[PATCH v3 3/4] RISC-V: Remove CLINT related code from timer and arch
Anup Patel
anup.patel at wdc.com
Wed Jul 15 03:15:04 EDT 2020
Right now the RISC-V timer driver is convoluted to support:
1. Linux RISC-V S-mode (with MMU) where it will use TIME CSR for
clocksource and SBI timer calls for clockevent device.
2. Linux RISC-V M-mode (without MMU) where it will use CLINT MMIO
counter register for clocksource and CLINT MMIO compare register
for clockevent device.
We now have a separate CLINT timer driver which also provide CLINT
based IPI operations so let's remove CLINT MMIO related code from
arch/riscv directory and RISC-V timer driver.
Signed-off-by: Anup Patel <anup.patel at wdc.com>
---
arch/riscv/Kconfig | 2 +-
arch/riscv/include/asm/clint.h | 39 ---------------------------
arch/riscv/include/asm/timex.h | 28 +++++---------------
arch/riscv/kernel/Makefile | 2 +-
arch/riscv/kernel/clint.c | 44 -------------------------------
arch/riscv/kernel/setup.c | 2 --
arch/riscv/kernel/smp.c | 1 -
arch/riscv/kernel/smpboot.c | 1 -
drivers/clocksource/Kconfig | 2 +-
drivers/clocksource/timer-riscv.c | 17 ++----------
10 files changed, 12 insertions(+), 126 deletions(-)
delete mode 100644 arch/riscv/include/asm/clint.h
delete mode 100644 arch/riscv/kernel/clint.c
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index fedb4a72b29a..57a72ae23d10 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -74,7 +74,7 @@ config RISCV
select PCI_DOMAINS_GENERIC if PCI
select PCI_MSI if PCI
select RISCV_INTC
- select RISCV_TIMER
+ select RISCV_TIMER if RISCV_SBI
select SPARSEMEM_STATIC if 32BIT
select SPARSE_IRQ
select SYSCTL_EXCEPTION_TRACE
diff --git a/arch/riscv/include/asm/clint.h b/arch/riscv/include/asm/clint.h
deleted file mode 100644
index a279b17a6aad..000000000000
--- a/arch/riscv/include/asm/clint.h
+++ /dev/null
@@ -1,39 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_RISCV_CLINT_H
-#define _ASM_RISCV_CLINT_H 1
-
-#include <linux/io.h>
-#include <linux/smp.h>
-
-#ifdef CONFIG_RISCV_M_MODE
-extern u32 __iomem *clint_ipi_base;
-
-void clint_init_boot_cpu(void);
-
-static inline void clint_send_ipi_single(unsigned long hartid)
-{
- writel(1, clint_ipi_base + hartid);
-}
-
-static inline void clint_send_ipi_mask(const struct cpumask *mask)
-{
- int cpu;
-
- for_each_cpu(cpu, mask)
- clint_send_ipi_single(cpuid_to_hartid_map(cpu));
-}
-
-static inline void clint_clear_ipi(unsigned long hartid)
-{
- writel(0, clint_ipi_base + hartid);
-}
-#else /* CONFIG_RISCV_M_MODE */
-#define clint_init_boot_cpu() do { } while (0)
-
-/* stubs to for code is only reachable under IS_ENABLED(CONFIG_RISCV_M_MODE): */
-void clint_send_ipi_single(unsigned long hartid);
-void clint_send_ipi_mask(const struct cpumask *hartid_mask);
-void clint_clear_ipi(unsigned long hartid);
-#endif /* CONFIG_RISCV_M_MODE */
-
-#endif /* _ASM_RISCV_CLINT_H */
diff --git a/arch/riscv/include/asm/timex.h b/arch/riscv/include/asm/timex.h
index bad2a7c2cda5..a3fb85d505d4 100644
--- a/arch/riscv/include/asm/timex.h
+++ b/arch/riscv/include/asm/timex.h
@@ -7,41 +7,27 @@
#define _ASM_RISCV_TIMEX_H
#include <asm/csr.h>
-#include <asm/mmio.h>
typedef unsigned long cycles_t;
-extern u64 __iomem *riscv_time_val;
-extern u64 __iomem *riscv_time_cmp;
-
-#ifdef CONFIG_64BIT
-#define mmio_get_cycles() readq_relaxed(riscv_time_val)
-#else
-#define mmio_get_cycles() readl_relaxed(riscv_time_val)
-#define mmio_get_cycles_hi() readl_relaxed(((u32 *)riscv_time_val) + 1)
-#endif
-
static inline cycles_t get_cycles(void)
{
- if (IS_ENABLED(CONFIG_RISCV_SBI))
- return csr_read(CSR_TIME);
- return mmio_get_cycles();
+ return csr_read(CSR_TIME);
}
#define get_cycles get_cycles
