On Mon, Feb 01, 2016 at 09:01:26AM +0000, Graeme Gregory wrote: > On Mon, Jan 25, 2016 at 05:45:22PM +0600, Aleksey Makarov wrote: > > 'ARM Server Base Boot Requiremets' [1] mention SPCR > > (Serial Port Console Redirection Table) [2] as a mandatory ACPI table > > that specifies the configuration of serial console. > > > > Parse this table and check if any registered console match > > the description. If it does, enable that console. > > > > To implement that, introduce a new member > > int (*acpi_match)(struct console *, struct acpi_table_spcr *) > > of struct console. It allows drivers to check if they provide > > a matching console device. > > > > Fails to compile on x86 > > kernel/built-in.o: In function `register_console': > (.text+0x48cba): undefined reference to `console_acpi_match' > Makefile:929: recipe for target 'vmlinux' failed > make: *** [vmlinux] Error 1 > > Because CONFIG_ACPI_SPCR_TABLE is never set. > > Graeme > > > > [1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0044a/index.html > > [2] http://msdn.microsoft.com/en-us/library/windows/hardware/dn639131(v=vs.85).aspx > > > > Signed-off-by: Aleksey Makarov <aleksey.makarov@xxxxxxxxxx> > > --- > > arch/arm64/Kconfig | 1 + > > drivers/acpi/Kconfig | 3 ++ > > drivers/acpi/Makefile | 1 + > > drivers/acpi/spcr.c | 85 +++++++++++++++++++++++++++++++++++++++++++++++++ > > include/linux/console.h | 12 +++++++ > > kernel/printk/printk.c | 82 +++++++++++++++++++++++++++++++++++++---------- > > 6 files changed, 167 insertions(+), 17 deletions(-) > > create mode 100644 drivers/acpi/spcr.c > > > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > > index 573bebc..bf31e3c 100644 > > --- a/arch/arm64/Kconfig > > +++ b/arch/arm64/Kconfig > > @@ -4,6 +4,7 @@ config ARM64 > > select ACPI_GENERIC_GSI if ACPI > > select ACPI_PCI_HOST_GENERIC if ACPI > > select ACPI_REDUCED_HARDWARE_ONLY if ACPI > > + select ACPI_SPCR_TABLE if ACPI > > select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE > > select ARCH_HAS_ELF_RANDOMIZE > > select ARCH_HAS_GCOV_PROFILE_ALL > > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig > > index e315061..142a338 100644 > > --- a/drivers/acpi/Kconfig > > +++ b/drivers/acpi/Kconfig > > @@ -60,6 +60,9 @@ config ACPI_CCA_REQUIRED > > config IORT_TABLE > > bool > > > > +config ACPI_SPCR_TABLE > > + bool > > + > > config ACPI_DEBUGGER > > bool "AML debugger interface (EXPERIMENTAL)" > > select ACPI_DEBUG > > diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile > > index 265eb90..8316859 100644 > > --- a/drivers/acpi/Makefile > > +++ b/drivers/acpi/Makefile > > @@ -81,6 +81,7 @@ obj-$(CONFIG_ACPI_CUSTOM_METHOD)+= custom_method.o > > obj-$(CONFIG_ACPI_BGRT) += bgrt.o > > obj-$(CONFIG_ACPI_CPPC_LIB) += cppc_acpi.o > > obj-$(CONFIG_IORT_TABLE) += iort.o > > +obj-$(CONFIG_ACPI_SPCR_TABLE) += spcr.o > > > > # processor has its own "processor." module_param namespace > > processor-y := processor_driver.o > > diff --git a/drivers/acpi/spcr.c b/drivers/acpi/spcr.c > > new file mode 100644 > > index 0000000..ccb19a0 > > --- /dev/null > > +++ b/drivers/acpi/spcr.c > > @@ -0,0 +1,85 @@ > > +/* > > + * Copyright (c) 2012, Intel Corporation > > + * Copyright (c) 2015, Red Hat, Inc. > > + * Copyright (c) 2015, 2016 Linaro Ltd. > > + * > > + * This program is free software; you can redistribute it and/or modify > > + * it under the terms of the GNU General Public License version 2 as > > + * published by the Free Software Foundation. > > + * > > + */ > > + > > +#define pr_fmt(fmt) "ACPI: SPCR: " fmt > > + > > +#include <linux/acpi.h> > > +#include <linux/console.h> > > +#include <linux/kernel.h> > > + > > +static struct acpi_table_spcr *spcr_table; > > + > > +int console_acpi_match(struct console *c, char **options) > > +{ > > + int err; > > + > > + if (!c->acpi_match) > > + return -ENODEV; > > + > > + if (!spcr_table) > > + return -EAGAIN; > > + > > + err = c->acpi_match(c, spcr_table); > > + if (err < 0) > > + return err; > > + > > + if (options) { > > + switch (spcr_table->baud_rate) { > > + case 3: > > + *options = "9600"; > > + break; > > + case 4: > > + *options = "19200"; > > + break; > > + case 6: > > + *options = "57600"; > > + break; > > + case 7: > > + *options = "115200"; > > + break; > > + default: > > + *options = ""; > > + break; > > + } > > + } > > + > > + return err; > > +} > > + > > +static int __init spcr_table_detect(void) > > +{ > > + struct acpi_table_header *table; > > + acpi_status status; > > + > > + if (acpi_disabled) > > + return -ENODEV; > > + > > + status = acpi_get_table(ACPI_SIG_SPCR, 0, &table); > > + if (ACPI_FAILURE(status)) { > > + const char *msg = acpi_format_exception(status); > > + > > + pr_err("Failed to get table, %s\n", msg); > > + return -EINVAL; > > + } > > + > > + if (table->revision < 2) > > + return -EOPNOTSUPP; > > + > > + spcr_table = (struct acpi_table_spcr *)table; > > + > > + pr_info("Console at 0x%016llx\n", spcr_table->serial_port.address); > > + > > + acpi_register_consoles_try_again(); > > + > > + return 