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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2017 SiFive
*/
#include <linux/of.h>
#include <asm/cacheflush.h>
#ifdef CONFIG_SMP
#include <asm/sbi.h>
static void ipi_remote_fence_i(void *info)
{
return local_flush_icache_all();
}
void flush_icache_all(void)
{
local_flush_icache_all();
if (IS_ENABLED(CONFIG_RISCV_SBI))
sbi_remote_fence_i(NULL);
else
on_each_cpu(ipi_remote_fence_i, NULL, 1);
}
EXPORT_SYMBOL(flush_icache_all);
/*
* Performs an icache flush for the given MM context. 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.
*/
void flush_icache_mm(struct mm_struct *mm, bool local)
{
unsigned int cpu;
cpumask_t others, *mask;
preempt_disable();
/* Mark every hart's icache as needing a flush for this MM. */
mask = &mm->context.icache_stale_mask;
cpumask_setall(mask);
/* Flush this hart's I$ now, and mark it as flushed. */
cpu = smp_processor_id();
cpumask_clear_cpu(cpu, mask);
local_flush_icache_all();
/*
* Flush the I$ of other harts concurrently executing, and mark them as
* flushed.
*/
cpumask_andnot(&others, mm_cpumask(mm), cpumask_of(cpu));
local |= cpumask_empty(&others);
if (mm == current->active_mm && local) {
/*
* It's assumed that at least one strongly ordered operation is
* performed on this hart between setting a hart's cpumask bit
* and scheduling this MM context on that hart. Sending an SBI
* remote message will do this, but in the case where no
* messages are sent we still need to order this hart's writes
* with flush_icache_deferred().
*/
smp_mb();
} else if (IS_ENABLED(CONFIG_RISCV_SBI)) {
sbi_remote_fence_i(&others);
} else {
on_each_cpu_mask(&others, ipi_remote_fence_i, NULL, 1);
}
preempt_enable();
}
#endif /* CONFIG_SMP */
#ifdef CONFIG_MMU
void flush_icache_pte(pte_t pte)
{
struct page *page = pte_page(pte);
/*
* HugeTLB pages are always fully mapped, so only setting head page's
* PG_dcache_clean flag is enough.
*/
if (PageHuge(page))
page = compound_head(page);
if (!test_and_set_bit(PG_dcache_clean, &page->flags))
flush_icache_all();
}
#endif /* CONFIG_MMU */
unsigned int riscv_cbom_block_size;
EXPORT_SYMBOL_GPL(riscv_cbom_block_size);
void riscv_init_cbom_blocksize(void)
{
struct device_node *node;
unsigned long cbom_hartid;
u32 val, probed_block_size;
int ret;
probed_block_size = 0;
for_each_of_cpu_node(node) {
unsigned long hartid;
ret = riscv_of_processor_hartid(node, &hartid);
if (ret)
continue;
/* set block-size for cbom extension if available */
ret = of_property_read_u32(node, "riscv,cbom-block-size", &val);
if (ret)
continue;
if (!probed_block_size) {
probed_block_size = val;
cbom_hartid = hartid;
} else {
if (probed_block_size != val)
pr_warn("cbom-block-size mismatched between harts %lu and %lu\n",
cbom_hartid, hartid);
}
}
if (probed_block_size)
riscv_cbom_block_size = probed_block_size;
}
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