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authorLinus Torvalds <torvalds@linux-foundation.org>2020-08-21 22:32:42 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-08-21 22:32:42 +0300
commitf22c5579a7d600fa03f8c1d150cf78188f8709b6 (patch)
tree9865bd0b054c4407029bbb1d411b14091fc8d9bf /drivers
parentc0a4f5b354dc26573cfaa541064fd35a794eb166 (diff)
parentfc26f5bbf19459930b7290c87b65a9ae6a274650 (diff)
downloadlinux-f22c5579a7d600fa03f8c1d150cf78188f8709b6.tar.xz
Merge tag 'riscv-for-linus-5.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V fixes from Palmer Dabbelt: - The CLINT driver has been split in two: one to handle the M-mode CLINT (memory mapped and used on NOMMU systems) and one to handle the S-mode CLINT (via SBI). - The addition of SiFive's drivers to rv32_defconfig * tag 'riscv-for-linus-5.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: Add SiFive drivers to rv32_defconfig dt-bindings: timer: Add CLINT bindings RISC-V: Remove CLINT related code from timer and arch clocksource/drivers: Add CLINT timer driver RISC-V: Add mechanism to provide custom IPI operations
Diffstat (limited to 'drivers')
-rw-r--r--drivers/clocksource/Kconfig12
-rw-r--r--drivers/clocksource/Makefile1
-rw-r--r--drivers/clocksource/timer-clint.c226
-rw-r--r--drivers/clocksource/timer-riscv.c17
4 files changed, 239 insertions, 17 deletions
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 3576ad7bd380..68b087bff59c 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -653,9 +653,8 @@ config ATCPIT100_TIMER
This option enables support for the Andestech ATCPIT100 timers.
config RISCV_TIMER
- bool "Timer for the RISC-V platform"
+ bool "Timer for the RISC-V platform" if COMPILE_TEST
depends on GENERIC_SCHED_CLOCK && RISCV
- default y
select TIMER_PROBE
select TIMER_OF
help
@@ -663,6 +662,15 @@ config RISCV_TIMER
is accessed via both the SBI and the rdcycle instruction. This is
required for all RISC-V systems.
+config CLINT_TIMER
+ bool "CLINT Timer for the RISC-V platform" if COMPILE_TEST
+ depends on GENERIC_SCHED_CLOCK && RISCV
+ select TIMER_PROBE
+ select TIMER_OF
+ help
+ This option enables the CLINT timer for RISC-V systems. The CLINT
+ driver is usually used for NoMMU RISC-V systems.
+
config CSKY_MP_TIMER
bool "SMP Timer for the C-SKY platform" if COMPILE_TEST
depends on CSKY
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index eaedb7240ae7..1c444cc3bb44 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -89,6 +89,7 @@ obj-$(CONFIG_CLKSRC_ST_LPC) += clksrc_st_lpc.o
obj-$(CONFIG_X86_NUMACHIP) += numachip.o
obj-$(CONFIG_ATCPIT100_TIMER) += timer-atcpit100.o
obj-$(CONFIG_RISCV_TIMER) += timer-riscv.o
+obj-$(CONFIG_CLINT_TIMER) += timer-clint.o
obj-$(CONFIG_CSKY_MP_TIMER) += timer-mp-csky.o
obj-$(CONFIG_GX6605S_TIMER) += timer-gx6605s.o
obj-$(CONFIG_HYPERV_TIMER) += hyperv_timer.o
diff --git a/drivers/clocksource/timer-clint.c b/drivers/clocksource/timer-clint.c
new file mode 100644
index 000000000000..8eeafa82c03d
--- /dev/null
+++ b/drivers/clocksource/timer-clint.c
@@ -0,0 +1,226 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 Western Digital Corporation or its affiliates.
+ *
+ * Most of the M-mode (i.e. NoMMU) RISC-V systems usually have a
+ * CLINT MMIO timer device.
