Merge tag 'timers-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner:
 "Time, timers and timekeeping updates:

   - No core updates

   - No new clocksource/event driver

   - A large rework of the ARM architected timer driver to prepare for
     the support of the upcoming ARMv8.6 support

   - Fix Kconfig options for Exynos MCT, Samsung PWM and TI DM timers

   - Address a namespace collison in the ARC sp804 timer driver"

* tag 'timers-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource/drivers/timer-ti-dm: Select TIMER_OF
  clocksource/drivers/exynosy: Depend on sub-architecture for Exynos MCT and Samsung PWM
  clocksource/drivers/arch_arm_timer: Move workaround synchronisation around
  clocksource/drivers/arm_arch_timer: Fix masking for high freq counters
  clocksource/drivers/arm_arch_timer: Drop unnecessary ISB on CVAL programming
  clocksource/drivers/arm_arch_timer: Remove any trace of the TVAL programming interface
  clocksource/drivers/arm_arch_timer: Work around broken CVAL implementations
  clocksource/drivers/arm_arch_timer: Advertise 56bit timer to the core code
  clocksource/drivers/arm_arch_timer: Move MMIO timer programming over to CVAL
  clocksource/drivers/arm_arch_timer: Fix MMIO base address vs callback ordering issue
  clocksource/drivers/arm_arch_timer: Move drop _tval from erratum function names
  clocksource/drivers/arm_arch_timer: Move system register timer programming over to CVAL
  clocksource/drivers/arm_arch_timer: Extend write side of timer register accessors to u64
  clocksource/drivers/arm_arch_timer: Drop CNT*_TVAL read accessors
  clocksource/arm_arch_timer: Add build-time guards for unhandled register accesses
  clocksource/drivers/arc_timer: Eliminate redefined macro error

3 files changed, 153 insertions, 99 deletions

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 0f5e3983951a..f65e31bab9ae 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -24,6 +24,7 @@ config I8253_LOCK
 
 config OMAP_DM_TIMER
 	bool
+	select TIMER_OF
 
 config CLKBLD_I8253
 	def_bool y if CLKSRC_I8253 || CLKEVT_I8253 || I8253_LOCK
@@ -418,12 +419,14 @@ config ATMEL_TCB_CLKSRC
 config CLKSRC_EXYNOS_MCT
 	bool "Exynos multi core timer driver" if COMPILE_TEST
 	depends on ARM || ARM64
+	depends on ARCH_EXYNOS || COMPILE_TEST
 	help
 	  Support for Multi Core Timer controller on Exynos SoCs.
 
 config CLKSRC_SAMSUNG_PWM
 	bool "PWM timer driver for Samsung S3C, S5P" if COMPILE_TEST
 	depends on HAS_IOMEM
+	depends on ARCH_EXYNOS || ARCH_S3C24XX || ARCH_S3C64XX || ARCH_S5PV210 || COMPILE_TEST
 	help
 	  This is a new clocksource driver for the PWM timer found in
 	  Samsung S3C, S5P and Exynos SoCs, replacing an earlier driver
diff --git a/drivers/clocksource/arc_timer.c b/drivers/clocksource/arc_timer.c
index de93dd1a8c7b..cb18524cc13d 100644
--- a/drivers/clocksource/arc_timer.c
+++ b/drivers/clocksource/arc_timer.c
@@ -225,7 +225,7 @@ static int __init arc_cs_setup_timer1(struct device_node *node)
 
 	write_aux_reg(ARC_REG_TIMER1_LIMIT, ARC_TIMERN_MAX);
 	write_aux_reg(ARC_REG_TIMER1_CNT, 0);
-	write_aux_reg(ARC_REG_TIMER1_CTRL, TIMER_CTRL_NH);
+	write_aux_reg(ARC_REG_TIMER1_CTRL, ARC_TIMER_CTRL_NH);
 
 	sched_clock_register(arc_timer1_clock_read, 32, arc_timer_freq);
 
@@ -245,7 +245,7 @@ static void arc_timer_event_setup(unsigned int cycles)
 	write_aux_reg(ARC_REG_TIMER0_LIMIT, cycles);
 	write_aux_reg(ARC_REG_TIMER0_CNT, 0);	/* start from 0 */
 
-	write_aux_reg(ARC_REG_TIMER0_CTRL, TIMER_CTRL_IE | TIMER_CTRL_NH);
+	write_aux_reg(ARC_REG_TIMER0_CTRL, ARC_TIMER_CTRL_IE | ARC_TIMER_CTRL_NH);
 }
 
