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-rw-r--r--Documentation/kernel-parameters.txt11
-rw-r--r--drivers/usb/early/ehci-dbgp.c120
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 */