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RISC-V: Remove CLINT related code from timer and arch

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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@wdc.com>
Tested-by: Emil Renner Berhing <kernel@esmil.dk>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
This commit is contained in:
Anup Patel
2020-08-17 18:12:50 +05:30
committed by Palmer Dabbelt
parent 2ac6795fcc
commit 2bc3fc877a
12 changed files with 16 additions and 126 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
arch/riscv/kernel/Makefile
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@@ -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

63
arch/riscv/kernel/clint.c
View File

@@ -1,63 +0,0 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2019 Christoph Hellwig.
*/
#include <linux/io.h>
#include <linux/of_address.h>
#include <linux/smp.h>
#include <linux/types.h>
#include <asm/clint.h>
#include <asm/csr.h>
#include <asm/timex.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;
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,
};
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();
riscv_set_ipi_ops(&clint_ipi_ops);
}

2
arch/riscv/kernel/setup.c
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@@ -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);

1
arch/riscv/kernel/smp.c
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@@ -18,7 +18,6 @@
#include <linux/delay.h>
#include <linux/irq_work.h>
#include <asm/clint.h>
#include <asm/sbi.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>

1
arch/riscv/kernel/smpboot.c
View File

@@ -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>