From 879eb9c3f9b854394c5a2014b9243c00eaa329f0 Mon Sep 17 00:00:00 2001 From: Huang Shijie Date: Wed, 23 Apr 2014 09:58:25 -0500 Subject: tty_ldisc: add more limits to the @write_wakeup In the uart_handle_cts_change(), uart_write_wakeup() is called after we call @uart_port->ops->start_tx(). The Documentation/serial/driver tells us: ----------------------------------------------- start_tx(port) Start transmitting characters. Locking: port->lock taken. Interrupts: locally disabled. ----------------------------------------------- So when the uart_write_wakeup() is called, the port->lock is taken by the upper. See the following callstack: |_ uart_write_wakeup |_ tty_wakeup |_ ld->ops->write_wakeup With the port->lock held, we call the @write_wakeup. Some implemetation of the @write_wakeup does not notice that the port->lock is held, and it still tries to send data with uart_write() which will try to grab the prot->lock. A dead lock occurs, see the following log caught in the Bluetooth by uart: -------------------------------------------------------------------- BUG: spinlock lockup suspected on CPU#0, swapper/0/0 lock: 0xdc3f4410, .magic: dead4ead, .owner: swapper/0/0, .owner_cpu: 0 CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 3.10.17-16839-ge4a1bef #1320 [<80014cbc>] (unwind_backtrace+0x0/0x138) from [<8001251c>] (show_stack+0x10/0x14) [<8001251c>] (show_stack+0x10/0x14) from [<802816ac>] (do_raw_spin_lock+0x108/0x184) [<802816ac>] (do_raw_spin_lock+0x108/0x184) from [<806a22b0>] (_raw_spin_lock_irqsave+0x54/0x60) [<806a22b0>] (_raw_spin_lock_irqsave+0x54/0x60) from [<802f5754>] (uart_write+0x38/0xe0) [<802f5754>] (uart_write+0x38/0xe0) from [<80455270>] (hci_uart_tx_wakeup+0xa4/0x168) [<80455270>] (hci_uart_tx_wakeup+0xa4/0x168) from [<802dab18>] (tty_wakeup+0x50/0x5c) [<802dab18>] (tty_wakeup+0x50/0x5c) from [<802f81a4>] (imx_rtsint+0x50/0x80) [<802f81a4>] (imx_rtsint+0x50/0x80) from [<802f88f4>] (imx_int+0x158/0x17c) [<802f88f4>] (imx_int+0x158/0x17c) from [<8007abe0>] (handle_irq_event_percpu+0x50/0x194) [<8007abe0>] (handle_irq_event_percpu+0x50/0x194) from [<8007ad60>] (handle_irq_event+0x3c/0x5c) -------------------------------------------------------------------- This patch adds more limits to the @write_wakeup, the one who wants to implemet the @write_wakeup should follow the limits which avoid the deadlock. Signed-off-by: Huang Shijie Signed-off-by: Felipe Balbi Signed-off-by: Greg Kroah-Hartman --- include/linux/tty_ldisc.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/tty_ldisc.h b/include/linux/tty_ldisc.h index add26da2faeb..00c9d688d7b7 100644 --- a/include/linux/tty_ldisc.h +++ b/include/linux/tty_ldisc.h @@ -92,7 +92,10 @@ * This function is called by the low-level tty driver to signal * that line discpline should try to send more characters to the * low-level driver for transmission. If the line discpline does - * not have any more data to send, it can just return. + * not have any more data to send, it can just return. If the line + * discipline does have some data to send, please arise a tasklet + * or workqueue to do the real data transfer. Do not send data in + * this hook, it may leads to a deadlock. * * int (*hangup)(struct tty_struct *) * -- cgit v1.3.1 From 9aac5887595b765b6f64b2af08b785e82e095b57 Mon Sep 17 00:00:00 2001 From: Rob Herring Date: Fri, 18 Apr 2014 17:19:55 -0500 Subject: tty/serial: add generic serial earlycon This introduces generic earlycon infrastructure for serial devices based on the 8250 earlycon. This allows for supporting earlycon option with other serial devices. The earlycon output is enabled at the time