2 * Copyright (C) 2017 SiFive
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation, version 2.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
14 #include <asm/pgtable.h>
15 #include <asm/cacheflush.h>
21 void flush_icache_all(void)
23 sbi_remote_fence_i(NULL);
27 * Performs an icache flush for the given MM context. RISC-V has no direct
28 * mechanism for instruction cache shoot downs, so instead we send an IPI that
29 * informs the remote harts they need to flush their local instruction caches.
30 * To avoid pathologically slow behavior in a common case (a bunch of
31 * single-hart processes on a many-hart machine, ie 'make -j') we avoid the
32 * IPIs for harts that are not currently executing a MM context and instead
33 * schedule a deferred local instruction cache flush to be performed before
34 * execution resumes on each hart.
36 void flush_icache_mm(struct mm_struct *mm, bool local)
39 cpumask_t others, hmask, *mask;
43 /* Mark every hart's icache as needing a flush for this MM. */
44 mask = &mm->context.icache_stale_mask;
46 /* Flush this hart's I$ now, and mark it as flushed. */
47 cpu = smp_processor_id();
48 cpumask_clear_cpu(cpu, mask);
49 local_flush_icache_all();
52 * Flush the I$ of other harts concurrently executing, and mark them as
55 cpumask_andnot(&others, mm_cpumask(mm), cpumask_of(cpu));
56 local |= cpumask_empty(&others);
57 if (mm != current->active_mm || !local) {
58 cpumask_clear(&hmask);
59 riscv_cpuid_to_hartid_mask(&others, &hmask);
60 sbi_remote_fence_i(hmask.bits);
63 * It's assumed that at least one strongly ordered operation is
64 * performed on this hart between setting a hart's cpumask bit
65 * and scheduling this MM context on that hart. Sending an SBI
66 * remote message will do this, but in the case where no
67 * messages are sent we still need to order this hart's writes
68 * with flush_icache_deferred().
76 #endif /* CONFIG_SMP */
78 void flush_icache_pte(pte_t pte)
80 struct page *page = pte_page(pte);
82 if (!test_and_set_bit(PG_dcache_clean, &page->flags))