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RISC-V: Init and Halt Code

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This contains the various __init C functions, the initial assembly
kernel entry point, and the code to reset the system.  When a file was
init-related this patch contains the entire file.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
This commit is contained in:
Palmer Dabbelt 2017-07-10 18:00:26 -07:00
parent 8caea50236
commit 76d2a0493a
15 changed files with 1524 additions and 0 deletions
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88
arch/riscv/include/asm/bug.h Normal file
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/*
* Copyright (C) 2012 Regents of the University of California
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#ifndef _ASM_RISCV_BUG_H
#define _ASM_RISCV_BUG_H
#include <linux/compiler.h>
#include <linux/const.h>
#include <linux/types.h>
#include <asm/asm.h>
#ifdef CONFIG_GENERIC_BUG
#define __BUG_INSN _AC(0x00100073, UL) /* ebreak */
#ifndef __ASSEMBLY__
typedef u32 bug_insn_t;
#ifdef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
#define __BUG_ENTRY_ADDR INT " 1b - 2b"
#define __BUG_ENTRY_FILE INT " %0 - 2b"
#else
#define __BUG_ENTRY_ADDR RISCV_PTR " 1b"
#define __BUG_ENTRY_FILE RISCV_PTR " %0"
#endif
#ifdef CONFIG_DEBUG_BUGVERBOSE
#define __BUG_ENTRY \
__BUG_ENTRY_ADDR "\n\t" \
__BUG_ENTRY_FILE "\n\t" \
SHORT " %1"
#else
#define __BUG_ENTRY \
__BUG_ENTRY_ADDR
#endif
#define BUG() \
do { \
__asm__ __volatile__ ( \
"1:\n\t" \
"ebreak\n" \
".pushsection __bug_table,\"a\"\n\t" \
"2:\n\t" \
__BUG_ENTRY "\n\t" \
".org 2b + %2\n\t" \
".popsection" \
: \
: "i" (__FILE__), "i" (__LINE__), \
"i" (sizeof(struct bug_entry))); \
unreachable(); \
} while (0)
#endif /* !__ASSEMBLY__ */
#else /* CONFIG_GENERIC_BUG */
#ifndef __ASSEMBLY__
#define BUG() \
do { \
__asm__ __volatile__ ("ebreak\n"); \
unreachable(); \
} while (0)
#endif /* !__ASSEMBLY__ */
#endif /* CONFIG_GENERIC_BUG */
#define HAVE_ARCH_BUG
#include <asm-generic/bug.h>
#ifndef __ASSEMBLY__
struct pt_regs;
struct task_struct;
extern void die(struct pt_regs *regs, const char *str);
extern void do_trap(struct pt_regs *regs, int signo, int code,
unsigned long addr, struct task_struct *tsk);
#endif /* !__ASSEMBLY__ */
#endif /* _ASM_RISCV_BUG_H */

22
arch/riscv/include/asm/cache.h Normal file
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/*
* Copyright (C) 2017 Chen Liqin <liqin.chen@sunplusct.com>
* Copyright (C) 2012 Regents of the University of California
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#ifndef _ASM_RISCV_CACHE_H
#define _ASM_RISCV_CACHE_H
#define L1_CACHE_SHIFT 6
#define L1_CACHE_BYTES (1 << L1_CACHE_SHIFT)
#endif /* _ASM_RISCV_CACHE_H */

52
arch/riscv/include/asm/smp.h Normal file
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/*
* Copyright (C) 2012 Regents of the University of California
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#ifndef _ASM_RISCV_SMP_H
#define _ASM_RISCV_SMP_H
/* This both needs asm-offsets.h and is used when generating it. */
#ifndef GENERATING_ASM_OFFSETS
#include <asm/asm-offsets.h>
#endif
#include <linux/cpumask.h>
#include <linux/irqreturn.h>
#ifdef CONFIG_SMP
/* SMP initialization hook for setup_arch */
void __init init_clockevent(void);
/* SMP initialization hook for setup_arch */
void __init setup_smp(void);
/* Hook for the generic smp_call_function_many() routine. */
void arch_send_call_function_ipi_mask(struct cpumask *mask);
/* Hook for the generic smp_call_function_single() routine. */
void arch_send_call_function_single_ipi(int cpu);
/*
* This is particularly ugly: it appears we can't actually get the definition
* of task_struct here, but we need access to the CPU this task is running on.
* Instead of using C we're using asm-offsets.h to get the current processor
* ID.
*/
#define raw_smp_processor_id() (*((int*)((char*)get_current() + TASK_TI_CPU)))
/* Interprocessor interrupt handler */
irqreturn_t handle_ipi(void);
#endif /* CONFIG_SMP */
#endif /* _ASM_RISCV_SMP_H */