early_params are processed. Only architectures that have fixmap support or have functional ioremap when early_params are processed are supported. This is the same restriction that the 8250 driver had. Signed-off-by: Rob Herring Cc: Jiri Slaby Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/Kconfig | 7 ++ drivers/tty/serial/Makefile | 2 + drivers/tty/serial/earlycon.c | 152 ++++++++++++++++++++++++++++++++++++++++++ include/linux/serial_core.h | 16 +++++ 4 files changed, 177 insertions(+) create mode 100644 drivers/tty/serial/earlycon.c (limited to 'include/linux') diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index 30530e47cdf0..9fb6028ad900 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -7,6 +7,13 @@ if TTY menu "Serial drivers" depends on HAS_IOMEM +config SERIAL_EARLYCON + bool + help + Support for early consoles with the earlycon parameter. This enables + the console before standard serial driver is probed. The console is + enabled when early_param is processed. + source "drivers/tty/serial/8250/Kconfig" comment "Non-8250 serial port support" diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile index 5f2a3f493ab9..28048178f308 100644 --- a/drivers/tty/serial/Makefile +++ b/drivers/tty/serial/Makefile @@ -5,6 +5,8 @@ obj-$(CONFIG_SERIAL_CORE) += serial_core.o obj-$(CONFIG_SERIAL_21285) += 21285.o +obj-$(CONFIG_SERIAL_EARLYCON) += earlycon.o + # These Sparc drivers have to appear before others such as 8250 # which share ttySx minor node space. Otherwise console device # names change and other unplesantries. diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c new file mode 100644 index 000000000000..73bf1e21aae0 --- /dev/null +++ b/drivers/tty/serial/earlycon.c @@ -0,0 +1,152 @@ +/* + * Copyright (C) 2014 Linaro Ltd. + * Author: Rob Herring + * + * Based on 8250 earlycon: + * (c) Copyright 2004 Hewlett-Packard Development Company, L.P. + * Bjorn Helgaas + * + * 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. + */ +#include +#include +#include +#include +#include + +#ifdef CONFIG_FIX_EARLYCON_MEM +#include +#endif + +#include + +static struct console early_con = { + .name = "earlycon", + .flags = CON_PRINTBUFFER | CON_BOOT, + .index = -1, +}; + +static struct earlycon_device early_console_dev = { + .con = &early_con, +}; + +static void __iomem * __init earlycon_map(unsigned long paddr, size_t size) +{ + void __iomem *base; +#ifdef CONFIG_FIX_EARLYCON_MEM + set_fixmap_io(FIX_EARLYCON_MEM_BASE, paddr & PAGE_MASK); + base = (void __iomem *)__fix_to_virt(FIX_EARLYCON_MEM_BASE); + base += paddr & ~PAGE_MASK; +#else + base = ioremap(paddr, size); +#endif + if (!base) + pr_err("%s: Couldn't map 0x%llx\n", __func__, + (unsigned long long)paddr); + + return base; +} + +static int __init parse_options(struct earlycon_device *device, + char *options) +{ + struct uart_port *port = &device->port; + int mmio, mmio32, length, ret; + unsigned long addr; + + if (!options) + return -ENODEV; + + mmio = !strncmp(options, "mmio,", 5); + mmio32 = !strncmp(options, "mmio32,", 7); + if (mmio || mmio32) { + port->iotype = (mmio ? UPIO_MEM : UPIO_MEM32); + options += mmio ? 