 
@@ -294,7 +294,7 @@ static irqreturn_t timer_irq_handler(int irq, void *dev_id)
 	 *      explicitly clears IP bit
 	 * 2. Re-arm interrupt if periodic by writing to IE bit [0]
 	 */
-	write_aux_reg(ARC_REG_TIMER0_CTRL, irq_reenable | TIMER_CTRL_NH);
+	write_aux_reg(ARC_REG_TIMER0_CTRL, irq_reenable | ARC_TIMER_CTRL_NH);
 
 	evt->event_handler(evt);
 
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index be6d741d404c..9a04eacc4412 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -44,23 +44,29 @@
 #define CNTACR_RWVT	BIT(4)
 #define CNTACR_RWPT	BIT(5)
 
-#define CNTVCT_LO	0x08
-#define CNTVCT_HI	0x0c
+#define CNTVCT_LO	0x00
+#define CNTPCT_LO	0x08
 #define CNTFRQ		0x10
-#define CNTP_TVAL	0x28
+#define CNTP_CVAL_LO	0x20
 #define CNTP_CTL	0x2c
-#define CNTV_TVAL	0x38
+#define CNTV_CVAL_LO	0x30
 #define CNTV_CTL	0x3c
 
-static unsigned arch_timers_present __initdata;
+/*
+ * The minimum amount of time a generic counter is guaranteed to not roll over
+ * (40 years)
+ */
+#define MIN_ROLLOVER_SECS	(40ULL * 365 * 24 * 3600)
 
-static void __iomem *arch_counter_base __ro_after_init;
+static unsigned arch_timers_present __initdata;
 
 struct arch_timer {
 	void __iomem *base;
 	struct clock_event_device evt;
 };
 
+static struct arch_timer *arch_timer_mem __ro_after_init;
+
 #define to_arch_timer(e) container_of(e, struct arch_timer, evt)
 
 static u32 arch_timer_rate __ro_after_init;
@@ -96,32 +102,57 @@ static int __init early_evtstrm_cfg(char *buf)
 early_param("clocksource.arm_arch_timer.evtstrm", early_evtstrm_cfg);
 
 /*
+ * Makes an educated guess at a valid counter width based on the Generic Timer
+ * specification. Of note:
+ *   1) the system counter is at least 56 bits wide
+ *   2) a roll-over time of not less than 40 years
+ *
+ * See 'ARM DDI 0487G.a D11.1.2 ("The system counter")' for more details.
+ */
+static int arch_counter_get_width(void)
+{
+	u64 min_cycles = MIN_ROLLOVER_SECS * arch_timer_rate;
+
+	/* guarantee the returned width is within the valid range */
+	return clamp_val(ilog2(min_cycles - 1) + 1, 56, 64);
+}
+
+/*
  * Architected system timer support.
  */
 