105
arch/riscv/kernel/cacheinfo.c Normal file
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/*
* Copyright (C) 2017 SiFive
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/cacheinfo.h>
#include <linux/cpu.h>
#include <linux/of.h>
#include <linux/of_device.h>
static void ci_leaf_init(struct cacheinfo *this_leaf,
struct device_node *node,
enum cache_type type, unsigned int level)
{
this_leaf->of_node = node;
this_leaf->level = level;
this_leaf->type = type;
/* not a sector cache */
this_leaf->physical_line_partition = 1;
/* TODO: Add to DTS */
this_leaf->attributes =
CACHE_WRITE_BACK
| CACHE_READ_ALLOCATE
| CACHE_WRITE_ALLOCATE;
}
static int __init_cache_level(unsigned int cpu)
{
struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
struct device_node *np = of_cpu_device_node_get(cpu);
int levels = 0, leaves = 0, level;
if (of_property_read_bool(np, "cache-size"))
++leaves;
if (of_property_read_bool(np, "i-cache-size"))
++leaves;
if (of_property_read_bool(np, "d-cache-size"))
++leaves;
if (leaves > 0)
levels = 1;
while ((np = of_find_next_cache_node(np))) {
if (!of_device_is_compatible(np, "cache"))
break;
if (of_property_read_u32(np, "cache-level", &level))
break;
if (level <= levels)
break;
if (of_property_read_bool(np, "cache-size"))
++leaves;
if (of_property_read_bool(np, "i-cache-size"))
++leaves;
if (of_property_read_bool(np, "d-cache-size"))
++leaves;
levels = level;
}
this_cpu_ci->num_levels = levels;
this_cpu_ci->num_leaves = leaves;
return 0;
}
static int __populate_cache_leaves(unsigned int cpu)
{
struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
struct cacheinfo *this_leaf = this_cpu_ci->info_list;
struct device_node *np = of_cpu_device_node_get(cpu);
int levels = 1, level = 1;
if (of_property_read_bool(np, "cache-size"))
ci_leaf_init(this_leaf++, np, CACHE_TYPE_UNIFIED, level);
if (of_property_read_bool(np, "i-cache-size"))
ci_leaf_init(this_leaf++, np, CACHE_TYPE_INST, level);
if (of_property_read_bool(np, "d-cache-size"))
ci_leaf_init(this_leaf++, np, CACHE_TYPE_DATA, level);
while ((np = of_find_next_cache_node(np))) {
if (!of_device_is_compatible(np, "cache"))
break;
if (of_property_read_u32(np, "cache-level", &level))
break;
if (level <= levels)
break;
if (of_property_read_bool(np, "cache-size"))
ci_leaf_init(this_leaf++, np, CACHE_TYPE_UNIFIED, level);
if (of_property_read_bool(np, "i-cache-size"))
ci_leaf_init(this_leaf++, np, CACHE_TYPE_INST, level);
if (of_property_read_bool(np, "d-cache-size"))
ci_leaf_init(this_leaf++, np, CACHE_TYPE_DATA, level);
levels = level;
}
return 0;
}
DEFINE_SMP_CALL_CACHE_FUNCTION(init_cache_level)
DEFINE_SMP_CALL_CACHE_FUNCTION(populate_cache_leaves)

108
arch/riscv/kernel/cpu.c Normal file
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/*
* Copyright (C) 2012 Regents of the University of California
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/init.h>
#include <linux/seq_file.h>
#include <linux/of.h>
/* Return -1 if not a valid hart */
int riscv_of_processor_hart(struct device_node *node)
{
const char *isa, *status;
u32 hart;
if (!of_device_is_compatible(node, "riscv")) {
pr_warn("Found incompatible CPU\n");
return -(ENODEV);
}
if (of_property_read_u32(node, "reg", &hart)) {
pr_warn("Found CPU without hart ID\n");
return -(ENODEV);
}
if (hart >= NR_CPUS) {
pr_info("Found hart ID %d, which is above NR_CPUs. Disabling this hart\n", hart);
return -(ENODEV);
}
if (of_property_read_string(node, "status", &status)) {
pr_warn("CPU with hartid=%d has no \"status\" property\n", hart);
return -(ENODEV);
}
if (strcmp(status, "okay")) {
pr_info("CPU with hartid=%d has a non-okay status of \"%s\"\n", hart, status);
return -(ENODEV);
}
if (of_property_read_string(node, "riscv,isa", &isa)) {
pr_warn("CPU with hartid=%d has no \"riscv,isa\" property\n", hart);
return -(ENODEV);
}
if (isa[0] != 'r' || isa[1] != 'v') {
pr_warn("CPU with hartid=%d has an invalid ISA of \"%s\"\n", hart, isa);
return -(ENODEV);
}
return hart;
}
#ifdef CONFIG_PROC_FS
static void *c_start(struct seq_file *m, loff_t *pos)
{
*pos = cpumask_next(*pos - 1, cpu_online_mask);
if ((*pos) < nr_cpu_ids)
return (void *)(uintptr_t)(1 + *pos);
return NULL;
}
static void *c_next(struct seq_file *m, void *v, loff_t *pos)
{
(*pos)++;
return c_start(m, pos);
}
static void c_stop(struct seq_file *m, void *v)
{
}
static int c_show(struct seq_file *m, void *v)
{
unsigned long hart_id = (unsigned long)v - 1;
struct device_node *node = of_get_cpu_node(hart_id, NULL);
const char *compat, *isa, *mmu;
seq_printf(m, "hart\t: %lu\n", hart_id);
if (!of_property_read_string(node, "riscv,isa", &isa)
&& isa[0] == 'r'
&& isa[1] == 'v')
seq_printf(m, "isa\t: %s\n", isa);
if (!of_property_read_string(node, "mmu-type", &mmu)
&& !strncmp(mmu, "riscv,", 6))
seq_printf(m, "mmu\t: %s\n", mmu+6);
if (!of_property_read_string(node, "compatible", &compat)
&& strcmp(compat, "riscv"))
seq_printf(m, "uarch\t: %s\n", compat);
seq_puts(m, "\n");
return 0;
}
const struct seq_operations cpuinfo_op = {
.start = c_start,
.next = c_next,
.stop = c_stop,
.show = c_show
};
#endif /* CONFIG_PROC_FS */

