On Thu, Sep 27, 2012 at 04:41:08PM +0800, Lv Zheng wrote:
> Microsoft Debug Port Table (DBGP or DBG2) is required for Windows SoC
> platforms. This patch is introduced to fix the gap between Windows
> and Linux.
>
> Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
> ---
> Documentation/kernel-parameters.txt | 1 +
> arch/x86/Kconfig.debug | 15 +++
> arch/x86/kernel/acpi/boot.c | 1 +
> arch/x86/kernel/early_printk.c | 13 +++
> drivers/acpi/Makefile | 2 +
> drivers/acpi/early_printk.c | 201 +++++++++++++++++++++++++++++++++++
> include/linux/acpi.h | 24 +++++
> 7 files changed, 257 insertions(+)
> create mode 100644 drivers/acpi/early_printk.c
>
> Index: linux-acpi/Documentation/kernel-parameters.txt
> ===================================================================
> --- linux-acpi.orig/Documentation/kernel-parameters.txt 2012-09-26 17:52:44.000000000 +0800
> +++ linux-acpi/Documentation/kernel-parameters.txt 2012-09-27 01:38:15.000000000 +0800
> @@ -763,6 +763,7 @@
> earlyprintk=serial[,ttySn[,baudrate]]
> earlyprintk=ttySn[,baudrate]
> earlyprintk=dbgp[debugController#]
> + earlyprintk=acpi[debugController#]
>
> Append ",keep" to not disable it when the real console
> takes over.
> Index: linux-acpi/arch/x86/Kconfig.debug
> ===================================================================
> --- linux-acpi.orig/arch/x86/Kconfig.debug 2012-09-26 17:52:44.000000000 +0800
> +++ linux-acpi/arch/x86/Kconfig.debug 2012-09-27 01:46:12.000000000 +0800
> @@ -59,6 +59,21 @@
> with klogd/syslogd or the X server. You should normally N here,
> unless you want to debug such a crash. You need usb debug device.
>
> +config EARLY_PRINTK_ACPI
> + bool "Early printk launcher via ACPI debug port tables"
> + depends on EARLY_PRINTK && ACPI
> + ---help---
> + Write kernel log output directly into the debug ports described
> + in the ACPI tables known as DBGP and DBG2.
> +
> + To enable such debugging facilities, you need to enable this
> + configuration option and append the "earlyprintk=acpi" kernel
> + parameter through the boot loaders. Please refer the
> + "Documentation/kernel-parameters.txt" for details. Since this
> + is an early console launcher, you still need to enable actual
> + early console drivers that are suitable for your platform.
> + If in doubt, say "N".
> +
> config DEBUG_STACKOVERFLOW
> bool "Check for stack overflows"
> depends on DEBUG_KERNEL
> Index: linux-acpi/arch/x86/kernel/acpi/boot.c
> ===================================================================
> --- linux-acpi.orig/arch/x86/kernel/acpi/boot.c 2012-09-26 17:52:44.000000000 +0800
> +++ linux-acpi/arch/x86/kernel/acpi/boot.c 2012-09-27 01:38:15.000000000 +0800
> @@ -1518,6 +1518,7 @@
> return;
> }
>
> + acpi_early_console_parse();
> acpi_table_parse(ACPI_SIG_BOOT, acpi_parse_sbf);
>
> /*
> Index: linux-acpi/arch/x86/kernel/early_printk.c
> ===================================================================
> --- linux-acpi.orig/arch/x86/kernel/early_printk.c 2012-09-26 17:52:44.000000000 +0800
> +++ linux-acpi/arch/x86/kernel/early_printk.c 2012-09-27 01:39:09.000000000 +0800
> @@ -200,6 +200,15 @@
> register_console(early_console);
> }
>
> +#ifdef CONFIG_EARLY_PRINTK_ACPI
> +#include <linux/acpi.h>
> +
> +int __init acpi_early_console_setup(struct acpi_debug_port *info)
> +{
> + return 0;
> +}
> +#endif
> +
> static int __init setup_early_printk(char *buf)
> {
> int keep;
> @@ -236,6 +245,10 @@
> if (!strncmp(buf, "dbgp", 4) && !early_dbgp_init(buf + 4))
> early_console_register(&early_dbgp_console, keep);
> #endif
> +#ifdef CONFIG_EARLY_PRINTK_ACPI
> + if (!strncmp(buf, "acpi", 4))
> + acpi_early_console_init(buf + 4, keep);
> +#endif
> #ifdef CONFIG_HVC_XEN
> if (!strncmp(buf, "xen", 3))
> early_console_register(&xenboot_console, keep);
> Index: linux-acpi/drivers/acpi/Makefile
> ===================================================================
> --- linux-acpi.orig/drivers/acpi/Makefile 2012-09-26 17:52:44.000000000 +0800
> +++ linux-acpi/drivers/acpi/Makefile 2012-09-27 01:38:15.000000000 +0800
> @@ -46,6 +46,8 @@
> acpi-y += video_detect.o
> endif
>
> +obj-$(CONFIG_EARLY_PRINTK_ACPI) += early_printk.o
> +
> # These are (potentially) separate modules
> obj-$(CONFIG_ACPI_AC) += ac.o
> obj-$(CONFIG_ACPI_BUTTON) += button.o
> Index: linux-acpi/drivers/acpi/early_printk.c
> ===================================================================
> --- /dev/null 1970-01-01 00:00:00.000000000 +0000
> +++ linux-acpi/drivers/acpi/early_printk.c 2012-09-27 01:38:15.000000000 +0800
> @@ -0,0 +1,201 @@
> +/*
> + * acpi/early_printk.c - ACPI Boot-Time Debug Ports
> + *
> + * Copyright (C) 2012 Lv Zheng <lv.zheng@xxxxxxxxx>
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + *
> + * 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 2 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, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Please remove the address.
