| Message ID | 1441716217-23786-5-git-send-email-leif.lindholm@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 2015-09-08 at 13:43 +0100, Leif Lindholm wrote: > From: Torez Smith <torez@redhat.com> > > If console= is not added to the kernel command line, the console > is not registered until much further into the booting process. This patch > adds support to parse the SPCR ACPI table to pull console support out, > then use the appropriate drivers to set up console support earlier in the > boot process. > > Signed-off-by: Jon Masters <jcm@redhat.com> > [rebased and cleaned up] > Signed-off-by: Torez Smith <torez@redhat.com> > [reworked to use _CRS, moved to drivers/acpi] > Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org> > --- > drivers/acpi/console.c | 157 +++++++++++++++++++++++++++++++++++++++ > drivers/tty/serial/serial_core.c | 14 +++- > include/linux/acpi.h | 11 ++- > 3 files changed, 179 insertions(+), 3 deletions(-) > > diff --git a/drivers/acpi/console.c b/drivers/acpi/console.c > index a985890..02883a1 100644 > --- a/drivers/acpi/console.c > +++ b/drivers/acpi/console.c > @@ -1,5 +1,6 @@ > /* > * Copyright (c) 2012, Intel Corporation > + * Copyright (c) 2015, Red Hat, Inc. > * Copyright (c) 2015, Linaro Ltd. > * > * This program is free software; you can redistribute it and/or modify > @@ -12,11 +13,17 @@ > #define pr_fmt(fmt) "ACPI: " KBUILD_MODNAME ": " fmt > > #include <linux/acpi.h> > +#include <linux/console.h> > #include <linux/kernel.h> > #include <linux/serial_core.h> > +#include <linux/tty.h> > > #define NUM_ELEMS(x) (sizeof(x) / sizeof(*x)) > > +static u64 acpi_serial_addr; > +static struct acpi_device *acpi_serial_device; > +static char *acpi_serial_options; > + > #ifdef CONFIG_SERIAL_EARLYCON > static int use_earlycon __initdata; > static int __init setup_acpi_earlycon(char *buf) > @@ -101,3 +108,153 @@ int __init acpi_early_console_probe(void) > return 0; > } > #endif /* CONFIG_SERIAL_EARLYCON */ > + > +/* > + * Parse the SPCR table. If we are not working with version 2 or > + * higher, bail. > + * Otherwise, pull out the baud rate and address to the console device. > + */ > +static int __init acpi_parse_spcr(struct acpi_table_header *table) > +{ > + struct acpi_table_spcr *spcr = (struct acpi_table_spcr *)table; > + > + if (table->revision < 2) > + return -EOPNOTSUPP; > + > + /* Handle possible alignment issues */ > + memcpy(&acpi_serial_addr, > + &spcr->serial_port.address, sizeof(acpi_serial_addr)); > + > + /* > + * The baud rate the BIOS used for redirection. Valid values are.... > + * 3 = 9600 > + * 4 = 19200 > + * 6 = 57600 > + * 7 = 115200 > + * 0-2, 5, 8 - 255 = reserved > + */ > + switch (spcr->baud_rate) { > + case 3: > + acpi_serial_options = "9600"; > + break; > + case 4: > + acpi_serial_options = "19200"; > + break; > + case 6: > + acpi_serial_options = "57600"; > + break; > + case 7: > + acpi_serial_options = "115200"; > + break; > + default: > + acpi_serial_options = ""; > + break; > + } > + > + pr_info("SPCR serial device: 0x%llx (options: %s)\n", > + acpi_serial_addr, acpi_serial_options); > + > + return 0; > +} > + > +/* > + * Parse an ACPI "Device" to determine if it represents the > + * data found in the SPCR table. If the associated Device has > + * and Address entry, and, that Address matches the one found > + * in our SPCR table, it's the entry we are interested in. > + * > + */ > +static acpi_status acpi_spcr_device_scan(acpi_handle handle, > + u32 level, void *context, void **retv) > +{ > + unsigned long long addr = 0; > + struct acpi_buffer name_buffer = { ACPI_ALLOCATE_BUFFER, NULL }; > + acpi_status status = AE_OK; > + struct acpi_device *adev; > + struct list_head resource_list; > + struct resource_entry *rentry; > + > + status = acpi_get_name(handle, ACPI_FULL_PATHNAME, &name_buffer); > + if (ACPI_FAILURE(status)) > + return status; > + acpi_get_name() is asked to allocate a buffer for the name, but that buffer doesn't get freed below. The name is only used in the pr_info call, so the acpi_get_name() call should probably be moved inside that if block and a kfree(name_buffer.pointer) added. > + adev = acpi_bus_get_acpi_device(handle); > + if (!adev) { > + pr_err("Err locating SPCR device from ACPI handle\n"); > + return AE_OK; /* skip this one */ > + } > + > + /* > + * Read device address from _CRS. > + */ > + INIT_LIST_HEAD(&resource_list); > + if (acpi_dev_get_resources(adev, &resource_list, NULL, NULL) <= 0) > + return AE_OK; > + > + list_for_each_entry(rentry, &resource_list, node) { > + if (resource_type(rentry->res) == IORESOURCE_MEM) > + addr = rentry->res->start; > + } > + acpi_dev_free_resource_list(&resource_list); > + > + if (addr == acpi_serial_addr) { > + acpi_serial_device = adev; > + > + pr_info("SPCR serial console: %s (0x%llx)\n", > + (char *)(name_buffer.pointer), addr); > + > + return AE_OK; /* harmless to continue */ > + } > + > + /* continue */ > + return AE_OK; /* continue */ > +} > + > +static int __init acpi_setup_spcr(void) > +{ > + if (0 != acpi_table_parse(ACPI_SIG_SPCR, acpi_parse_spcr)) { > + pr_warn("SPCR table not found - auto console disabled\n"); > + return -ENODEV; > + } > + > + acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, > + ACPI_UINT32_MAX, acpi_spcr_device_scan, > + NULL, NULL, NULL); > + > + return 0; > +} > + > +static int __init acpi_spcr_setup(void) > +{ > + /* > + * If ACPI is enabled, scan the tables for > + * automatic console configuration > + */ > + if (!acpi_disabled) > + acpi_setup_spcr(); > + > + return 0; > +} > +subsys_initcall_sync(acpi_spcr_setup); > + > +/** > + * acpi_console_check() - Check for and configure console from ACPI information > + * @adev - Pointer to device > + * @name - Name to use for preferred console without index. ex. "ttyS" > + * @index - Index to use for preferred console. > + * > + * Check if the given device matches the information provided in the SPCR table > + * If it does then register it as the preferred console and return TRUE. > + * Otherwise return FALSE. > + */ > +bool acpi_console_check(struct acpi_device *adev, char *name, int index) > +{ > + if (acpi_disabled || !adev || adev != acpi_serial_device > + || console_set_on_cmdline) > + return false; > + > + pr_info("adding preferred console [%s]\n", name); > + > + return !add_preferred_console(name, index, > + kstrdup(acpi_serial_options, GFP_KERNEL)); > +} > diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c > index 603d2cc..4b20bc6 100644 > --- a/drivers/tty/serial/serial_core.c > +++ b/drivers/tty/serial/serial_core.c > @@ -34,6 +34,7 @@ > #include <linux/serial_core.h> > #include <linux/delay.h> > #include <linux/mutex.h> > +#include <linux/acpi.h> > > #include <asm/irq.h> > #include <asm/uaccess.h> > @@ -2696,9 +2697,18 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport) > spin_lock_init(&uport->lock); > lockdep_set_class(&uport->lock, &port_lock_key); > } > - if (uport->cons && uport->dev) > - of_console_check(uport->dev->of_node, uport->cons->name, uport->line); > > + /* > + * Support both open FW and ACPI access to console definitions. > + * Both of_console_check() and acpi_console_check() will call > + * add_preferred_console() if a console definition is found. > + */ > + if (uport->cons && uport->dev) { > + if (!acpi_console_check(ACPI_COMPANION(uport->dev), > + uport->cons->name, uport->line)) > + of_console_check(uport->dev->of_node, > + uport->cons->name, uport->line); > + } > uart_configure_port(drv, state, uport); > > num_groups = 2; > diff --git a/include/linux/acpi.h b/include/linux/acpi.h > index 88cb9c1..f1b9a64 100644 > --- a/include/linux/acpi.h > +++ b/include/linux/acpi.h > @@ -811,8 +811,17 @@ static inline struct acpi_device *acpi_get_next_child(struct device *dev, > > #endif > > -#if defined(CONFIG_ACPI) && defined(CONFIG_SERIAL_EARLYCON) > +#if defined(CONFIG_ACPI) > +# if defined(CONFIG_SERIAL_EARLYCON) > int __init acpi_early_console_probe(void); > +# endif > +bool acpi_console_check(struct acpi_device *adev, char *name, int index); > +#else > +static inline bool acpi_console_check(struct acpi_device *adev, char *name, > + int index) > +{ > + return FALSE; > +} > #endif > > #endif /*_LINUX_ACPI_H*/
diff --git a/drivers/acpi/console.c b/drivers/acpi/console.c index a985890..02883a1 100644 --- a/drivers/acpi/console.c +++ b/drivers/acpi/console.c @@ -1,5 +1,6 @@ /* * Copyright (c) 2012, Intel Corporation + * Copyright (c) 2015, Red Hat, Inc. * Copyright (c) 2015, Linaro Ltd. * * This program is free software; you can redistribute it and/or modify @@ -12,11 +13,17 @@ #define pr_fmt(fmt) "ACPI: " KBUILD_MODNAME ": " fmt #include <linux/acpi.h> +#include <linux/console.h> #include <linux/kernel.h> #include <linux/serial_core.h> +#include <linux/tty.h> #define NUM_ELEMS(x) (sizeof(x) / sizeof(*x)) +static u64 acpi_serial_addr; +static struct acpi_device *acpi_serial_device; +static char *acpi_serial_options; + #ifdef CONFIG_SERIAL_EARLYCON static int use_earlycon __initdata; static int __init setup_acpi_earlycon(char *buf) @@ -101,3 +108,153 @@ int __init acpi_early_console_probe(void) return 0; } #endif /* CONFIG_SERIAL_EARLYCON */ + +/* + * Parse the SPCR table. If we are not working with version 2 or + * higher, bail. + * Otherwise, pull out the baud rate and address to the console device. + */ +static int __init acpi_parse_spcr(struct acpi_table_header *table) +{ + struct acpi_table_spcr *spcr = (struct acpi_table_spcr *)table; + + if (table->revision < 2) + return -EOPNOTSUPP; + + /* Handle possible alignment issues */ + memcpy(&acpi_serial_addr, + &spcr->serial_port.address, sizeof(acpi_serial_addr)); + + /* + * The baud rate the BIOS used for redirection. Valid values are.... + * 3 = 9600 + * 4 = 19200 + * 6 = 57600 + * 7 = 115200 + * 0-2, 5, 8 - 255 = reserved + */ + switch (spcr->baud_rate) { + case 3: + acpi_serial_options = "9600"; + break; + case 4: + acpi_serial_options = "19200"; + break; + case 6: + acpi_serial_options = "57600"; + break; + case 7: + acpi_serial_options = "115200"; + break; + default: + acpi_serial_options = ""; + break; + } + + pr_info("SPCR serial device: 0x%llx (options: %s)\n", + acpi_serial_addr, acpi_serial_options); + + return 0; +} + +/* + * Parse an ACPI "Device" to determine if it represents the + * data found in the SPCR table. If the associated Device has + * and Address entry, and, that Address matches the one found + * in our SPCR table, it's the entry we are interested in. + * + */ +static acpi_status acpi_spcr_device_scan(acpi_handle handle, + u32 level, void *context, void **retv) +{ + unsigned long long addr = 0; + struct acpi_buffer name_buffer = { ACPI_ALLOCATE_BUFFER, NULL }; + acpi_status status = AE_OK; + struct acpi_device *adev; + struct list_head resource_list; + struct resource_entry *rentry; + + status = acpi_get_name(handle, ACPI_FULL_PATHNAME, &name_buffer); + if (ACPI_FAILURE(status)) + return status; + + adev = acpi_bus_get_acpi_device(handle); + if (!adev) { + pr_err("Err