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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2017 SiFive
*/
#include <linux/acpi.h>
#include <linux/of.h>
#include <asm/acpi.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) && !riscv_use_ipi_for_rfence())
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) &&
!riscv_use_ipi_for_rfence()) {
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(struct mm_struct *mm, pte_t pte)
{
struct folio *folio = page_folio(pte_page(pte));
if (!test_bit(PG_dcache_clean, &folio->flags)) {
flush_icache_mm(mm, false);
set_bit(PG_dcache_clean, &folio->flags);
}
}
#endif /* CONFIG_MMU */
unsigned int riscv_cbom_block_size;
EXPORT_SYMBOL_GPL(riscv_cbom_block_size);
unsigned int riscv_cboz_block_size;
EXPORT_SYMBOL_GPL(riscv_cboz_block_size);
static void __init cbo_get_block_size(struct device_node *node,
const char *name, u32 *block_size,
unsigned long *first_hartid)
{
unsigned long hartid;
u32 val;
if (riscv_of_processor_hartid(node, &hartid))
return;
if (of_property_read_u32(node, name, &val))
return;
if (!*block_size) {
*block_size = val;
*first_hartid = hartid;
} else if (*block_size != val) {
pr_warn("%s mismatched between harts %lu and %lu\n",
name, *first_hartid, hartid);
}
}
void __init riscv_init_cbo_blocksizes(void)
{
unsigned long cbom_hartid, cboz_hartid;
u32 cbom_block_size = 0, cboz_block_size = 0;
struct device_node *node;
struct acpi_table_header *rhct;
acpi_status status;
if (acpi_disabled) {
for_each_of_cpu_node(node) {
/* set block-size for cbom and/or cboz extension if available */
cbo_get_block_size(node, "riscv,cbom-block-size",
&cbom_block_size, &cbom_hartid);
cbo_get_block_size(node, "riscv,cboz-block-size",
&cboz_block_size, &cboz_hartid);
}
} else {
status = acpi_get_table(ACPI_SIG_RHCT, 0, &rhct);
if (ACPI_FAILURE(status))
return;
acpi_get_cbo_block_size(rhct, &cbom_block_size, &cboz_block_size, NULL);
acpi_put_table((struct acpi_table_header *)rhct);
}
if (cbom_block_size)
riscv_cbom_block_size = cbom_block_size;
if (cboz_block_size)
riscv_cboz_block_size = cboz_block_size;
}
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