 static __always_inline
-void arch_timer_reg_write(int access, enum arch_timer_reg reg, u32 val,
+void arch_timer_reg_write(int access, enum arch_timer_reg reg, u64 val,
 			  struct clock_event_device *clk)
 {
 	if (access == ARCH_TIMER_MEM_PHYS_ACCESS) {
 		struct arch_timer *timer = to_arch_timer(clk);
 		switch (reg) {
 		case ARCH_TIMER_REG_CTRL:
-			writel_relaxed(val, timer->base + CNTP_CTL);
+			writel_relaxed((u32)val, timer->base + CNTP_CTL);
 			break;
-		case ARCH_TIMER_REG_TVAL:
-			writel_relaxed(val, timer->base + CNTP_TVAL);
+		case ARCH_TIMER_REG_CVAL:
+			/*
+			 * Not guaranteed to be atomic, so the timer
+			 * must be disabled at this point.
+			 */
+			writeq_relaxed(val, timer->base + CNTP_CVAL_LO);
 			break;
+		default:
+			BUILD_BUG();
 		}
 	} else if (access == ARCH_TIMER_MEM_VIRT_ACCESS) {
 		struct arch_timer *timer = to_arch_timer(clk);
 		switch (reg) {
 		case ARCH_TIMER_REG_CTRL:
-			writel_relaxed(val, timer->base + CNTV_CTL);
+			writel_relaxed((u32)val, timer->base + CNTV_CTL);
 			break;
-		case ARCH_TIMER_REG_TVAL:
-			writel_relaxed(val, timer->base + CNTV_TVAL);
+		case ARCH_TIMER_REG_CVAL:
+			/* Same restriction as above */
+			writeq_relaxed(val, timer->base + CNTV_CVAL_LO);
 			break;
+		default:
+			BUILD_BUG();
 		}
 	} else {
 		arch_timer_reg_write_cp15(access, reg, val);
@@ -140,9 +171,8 @@ u32 arch_timer_reg_read(int access, enum arch_timer_reg reg,
 		case ARCH_TIMER_REG_CTRL:
 			val = readl_relaxed(timer->base + CNTP_CTL);
 			break;
-		case ARCH_TIMER_REG_TVAL:
-			val = readl_relaxed(timer->base + CNTP_TVAL);
-			break;
+		default:
+			BUILD_BUG();
 		}
 	} else if (access == ARCH_TIMER_MEM_VIRT_ACCESS) {
 		struct arch_timer *timer = to_arch_timer(clk);
@@ -150,9 +180,8 @@ u32 arch_timer_reg_read(int access, enum arch_timer_reg reg,
 		case ARCH_TIMER_REG_CTRL:
 			val = readl_relaxed(timer->base + CNTV_CTL);
 			break;
-		case ARCH_TIMER_REG_TVAL:
-			val = readl_relaxed(timer->base + CNTV_TVAL);
-			break;
+		default:
+			BUILD_BUG();
 		}
 	} else {
 		val = arch_timer_reg_read_cp15(access, reg);
@@ -205,13 +234,11 @@ static struct clocksource clocksource_counter = {
 	.id	= CSID_ARM_ARCH_COUNTER,
 	.rating	= 400,
 	.read	= arch_counter_read,
-	.mask	= CLOCKSOURCE_MASK(56),
 	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
 static struct cyclecounter cyclecounter __ro_after_init = {
 	.read	= arch_counter_read_cc,
-	.mask	= CLOCKSOURCE_MASK(56),
 };
 
 struct ate_acpi_oem_info {
@@ -239,16 +266,6 @@ struct ate_acpi_oem_info {
 	_new;						\
 })
 
-static u32 notrace fsl_a008585_read_cntp_tval_el0(void)
-{
-	return __fsl_a008585_read_reg(cntp_tval_el0);
-}
-
-static u32 notrace fsl_a008585_read_cntv_tval_el0(void)
-{
-	return __fsl_a008585_read_reg(cntv_tval_el0);
-}
-
 static u64 notrace fsl_a008585_read_cntpct_el0(void)
 {
 	return __fsl_a008585_read_reg(cntpct_el0);
@@ -285,16 +302,6 @@ static u64 notrace fsl_a008585_read_cntvct_el0(void)
 	_new;							\
 })
 
-static u32 notrace hisi_161010101_read_cntp_tval_el0(void)
-{
-	return __hisi_161010101_read_reg(cntp_tval_el0);
-}
-
-static u32 notrace hisi_161010101_read_cntv_tval_el0(void)
-{
-	return __hisi_161010101_read_reg(cntv_tval_el0);
-}
-
 static u64 notrace hisi_161010101_read_cntpct_el0(void)
 {
 	return __hisi_161010101_read_reg(cntpct_el0);
@@ -379,16 +386,6 @@ static u64 notrace sun50i_a64_read_cntvct_el0(void)
 {
 	return __sun50i_a64_read_reg(cntvct_el0);
 }
-
-static u32 notrace sun50i_a64_read_cntp_tval_el0(void)
-{
-	return read_sysreg(cntp_cval_el0) - sun50i_a64_read_cntpct_el0();
-}
-
-static u32 notrace sun50i_a64_read_cntv_tval_el0(void)
-{
-	return read_sysreg(cntv_cval_el0) - sun50i_a64_read_cntvct_el0();
-}
 #endif
 
 #ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND
@@ -397,7 +394,7 @@ EXPORT_SYMBOL_GPL(timer_unstable_counter_workaround);
 
 static atomic_t timer_unstable_counter_workaround_in_use = ATOMIC_INIT(0);
 
-static void erratum_set_next_event_tval_generic(const int access, unsigned long evt,
+static void erratum_set_next_event_generic(const int access, unsigned long evt,
 						struct clock_event_device *clk)
 {
 	unsigned long ctrl;
@@ -418,17 +415,17 @@ static void erratum_set_next_event_tval_generic(const int access, unsigned long
 	arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
 }
 