5 : 7; + ret = kstrtoul(options, 0, &addr); + if (ret) + return ret; + port->mapbase = addr; + if (mmio32) + port->regshift = 2; + } else if (!strncmp(options, "io,", 3)) { + port->iotype = UPIO_PORT; + options += 3; + ret = kstrtoul(options, 0, &addr); + if (ret) + return ret; + port->iobase = addr; + mmio = 0; + } else if (!strncmp(options, "0x", 2)) { + port->iotype = UPIO_MEM; + ret = kstrtoul(options, 0, &addr); + if (ret) + return ret; + port->mapbase = addr; + } else { + return -EINVAL; + } + + port->uartclk = BASE_BAUD * 16; + + options = strchr(options, ','); + if (options) { + options++; + ret = kstrtouint(options, 0, &device->baud); + if (ret) + return ret; + length = min(strcspn(options, " ") + 1, + (size_t)(sizeof(device->options))); + strlcpy(device->options, options, length); + } + + if (mmio || mmio32) + pr_info("Early serial console at MMIO%s 0x%llx (options '%s')\n", + mmio32 ? "32" : "", + (unsigned long long)port->mapbase, + device->options); + else + pr_info("Early serial console at I/O port 0x%lx (options '%s')\n", + port->iobase, + device->options); + + return 0; +} + +int __init setup_earlycon(char *buf, const char *match, + int (*setup)(struct earlycon_device *, const char *)) +{ + int err; + size_t len; + struct uart_port *port = &early_console_dev.port; + + if (!buf || !match || !setup) + return 0; + + len = strlen(match); + if (strncmp(buf, match, len)) + return 0; + if (buf[len] && (buf[len] != ',')) + return 0; + + buf += len + 1; + + err = parse_options(&early_console_dev, buf); + /* On parsing error, pass the options buf to the setup function */ + if (!err) + buf = NULL; + + if (port->mapbase) + port->membase = earlycon_map(port->mapbase, 64); + + early_console_dev.con->data = &early_console_dev; + err = setup(&early_console_dev, buf); + if (err < 0) + return err; + if (!early_console_dev.con->write) + return -ENODEV; + + register_console(early_console_dev.con); + return 0; +} diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index f729be981da0..7a15b5b24c0b 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -285,6 +285,22 @@ static inline int uart_poll_timeout(struct uart_port *port) /* * Console helpers. */ +struct earlycon_device { + struct console *con; + struct uart_port port; + char options[16]; /* e.g., 115200n8 */ + unsigned int baud; +}; +int setup_earlycon(char *buf, const char *match, + int (*setup)(struct earlycon_device *, const char *)); + +#define EARLYCON_DECLARE(name, func) \ +static int __init name ## _setup_earlycon(char *buf) \ +{ \ + return setup_earlycon(buf, __stringify(name), func); \ +} \ +early_param("earlycon", name ## _setup_earlycon); + struct uart_port *uart_get_console(struct uart_port *ports, int nr, struct console *c); void uart_parse_options(char *options, int *baud, int *parity, int *bits, -- cgit v1.3.1 From 9dd3107576c4bbd40e1c2c8b24d560abf9a7b991 Mon Sep 17 00:00:00 2001 From: Rob Herring Date: Thu, 8 May 2014 16:06:17 -0500 Subject: of: align RESERVEDMEM_OF_DECLARE function callbacks to other callbacks All the parameters for RESERVEDMEM_OF_DECLARE function callbacks are members of struct reserved_mem, so just pass the struct ptr to callback functions so the function callback is more in line with other OF match table callbacks. Acked-by: Marek Szyprowski Acked-by: Grant Likely Signed-off-by: Rob Herring --- drivers/of/of_reserved_mem.c | 2 +- include/linux/of_reserved_mem.h | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c index e420eb52e5c9..632aae861375 100644 --- a/drivers/of/of_reserved_mem.c +++ b/drivers/of/of_reserved_mem.c @@ -188,7 +188,7 @@ static int __init __reserved_mem_init_node(struct reserved_mem *rmem) if (!of_flat_dt_is_compatible(rmem->fdt_node, compat)) continue; - if (initfn(rmem, rmem->fdt_node, rmem->name) == 0) { + if (initfn(rmem) == 0) { pr_info("Reserved memory: initialized node %s, compatible id %s\n", rmem->name, compat); return 0; diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_mem.h index 9b1fbb7f29fc..4c81b84e95ff 100644 --- a/include/linux/of_reserved_mem.h +++ b/include/linux/of_reserved_mem.h @@ -21,8 +21,8 @@ struct