+ */
+
+#define pr_fmt(fmt) "clint: " fmt
+#include <linux/bitops.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/cpu.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/sched_clock.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
+#include <linux/interrupt.h>
+#include <linux/of_irq.h>
+#include <linux/smp.h>
+
+#define CLINT_IPI_OFF 0
+#define CLINT_TIMER_CMP_OFF 0x4000
+#define CLINT_TIMER_VAL_OFF 0xbff8
+
+/* CLINT manages IPI and Timer for RISC-V M-mode */
+static u32 __iomem *clint_ipi_base;
+static u64 __iomem *clint_timer_cmp;
+static u64 __iomem *clint_timer_val;
+static unsigned long clint_timer_freq;
+static unsigned int clint_timer_irq;
+
+static void clint_send_ipi(const struct cpumask *target)
+{
+ unsigned int cpu;
+
+ for_each_cpu(cpu, target)
+ writel(1, clint_ipi_base + cpuid_to_hartid_map(cpu));
+}
+
+static void clint_clear_ipi(void)
+{
+ writel(0, clint_ipi_base + cpuid_to_hartid_map(smp_processor_id()));
+}
+
+static struct riscv_ipi_ops clint_ipi_ops = {
+ .ipi_inject = clint_send_ipi,
+ .ipi_clear = clint_clear_ipi,
+};
+
+#ifdef CONFIG_64BIT
+#define clint_get_cycles() readq_relaxed(clint_timer_val)
+#else
+#define clint_get_cycles() readl_relaxed(clint_timer_val)
+#define clint_get_cycles_hi() readl_relaxed(((u32 *)clint_timer_val) + 1)
+#endif
+
+#ifdef CONFIG_64BIT
+static u64 notrace clint_get_cycles64(void)
+{
+ return clint_get_cycles();
+}
+#else /* CONFIG_64BIT */
+static u64 notrace clint_get_cycles64(void)
+{
+ u32 hi, lo;
+
+ do {
+ hi = clint_get_cycles_hi();
+ lo = clint_get_cycles();
+ } while (hi != clint_get_cycles_hi());
+
+ return ((u64)hi << 32) | lo;
+}
+#endif /* CONFIG_64BIT */
+
+static u64 clint_rdtime(struct clocksource *cs)
+{
+ return clint_get_cycles64();
+}
+
+static struct clocksource clint_clocksource = {
+ .name = "clint_clocksource",
+ .rating = 300,
+ .mask = CLOCKSOURCE_MASK(64),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+ .read = clint_rdtime,
+};
+
+static int clint_clock_next_event(unsigned long delta,
+ struct clock_event_device *ce)
+{
+ void __iomem *r = clint_timer_cmp +
+ cpuid_to_hartid_map(smp_processor_id());
+
+ csr_set(CSR_IE, IE_TIE);
+ writeq_relaxed(clint_get_cycles64() + delta, r);
+ return 0;
+}
+
+static DEFINE_PER_CPU(struct clock_event_device, clint_clock_event) = {
+ .name = "clint_clockevent",
+ .features = CLOCK_EVT_FEAT_ONESHOT,
+ .rating = 100,
+ .set_next_event = clint_clock_next_event,
+};
+
+static int clint_timer_starting_cpu(unsigned int cpu)
+{
+ struct clock_event_device *ce = per_cpu_ptr(&clint_clock_event, cpu);
+
+ ce->cpumask = cpumask_of(cpu);
+ clockevents_config_and_register(ce, clint_timer_freq, 100, 0x7fffffff);
+
+ enable_percpu_irq(clint_timer_irq,
+ irq_get_trigger_type(clint_timer_irq));
+ return 0;
+}
+
+static int clint_timer_dying_cpu(unsigned int cpu)
+{
+ disable_percpu_irq(clint_timer_irq);
+ return 0;
+}
+
+static irqreturn_t clint_timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evdev = this_cpu_ptr(&clint_clock_event);
+
+ csr_clear(CSR_IE, IE_TIE);
+ evdev->event_handler(evdev);
+
+ return IRQ_HANDLED;
+}
+
+static int __init clint_timer_init_dt(struct device_node *np)
+{
+ int rc;
+ u32 i, nr_irqs;
+ void __iomem *base;
+ struct of_phandle_args oirq;
+
+ /*
+ * Ensure that CLINT device interrupts are either RV_IRQ_TIMER or
+ * RV_IRQ_SOFT. If it's anything else then we ignore the device.
