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authorGary Guo <gary@garyguo.net>2019-03-27 00:41:29 +0000
committerPalmer Dabbelt <palmer@sifive.com>2019-05-16 20:42:12 -0700
commitf6635f873a605576fa1983c605655a8721475c22 (patch)
treee90d492641c5dbbc02307894264a20ed9ccf53b7 /arch/riscv/include/asm
parent58de77545e53b94cd6c816776197dade598632c5 (diff)
riscv: move switch_mm to its own file
switch_mm is an expensive operations that has two users. flush_icache_deferred is only called within switch_mm and can be moved together. The function is expected to be more complicated when ASID support is added, so clean up eagerly. By moving them to a separate file we also removes some excessive dependency of tlbflush.h and cacheflush.h. Signed-off-by: Gary Guo <gary@garyguo.net> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Diffstat (limited to 'arch/riscv/include/asm')
-rw-r--r--arch/riscv/include/asm/mmu_context.h54
1 files changed, 2 insertions, 52 deletions
diff --git a/arch/riscv/include/asm/mmu_context.h b/arch/riscv/include/asm/mmu_context.h
index 98c76c821367..bf4f097a9051 100644
--- a/arch/riscv/include/asm/mmu_context.h
+++ b/arch/riscv/include/asm/mmu_context.h
@@ -20,8 +20,6 @@
#include <linux/mm.h>
#include <linux/sched.h>
-#include <asm/tlbflush.h>
-#include <asm/cacheflush.h>
static inline void enter_lazy_tlb(struct mm_struct *mm,
struct task_struct *task)
@@ -39,56 +37,8 @@ static inline void destroy_context(struct mm_struct *mm)
{
}
-/*
- * 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
-}
-
-static inline void switch_mm(struct mm_struct *prev,
- struct mm_struct *next, struct task_struct *task)
-{
- if (likely(prev != next)) {
- /*
- * 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
- */
- unsigned int 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);
- }
-}
+void switch_mm(struct mm_struct *prev, struct mm_struct *next,
+ struct task_struct *task);
static inline void activate_mm(struct mm_struct *prev,
struct mm_struct *next)