reserved_mem_ops { struct device *dev); }; -typedef int (*reservedmem_of_init_fn)(struct reserved_mem *rmem, - unsigned long node, const char *uname); +typedef int (*reservedmem_of_init_fn)(struct reserved_mem *rmem); + #ifdef CONFIG_OF_RESERVED_MEM void fdt_init_reserved_mem(void); -- cgit v1.3.1 From 54196ccbe0ba1f268a646059473313589db35b01 Mon Sep 17 00:00:00 2001 From: Rob Herring Date: Thu, 8 May 2014 16:09:24 -0500 Subject: of: consolidate linker section OF match table declarations We now have several OF match tables using linker sections that are nearly the same definition. The only variation is the callback function prototype. Create a common define for creating linker section OF match table entries which each table declaration can use. Acked-by: Grant Likely Signed-off-by: Rob Herring --- drivers/clocksource/clksrc-of.c | 2 +- drivers/irqchip/irqchip.h | 7 +++---- include/linux/clk-provider.h | 5 +---- include/linux/clocksource.h | 16 +++------------- include/linux/of.h | 22 ++++++++++++++++++++++ include/linux/of_reserved_mem.h | 18 ++---------------- 6 files changed, 32 insertions(+), 38 deletions(-) (limited to 'include/linux') diff --git a/drivers/clocksource/clksrc-of.c b/drivers/clocksource/clksrc-of.c index ae2e4278c42a..0093a8e49e14 100644 --- a/drivers/clocksource/clksrc-of.c +++ b/drivers/clocksource/clksrc-of.c @@ -27,7 +27,7 @@ void __init clocksource_of_init(void) { struct device_node *np; const struct of_device_id *match; - clocksource_of_init_fn init_func; + of_init_fn_1 init_func; unsigned clocksources = 0; for_each_matching_node_and_match(np, __clksrc_of_table, &match) { diff --git a/drivers/irqchip/irqchip.h b/drivers/irqchip/irqchip.h index e445ba2d6add..0f6486d4f1b0 100644 --- a/drivers/irqchip/irqchip.h +++ b/drivers/irqchip/irqchip.h @@ -11,6 +11,8 @@ #ifndef _IRQCHIP_H #define _IRQCHIP_H +#include + /* * This macro must be used by the different irqchip drivers to declare * the association between their DT compatible string and their @@ -21,9 +23,6 @@ * @compstr: compatible string of the irqchip driver * @fn: initialization function */ -#define IRQCHIP_DECLARE(name,compstr,fn) \ - static const struct of_device_id irqchip_of_match_##name \ - __used __section(__irqchip_of_table) \ - = { .compatible = compstr, .data = fn } +#define IRQCHIP_DECLARE(name, compat, fn) OF_DECLARE_2(irqchip, name, compat, fn) #endif diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 511917416fb0..a6e4008a0bf7 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -498,10 +498,7 @@ struct clk_onecell_data { extern struct of_device_id __clk_of_table; -#define CLK_OF_DECLARE(name, compat, fn) \ - static const struct of_device_id __clk_of_table_##name \ - __used __section(__clk_of_table) \ - = { .compatible = compat, .data = fn }; +#define CLK_OF_DECLARE(name, compat, fn) OF_DECLARE_1(clk, name, compat, fn) #ifdef CONFIG_OF int of_clk_add_provider(struct device_node *np, diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 67301a405712..a16b497d5159 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -339,23 +339,13 @@ extern int clocksource_mmio_init(void __iomem *, const char *, extern int clocksource_i8253_init(void); -struct device_node; -typedef void(*clocksource_of_init_fn)(struct device_node *); +#define CLOCKSOURCE_OF_DECLARE(name, compat, fn) \ + OF_DECLARE_1(clksrc, name, compat, fn) + #ifdef CONFIG_CLKSRC_OF extern void clocksource_of_init(void); - -#define CLOCKSOURCE_OF_DECLARE(name, compat, fn) \ - static const struct of_device_id __clksrc_of_table_##name \ - __used __section(__clksrc_of_table) \ - = { .compatible = compat, \ - .data = (fn == (clocksource_of_init_fn)NULL) ? fn : fn } #else static inline void clocksource_of_init(void) {} -#define CLOCKSOURCE_OF_DECLARE(name, compat, fn) \ - static const struct of_device_id __clksrc_of_table_##name \ - __attribute__((unused)) \ - = { .compatible = compat, \ - .data = (fn == (clocksource_of_init_fn)NULL) ? fn : fn } #endif #endif /* _LINUX_CLOCKSOURCE_H */ diff --git a/include/linux/of.h b/include/linux/of.h index 3bad8d106e0e..bf65335b4d05 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -757,4 +757,26 @@ static inline int of_get_available_child_count(const struct device_node *np) return num; } +#ifdef CONFIG_OF +#define _OF_DECLARE(table, name, compat, fn, fn_type) \ + static const struct of_device_id __of_table_##name \ + __used __section(__##table##_of_table) \ + = { .compatible = compat, \ + .data = (fn == (fn_type)NULL) ? fn : fn } +#else +#define _OF_DECLARE(table, name, compat, fn, fn_type) \ + static const struct of_device_id __of_table_##name \ + __attribute__((unused)) \ + = { .compatible = compat, \ + .data = (fn == (fn_type)NULL) ? fn : fn } +#endif + +typedef int (*of_init_fn_2)(struct device_node *, struct device_node *); +typedef void (*of_init_fn_1)(struct device_node *); + +#define OF_DECLARE_1(table, name, compat, fn) \ + _OF_DECLARE(table, name, compat, fn, of_init_fn_1) +#define OF_DECLARE_2(table, name, compat, fn) \ + _OF_DECLARE(table, name, compat, fn, of_init_fn_2) + #endif /* _LINUX_OF_H */ diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_mem.h index 4c81b84e95ff..4669ddfdd5af 100644 --- a/include/linux/of_reserved_mem.h +++ b/include/linux/of_reserved_mem.h @@ -23,31 +23,17 @@ struct reserved_mem_ops { typedef int (*reservedmem_of_init_fn)(struct reserved_mem *rmem); +#define RESERVEDMEM_OF_DECLARE(name, compat, init) \ + _OF_DECLARE(reservedmem, name, compat, init, reservedmem_of_init_fn) #ifdef CONFIG_OF_RESERVED_MEM void fdt_init_reserved_mem(void); void fdt_reserved_mem_save_node(unsigned long node, const char *uname, phys_addr_t base, phys_addr_t size); - -#define RESERVEDMEM_OF_DECLARE(name, compat, init) \ - static const struct of_device_id __reservedmem_of_table_##name \ - __used __section(__reservedmem_of_table) \ - = { .compatible = compat, \ - .data = (init == (reservedmem_of_init_fn)NULL) ? \ - init : init } - #else static inline void fdt_init_reserved_mem(void) { } static inline void fdt_reserved_mem_save_node(unsigned long node, const char *uname, phys_addr_t base, phys_addr_t size) { } - -#define RESERVEDMEM_OF_DECLARE(name, compat, init) \ - static const struct of_device_id __reservedmem_of_table_##name \ - __attribute__((unused)) \ - = { .compatible = compat, \ - .data = (init == (reservedmem_of_init_fn)NULL) ? \ - init : init } - #endif #endif /* __OF_RESERVED_MEM_H */ -- cgit v1.3.1 From b0b6abd34c1b508d4ac95dbc614f36c49d29e65a Mon Sep 17 00:00:00 2001 From: Rob Herring Date: Thu, 27 Mar 2014 08:06:16 -0500 Subject: serial: earlycon: add DT support This adds the infrastructure to generic earlycon for earlycon setup using DT. The actual setup is not enabled until a following commit to add the FDT parsing. Signed-off-by: Rob Herring Cc: Greg Kroah-Hartman Cc: Jiri Slaby Cc: Arnd Bergmann Acked-by: Grant Likely --- drivers/tty/serial/earlycon.c | 28 ++++++++++++++++++++++++++++ include/asm-generic/vmlinux.lds.h | 4 +++- include/linux/serial_core.h | 6 ++++++ 3 files changed, 37 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c index c92e83088adb..5131b5ee6164 100644 --- a/drivers/tty/serial/earlycon.c +++ b/drivers/tty/serial/earlycon.c @@ -15,6 +15,8 @@ #include #include #include +#include +#include #ifdef CONFIG_FIX_EARLYCON_MEM #include @@ -32,6 +34,9 @@ static struct earlycon_device early_console_dev = { .con = &early_con, }; +static const struct of_device_id __earlycon_of_table_sentinel + __used __section(__earlycon_of_table_end); + static void __iomem * __init earlycon_map(unsigned long paddr, size_t size) { void __iomem *base; @@ -142,3 +147,26 @@ int __init setup_earlycon(char *buf, const char *match, register_console(early_console_dev.con); return 0; } + +int __init of_setup_earlycon(unsigned long addr, + int (*setup)(struct earlycon_device *, const char *)) +{ + int err; + struct uart_port *port = &early_console_dev.port; + + port->iotype = UPIO_MEM; + port->mapbase = addr; + port->uartclk = BASE_BAUD * 16; + port->membase = earlycon_map(addr, SZ_4K); + + early_console_dev.con->data = &early_console_dev; + err = setup(&early_console_dev, NULL); + if (err < 0) + return err; + if (!early_console_dev.con->write) + return -ENODEV; + + + register_console(early_console_dev.con); + return 0; +} diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index b9404f6590f1..d647637cd699 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -155,6 +155,7 @@ #define CLK_OF_TABLES() OF_TABLE(CONFIG_COMMON_CLK, clk) #define RESERVEDMEM_OF_TABLES() OF_TABLE(CONFIG_OF_RESERVED_MEM, reservedmem) #define CPU_METHOD_OF_TABLES() OF_TABLE(CONFIG_SMP, cpu_method) +#define EARLYCON_OF_TABLES() OF_TABLE(CONFIG_SERIAL_EARLYCON, earlycon) #define KERNEL_DTB() \ STRUCT_ALIGN(); \ @@ -483,7 +484,8 @@ CLKSRC_OF_TABLES() \ CPU_METHOD_OF_TABLES() \ KERNEL_DTB() \ - IRQCHIP_OF_MATCH_TABLE() + IRQCHIP_OF_MATCH_TABLE() \ + EARLYCON_OF_TABLES() #define INIT_TEXT \ *(.init.text) \ diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index 7a15b5b24c0b..5bbb809ee197 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -294,6 +294,9 @@ struct earlycon_device { int setup_earlycon(char *buf, const char *match, int (*setup)(struct earlycon_device *, const char *)); +extern int of_setup_earlycon(unsigned long addr, + int (*setup)(struct earlycon_device *, const char *)); + #define EARLYCON_DECLARE(name, func) \ static int __init name ## _setup_earlycon(char *buf) \ { \ @@ -301,6 +304,9 @@ static int __init name ## _setup_earlycon(char *buf) \ } \ early_param("earlycon", name ## _setup_earlycon); +#define OF_EARLYCON_DECLARE(name, compat, fn) \ + _OF_DECLARE(earlycon, name, compat, fn, void *) + struct uart_port *uart_get_console(struct uart_port *ports, int nr, struct console *c); void uart_parse_options(char *options, int *baud, int *parity, int *bits, -- cgit v1.3.1 From e06e8b27082852bdab417af884241a4ed2037c73 Mon Sep 17 00:00:00 2001 From: Rob Herring Date: Thu, 27 Mar 2014 07:37:43 -0500 Subject: of/fdt: add FDT address translation support Copy u-boot's FDT address translation code from common/fdt_support. This code was originally based on the kernel's unflattened DT address parsing code. This commit can be reverted once relicensing of this code to GPLv2/BSD is done and it is added to libfdt. Signed-off-by: Rob Herring Acked-by: Grant Likely --- drivers/of/Makefile | 2 + drivers/of/fdt_address.c | 241 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/of_fdt.h | 1 + 3 files changed, 244 insertions(+) create mode 100644 drivers/of/fdt_address.c (limited to 'include/linux') diff --git a/drivers/of/Makefile b/drivers/of/Makefile index 9891232f999e..099b1fb00af4 100644 --- a/drivers/of/Makefile +++ b/drivers/of/Makefile @@ -1,5 +1,6 @@ obj-y = base.o device.o platform.o obj-$(CONFIG_OF_FLATTREE) += fdt.o +obj-$(CONFIG_OF_EARLY_FLATTREE) += fdt_address.o obj-$(CONFIG_OF_PROMTREE) += pdt.o