0; > > +} > > + > > +arch_initcall(spcr_table_detect); > > diff --git a/include/linux/console.h b/include/linux/console.h > > index bd19434..94d0bd8 100644 > > --- a/include/linux/console.h > > +++ b/include/linux/console.h > > @@ -117,6 +117,7 @@ static inline int con_debug_leave(void) > > #define CON_BRL (32) /* Used for a braille device */ > > #define CON_EXTENDED (64) /* Use the extended output format a la /dev/kmsg */ > > > > +struct acpi_table_spcr; > > struct console { > > char name[16]; > > void (*write)(struct console *, const char *, unsigned); > > @@ -125,6 +126,7 @@ struct console { > > void (*unblank)(void); > > int (*setup)(struct console *, char *); > > int (*match)(struct console *, char *name, int idx, char *options); > > + int (*acpi_match)(struct console *, struct acpi_table_spcr *); > > short flags; > > short index; > > int cflag; > > @@ -132,6 +134,16 @@ struct console { > > struct console *next; > > }; > > > > +#ifdef CONFIG_ACPI This should be #ifdef CONFIG_ACPI_SPCR_TABLE > > +int console_acpi_match(struct console *c, char **options); > > +#else > > +static inline int console_acpi_match(struct console *c, char **options) > > +{ > > + return -ENODEV; This requires a #include <linux/errno.h> at the top of the file to work. Graeme > > +} > > +#endif > > +void acpi_register_consoles_try_again(void); > > + > > /* > > * for_each_console() allows you to iterate on each console > > */ > > diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c > > index 37e531f..3cf8cba 100644 > > --- a/kernel/printk/printk.c > > +++ b/kernel/printk/printk.c > > @@ -2430,6 +2430,25 @@ static int __init keep_bootcon_setup(char *str) > > > > early_param("keep_bootcon", keep_bootcon_setup); > > > > +static DEFINE_MUTEX(acpi_consoles_delayed_mutex); > > +static struct console *acpi_consoles_delayed; > > + > > +void acpi_register_consoles_try_again(void) > > +{ > > + mutex_lock(&acpi_consoles_delayed_mutex); > > + while (acpi_consoles_delayed) { > > + > > + struct console *c = acpi_consoles_delayed; > > + > > + acpi_consoles_delayed = acpi_consoles_delayed->next; > > + > > + mutex_unlock(&acpi_consoles_delayed_mutex); > > + register_console(c); > > + mutex_lock(&acpi_consoles_delayed_mutex); > > + } > > + mutex_unlock(&acpi_consoles_delayed_mutex); > > +} > > + > > /* > > * The console driver calls this routine during kernel initialization > > * to register the console printing procedure with printk() and to > > @@ -2538,8 +2557,30 @@ void register_console(struct console *newcon) > > break; > > } > > > > - if (!(newcon->flags & CON_ENABLED)) > > - return; > > + if (!(newcon->flags & CON_ENABLED)) { > > + char *opts; > > + int err; > > + > > + if (newcon->index < 0) > > + newcon->index = 0; > > + > > + err = console_acpi_match(newcon, &opts); > > + > > + if (err == -EAGAIN) { > > + mutex_lock(&acpi_consoles_delayed_mutex); > > + newcon->next = acpi_consoles_delayed; > > + acpi_consoles_delayed = newcon; > > + mutex_unlock(&acpi_consoles_delayed_mutex); > > + return; > > + } else if (err < 0) { > > + return; > > + } else { > > + if (newcon->setup && newcon->setup(newcon, opts) != 0) > > + return; > > + newcon->flags |= CON_ENABLED | CON_CONSDEV; > > + preferred_console = true; > > + } > > + } > > > > /* > > * If we have a bootconsole, and are switching to a real console, > > @@ -2612,34 +2653,41 @@ void register_console(struct console *newcon) > > } > > EXPORT_SYMBOL(register_console); > > > > +static int delete_from_console_list(struct console **list, struct console *c) > > +{ > > + while (*list) { > > + struct console *cur = *list; > > + > > + if (cur == c) { > > + *list = cur->next; > > + return 0; > > + } > > + list = &cur->next; > > + } > > + return 1; > > +} > > + > > int unregister_console(struct console *console) > > { > > - struct console *a, *b; > > int res; > > > > pr_info("%sconsole [%s%d] disabled\n", > > (console->flags & CON_BOOT) ? "boot" : "" , > > console->name, console->index); > > > > + mutex_lock(&acpi_consoles_delayed_mutex); > > + res = delete_from_console_list(&acpi_consoles_delayed, console); > > + mutex_unlock(&acpi_consoles_delayed_mutex); > > + if (res == 0) > > + return res; > > + > > res = _braille_unregister_console(console); > > if (res) > > return res; > > > > - res = 1; > > console_lock(); > > - if (console_drivers == console) { > > - console_drivers=console->next; > > - res = 0; > > - } else if (console_drivers) { > > - for (a=console_drivers->next, b=console_drivers ; > > - a; b=a, a=b->next) { > > - if (a == console) { > > - b->next = a->next; > > - res = 0; > > - break; > > - } > > - } > > - } > > + > > + res = delete_from_console_list(&console_drivers, console); > > > > if (!res && (console->flags & CON_EXTENDED)) > > nr_ext_console_drivers--; > > -- > > 2.7.0 > > > > > > _______________________________________________ > > linux-arm-kernel mailing list > > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