-static __maybe_unused int erratum_set_next_event_tval_virt(unsigned long evt,
+static __maybe_unused int erratum_set_next_event_virt(unsigned long evt,
 					    struct clock_event_device *clk)
 {
-	erratum_set_next_event_tval_generic(ARCH_TIMER_VIRT_ACCESS, evt, clk);
+	erratum_set_next_event_generic(ARCH_TIMER_VIRT_ACCESS, evt, clk);
 	return 0;
 }
 
-static __maybe_unused int erratum_set_next_event_tval_phys(unsigned long evt,
+static __maybe_unused int erratum_set_next_event_phys(unsigned long evt,
 					    struct clock_event_device *clk)
 {
-	erratum_set_next_event_tval_generic(ARCH_TIMER_PHYS_ACCESS, evt, clk);
+	erratum_set_next_event_generic(ARCH_TIMER_PHYS_ACCESS, evt, clk);
 	return 0;
 }
 
@@ -438,12 +435,10 @@ static const struct arch_timer_erratum_workaround ool_workarounds[] = {
 		.match_type = ate_match_dt,
 		.id = "fsl,erratum-a008585",
 		.desc = "Freescale erratum a005858",
-		.read_cntp_tval_el0 = fsl_a008585_read_cntp_tval_el0,
-		.read_cntv_tval_el0 = fsl_a008585_read_cntv_tval_el0,
 		.read_cntpct_el0 = fsl_a008585_read_cntpct_el0,
 		.read_cntvct_el0 = fsl_a008585_read_cntvct_el0,
-		.set_next_event_phys = erratum_set_next_event_tval_phys,
-		.set_next_event_virt = erratum_set_next_event_tval_virt,
+		.set_next_event_phys = erratum_set_next_event_phys,
+		.set_next_event_virt = erratum_set_next_event_virt,
 	},
 #endif
 #ifdef CONFIG_HISILICON_ERRATUM_161010101
@@ -451,23 +446,19 @@ static const struct arch_timer_erratum_workaround ool_workarounds[] = {
 		.match_type = ate_match_dt,
 		.id = "hisilicon,erratum-161010101",
 		.desc = "HiSilicon erratum 161010101",
-		.read_cntp_tval_el0 = hisi_161010101_read_cntp_tval_el0,
-		.read_cntv_tval_el0 = hisi_161010101_read_cntv_tval_el0,
 		.read_cntpct_el0 = hisi_161010101_read_cntpct_el0,
 		.read_cntvct_el0 = hisi_161010101_read_cntvct_el0,
-		.set_next_event_phys = erratum_set_next_event_tval_phys,
-		.set_next_event_virt = erratum_set_next_event_tval_virt,
+		.set_next_event_phys = erratum_set_next_event_phys,
+		.set_next_event_virt = erratum_set_next_event_virt,
 	},
 	{
 		.match_type = ate_match_acpi_oem_info,
 		.id = hisi_161010101_oem_info,
 		.desc = "HiSilicon erratum 161010101",
-		.read_cntp_tval_el0 = hisi_161010101_read_cntp_tval_el0,
-		.read_cntv_tval_el0 = hisi_161010101_read_cntv_tval_el0,
 		.read_cntpct_el0 = hisi_161010101_read_cntpct_el0,
 		.read_cntvct_el0 = hisi_161010101_read_cntvct_el0,
-		.set_next_event_phys = erratum_set_next_event_tval_phys,
-		.set_next_event_virt = erratum_set_next_event_tval_virt,
+		.set_next_event_phys = erratum_set_next_event_phys,
+		.set_next_event_virt = erratum_set_next_event_virt,
 	},
 #endif
 #ifdef CONFIG_ARM64_ERRATUM_858921
@@ -484,12 +475,10 @@ static const struct arch_timer_erratum_workaround ool_workarounds[] = {
 		.match_type = ate_match_dt,
 		.id = "allwinner,erratum-unknown1",
 		.desc = "Allwinner erratum UNKNOWN1",
-		.read_cntp_tval_el0 = sun50i_a64_read_cntp_tval_el0,
-		.read_cntv_tval_el0 = sun50i_a64_read_cntv_tval_el0,
 		.read_cntpct_el0 = sun50i_a64_read_cntpct_el0,
 		.read_cntvct_el0 = sun50i_a64_read_cntvct_el0,
-		.set_next_event_phys = erratum_set_next_event_tval_phys,
-		.set_next_event_virt = erratum_set_next_event_tval_virt,
+		.set_next_event_phys = erratum_set_next_event_phys,
+		.set_next_event_virt = erratum_set_next_event_virt,
 	},
 #endif
 #ifdef CONFIG_ARM64_ERRATUM_1418040
@@ -727,10 +716,18 @@ static __always_inline void set_next_event(const int access, unsigned long evt,
 					   struct clock_event_device *clk)
 {
 	unsigned long ctrl;
+	u64 cnt;
+
 	ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, clk);
 	ctrl |= ARCH_TIMER_CTRL_ENABLE;
 	ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
-	arch_timer_reg_write(access, ARCH_TIMER_REG_TVAL, evt, clk);
+
+	if (access == ARCH_TIMER_PHYS_ACCESS)
+		cnt = __arch_counter_get_cntpct();
+	else
+		cnt = __arch_counter_get_cntvct();
+
+	arch_timer_reg_write(access, ARCH_TIMER_REG_CVAL, evt + cnt, clk);
 	arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
 }
 
