linux/arch/riscv/mm/context.c
Paul Walmsley 5ed881bc3a riscv: add missing header file includes
sparse identifies several missing prototypes caused by missing
preprocessor include directives:

arch/riscv/kernel/cpufeature.c:16:6: warning: symbol 'has_fpu' was not declared. Should it be static?
arch/riscv/kernel/process.c:26:6: warning: symbol 'arch_cpu_idle' was not declared. Should it be static?
arch/riscv/kernel/reset.c:15:6: warning: symbol 'pm_power_off' was not declared. Should it be static?
arch/riscv/kernel/syscall_table.c:15:6: warning: symbol 'sys_call_table' was not declared. Should it be static?
arch/riscv/kernel/traps.c:149:13: warning: symbol 'trap_init' was not declared. Should it be static?
arch/riscv/kernel/vdso.c:54:5: warning: symbol 'arch_setup_additional_pages' was not declared. Should it be static?
arch/riscv/kernel/smp.c:64:6: warning: symbol 'arch_match_cpu_phys_id' was not declared. Should it be static?
arch/riscv/kernel/module-sections.c:89:5: warning: symbol 'module_frob_arch_sections' was not declared. Should it be static?
arch/riscv/mm/context.c:42:6: warning: symbol 'switch_mm' was not declared. Should it be static?

Fix by including the appropriate header files in the appropriate
source files.

This patch should have no functional impact.

Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2019-10-28 00:46:01 -07:00

66 lines
1.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2012 Regents of the University of California
* Copyright (C) 2017 SiFive
*/
#include <linux/mm.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>
#include <asm/mmu_context.h>
/*
* When necessary, performs a deferred icache flush for the given MM context,
* on the local CPU. RISC-V has no direct mechanism for instruction cache
* shoot downs, so instead we send an IPI that informs the remote harts they
* need to flush their local instruction caches. To avoid pathologically slow
* behavior in a common case (a bunch of single-hart processes on a many-hart
* machine, ie 'make -j') we avoid the IPIs for harts that are not currently
* executing a MM context and instead schedule a deferred local instruction
* cache flush to be performed before execution resumes on each hart. This
* actually performs that local instruction cache flush, which implicitly only
* refers to the current hart.
*/
static inline void flush_icache_deferred(struct mm_struct *mm)
{
#ifdef CONFIG_SMP
unsigned int cpu = smp_processor_id();
cpumask_t *mask = &mm->context.icache_stale_mask;
if (cpumask_test_cpu(cpu, mask)) {
cpumask_clear_cpu(cpu, mask);
/*
* Ensure the remote hart's writes are visible to this hart.
* This pairs with a barrier in flush_icache_mm.
*/
smp_mb();
local_flush_icache_all();
}
#endif
}
void switch_mm(struct mm_struct *prev, struct mm_struct *next,
struct task_struct *task)
{
unsigned int cpu;
if (unlikely(prev == next))
return;
/*
* Mark the current MM context as inactive, and the next as
* active. This is at least used by the icache flushing
* routines in order to determine who should be flushed.
*/
cpu = smp_processor_id();
cpumask_clear_cpu(cpu, mm_cpumask(prev));
cpumask_set_cpu(cpu, mm_cpumask(next));
csr_write(CSR_SATP, virt_to_pfn(next->pgd) | SATP_MODE);
local_flush_tlb_all();
flush_icache_deferred(next);
}