diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 11 | ||||
| -rw-r--r-- | drivers/usb/early/ehci-dbgp.c | 120 |
2 files changed, 122 insertions, 9 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 4c44d01c67f4..f5fce483930c 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1127,6 +1127,17 @@ and is between 256 and 4096 characters. It is defined in the file use the HighMem zone if it exists, and the Normal zone if it does not. + kgdbdbgp= [KGDB,HW] kgdb over EHCI usb debug port. + Format: <Controller#>[,poll interval] + The controller # is the number of the ehci usb debug + port as it is probed via PCI. The poll interval is + optional and is the number seconds in between + each poll cycle to the debug port in case you need + the functionality for interrupting the kernel with + gdb or control-c on the dbgp connection. When + not using this parameter you use sysrq-g to break into + the kernel debugger. + kgdboc= [KGDB,HW] kgdb over consoles. Requires a tty driver that supports console polling, or a supported polling keyboard driver (non-usb). diff --git a/drivers/usb/early/ehci-dbgp.c b/drivers/usb/early/ehci-dbgp.c index 6e98a3697844..94ecdbc758ce 100644 --- a/drivers/usb/early/ehci-dbgp.c +++ b/drivers/usb/early/ehci-dbgp.c @@ -19,6 +19,9 @@ #include <linux/usb/ch9.h> #include <linux/usb/ehci_def.h> #include <linux/delay.h> +#include <linux/serial_core.h> +#include <linux/kgdb.h> +#include <linux/kthread.h> #include <asm/io.h> #include <asm/pci-direct.h> #include <asm/fixmap.h> @@ -55,6 +58,7 @@ static struct ehci_regs __iomem *ehci_regs; static struct ehci_dbg_port __iomem *ehci_debug; static int dbgp_not_safe; /* Cannot use debug device during ehci reset */ static unsigned int dbgp_endpoint_out; +static unsigned int dbgp_endpoint_in; struct ehci_dev { u32 bus; @@ -91,6 +95,13 @@ static inline u32 dbgp_len_update(u32 x, u32 len) return (x & ~0x0f) | (len & 0x0f); } +#ifdef CONFIG_KGDB +static struct kgdb_io kgdbdbgp_io_ops; +#define dbgp_kgdb_mode (dbg_io_ops == &kgdbdbgp_io_ops) +#else +#define dbgp_kgdb_mode (0) +#endif + /* * USB Packet IDs (PIDs) */ @@ -182,11 +193,10 @@ static void dbgp_breath(void) /* Sleep to give the debug port a chance to breathe */ } -static int dbgp_wait_until_done(unsigned ctrl) +static int dbgp_wait_until_done(unsigned ctrl, int loop) { u32 pids, lpid; int ret; - int loop = DBGP_LOOPS; retry: writel(ctrl | DBGP_GO, &ehci_debug->control); @@ -276,13 +286,13 @@ static int dbgp_bulk_write(unsigned devnum, unsigned endpoint, dbgp_set_data(bytes, size); writel(addr, &ehci_debug->address); writel(pids, &ehci_debug->pids); - ret = dbgp_wait_until_done(ctrl); + ret = dbgp_wait_until_done(ctrl, DBGP_LOOPS); return ret; } static int dbgp_bulk_read(unsigned devnum, unsigned endpoint, void *data, - int size) + int size, int loops) { u32 pids, addr, ctrl; int ret; @@ -302,7 +312,7 @@ static int dbgp_bulk_read(unsigned devnum, unsigned endpoint, void *data, writel(addr, &ehci_debug->address); writel(pids, &ehci_debug->pids); - ret = dbgp_wait_until_done(ctrl); + ret = dbgp_wait_until_done(ctrl, loops); if (ret < 