@@ -748,23 +745,79 @@ static int arch_timer_set_next_event_phys(unsigned long evt,
 	return 0;
 }
 
+static u64 arch_counter_get_cnt_mem(struct arch_timer *t, int offset_lo)
+{
+	u32 cnt_lo, cnt_hi, tmp_hi;
+
+	do {
+		cnt_hi = readl_relaxed(t->base + offset_lo + 4);
+		cnt_lo = readl_relaxed(t->base + offset_lo);
+		tmp_hi = readl_relaxed(t->base + offset_lo + 4);
+	} while (cnt_hi != tmp_hi);
+
+	return ((u64) cnt_hi << 32) | cnt_lo;
+}
+
+static __always_inline void set_next_event_mem(const int access, unsigned long evt,
+					   struct clock_event_device *clk)
+{
+	struct arch_timer *timer = to_arch_timer(clk);
+	unsigned long ctrl;
+	u64 cnt;
+
+	ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, clk);
+	ctrl |= ARCH_TIMER_CTRL_ENABLE;
+	ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
+
+	if (access ==  ARCH_TIMER_MEM_VIRT_ACCESS)
+		cnt = arch_counter_get_cnt_mem(timer, CNTVCT_LO);
+	else
+		cnt = arch_counter_get_cnt_mem(timer, CNTPCT_LO);
+
+	arch_timer_reg_write(access, ARCH_TIMER_REG_CVAL, evt + cnt, clk);
+	arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
+}
+
 static int arch_timer_set_next_event_virt_mem(unsigned long evt,
 					      struct clock_event_device *clk)
 {
-	set_next_event(ARCH_TIMER_MEM_VIRT_ACCESS, evt, clk);
+	set_next_event_mem(ARCH_TIMER_MEM_VIRT_ACCESS, evt, clk);
 	return 0;
 }
 
 static int arch_timer_set_next_event_phys_mem(unsigned long evt,
 					      struct clock_event_device *clk)
 {
-	set_next_event(ARCH_TIMER_MEM_PHYS_ACCESS, evt, clk);
+	set_next_event_mem(ARCH_TIMER_MEM_PHYS_ACCESS, evt, clk);
 	return 0;
 }
 
+static u64 __arch_timer_check_delta(void)
+{
+#ifdef CONFIG_ARM64
+	const struct midr_range broken_cval_midrs[] = {
+		/*
+		 * XGene-1 implements CVAL in terms of TVAL, meaning
+		 * that the maximum timer range is 32bit. Shame on them.
+		 */
+		MIDR_ALL_VERSIONS(MIDR_CPU_MODEL(ARM_CPU_IMP_APM,
+						 APM_CPU_PART_POTENZA)),
+		{},
+	};
+
+	if (is_midr_in_range_list(read_cpuid_id(), broken_cval_midrs)) {
+		pr_warn_once("Broken CNTx_CVAL_EL1, limiting width to 32bits");
+		return CLOCKSOURCE_MASK(32);
+	}
+#endif
+	return CLOCKSOURCE_MASK(arch_counter_get_width());
+}
+
 static void __arch_timer_setup(unsigned type,
 			       struct clock_event_device *clk)
 {
+	u64 max_delta;
+
 	clk->features = CLOCK_EVT_FEAT_ONESHOT;
 
 	if (type == ARCH_TIMER_TYPE_CP15) {
@@ -796,6 +849,7 @@ static void __arch_timer_setup(unsigned type,
 		}
 
 		clk->set_next_event = sne;
+		max_delta = __arch_timer_check_delta();
 	} else {
 		clk->features |= CLOCK_EVT_FEAT_DYNIRQ;
 		clk->name = "arch_mem_timer";
@@ -812,11 +866,13 @@ static void __arch_timer_setup(unsigned type,
 			clk->set_next_event =
 				arch_timer_set_next_event_phys_mem;
 		}
+
+		max_delta = CLOCKSOURCE_MASK(56);
 	}
 
 	clk->set_state_shutdown(clk);
 