157
arch/riscv/kernel/head.S Normal file
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/*
* Copyright (C) 2012 Regents of the University of California
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <asm/thread_info.h>
#include <asm/asm-offsets.h>
#include <asm/asm.h>
#include <linux/init.h>
#include <linux/linkage.h>
#include <asm/thread_info.h>
#include <asm/page.h>
#include <asm/csr.h>
__INIT
ENTRY(_start)
/* Mask all interrupts */
csrw sie, zero
/* Load the global pointer */
.option push
.option norelax
la gp, __global_pointer$
.option pop
/*
* Disable FPU to detect illegal usage of
* floating point in kernel space
*/
li t0, SR_FS
csrc sstatus, t0
/* Pick one hart to run the main boot sequence */
la a3, hart_lottery
li a2, 1
amoadd.w a3, a2, (a3)
bnez a3, .Lsecondary_start
/* Save hart ID and DTB physical address */
mv s0, a0
mv s1, a1
/* Initialize page tables and relocate to virtual addresses */
la sp, init_thread_union + THREAD_SIZE
call setup_vm
call relocate
/* Restore C environment */
la tp, init_task
sw s0, TASK_TI_CPU(tp)
la sp, init_thread_union
li a0, ASM_THREAD_SIZE
add sp, sp, a0
/* Start the kernel */
mv a0, s0
mv a1, s1
call sbi_save
tail start_kernel
relocate:
/* Relocate return address */
li a1, PAGE_OFFSET
la a0, _start
sub a1, a1, a0
add ra, ra, a1
/* Point stvec to virtual address of intruction after sptbr write */
la a0, 1f
add a0, a0, a1
csrw stvec, a0
/* Compute sptbr for kernel page tables, but don't load it yet */
la a2, swapper_pg_dir
srl a2, a2, PAGE_SHIFT
li a1, SPTBR_MODE
or a2, a2, a1
/*
* Load trampoline page directory, which will cause us to trap to
* stvec if VA != PA, or simply fall through if VA == PA
*/
la a0, trampoline_pg_dir
srl a0, a0, PAGE_SHIFT
or a0, a0, a1
sfence.vma
csrw sptbr, a0
1:
/* Set trap vector to spin forever to help debug */
la a0, .Lsecondary_park
csrw stvec, a0
/* Reload the global pointer */
.option push
.option norelax
la gp, __global_pointer$
.option pop
/* Switch to kernel page tables */
csrw sptbr, a2
ret
.Lsecondary_start:
#ifdef CONFIG_SMP
li a1, CONFIG_NR_CPUS
bgeu a0, a1, .Lsecondary_park
/* Set trap vector to spin forever to help debug */
la a3, .Lsecondary_park
csrw stvec, a3
slli a3, a0, LGREG
la a1, __cpu_up_stack_pointer
la a2, __cpu_up_task_pointer
add a1, a3, a1
add a2, a3, a2
/*
* This hart didn't win the lottery, so we wait for the winning hart to
* get far enough along the boot process that it should continue.
*/
.Lwait_for_cpu_up:
/* FIXME: We should WFI to save some energy here. */
REG_L sp, (a1)
REG_L tp, (a2)
beqz sp, .Lwait_for_cpu_up
beqz tp, .Lwait_for_cpu_up
fence
/* Enable virtual memory and relocate to virtual address */
call relocate
tail smp_callin
#endif
.Lsecondary_park:
/* We lack SMP support or have too many harts, so park this hart */
wfi
j .Lsecondary_park
END(_start)
__PAGE_ALIGNED_BSS
/* Empty zero page */
.balign PAGE_SIZE
ENTRY(empty_zero_page)
.fill (empty_zero_page + PAGE_SIZE) - ., 1, 0x00
END(empty_zero_page)

