Retrieving a full system memory dump is also possible over the FireWire,
using data transfer rates in the order of 10MB/s or more.
-Memory access is currently limited to the low 4G of physical address
-space which can be a problem on IA64 machines where memory is located
-mostly above that limit, but it is rarely a problem on more common
-hardware such as hardware based on x86, x86-64 and PowerPC.
+With most FireWire controllers, memory access is limited to the low 4 GB
+of physical address space. This can be a problem on IA64 machines where
+memory is located mostly above that limit, but it is rarely a problem on
+more common hardware such as x86, x86-64 and PowerPC. However, at least
+Agere/LSI FW643e and FW643e2 controllers are known to support access to
+physical addresses above 4 GB.
Together with a early initialization of the OHCI-1394 controller for debugging,
this facility proved most useful for examining long debugs logs in the printk
Drivers
-------
-The ohci1394 driver in drivers/ieee1394 initializes the OHCI-1394 controllers
-to a working state and enables physical DMA by default for all remote nodes.
-This can be turned off by ohci1394's module parameter phys_dma=0.
-
-The alternative firewire-ohci driver in drivers/firewire uses filtered physical
+The firewire-ohci driver in drivers/firewire uses filtered physical
DMA by default, which is more secure but not suitable for remote debugging.
-Compile the driver with CONFIG_FIREWIRE_OHCI_REMOTE_DMA (Kernel hacking menu:
-Remote debugging over FireWire with firewire-ohci) to get unfiltered physical
-DMA.
+Pass the remote_dma=1 parameter to the driver to get unfiltered physical DMA.
-Because ohci1394 and firewire-ohci depend on the PCI enumeration to be
+Because the firewire-ohci driver depends on the PCI enumeration to be
completed, an initialization routine which runs pretty early has been
implemented for x86. This routine runs long before console_init() can be
called, i.e. before the printk buffer appears on the console.
Bernhard Kaindl enhanced firescope to support accessing 64-bit machines
from 32-bit firescope and vice versa:
-- http://halobates.de/firewire/firescope-0.2.2.tar.bz2
+- http://v3.sk/~lkundrak/firescope/
and he implemented fast system dump (alpha version - read README.txt):
- http://halobates.de/firewire/firedump-0.1.tar.bz2
1) Verify that your hardware is supported:
- Load the ohci1394 or the fw-ohci module and check your kernel logs.
+ Load the firewire-ohci module and check your kernel logs.
You should see a line similar to
- ohci1394: fw-host0: OHCI-1394 1.1 (PCI): IRQ=[18] MMIO=[fe9ff800-fe9fffff]
- ... Max Packet=[2048] IR/IT contexts=[4/8]
+ firewire_ohci 0000:15:00.1: added OHCI v1.0 device as card 2, 4 IR + 4 IT
+ ... contexts, quirks 0x11
when loading the driver. If you have no supported controller, many PCI,
CardBus and even some Express cards which are fully compliant to OHCI-1394
compliant, they are based on TI PCILynx chips and require drivers for Win-
dows operating systems.
+ The mentioned kernel log message contains ">4 GB phys DMA" in case of
+ OHCI-1394 controllers which support accesses above this limit.
+
2) Establish a working FireWire cable connection:
Any FireWire cable, as long at it provides electrically and mechanically
If an driver is running on both machines you should see a line like
- ieee1394: Node added: ID:BUS[0-01:1023] GUID[0090270001b84bba]
+ firewire_core 0000:15:00.1: created device fw1: GUID 00061b0020105917, S400
on both machines in the kernel log when the cable is plugged in
and connects the two machines.
3) Test physical DMA using firescope:
- On the debug host,
- - load the raw1394 module,
- - make sure that /dev/raw1394 is accessible,
+ On the debug host, make sure that /dev/fw* is accessible,
then start firescope:
$ firescope
- Port 0 (ohci1394) opened, 2 nodes detected
+ Port 0 (/dev/fw1) opened, 2 nodes detected
FireScope
---------
kernel messages using the serial console. This may provide you with some
information about the reasons of the suspend (resume) failure. Alternatively,
it may be possible to use a FireWire port for debugging with firescope
-(ftp://ftp.firstfloor.org/pub/ak/firescope/). On x86 it is also possible to
+(http://v3.sk/~lkundrak/firescope/). On x86 it is also possible to
use the PM_TRACE mechanism documented in Documentation/power/s2ram.txt .
