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/*
* Copyright (c) 2014-2017 Richard Braun.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <kern/assert.h>
#include <kern/error.h>
#include <kern/init.h>
#include <kern/macros.h>
#include <kern/panic.h>
#include <kern/param.h>
#include <kern/percpu.h>
#include <kern/printk.h>
#include <kern/stddef.h>
#include <kern/stdint.h>
#include <kern/string.h>
#include <machine/cpu.h>
#include <vm/vm_kmem.h>
#include <vm/vm_page.h>
void *percpu_areas[MAX_CPUS] __read_mostly;
static void *percpu_area_content __initdata;
static size_t percpu_area_size __initdata;
static int percpu_skip_warning __initdata;
void __init
percpu_bootstrap(void)
{
percpu_areas[0] = &_percpu;
}
void __init
percpu_setup(void)
{
struct vm_page *page;
unsigned int order;
percpu_area_size = &_epercpu - &_percpu;
printk("percpu: max_cpus: %u, section size: %zuk\n", MAX_CPUS,
percpu_area_size >> 10);
assert(vm_page_aligned(percpu_area_size));
if (percpu_area_size == 0) {
return;
}
order = vm_page_order(percpu_area_size);
page = vm_page_alloc(order, VM_PAGE_SEL_DIRECTMAP, VM_PAGE_KERNEL);
if (page == NULL) {
panic("percpu: unable to allocate memory for percpu area content");
}
percpu_area_content = vm_page_direct_ptr(page);
memcpy(percpu_area_content, &_percpu, percpu_area_size);
}
int __init
percpu_add(unsigned int cpu)
{
struct vm_page *page;
unsigned int order;
if (cpu >= ARRAY_SIZE(percpu_areas)) {
if (!percpu_skip_warning) {
printk("percpu: ignoring processor beyond id %zu\n",
ARRAY_SIZE(percpu_areas) - 1);
percpu_skip_warning = 1;
}
return ERROR_INVAL;
}
if (percpu_areas[cpu] != NULL) {
printk("percpu: error: id %u ignored, already registered\n", cpu);
return ERROR_INVAL;
}
if (percpu_area_size == 0) {
goto out;
}
order = vm_page_order(percpu_area_size);
page = vm_page_alloc(order, VM_PAGE_SEL_DIRECTMAP, VM_PAGE_KERNEL);
if (page == NULL) {
printk("percpu: error: unable to allocate percpu area\n");
return ERROR_NOMEM;
}
percpu_areas[cpu] = vm_page_direct_ptr(page);
memcpy(percpu_area(cpu), percpu_area_content, percpu_area_size);
out:
return 0;
}
void
percpu_cleanup(void)
{
struct vm_page *page;
uintptr_t va;
va = (uintptr_t)percpu_area_content;
page = vm_page_lookup(vm_page_direct_pa(va));
vm_page_free(page, vm_page_order(percpu_area_size));
}
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