39
arch/riscv/kernel/irq.c Normal file
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/*
* Copyright (C) 2012 Regents of the University of California
* Copyright (C) 2017 SiFive
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/interrupt.h>
#include <linux/irqchip.h>
#include <linux/irqdomain.h>
#ifdef CONFIG_RISCV_INTC
#include <linux/irqchip/irq-riscv-intc.h>
#endif
void __init init_IRQ(void)
{
irqchip_init();
}
asmlinkage void __irq_entry do_IRQ(unsigned int cause, struct pt_regs *regs)
{
#ifdef CONFIG_RISCV_INTC
/*
* FIXME: We don't want a direct call to riscv_intc_irq here. The plan
* is to put an IRQ domain here and let the interrupt controller
* register with that, but I poked around the arm64 code a bit and
* there might be a better way to do it (ie, something fully generic).
*/
riscv_intc_irq(cause, regs);
#endif
}

36
arch/riscv/kernel/reset.c Normal file
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/*
* Copyright (C) 2012 Regents of the University of California
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/reboot.h>
#include <linux/export.h>
#include <asm/sbi.h>
void (*pm_power_off)(void) = machine_power_off;
EXPORT_SYMBOL(pm_power_off);
void machine_restart(char *cmd)
{
do_kernel_restart(cmd);
while (1);
}
void machine_halt(void)
{
machine_power_off();
}
void machine_power_off(void)
{
sbi_shutdown();
while (1);
}