-	clockevents_config_and_register(clk, arch_timer_rate, 0xf, 0x7fffffff);
+	clockevents_config_and_register(clk, arch_timer_rate, 0xf, max_delta);
 }
 
 static void arch_timer_evtstrm_enable(int divider)
@@ -986,15 +1042,7 @@ bool arch_timer_evtstrm_available(void)
 
 static u64 arch_counter_get_cntvct_mem(void)
 {
-	u32 vct_lo, vct_hi, tmp_hi;
-
-	do {
-		vct_hi = readl_relaxed(arch_counter_base + CNTVCT_HI);
-		vct_lo = readl_relaxed(arch_counter_base + CNTVCT_LO);
-		tmp_hi = readl_relaxed(arch_counter_base + CNTVCT_HI);
-	} while (vct_hi != tmp_hi);
-
-	return ((u64) vct_hi << 32) | vct_lo;
+	return arch_counter_get_cnt_mem(arch_timer_mem, CNTVCT_LO);
 }
 
 static struct arch_timer_kvm_info arch_timer_kvm_info;
@@ -1007,6 +1055,7 @@ struct arch_timer_kvm_info *arch_timer_get_kvm_info(void)
 static void __init arch_counter_register(unsigned type)
 {
 	u64 start_count;
+	int width;
 
 	/* Register the CP15 based counter if we have one */
 	if (type & ARCH_TIMER_TYPE_CP15) {
@@ -1031,6 +1080,10 @@ static void __init arch_counter_register(unsigned type)
 		arch_timer_read_counter = arch_counter_get_cntvct_mem;
 	}
 
+	width = arch_counter_get_width();
+	clocksource_counter.mask = CLOCKSOURCE_MASK(width);
+	cyclecounter.mask = CLOCKSOURCE_MASK(width);
+
 	if (!arch_counter_suspend_stop)
 		clocksource_counter.flags |= CLOCK_SOURCE_SUSPEND_NONSTOP;
 	start_count = arch_timer_read_counter();
@@ -1040,8 +1093,7 @@ static void __init arch_counter_register(unsigned type)
 	timecounter_init(&arch_timer_kvm_info.timecounter,
 			 &cyclecounter, start_count);
 
-	/* 56 bits minimum, so we assume worst case rollover */
-	sched_clock_register(arch_timer_read_counter, 56, arch_timer_rate);
+	sched_clock_register(arch_timer_read_counter, width, arch_timer_rate);
 }
 
 static void arch_timer_stop(struct clock_event_device *clk)
@@ -1182,25 +1234,25 @@ static int __init arch_timer_mem_register(void __iomem *base, unsigned int irq)
 {
 	int ret;
 	irq_handler_t func;
-	struct arch_timer *t;
 
-	t = kzalloc(sizeof(*t), GFP_KERNEL);
-	if (!t)
+	arch_timer_mem = kzalloc(sizeof(*arch_timer_mem), GFP_KERNEL);
+	if (!arch_timer_mem)
 		return -ENOMEM;
 
-	t->base = base;
-	t->evt.irq = irq;
-	__arch_timer_setup(ARCH_TIMER_TYPE_MEM, &t->evt);
+	arch_timer_mem->base = base;
+	arch_timer_mem->evt.irq = irq;
+	__arch_timer_setup(ARCH_TIMER_TYPE_MEM, &arch_timer_mem->evt);
 
 	if (arch_timer_mem_use_virtual)
 		func = arch_timer_handler_virt_mem;
 	else
 		func = arch_timer_handler_phys_mem;
 
-	ret = request_irq(irq, func, IRQF_TIMER, "arch_mem_timer", &t->evt);
+	ret = request_irq(irq, func, IRQF_TIMER, "arch_mem_timer", &arch_timer_mem->evt);
 	if (ret) {
 		pr_err("Failed to request mem timer irq\n");
-		kfree(t);
+		kfree(arch_timer_mem);
+		arch_timer_mem = NULL;
 	}
 
 	return ret;
@@ -1458,7 +1510,6 @@ arch_timer_mem_frame_register(struct arch_timer_mem_frame *frame)
 		return ret;
 	}
 
-	arch_counter_base = base;
 	arch_timers_present |= ARCH_TIMER_TYPE_MEM;
 
 	return 0;