obj-$(CONFIG_OF_ADDRESS) += address.o obj-$(CONFIG_OF_IRQ) += irq.o @@ -12,3 +13,4 @@ obj-$(CONFIG_OF_MTD) += of_mtd.o obj-$(CONFIG_OF_RESERVED_MEM) += of_reserved_mem.o CFLAGS_fdt.o = -I$(src)/../../scripts/dtc/libfdt +CFLAGS_fdt_address.o = -I$(src)/../../scripts/dtc/libfdt diff --git a/drivers/of/fdt_address.c b/drivers/of/fdt_address.c new file mode 100644 index 000000000000..8d3dc6fbdb7a --- /dev/null +++ b/drivers/of/fdt_address.c @@ -0,0 +1,241 @@ +/* + * FDT Address translation based on u-boot fdt_support.c which in turn was + * based on the kernel unflattened DT address translation code. + * + * (C) Copyright 2007 + * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com + * + * Copyright 2010-2011 Freescale Semiconductor, Inc. + * + * 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, or (at your option) + * any later version. + */ +#include +#include +#include +#include +#include + +/* Max address size we deal with */ +#define OF_MAX_ADDR_CELLS 4 +#define OF_CHECK_COUNTS(na, ns) ((na) > 0 && (na) <= OF_MAX_ADDR_CELLS && \ + (ns) > 0) + +/* Debug utility */ +#ifdef DEBUG +static void __init of_dump_addr(const char *s, const __be32 *addr, int na) +{ + pr_debug("%s", s); + while(na--) + pr_cont(" %08x", *(addr++)); + pr_debug("\n"); +} +#else +static void __init of_dump_addr(const char *s, const __be32 *addr, int na) { } +#endif + +/* Callbacks for bus specific translators */ +struct of_bus { + void (*count_cells)(const void *blob, int parentoffset, + int *addrc, int *sizec); + u64 (*map)(__be32 *addr, const __be32 *range, + int na, int ns, int pna); + int (*translate)(__be32 *addr, u64 offset, int na); +}; + +/* Default translator (generic bus) */ +static void __init fdt_bus_default_count_cells(const void *blob, int parentoffset, + int *addrc, int *sizec) +{ + const __be32 *prop; + + if (addrc) { + prop = fdt_getprop(blob, parentoffset, "#address-cells", NULL); + if (prop) + *addrc = be32_to_cpup(prop); + else + *addrc = dt_root_addr_cells; + } + + if (sizec) { + prop = fdt_getprop(blob, parentoffset, "#size-cells", NULL); + if (prop) + *sizec = be32_to_cpup(prop); + else + *sizec = dt_root_size_cells; + } +} + +static u64 __init fdt_bus_default_map(__be32 *addr, const __be32 *range, + int na, int ns, int pna) +{ + u64 cp, s, da; + + cp = of_read_number(range, na); + s = of_read_number(range + na + pna, ns); + da = of_read_number(addr, na); + + pr_debug("FDT: default map, cp=%llx, s=%llx, da=%llx\n", + cp, s, da); + + if (da < cp || da >= (cp + s)) + return OF_BAD_ADDR; + return da - cp; +} + +static int __init fdt_bus_default_translate(__be32 *addr, u64 offset, int na) +{ + u64 a = of_read_number(addr, na); + memset(addr, 0, na * 4); + a += offset; + if (na > 1) + addr[na - 2] = cpu_to_fdt32(a >> 32); + addr[na - 1] = cpu_to_fdt32(a & 0xffffffffu); + + return 0; +} + +/* Array of bus specific translators */ +static const struct of_bus of_busses[] __initconst = { + /* Default */ + { + .count_cells = fdt_bus_default_count_cells, + .map = fdt_bus_default_map, + .translate = fdt_bus_default_translate, + }, +}; + +static int __init fdt_translate_one(const void *blob, int parent, + const struct of_bus *bus, + const struct of_bus *pbus, __be32 *addr, + int na, int ns, int pna, const char *rprop) +{ + const __be32 *ranges; + int rlen; + int rone; + u64 offset = OF_BAD_ADDR; + + ranges = fdt_getprop(blob, parent, rprop, &rlen); + if (!ranges) + return 1; + if (rlen == 0) { + offset = of_read_number(addr, na); + memset(addr, 0, pna * 4); + pr_debug("FDT: empty ranges, 1:1 translation\n"); + goto finish; + } + + pr_debug("FDT: walking ranges...