELx_SYS64_ISS_SYS_OP_MASK) == ESR_ELx_SYS64_ISS_SYS_CNTVCT) {
+		cntvct_read_handler(esr, regs);
+		return;
+	} else if ((esr & ESR_ELx_SYS64_ISS_SYS_OP_MASK) == ESR_ELx_SYS64_ISS_SYS_CNTFRQ) {
+		cntfrq_read_handler(esr, regs);
+		return;
+	}
+
+	do_undefinstr(regs);
+}
+
 long compat_arm_syscall(struct pt_regs *regs);
 
 asmlinkage long do_ni_syscall(struct pt_regs *regs)

drivers/clocksource/Kconfig

@@ -82,6 +82,14 @@ config ARM_ARCH_TIMER_EVTSTREAM
 	  This must be disabled for hardware validation purposes to detect any
 	  hardware anomalies of missing events.
 
+config ARM_ARCH_TIMER_VCT_ACCESS
+	bool "Support for ARM architected timer virtual counter access in userspace"
+	default !ARM64
+	depends on ARM_ARCH_TIMER
+	help
+	  This option enables support for reading the ARM architected timer's
+	  virtual counter in userspace.
+
 config CLKSRC_METAG_GENERIC
 	def_bool y if METAG
 	help

drivers/clocksource/arm_arch_timer.c

@@ -320,7 +320,11 @@ static void arch_counter_set_user_access(void)
 			| ARCH_TIMER_VIRT_EVT_EN);
 
 	/* Enable user access to the virtual and physical counters */
-	cntkctl |= ARCH_TIMER_USR_VCT_ACCESS_EN | ARCH_TIMER_USR_PCT_ACCESS_EN;
+	cntkctl |= ARCH_TIMER_USR_PCT_ACCESS_EN;
+	if (IS_ENABLED(CONFIG_ARM_ARCH_TIMER_VCT_ACCESS))
+		cntkctl |= ARCH_TIMER_USR_VCT_ACCESS_EN;
+	else
+		cntkctl &= ~ARCH_TIMER_USR_VCT_ACCESS_EN;
 
 	arch_timer_set_cntkctl(cntkctl);
 }