257
arch/riscv/kernel/setup.c Normal file
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/*
* Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
* Chen Liqin <liqin.chen@sunplusct.com>
* Lennox Wu <lennox.wu@sunplusct.com>
* Copyright (C) 2012 Regents of the University of California
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see the file COPYING, or write
* to the Free Software Foundation, Inc.,
*/
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/memblock.h>
#include <linux/sched.h>
#include <linux/initrd.h>
#include <linux/console.h>
#include <linux/screen_info.h>
#include <linux/of_fdt.h>
#include <linux/of_platform.h>
#include <linux/sched/task.h>
#include <asm/setup.h>
#include <asm/sections.h>
#include <asm/pgtable.h>
#include <asm/smp.h>
#include <asm/sbi.h>
#include <asm/tlbflush.h>
#include <asm/thread_info.h>
#ifdef CONFIG_HVC_RISCV_SBI
#include <asm/hvc_riscv_sbi.h>
#endif
#ifdef CONFIG_DUMMY_CONSOLE
struct screen_info screen_info = {
.orig_video_lines = 30,
.orig_video_cols = 80,
.orig_video_mode = 0,
.orig_video_ega_bx = 0,
.orig_video_isVGA = 1,
.orig_video_points = 8
};
#endif
#ifdef CONFIG_CMDLINE_BOOL
static char __initdata builtin_cmdline[COMMAND_LINE_SIZE] = CONFIG_CMDLINE;
#endif /* CONFIG_CMDLINE_BOOL */
unsigned long va_pa_offset;
unsigned long pfn_base;
/* The lucky hart to first increment this variable will boot the other cores */
atomic_t hart_lottery;
#ifdef CONFIG_BLK_DEV_INITRD
static void __init setup_initrd(void)
{
extern char __initramfs_start[];
extern unsigned long __initramfs_size;
unsigned long size;
if (__initramfs_size > 0) {
initrd_start = (unsigned long)(&__initramfs_start);
initrd_end = initrd_start + __initramfs_size;
}
if (initrd_start >= initrd_end) {
printk(KERN_INFO "initrd not found or empty");
goto disable;
}
if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
printk(KERN_ERR "initrd extends beyond end of memory");
goto disable;
}
size = initrd_end - initrd_start;
memblock_reserve(__pa(initrd_start), size);
initrd_below_start_ok = 1;
printk(KERN_INFO "Initial ramdisk at: 0x%p (%lu bytes)\n",
(void *)(initrd_start), size);
return;
disable:
pr_cont(" - disabling initrd\n");
initrd_start = 0;
initrd_end = 0;
}
#endif /* CONFIG_BLK_DEV_INITRD */
pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
#ifndef __PAGETABLE_PMD_FOLDED
#define NUM_SWAPPER_PMDS ((uintptr_t)-PAGE_OFFSET >> PGDIR_SHIFT)
pmd_t swapper_pmd[PTRS_PER_PMD*((-PAGE_OFFSET)/PGDIR_SIZE)] __page_aligned_bss;
pmd_t trampoline_pmd[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
#endif
asmlinkage void __init setup_vm(void)
{
extern char _start;
uintptr_t i;
uintptr_t pa = (uintptr_t) &_start;
pgprot_t prot = __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_EXEC);
va_pa_offset = PAGE_OFFSET - pa;
pfn_base = PFN_DOWN(pa);
/* Sanity check alignment and size */
BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
BUG_ON((pa % (PAGE_SIZE * PTRS_PER_PTE)) != 0);
#ifndef __PAGETABLE_PMD_FOLDED
trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
pfn_pgd(PFN_DOWN((uintptr_t)trampoline_pmd),
__pgprot(_PAGE_TABLE));
trampoline_pmd[0] = pfn_pmd(PFN_DOWN(pa), prot);
for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
swapper_pg_dir[o] =
pfn_pgd(PFN_DOWN((uintptr_t)swapper_pmd) + i,
__pgprot(_PAGE_TABLE));
}
for (i = 0; i < ARRAY_SIZE(swapper_pmd); i++)
swapper_pmd[i] = pfn_pmd(PFN_DOWN(pa + i * PMD_SIZE), prot);
#else
trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
pfn_pgd(PFN_DOWN(pa), prot);
for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
swapper_pg_dir[o] =
pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot);
}
#endif
}
void __init sbi_save(unsigned int hartid, void *dtb)
{
early_init_dt_scan(__va(dtb));
}
/*
* Allow the user to manually add a memory region (in case DTS is broken);
* "mem_end=nn[KkMmGg]"
*/
static int __init mem_end_override(char *p)
{
resource_size_t base, end;
if (!p)
return -EINVAL;
base = (uintptr_t) __pa(PAGE_OFFSET);
end = memparse(p, &p) & PMD_MASK;
if (end == 0)
return -EINVAL;
memblock_add(base, end - base);
return 0;
}
early_param("mem_end", mem_end_override);
static void __init setup_bootmem(void)
{
struct memblock_region *reg;
phys_addr_t mem_size = 0;
/* Find the memory region containing the kernel */
for_each_memblock(memory, reg) {
phys_addr_t vmlinux_end = __pa(_end);
phys_addr_t end = reg->base + reg->size;
if (reg->base <= vmlinux_end && vmlinux_end <= end) {
/*
* Reserve from the start of the region to the end of
* the kernel
*/
memblock_reserve(reg->base, vmlinux_end - reg->base);
mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET);
}
}
BUG_ON(mem_size == 0);
set_max_mapnr(PFN_DOWN(mem_size));
max_low_pfn = pfn_base + PFN_DOWN(mem_size);
#ifdef CONFIG_BLK_DEV_INITRD
setup_initrd();
#endif /* CONFIG_BLK_DEV_INITRD */
early_init_fdt_reserve_self();
early_init_fdt_scan_reserved_mem();
memblock_allow_resize();
memblock_dump_all();
}
void __init setup_arch(char **cmdline_p)
{
#if defined(CONFIG_HVC_RISCV_SBI)
if (likely(early_console == NULL)) {
early_console = &riscv_sbi_early_console_dev;
register_console(early_console);
}
#endif
#ifdef CONFIG_CMDLINE_BOOL
#ifdef CONFIG_CMDLINE_OVERRIDE
strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
#else
if (builtin_cmdline[0] != '\0') {
/* Append bootloader command line to built-in */
strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);
strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);
strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
}
#endif /* CONFIG_CMDLINE_OVERRIDE */
#endif /* CONFIG_CMDLINE_BOOL */
*cmdline_p = boot_command_line;
parse_early_param();
init_mm.start_code = (unsigned long) _stext;
init_mm.end_code = (unsigned long) _etext;
init_mm.end_data = (unsigned long) _edata;
init_mm.brk = (unsigned long) _end;
setup_bootmem();
paging_init();
unflatten_device_tree();
#ifdef CONFIG_SMP
setup_smp();
#endif
#ifdef CONFIG_DUMMY_CONSOLE
conswitchp = &dummy_con;
#endif
riscv_fill_hwcap();
}
static int __init riscv_device_init(void)
{
return of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
}
subsys_initcall_sync(riscv_device_init);