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + *
> + */
> +
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/string.h>
> +#include <linux/types.h>
> +#include <linux/errno.h>
> +#include <linux/acpi.h>
> +#include <linux/bootmem.h>
> +
> +#define ACPI_EARLY_DISABLED 0x0000
> +#define ACPI_EARLY_ENABLED 0x0001
> +#define ACPI_EARLY_KEEP 0x0002
> +#define ACPI_EARLY_PORT_MSK 0xFF00
> +#define ACPI_EARLY_PORT_OFF 8
> +
> +u16 acpi_early_flags = ACPI_EARLY_DISABLED;
> +
> +static inline bool acpi_early_enabled(void)
> +{
> + return acpi_early_flags & ACPI_EARLY_ENABLED;
> +}
> +
> +static inline u8 acpi_early_port_index(void)
> +{
> + return (acpi_early_flags & ACPI_EARLY_PORT_MSK) >> ACPI_EARLY_PORT_OFF;
> +}
> +
> +int __init acpi_early_console_keep(void)
> +{
> + return acpi_early_flags & ACPI_EARLY_KEEP ? 1 : 0;
> +}
> +
> +static inline int acpi_table_parse_dbg2(acpi_early_console_handler handler)
Why inline?
And somehow I am not able to find acpi_early_console_handler?
> +{
> + struct acpi_table_header *table_header = NULL;
> + struct acpi_dbg2_device *entry;
> + unsigned int count = 0;
> + unsigned long table_end;
> + acpi_size tbl_size;
> + unsigned int max_entries;
> + struct acpi_debug_port devinfo;
> +
> + if (acpi_disabled)
> + return -ENODEV;
> +
> + if (!handler)
> + return -EINVAL;
> +
> + acpi_get_table(ACPI_SIG_DBG2, 0, &table_header);
> + if (!table_header) {
> + pr_warn("DBG2 not present\n");
Um, pr_warn in an early printk driver? Perhaps pr_debug?
> + return -ENODEV;
> + }
> + tbl_size = table_header->length;
> + table_end = (unsigned long)table_header + table_header->length;
> +
> + entry = (struct acpi_dbg2_device *)
> + ((unsigned long)table_header +
> + ((struct acpi_table_dbg2 *)table_header)->info_offset);
> + max_entries = ((struct acpi_table_dbg2 *)table_header)->info_count;
> +
> + while (((unsigned long)entry) + sizeof(struct acpi_dbg2_device) <
> + table_end) {
> + if (entry->revision != 0) {
> + pr_warn("DBG2 revision %d not supported\n",
> + entry->revision);
> + count = -ENODEV;
> + goto fail;
> + }
> + if (!max_entries || count++ < max_entries) {
> + devinfo.port_index = (u8)count;
> + devinfo.port_type = entry->port_type;
> + devinfo.port_subtype = entry->port_subtype;
> + devinfo.register_count = entry->register_count;
> + devinfo.registers = (struct acpi_generic_address *)
> + ((unsigned long)entry + entry->base_address_offset);
> + devinfo.namepath_length = entry->namepath_length;
> + devinfo.namepath = (char *)
> + ((unsigned long)entry + entry->namepath_offset);
> + devinfo.oem_data_length = entry->oem_data_length;
> + devinfo.oem_data = (u8 *)
> + ((unsigned long)entry + entry->oem_data_offset);
> +
> + if (handler(&devinfo, table_end)) {
Oh! it is a function! Perhaps call it 'func' or just use the raw
decleration in the arguments instead of using a typedef.