0) return ret; @@ -343,12 +353,12 @@ static int dbgp_control_msg(unsigned devnum, int requesttype, dbgp_set_data(&req, sizeof(req)); writel(addr, &ehci_debug->address); writel(pids, &ehci_debug->pids); - ret = dbgp_wait_until_done(ctrl); + ret = dbgp_wait_until_done(ctrl, DBGP_LOOPS); if (ret < 0) return ret; /* Read the result */ - return dbgp_bulk_read(devnum, 0, data, size); + return dbgp_bulk_read(devnum, 0, data, size, DBGP_LOOPS); } /* Find a PCI capability */ @@ -559,6 +569,7 @@ try_again: goto err; } dbgp_endpoint_out = dbgp_desc.bDebugOutEndpoint; + dbgp_endpoint_in = dbgp_desc.bDebugInEndpoint; /* Move the device to 127 if it isn't already there */ if (devnum != USB_DEBUG_DEVNUM) { @@ -968,8 +979,9 @@ int dbgp_reset_prep(void) if (!ehci_debug) return 0; - if (early_dbgp_console.index != -1 && - !(early_dbgp_console.flags & CON_BOOT)) + if ((early_dbgp_console.index != -1 && + !(early_dbgp_console.flags & CON_BOOT)) || + dbgp_kgdb_mode) return 1; /* This means the console is not initialized, or should get * shutdown so as to allow for reuse of the usb device, which @@ -982,3 +994,93 @@ int dbgp_reset_prep(void) return 0; } EXPORT_SYMBOL_GPL(dbgp_reset_prep); + +#ifdef CONFIG_KGDB + +static char kgdbdbgp_buf[DBGP_MAX_PACKET]; +static int kgdbdbgp_buf_sz; +static int kgdbdbgp_buf_idx; +static int kgdbdbgp_loop_cnt = DBGP_LOOPS; + +static int kgdbdbgp_read_char(void) +{ + int ret; + + if (kgdbdbgp_buf_idx < kgdbdbgp_buf_sz) { + char ch = kgdbdbgp_buf[kgdbdbgp_buf_idx++]; + return ch; + } + + ret = dbgp_bulk_read(USB_DEBUG_DEVNUM, dbgp_endpoint_in, + &kgdbdbgp_buf, DBGP_MAX_PACKET, + kgdbdbgp_loop_cnt); + if (ret <= 0) + return NO_POLL_CHAR; + kgdbdbgp_buf_sz = ret; + kgdbdbgp_buf_idx = 1; + return kgdbdbgp_buf[0]; +} + +static void kgdbdbgp_write_char(u8 chr) +{ + early_dbgp_write(NULL, &chr, 1); +} + +static struct kgdb_io kgdbdbgp_io_ops = { + .name = "kgdbdbgp", + .read_char = kgdbdbgp_read_char, + .write_char = kgdbdbgp_write_char, +}; + +static int kgdbdbgp_wait_time; + +static int __init kgdbdbgp_parse_config(char *str) +{ + char *ptr; + + if (!ehci_debug) { + if (early_dbgp_init(str)) + return -1; + } + ptr = strchr(str, ','); + if (ptr) { + ptr++; + kgdbdbgp_wait_time = simple_strtoul(ptr, &ptr, 10); + } + kgdb_register_io_module(&kgdbdbgp_io_ops); + kgdbdbgp_io_ops.is_console = early_dbgp_console.index != -1; + + return 0; +} +early_param("kgdbdbgp", kgdbdbgp_parse_config); + +static int kgdbdbgp_reader_thread(void *ptr) +{ + int ret; + + while (readl(&ehci_debug->control) & DBGP_ENABLED) { + kgdbdbgp_loop_cnt = 1; + ret = kgdbdbgp_read_char(); + kgdbdbgp_loop_cnt = DBGP_LOOPS; + if (ret != NO_POLL_CHAR) { + if (ret == 0x3 || ret == '$') { + if (ret == '$') + kgdbdbgp_buf_idx--; + kgdb_breakpoint(); + } + continue; + } + schedule_timeout_interruptible(kgdbdbgp_wait_time * HZ); + } + return 0; +} + +static int __init kgdbdbgp_start_thread(void) +{ + if (dbgp_kgdb_mode && kgdbdbgp_wait_time) + kthread_run(kgdbdbgp_reader_thread, NULL, "%s", "dbgp"); + + return 0; +} +module_init(kgdbdbgp_start_thread); +#endif /* CONFIG_KGDB */ |