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/*
* SMP initialisation and IPI support
* Based on arch/arm64/kernel/smp.c
*
* Copyright (C) 2012 ARM Ltd.
* Copyright (C) 2015 Regents of the University of California
* Copyright (C) 2017 SiFive
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/interrupt.h>
#include <linux/smp.h>
#include <linux/sched.h>
#include <asm/sbi.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>
/* A collection of single bit ipi messages. */
static struct {
unsigned long bits ____cacheline_aligned;
} ipi_data[NR_CPUS] __cacheline_aligned;
enum ipi_message_type {
IPI_RESCHEDULE,
IPI_CALL_FUNC,
IPI_MAX
};
irqreturn_t handle_ipi(void)
{
unsigned long *pending_ipis = &ipi_data[smp_processor_id()].bits;
/* Clear pending IPI */
csr_clear(sip, SIE_SSIE);
while (true) {
unsigned long ops;
/* Order bit clearing and data access. */
mb();
ops = xchg(pending_ipis, 0);
if (ops == 0)
return IRQ_HANDLED;
if (ops & (1 << IPI_RESCHEDULE))
scheduler_ipi();
if (ops & (1 << IPI_CALL_FUNC))
generic_smp_call_function_interrupt();
BUG_ON((ops >> IPI_MAX) != 0);
/* Order data access and bit testing. */
mb();
}
return IRQ_HANDLED;
}
static void
send_ipi_message(const struct cpumask *to_whom, enum ipi_message_type operation)
{
int i;
mb();
for_each_cpu(i, to_whom)
set_bit(operation, &ipi_data[i].bits);
mb();
sbi_send_ipi(cpumask_bits(to_whom));
}
void arch_send_call_function_ipi_mask(struct cpumask *mask)
{
send_ipi_message(mask, IPI_CALL_FUNC);
}
void arch_send_call_function_single_ipi(int cpu)
{
send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC);
}
static void ipi_stop(void *unused)
{
while (1)
wait_for_interrupt();
}
void smp_send_stop(void)
{
on_each_cpu(ipi_stop, NULL, 1);
}
void smp_send_reschedule(int cpu)
{
send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE);
}

114
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/*
* SMP initialisation and IPI support
* Based on arch/arm64/kernel/smp.c
*
* Copyright (C) 2012 ARM Ltd.
* Copyright (C) 2015 Regents of the University of California
* Copyright (C) 2017 SiFive
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/kernel_stat.h>
#include <linux/notifier.h>
#include <linux/cpu.h>
#include <linux/percpu.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/irq.h>
#include <linux/of.h>
#include <linux/sched/task_stack.h>
#include <asm/irq.h>
#include <asm/mmu_context.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>
#include <asm/sbi.h>
void *__cpu_up_stack_pointer[NR_CPUS];
void *__cpu_up_task_pointer[NR_CPUS];
void __init smp_prepare_boot_cpu(void)
{
}
void __init smp_prepare_cpus(unsigned int max_cpus)
{
}
void __init setup_smp(void)
{
struct device_node *dn = NULL;
int hart, im_okay_therefore_i_am = 0;
while ((dn = of_find_node_by_type(dn, "cpu"))) {
hart = riscv_of_processor_hart(dn);
if (hart >= 0) {
set_cpu_possible(hart, true);
set_cpu_present(hart, true);
if (hart == smp_processor_id()) {
BUG_ON(im_okay_therefore_i_am);
im_okay_therefore_i_am = 1;
}
}
}
BUG_ON(!im_okay_therefore_i_am);
}
int __cpu_up(unsigned int cpu, struct task_struct *tidle)
{
tidle->thread_info.cpu = cpu;
/*
* On RISC-V systems, all harts boot on their own accord. Our _start
* selects the first hart to boot the kernel and causes the remainder
* of the harts to spin in a loop waiting for their stack pointer to be
* setup by that main hart. Writing __cpu_up_stack_pointer signals to
* the spinning harts that they can continue the boot process.
*/
smp_mb();
__cpu_up_stack_pointer[cpu] = task_stack_page(tidle) + THREAD_SIZE;
__cpu_up_task_pointer[cpu] = tidle;
while (!cpu_online(cpu))
cpu_relax();
return 0;
}
void __init smp_cpus_done(unsigned int max_cpus)
{
}
/*
* C entry point for a secondary processor.
*/
asmlinkage void __init smp_callin(void)
{
struct mm_struct *mm = &init_mm;
/* All kernel threads share the same mm context. */
atomic_inc(&mm->mm_count);
current->active_mm = mm;
trap_init();
init_clockevent();
notify_cpu_starting(smp_processor_id());
set_cpu_online(smp_processor_id(), 1);
local_flush_tlb_all();
local_irq_enable();
preempt_disable();
cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
}

61
arch/riscv/kernel/time.c Normal file
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/*
* Copyright (C) 2012 Regents of the University of California
* Copyright (C) 2017 SiFive
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <linux/delay.h>
#ifdef CONFIG_RISCV_TIMER
#include <linux/timer_riscv.h>
#endif
#include <asm/sbi.h>
unsigned long riscv_timebase;
DECLARE_PER_CPU(struct clock_event_device, riscv_clock_event);
void riscv_timer_interrupt(void)
{
#ifdef CONFIG_RISCV_TIMER
/*
* FIXME: This needs to be cleaned up along with the rest of the IRQ
* handling cleanup. See irq.c for more details.
*/
struct clock_event_device *evdev = this_cpu_ptr(&riscv_clock_event);
evdev->event_handler(evdev);
#endif
}
void __init init_clockevent(void)
{
timer_probe();
csr_set(sie, SIE_STIE);
}
void __init time_init(void)
{
struct device_node *cpu;
u32 prop;
cpu = of_find_node_by_path("/cpus");
if (!cpu || of_property_read_u32(cpu, "timebase-frequency", &prop))
panic(KERN_WARNING "RISC-V system with no 'timebase-frequency' in DTS\n");
riscv_timebase = prop;
lpj_fine = riscv_timebase / HZ;
init_clockevent();
}