locating SPCR device from ACPI handle\n"); + return AE_OK; /* skip this one */ + } + + /* + * Read device address from _CRS. + */ + INIT_LIST_HEAD(&resource_list); + if (acpi_dev_get_resources(adev, &resource_list, NULL, NULL) <= 0) + return AE_OK; + + list_for_each_entry(rentry, &resource_list, node) { + if (resource_type(rentry->res) == IORESOURCE_MEM) + addr = rentry->res->start; + } + acpi_dev_free_resource_list(&resource_list); + + if (addr == acpi_serial_addr) { + acpi_serial_device = adev; + + pr_info("SPCR serial console: %s (0x%llx)\n", + (char *)(name_buffer.pointer), addr); + + return AE_OK; /* harmless to continue */ + } + + /* continue */ + return AE_OK; /* continue */ +} + +static int __init acpi_setup_spcr(void) +{ + if (0 != acpi_table_parse(ACPI_SIG_SPCR, acpi_parse_spcr)) { + pr_warn("SPCR table not found - auto console disabled\n"); + return -ENODEV; + } + + acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, + ACPI_UINT32_MAX, acpi_spcr_device_scan, + NULL, NULL, NULL); + + return 0; +} + +static int __init acpi_spcr_setup(void) +{ + /* + * If ACPI is enabled, scan the tables for + * automatic console configuration + */ + if (!acpi_disabled) + acpi_setup_spcr(); + + return 0; +} +subsys_initcall_sync(acpi_spcr_setup); + +/** + * acpi_console_check() - Check for and configure console from ACPI information + * @adev - Pointer to device + * @name - Name to use for preferred console without index. ex. "ttyS" + * @index - Index to use for preferred console. + * + * Check if the given device matches the information provided in the SPCR table + * If it does then register it as the preferred console and return TRUE. + * Otherwise return FALSE. + */ +bool acpi_console_check(struct acpi_device *adev, char *name, int index) +{ + if (acpi_disabled || !adev || adev != acpi_serial_device + || console_set_on_cmdline) + return false; + + pr_info("adding preferred console [%s]\n", name); + + return !add_preferred_console(name, index, + kstrdup(acpi_serial_options, GFP_KERNEL)); +} diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 603d2cc..4b20bc6 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -34,6 +34,7 @@ #include <linux/serial_core.h> #include <linux/delay.h> #include <linux/mutex.h> +#include <linux/acpi.h> #include <asm/irq.h> #include <asm/uaccess.h> @@ -2696,9 +2697,18 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport) spin_lock_init(&uport->lock); lockdep_set_class(&uport->lock, &port_lock_key); } - if (uport->cons && uport->dev) - of_console_check(uport->dev->of_node, uport->cons->name, uport->line); + /* + * Support both open FW and ACPI access to console definitions. + * Both of_console_check() and acpi_console_check() will call + * add_preferred_console() if a console definition is found. + */ + if (uport->cons && uport->dev) { + if (!acpi_console_check(ACPI_COMPANION(uport->dev), + uport->cons->name, uport->line)) + of_console_check(uport->dev->of_node, + uport->cons->name, uport->line); + } uart_configure_port(drv, state, uport); num_groups = 2; diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 88cb9c1..f1b9a64 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -811,8 +811,17 @@ static inline struct acpi_device *acpi_get_next_child(struct device *dev, #endif -#if defined(CONFIG_ACPI) && defined(CONFIG_SERIAL_EARLYCON) +#if defined(CONFIG_ACPI) +# if defined(CONFIG_SERIAL_EARLYCON) int __init acpi_early_console_probe(void); +# endif +bool acpi_console_check(struct acpi_device *adev, char *name, int index); +#else +static inline bool acpi_console_check(struct acpi_device *adev, char *name, + int index) +{ + return FALSE; +} #endif #endif /*_LINUX_ACPI_H*/