+ */
+ nr_irqs = of_irq_count(np);
+ for (i = 0; i < nr_irqs; i++) {
+ if (of_irq_parse_one(np, i, &oirq)) {
+ pr_err("%pOFP: failed to parse irq %d.\n", np, i);
+ continue;
+ }
+
+ if ((oirq.args_count != 1) ||
+ (oirq.args[0] != RV_IRQ_TIMER &&
+ oirq.args[0] != RV_IRQ_SOFT)) {
+ pr_err("%pOFP: invalid irq %d (hwirq %d)\n",
+ np, i, oirq.args[0]);
+ return -ENODEV;
+ }
+
+ /* Find parent irq domain and map timer irq */
+ if (!clint_timer_irq &&
+ oirq.args[0] == RV_IRQ_TIMER &&
+ irq_find_host(oirq.np))
+ clint_timer_irq = irq_of_parse_and_map(np, i);
+ }
+
+ /* If CLINT timer irq not found then fail */
+ if (!clint_timer_irq) {
+ pr_err("%pOFP: timer irq not found\n", np);
+ return -ENODEV;
+ }
+
+ base = of_iomap(np, 0);
+ if (!base) {
+ pr_err("%pOFP: could not map registers\n", np);
+ return -ENODEV;
+ }
+
+ clint_ipi_base = base + CLINT_IPI_OFF;
+ clint_timer_cmp = base + CLINT_TIMER_CMP_OFF;
+ clint_timer_val = base + CLINT_TIMER_VAL_OFF;
+ clint_timer_freq = riscv_timebase;
+
+ pr_info("%pOFP: timer running at %ld Hz\n", np, clint_timer_freq);
+
+ rc = clocksource_register_hz(&clint_clocksource, clint_timer_freq);
+ if (rc) {
+ pr_err("%pOFP: clocksource register failed [%d]\n", np, rc);
+ goto fail_iounmap;
+ }
+
+ sched_clock_register(clint_get_cycles64, 64, clint_timer_freq);
+
+ rc = request_percpu_irq(clint_timer_irq, clint_timer_interrupt,
+ "clint-timer", &clint_clock_event);
+ if (rc) {
+ pr_err("registering percpu irq failed [%d]\n", rc);
+ goto fail_iounmap;
+ }
+
+ rc = cpuhp_setup_state(CPUHP_AP_CLINT_TIMER_STARTING,
+ "clockevents/clint/timer:starting",
+ clint_timer_starting_cpu,
+ clint_timer_dying_cpu);
+ if (rc) {
+ pr_err("%pOFP: cpuhp setup state failed [%d]\n", np, rc);
+ goto fail_free_irq;
+ }
+
+ riscv_set_ipi_ops(&clint_ipi_ops);
+ clint_clear_ipi();
+
+ return 0;
+
+fail_free_irq:
+ free_irq(clint_timer_irq, &clint_clock_event);
+fail_iounmap:
+ iounmap(base);
+ return rc;
+}
+
+TIMER_OF_DECLARE(clint_timer, "riscv,clint0", clint_timer_init_dt);
+TIMER_OF_DECLARE(clint_timer1, "sifive,clint0", clint_timer_init_dt);
diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c
index 9de1dabfb126..c51c5ed15aa7 100644
--- a/drivers/clocksource/timer-riscv.c
+++ b/drivers/clocksource/timer-riscv.c
@@ -19,26 +19,13 @@
#include <linux/of_irq.h>
#include <asm/smp.h>
#include <asm/sbi.h>
-
-u64 __iomem *riscv_time_cmp;
-u64 __iomem *riscv_time_val;
-
-static inline void mmio_set_timer(u64 val)
-{
- void __iomem *r;
-
- r = riscv_time_cmp + cpuid_to_hartid_map(smp_processor_id());
- writeq_relaxed(val, r);
-}
+#include <asm/timex.h>
static int riscv_clock_next_event(unsigned long delta,
struct clock_event_device *ce)
{
csr_set(CSR_IE, IE_TIE);
- if (IS_ENABLED(CONFIG_RISCV_SBI))
- sbi_set_timer(get_cycles64() + delta);
- else
- mmio_set_timer(get_cycles64() + delta);
+ sbi_set_timer(get_cycles64() + delta);
return 0;
}