180
arch/riscv/kernel/traps.c Normal file
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/*
* Copyright (C) 2012 Regents of the University of California
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/sched/signal.h>
#include <linux/signal.h>
#include <linux/kdebug.h>
#include <linux/uaccess.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/irq.h>
#include <asm/processor.h>
#include <asm/ptrace.h>
#include <asm/csr.h>
int show_unhandled_signals = 1;
extern asmlinkage void handle_exception(void);
static DEFINE_SPINLOCK(die_lock);
void die(struct pt_regs *regs, const char *str)
{
static int die_counter;
int ret;
oops_enter();
spin_lock_irq(&die_lock);
console_verbose();
bust_spinlocks(1);
pr_emerg("%s [#%d]\n", str, ++die_counter);
print_modules();
show_regs(regs);
ret = notify_die(DIE_OOPS, str, regs, 0, regs->scause, SIGSEGV);
bust_spinlocks(0);
add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
spin_unlock_irq(&die_lock);
oops_exit();
if (in_interrupt())
panic("Fatal exception in interrupt");
if (panic_on_oops)
panic("Fatal exception");
if (ret != NOTIFY_STOP)
do_exit(SIGSEGV);
}
static inline void do_trap_siginfo(int signo, int code,
unsigned long addr, struct task_struct *tsk)
{
siginfo_t info;
info.si_signo = signo;
info.si_errno = 0;
info.si_code = code;
info.si_addr = (void __user *)addr;
force_sig_info(signo, &info, tsk);
}
void do_trap(struct pt_regs *regs, int signo, int code,
unsigned long addr, struct task_struct *tsk)
{
if (show_unhandled_signals && unhandled_signal(tsk, signo)
&& printk_ratelimit()) {
pr_info("%s[%d]: unhandled signal %d code 0x%x at 0x" REG_FMT,
tsk->comm, task_pid_nr(tsk), signo, code, addr);
print_vma_addr(KERN_CONT " in ", GET_IP(regs));
pr_cont("\n");
show_regs(regs);
}
do_trap_siginfo(signo, code, addr, tsk);
}
static void do_trap_error(struct pt_regs *regs, int signo, int code,
unsigned long addr, const char *str)
{
if (user_mode(regs)) {
do_trap(regs, signo, code, addr, current);
} else {
if (!fixup_exception(regs))
die(regs, str);
}
}
#define DO_ERROR_INFO(name, signo, code, str) \
asmlinkage void name(struct pt_regs *regs) \
{ \
do_trap_error(regs, signo, code, regs->sepc, "Oops - " str); \
}
DO_ERROR_INFO(do_trap_unknown,
SIGILL, ILL_ILLTRP, "unknown exception");
DO_ERROR_INFO(do_trap_insn_misaligned,
SIGBUS, BUS_ADRALN, "instruction address misaligned");
DO_ERROR_INFO(do_trap_insn_fault,
SIGSEGV, SEGV_ACCERR, "instruction access fault");
DO_ERROR_INFO(do_trap_insn_illegal,
SIGILL, ILL_ILLOPC, "illegal instruction");
DO_ERROR_INFO(do_trap_load_misaligned,
SIGBUS, BUS_ADRALN, "load address misaligned");
DO_ERROR_INFO(do_trap_load_fault,
SIGSEGV, SEGV_ACCERR, "load access fault");
DO_ERROR_INFO(do_trap_store_misaligned,
SIGBUS, BUS_ADRALN, "store (or AMO) address misaligned");
DO_ERROR_INFO(do_trap_store_fault,
SIGSEGV, SEGV_ACCERR, "store (or AMO) access fault");
DO_ERROR_INFO(do_trap_ecall_u,
SIGILL, ILL_ILLTRP, "environment call from U-mode");
DO_ERROR_INFO(do_trap_ecall_s,
SIGILL, ILL_ILLTRP, "environment call from S-mode");
DO_ERROR_INFO(do_trap_ecall_m,
SIGILL, ILL_ILLTRP, "environment call from M-mode");
asmlinkage void do_trap_break(struct pt_regs *regs)
{
#ifdef CONFIG_GENERIC_BUG
if (!user_mode(regs)) {
enum bug_trap_type type;
type = report_bug(regs->sepc, regs);
switch (type) {
case BUG_TRAP_TYPE_NONE:
break;
case BUG_TRAP_TYPE_WARN:
regs->sepc += sizeof(bug_insn_t);
return;
case BUG_TRAP_TYPE_BUG:
die(regs, "Kernel BUG");
}
}
#endif /* CONFIG_GENERIC_BUG */
do_trap_siginfo(SIGTRAP, TRAP_BRKPT, regs->sepc, current);
regs->sepc += 0x4;
}
#ifdef CONFIG_GENERIC_BUG
int is_valid_bugaddr(unsigned long pc)
{
bug_insn_t insn;
if (pc < PAGE_OFFSET)
return 0;
if (probe_kernel_address((bug_insn_t __user *)pc, insn))
return 0;
return (insn == __BUG_INSN);
}
#endif /* CONFIG_GENERIC_BUG */
void __init trap_init(void)
{
/*
* Set sup0 scratch register to 0, indicating to exception vector
* that we are presently executing in the kernel
*/
csr_write(sscratch, 0);
/* Set the exception vector address */
csr_write(stvec, &handle_exception);
/* Enable all interrupts */
csr_write(sie, -1);
}