+static inline u32 get_cycles_hi(void)
+{
+ return csr_read(CSR_TIMEH);
+}
+#define get_cycles_hi get_cycles_hi
+
#ifdef CONFIG_64BIT
static inline u64 get_cycles64(void)
{
return get_cycles();
}
#else /* CONFIG_64BIT */
-static inline u32 get_cycles_hi(void)
-{
- if (IS_ENABLED(CONFIG_RISCV_SBI))
- return csr_read(CSR_TIMEH);
- return mmio_get_cycles_hi();
-}
-
static inline u64 get_cycles64(void)
{
u32 hi, lo;
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index b355cf485671..7edf15643146 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -31,7 +31,7 @@ obj-y += cacheinfo.o
obj-y += patch.o
obj-$(CONFIG_MMU) += vdso.o vdso/
-obj-$(CONFIG_RISCV_M_MODE) += clint.o traps_misaligned.o
+obj-$(CONFIG_RISCV_M_MODE) += traps_misaligned.o
obj-$(CONFIG_FPU) += fpu.o
obj-$(CONFIG_SMP) += smpboot.o
obj-$(CONFIG_SMP) += smp.o
diff --git a/arch/riscv/kernel/clint.c b/arch/riscv/kernel/clint.c
deleted file mode 100644
index 3647980d14c3..000000000000
--- a/arch/riscv/kernel/clint.c
+++ /dev/null
@@ -1,44 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright (c) 2019 Christoph Hellwig.
- */
-
-#include <linux/io.h>
-#include <linux/of_address.h>
-#include <linux/types.h>
-#include <asm/clint.h>
-#include <asm/csr.h>
-#include <asm/timex.h>
-#include <asm/smp.h>
-
-/*
- * This is the layout used by the SiFive clint, which is also shared by the qemu
- * virt platform, and the Kendryte KD210 at least.
- */
-#define CLINT_IPI_OFF 0
-#define CLINT_TIME_CMP_OFF 0x4000
-#define CLINT_TIME_VAL_OFF 0xbff8
-
-u32 __iomem *clint_ipi_base;
-
-void clint_init_boot_cpu(void)
-{
- struct device_node *np;
- void __iomem *base;
-
- np = of_find_compatible_node(NULL, NULL, "riscv,clint0");
- if (!np) {
- panic("clint not found");
- return;
- }
-
- base = of_iomap(np, 0);
- if (!base)
- panic("could not map CLINT");
-
- clint_ipi_base = base + CLINT_IPI_OFF;
- riscv_time_cmp = base + CLINT_TIME_CMP_OFF;
- riscv_time_val = base + CLINT_TIME_VAL_OFF;
-
- clint_clear_ipi(boot_cpu_hartid);
-}
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index f04373be54a6..2c6dd329312b 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -18,7 +18,6 @@
#include <linux/swiotlb.h>
#include <linux/smp.h>
-#include <asm/clint.h>
#include <asm/cpu_ops.h>
#include <asm/setup.h>
#include <asm/sections.h>
@@ -79,7 +78,6 @@ void __init setup_arch(char **cmdline_p)
#else
unflatten_device_tree();
#endif
- clint_init_boot_cpu();
#ifdef CONFIG_SWIOTLB
swiotlb_init(1);
diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c
index 8b85683ce203..07626be78c23 100644
--- a/arch/riscv/kernel/smp.c
+++ b/arch/riscv/kernel/smp.c
@@ -17,7 +17,6 @@
#include <linux/seq_file.h>
#include <linux/delay.h>
-#include <asm/clint.h>
#include <asm/sbi.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>
diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
index 5fe849791bf0..a6cfa9842d4b 100644
--- a/arch/riscv/kernel/smpboot.c
+++ b/arch/riscv/kernel/smpboot.c
@@ -24,7 +24,6 @@
#include <linux/of.h>
#include <linux/sched/task_stack.h>
#include <linux/sched/mm.h>
-#include <asm/clint.h>
#include <asm/cpu_ops.h>
#include <asm/irq.h>
#include <asm/mmu_context.h>
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index eabcf1cfb0c0..d3bf66123c4e 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -649,7 +649,7 @@ config ATCPIT100_TIMER
config RISCV_TIMER
bool "Timer for the RISC-V platform"
- depends on GENERIC_SCHED_CLOCK && RISCV
+ depends on GENERIC_SCHED_CLOCK && RISCV_SBI
default y
select TIMER_PROBE
select TIMER_OF
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;
}
--
2.25.1
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