\n"); + + /* Now walk through the ranges */ + rlen /= 4; + rone = na + pna + ns; + for (; rlen >= rone; rlen -= rone, ranges += rone) { + offset = bus->map(addr, ranges, na, ns, pna); + if (offset != OF_BAD_ADDR) + break; + } + if (offset == OF_BAD_ADDR) { + pr_debug("FDT: not found !\n"); + return 1; + } + memcpy(addr, ranges + na, 4 * pna); + + finish: + of_dump_addr("FDT: parent translation for:", addr, pna); + pr_debug("FDT: with offset: %llx\n", offset); + + /* Translate it into parent bus space */ + return pbus->translate(addr, offset, pna); +} + +/* + * Translate an address from the device-tree into a CPU physical address, + * this walks up the tree and applies the various bus mappings on the + * way. + * + * Note: We consider that crossing any level with #size-cells == 0 to mean + * that translation is impossible (that is we are not dealing with a value + * that can be mapped to a cpu physical address). This is not really specified + * that way, but this is traditionally the way IBM at least do things + */ +u64 __init fdt_translate_address(const void *blob, int node_offset) +{ + int parent, len; + const struct of_bus *bus, *pbus; + const __be32 *reg; + __be32 addr[OF_MAX_ADDR_CELLS]; + int na, ns, pna, pns; + u64 result = OF_BAD_ADDR; + + pr_debug("FDT: ** translation for device %s **\n", + fdt_get_name(blob, node_offset, NULL)); + + reg = fdt_getprop(blob, node_offset, "reg", &len); + if (!reg) { + pr_err("FDT: warning: device tree node '%s' has no address.\n", + fdt_get_name(blob, node_offset, NULL)); + goto bail; + } + + /* Get parent & match bus type */ + parent = fdt_parent_offset(blob, node_offset); + if (parent < 0) + goto bail; + bus = &of_busses[0]; + + /* Cound address cells & copy address locally */ + bus->count_cells(blob, parent, &na, &ns); + if (!OF_CHECK_COUNTS(na, ns)) { + pr_err("FDT: Bad cell count for %s\n", + fdt_get_name(blob, node_offset, NULL)); + goto bail; + } + memcpy(addr, reg, na * 4); + + pr_debug("FDT: bus (na=%d, ns=%d) on %s\n", + na, ns, fdt_get_name(blob, parent, NULL)); + of_dump_addr("OF: translating address:", addr, na); + + /* Translate */ + for (;;) { + /* Switch to parent bus */ + node_offset = parent; + parent = fdt_parent_offset(blob, node_offset); + + /* If root, we have finished */ + if (parent < 0) { + pr_debug("FDT: reached root node\n"); + result = of_read_number(addr, na); + break; + } + + /* Get new parent bus and counts */ + pbus = &of_busses[0]; + pbus->count_cells(blob, parent, &pna, &pns); + if (!OF_CHECK_COUNTS(pna, pns)) { + pr_err("FDT: Bad cell count for %s\n", + fdt_get_name(blob, node_offset, NULL)); + break; + } + + pr_debug("FDT: parent bus (na=%d, ns=%d) on %s\n", + pna, pns, fdt_get_name(blob, parent, NULL)); + + /* Apply bus translation */ + if (fdt_translate_one(blob, node_offset, bus, pbus, + addr, na, ns, pna, "ranges")) + break; + + /* Complete the move up one level */ + na = pna; + ns = pns; + bus = pbus; + + of_dump_addr("FDT: one level translation:", addr, na); + } + bail: + return result; +} diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h index 5c0ab057eecf..05117899fcb4 100644 --- a/include/linux/of_fdt.h +++ b/include/linux/of_fdt.h @@ -83,6 +83,7 @@ extern void unflatten_device_tree(void); extern void unflatten_and_copy_device_tree(void); extern void early_init_devtree(void *); extern void early_get_first_memblock_info(void *, phys_addr_t *); +extern u64 fdt_translate_address(const void *blob, int node_offset); #else /* CONFIG_OF_FLATTREE */ static inline void early_init_fdt_scan_reserved_mem(void) {} static inline const char *of_flat_dt_get_machine_name(void) { return NULL; } -- cgit v1.3.1