2. Testing suspend to RAM (STR)
static LIST_HEAD(address_handler_list);
const struct fw_address_region fw_high_memory_region =
- { .start = 0x000100000000ULL, .end = 0xffffe0000000ULL, };
+ { .start = FW_MAX_PHYSICAL_RANGE, .end = 0xffffe0000000ULL, };
EXPORT_SYMBOL(fw_high_memory_region);
static const struct fw_address_region low_memory_region =
- { .start = 0x000000000000ULL, .end = 0x000100000000ULL, };
+ { .start = 0x000000000000ULL, .end = FW_MAX_PHYSICAL_RANGE, };
#if 0
const struct fw_address_region fw_private_region =
}
static struct fw_address_handler low_memory = {
- .length = 0x000100000000ULL,
+ .length = FW_MAX_PHYSICAL_RANGE,
.address_callback = handle_low_memory,
};
#define LOCAL_BUS 0xffc0
+/* arbitrarily chosen maximum range for physical DMA: 128 TB */
+#define FW_MAX_PHYSICAL_RANGE (128ULL << 40)
+
void fw_core_handle_request(struct fw_card *card, struct fw_packet *request);
void fw_core_handle_response(struct fw_card *card, struct fw_packet *packet);
int fw_get_response_length(struct fw_request *request);
", busReset events = " __stringify(OHCI_PARAM_DEBUG_BUSRESETS)
", or a combination, or all = -1)");
+static bool param_remote_dma;
+module_param_named(remote_dma, param_remote_dma, bool, 0444);
+MODULE_PARM_DESC(remote_dma, "Enable unfiltered remote DMA (default = N)");
+
static void log_irqs(struct fw_ohci *ohci, u32 evt)
{
if (likely(!(param_debug &
be32_to_cpu(ohci->next_header));
}
-#ifdef CONFIG_FIREWIRE_OHCI_REMOTE_DMA
- reg_write(ohci, OHCI1394_PhyReqFilterHiSet, ~0);
- reg_write(ohci, OHCI1394_PhyReqFilterLoSet, ~0);
-#endif
+ if (param_remote_dma) {
+ reg_write(ohci, OHCI1394_PhyReqFilterHiSet, ~0);
+ reg_write(ohci, OHCI1394_PhyReqFilterLoSet, ~0);
+ }
spin_unlock_irq(&ohci->lock);
reg_write(ohci, OHCI1394_FairnessControl, 0);
card->priority_budget_implemented = ohci->pri_req_max != 0;
- reg_write(ohci, OHCI1394_PhyUpperBound, 0x00010000);
+ reg_write(ohci, OHCI1394_PhyUpperBound, FW_MAX_PHYSICAL_RANGE >> 16);
reg_write(ohci, OHCI1394_IntEventClear, ~0);
reg_write(ohci, OHCI1394_IntMaskClear, ~0);
static int ohci_enable_phys_dma(struct fw_card *card,
int node_id, int generation)
{
-#ifdef CONFIG_FIREWIRE_OHCI_REMOTE_DMA
- return 0;
-#else
struct fw_ohci *ohci = fw_ohci(card);
unsigned long flags;
int n, ret = 0;
+ if (param_remote_dma)
+ return 0;
+
/*
* FIXME: Make sure this bitmask is cleared when we clear the busReset
* interrupt bit. Clear physReqResourceAllBuses on bus reset.
spin_unlock_irqrestore(&ohci->lock, flags);
return ret;
-#endif /* CONFIG_FIREWIRE_OHCI_REMOTE_DMA */
}
static u32 ohci_read_csr(struct fw_card *card, int csr_offset)
version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
ohci_notice(ohci,
"added OHCI v%x.%x device as card %d, "
- "%d IR + %d IT contexts, quirks 0x%x\n",
+ "%d IR + %d IT contexts, quirks 0x%x%s\n",
version >> 16, version & 0xff, ohci->card.index,
- ohci->n_ir, ohci->n_it, ohci->quirks);
+ ohci->n_ir, ohci->n_it, ohci->quirks,
+ reg_read(ohci, OHCI1394_PhyUpperBound) ?
+ ", >4 GB phys DMA" : "");
return 0;
See Documentation/debugging-via-ohci1394.txt for more information.
-config FIREWIRE_OHCI_REMOTE_DMA
- bool "Remote debugging over FireWire with firewire-ohci"
- depends on FIREWIRE_OHCI
- help
- This option lets you use the FireWire bus for remote debugging
- with help of the firewire-ohci driver. It enables unfiltered
- remote DMA in firewire-ohci.
- See Documentation/debugging-via-ohci1394.txt for more information.
-
- If unsure, say N.
-
config BUILD_DOCSRC
bool "Build targets in Documentation/ tree"
depends on HEADERS_CHECK
projects / ~andy / linux / commitdiff