125
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/*
* Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp.
* <benh@kernel.crashing.org>
* Copyright (C) 2012 ARM Limited
* Copyright (C) 2015 Regents of the University of California
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/binfmts.h>
#include <linux/err.h>
#include <asm/vdso.h>
extern char vdso_start[], vdso_end[];
static unsigned int vdso_pages;
static struct page **vdso_pagelist;
/*
* The vDSO data page.
*/
static union {
struct vdso_data data;
u8 page[PAGE_SIZE];
} vdso_data_store __page_aligned_data;
struct vdso_data *vdso_data = &vdso_data_store.data;
static int __init vdso_init(void)
{
unsigned int i;
vdso_pages = (vdso_end - vdso_start) >> PAGE_SHIFT;
vdso_pagelist =
kcalloc(vdso_pages + 1, sizeof(struct page *), GFP_KERNEL);
if (unlikely(vdso_pagelist == NULL)) {
pr_err("vdso: pagelist allocation failed\n");
return -ENOMEM;
}
for (i = 0; i < vdso_pages; i++) {
struct page *pg;
pg = virt_to_page(vdso_start + (i << PAGE_SHIFT));
ClearPageReserved(pg);
vdso_pagelist[i] = pg;
}
vdso_pagelist[i] = virt_to_page(vdso_data);
return 0;
}
arch_initcall(vdso_init);
int arch_setup_additional_pages(struct linux_binprm *bprm,
int uses_interp)
{
struct mm_struct *mm = current->mm;
unsigned long vdso_base, vdso_len;
int ret;
vdso_len = (vdso_pages + 1) << PAGE_SHIFT;
down_write(&mm->mmap_sem);
vdso_base = get_unmapped_area(NULL, 0, vdso_len, 0, 0);
if (unlikely(IS_ERR_VALUE(vdso_base))) {
ret = vdso_base;
goto end;
}
/*
* Put vDSO base into mm struct. We need to do this before calling
* install_special_mapping or the perf counter mmap tracking code
* will fail to recognise it as a vDSO (since arch_vma_name fails).
*/
mm->context.vdso = (void *)vdso_base;
ret = install_special_mapping(mm, vdso_base, vdso_len,
(VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC),
vdso_pagelist);
if (unlikely(ret))
mm->context.vdso = NULL;
end:
up_write(&mm->mmap_sem);
return ret;
}
const char *arch_vma_name(struct vm_area_struct *vma)
{
if (vma->vm_mm && (vma->vm_start == (long)vma->vm_mm->context.vdso))
return "[vdso]";
return NULL;
}
/*
* Function stubs to prevent linker errors when AT_SYSINFO_EHDR is defined
*/
int in_gate_area_no_mm(unsigned long addr)
{
return 0;
}
int in_gate_area(struct mm_struct *mm, unsigned long addr)
{
return 0;
}
struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
{
return NULL;
}

70
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/*
* Copyright (C) 2012 Regents of the University of California
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/bootmem.h>
#include <linux/initrd.h>
#include <linux/memblock.h>
#include <linux/swap.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>
#include <asm/pgtable.h>
#include <asm/io.h>
static void __init zone_sizes_init(void)
{
unsigned long zones_size[MAX_NR_ZONES];
memset(zones_size, 0, sizeof(zones_size));
zones_size[ZONE_NORMAL] = max_mapnr;
free_area_init_node(0, zones_size, pfn_base, NULL);
}
void setup_zero_page(void)
{
memset((void *)empty_zero_page, 0, PAGE_SIZE);
}
void __init paging_init(void)
{
init_mm.pgd = (pgd_t *)pfn_to_virt(csr_read(sptbr));
setup_zero_page();
local_flush_tlb_all();
zone_sizes_init();
}
void __init mem_init(void)
{
#ifdef CONFIG_FLATMEM
BUG_ON(!mem_map);
#endif /* CONFIG_FLATMEM */
high_memory = (void *)(__va(PFN_PHYS(max_low_pfn)));
free_all_bootmem();
mem_init_print_info(NULL);
}
void free_initmem(void)
{
free_initmem_default(0);
}
#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
}
#endif /* CONFIG_BLK_DEV_INITRD */