mirror of https://gitee.com/openkylin/linux.git
110 lines
2.3 KiB
C
110 lines
2.3 KiB
C
/*
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* memconsole-coreboot.c
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*
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* Memory based BIOS console accessed through coreboot table.
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*
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* Copyright 2017 Google Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License v2.0 as published by
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* the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include "memconsole.h"
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#include "coreboot_table.h"
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#define CB_TAG_CBMEM_CONSOLE 0x17
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/* CBMEM firmware console log descriptor. */
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struct cbmem_cons {
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u32 buffer_size;
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u32 buffer_cursor;
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u8 buffer_body[0];
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} __packed;
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static struct cbmem_cons __iomem *cbmem_console;
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static int memconsole_coreboot_init(phys_addr_t physaddr)
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{
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struct cbmem_cons __iomem *tmp_cbmc;
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tmp_cbmc = memremap(physaddr, sizeof(*tmp_cbmc), MEMREMAP_WB);
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if (!tmp_cbmc)
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return -ENOMEM;
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cbmem_console = memremap(physaddr,
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tmp_cbmc->buffer_size + sizeof(*cbmem_console),
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MEMREMAP_WB);
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memunmap(tmp_cbmc);
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if (!cbmem_console)
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return -ENOMEM;
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memconsole_setup(cbmem_console->buffer_body,
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min(cbmem_console->buffer_cursor, cbmem_console->buffer_size));
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return 0;
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}
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static int memconsole_probe(struct platform_device *pdev)
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{
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int ret;
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struct lb_cbmem_ref entry;
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ret = coreboot_table_find(CB_TAG_CBMEM_CONSOLE, &entry, sizeof(entry));
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if (ret)
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return ret;
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ret = memconsole_coreboot_init(entry.cbmem_addr);
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if (ret)
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return ret;
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return memconsole_sysfs_init();
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}
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static int memconsole_remove(struct platform_device *pdev)
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{
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memconsole_exit();
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if (cbmem_console)
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memunmap(cbmem_console);
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return 0;
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}
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static struct platform_driver memconsole_driver = {
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.probe = memconsole_probe,
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.remove = memconsole_remove,
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.driver = {
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.name = "memconsole",
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},
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};
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static int __init platform_memconsole_init(void)
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{
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struct platform_device *pdev;
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pdev = platform_device_register_simple("memconsole", -1, NULL, 0);
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if (IS_ERR(pdev))
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return PTR_ERR(pdev);
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platform_driver_register(&memconsole_driver);
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return 0;
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}
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module_init(platform_memconsole_init);
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MODULE_AUTHOR("Google, Inc.");
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MODULE_LICENSE("GPL");
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