> + count = -ENODEV;
> + goto fail;
> + }
> + }
> +
> + entry = (struct acpi_dbg2_device *)
> + ((unsigned long)entry + entry->length);
> + }
> +
> +fail:
> + early_acpi_os_unmap_memory((char *)table_header, tbl_size);
> + return count;
> +}
> +
> +static int __init acpi_parse_early_console(struct acpi_debug_port *info,
> + const unsigned long end)
> +{
> + pr_info("early: DBG2 console %d detected: %04x:%04x.\n",
> + info->port_index, info->port_type, info->port_subtype);
Um, pr_info in a earlyconsole driver? Perhaps it should be
pr_debug
> +
> + if (acpi_early_port_index() != 0 &&
> + acpi_early_port_index() != info->port_index)
> + return 0;
> +
> + acpi_early_console_setup(info);
> +
> + return 0;
> +}
> +
> +static int __init acpi_parse_dbgp(struct acpi_table_header *table)
> +{
> + struct acpi_table_dbgp *dbgp;
> + struct acpi_debug_port devinfo;
> +
> + if (acpi_early_port_index() != 0 &&
> + acpi_early_port_index() != 1)
> + return 0;
> +
> + dbgp = (struct acpi_table_dbgp *)table;
> + if (!dbgp) {
> + pr_warn("Unable to map DBGP\n");
> + return -ENODEV;
> + }
> +
> + pr_info("early: DBGP console detected: %04x.\n",
> + dbgp->type);
> +
> + devinfo.port_index = 1;
> + devinfo.port_type = ACPI_DBG2_SERIAL_PORT;
> + devinfo.port_subtype = dbgp->type;
> + devinfo.register_count = 1;
> + devinfo.registers = (struct acpi_generic_address *)&dbgp->debug_port;
> + devinfo.namepath_length = 0;
> + devinfo.namepath = NULL;
> + devinfo.oem_data_length = 0;
> + devinfo.oem_data = NULL;
> +
> + acpi_parse_early_console(&devinfo, 0);
> +
> + return 0;
> +}
> +
> +int __init acpi_early_console_parse(void)
> +{
> + if (!acpi_early_enabled())
> + return -EINVAL;
> +
> + if (acpi_table_parse_dbg2(acpi_parse_early_console) == 0)
> + acpi_table_parse(ACPI_SIG_DBGP, acpi_parse_dbgp);
> +
> + return 0;
> +}
> +
> +int __init acpi_early_console_init(char *s, int keep)
> +{
> + char *e;
> +
> + acpi_early_flags = ACPI_EARLY_ENABLED;
> + if (keep)
> + acpi_early_flags |= ACPI_EARLY_KEEP;
> +
> + if (*s) {
> + u8 port;
> +
> + port = (u8)simple_strtoul(s, &e, 10);
> + acpi_early_flags |= (port) << ACPI_EARLY_PORT_OFF;
> + }
> +
> + pr_info("early: debug port index %d.\n", acpi_early_port_index());
> +
> + return 0;
> +}
> +
> Index: linux-acpi/include/linux/acpi.h
> ===================================================================
> --- linux-acpi.orig/include/linux/acpi.h 2012-09-26 17:52:44.000000000 +0800
> +++ linux-acpi/include/linux/acpi.h 2012-09-27 01:38:16.000000000 +0800
> @@ -430,4 +430,28 @@
> #define acpi_os_set_prepare_sleep(func, pm1a_ctrl, pm1b_ctrl) do { } while (0)
> #endif
>
> +#ifdef CONFIG_EARLY_PRINTK_ACPI
> +struct acpi_debug_port {
> + u8 port_index;
> + u16 port_type;
> + u16 port_subtype;
> + u16 register_count;
> + struct acpi_generic_address *registers;
> + u16 namepath_length;
> + char *namepath;
> + u16 oem_data_length;
> + u8 *oem_data;
> +};
> +
> +typedef int (*acpi_early_console_handler)(struct acpi_debug_port *dev,
> + const unsigned long end);
> +
> +int __init acpi_early_console_keep(void);
> +int __init acpi_early_console_init(char *s, int keep);
> +int __init acpi_early_console_parse(void);
> +int __init acpi_early_console_setup(struct acpi_debug_port *info);
> +#else
> +static int acpi_early_console_parse(void) { return 0; }
> +#endif
> +
> #endif /*_LINUX_ACPI_H*/
> --
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