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IEEE 1394 (FireWire) subsystem changes:

Browse Source 
- make remote debugging over 1394 a runtime option instead of a
     buildtime option
 
   - extend remote debug access past the 4 GB barrier on respectively
     capable hardware
 
   - documentation update
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Merge tag 'firewire-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394

Pull firewire updates from Stefan Richter:
 "IEEE 1394 (FireWire) subsystem changes:

   - make remote debugging over 1394 a runtime option instead of a
     buildtime option
   - extend remote debug access past the 4 GB barrier on respectively
     capable hardware
   - documentation update"

* tag 'firewire-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394:
  firewire: Enable remote DMA above 4 GB
  firewire: ohci: Turn remote DMA support into a module parameter
  Documentation/: update FireWire debugging documentation
This commit is contained in:
Linus Torvalds 2014-01-27 08:14:08 -08:00
commit 028e219eff
6 changed files with 42 additions and 48 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

41
Documentation/debugging-via-ohci1394.txt
View File

@ -22,10 +22,12 @@ locations such as buffers like the printk buffer or the process table.
Retrieving a full system memory dump is also possible over the FireWire, Retrieving a full system memory dump is also possible over the FireWire,
using data transfer rates in the order of 10MB/s or more. using data transfer rates in the order of 10MB/s or more.
Memory access is currently limited to the low 4G of physical address With most FireWire controllers, memory access is limited to the low 4 GB
space which can be a problem on IA64 machines where memory is located of physical address space. This can be a problem on IA64 machines where
mostly above that limit, but it is rarely a problem on more common memory is located mostly above that limit, but it is rarely a problem on
hardware such as hardware based on x86, x86-64 and PowerPC. 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, 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 this facility proved most useful for examining long debugs logs in the printk
@ -36,17 +38,11 @@ available (notebooks) or too slow for extensive debug information (like ACPI).
Drivers Drivers
------- -------
The ohci1394 driver in drivers/ieee1394 initializes the OHCI-1394 controllers The firewire-ohci driver in drivers/firewire uses filtered physical
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
DMA by default, which is more secure but not suitable for remote debugging. 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: Pass the remote_dma=1 parameter to the driver to get unfiltered physical DMA.
Remote debugging over FireWire with firewire-ohci) 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 completed, an initialization routine which runs pretty early has been
implemented for x86. This routine runs long before console_init() can be implemented for x86. This routine runs long before console_init() can be
called, i.e. before the printk buffer appears on the console. called, i.e. before the printk buffer appears on the console.
@ -64,7 +60,7 @@ be used to view the printk buffer of a remote machine, even with live update.
Bernhard Kaindl enhanced firescope to support accessing 64-bit machines Bernhard Kaindl enhanced firescope to support accessing 64-bit machines
from 32-bit firescope and vice versa: 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): and he implemented fast system dump (alpha version - read README.txt):
- http://halobates.de/firewire/firedump-0.1.tar.bz2 - http://halobates.de/firewire/firedump-0.1.tar.bz2
@ -92,11 +88,11 @@ Step-by-step instructions for using firescope with early OHCI initialization:
1) Verify that your hardware is supported: 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 You should see a line similar to
ohci1394: fw-host0: OHCI-1394 1.1 (PCI): IRQ=[18] MMIO=[fe9ff800-fe9fffff] firewire_ohci 0000:15:00.1: added OHCI v1.0 device as card 2, 4 IR + 4 IT
... Max Packet=[2048] IR/IT contexts=[4/8] ... contexts, quirks 0x11
when loading the driver. If you have no supported controller, many PCI, 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 CardBus and even some Express cards which are fully compliant to OHCI-1394
@ -105,6 +101,9 @@ Step-by-step instructions for using firescope with early OHCI initialization:
compliant, they are based on TI PCILynx chips and require drivers for Win- compliant, they are based on TI PCILynx chips and require drivers for Win-
dows operating systems. 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: 2) Establish a working FireWire cable connection:
Any FireWire cable, as long at it provides electrically and mechanically Any FireWire cable, as long at it provides electrically and mechanically
@ -113,20 +112,18 @@ Step-by-step instructions for using firescope with early OHCI initialization:
If an driver is running on both machines you should see a line like 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 on both machines in the kernel log when the cable is plugged in
and connects the two machines. and connects the two machines.
3) Test physical DMA using firescope: 3) Test physical DMA using firescope:
On the debug host, On the debug host, make sure that /dev/fw* is accessible,
- load the raw1394 module,
- make sure that /dev/raw1394 is accessible,
then start firescope: then start firescope:
$ firescope $ firescope
Port 0 (ohci1394) opened, 2 nodes detected Port 0 (/dev/fw1) opened, 2 nodes detected
FireScope FireScope
--------- ---------

2
Documentation/power/basic-pm-debugging.txt
View File

@ -172,7 +172,7 @@ you can boot the kernel with the 'no_console_suspend' parameter and try to log
kernel messages using the serial console. This may provide you with some kernel messages using the serial console. This may provide you with some
information about the reasons of the suspend (resume) failure. Alternatively, information about the reasons of the suspend (resume) failure. Alternatively,
it may be possible to use a FireWire port for debugging with firescope 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 . use the PM_TRACE mechanism documented in Documentation/power/s2ram.txt .
2. Testing suspend to RAM (STR) 2. Testing suspend to RAM (STR)

6
drivers/firewire/core-transaction.c
View File

@ -523,11 +523,11 @@ static DEFINE_SPINLOCK(address_handler_list_lock);
static LIST_HEAD(address_handler_list); static LIST_HEAD(address_handler_list);
const struct fw_address_region fw_high_memory_region = 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); EXPORT_SYMBOL(fw_high_memory_region);
static const struct fw_address_region low_memory_region = static const struct fw_address_region low_memory_region =
{ .start = 0x000000000000ULL, .end = 0x000100000000ULL, }; { .start = 0x000000000000ULL, .end = FW_MAX_PHYSICAL_RANGE, };
#if 0 #if 0
const struct fw_address_region fw_private_region = const struct fw_address_region fw_private_region =
@ -1217,7 +1217,7 @@ static void handle_low_memory(struct fw_card *card, struct fw_request *request,
} }
static struct fw_address_handler low_memory = { static struct fw_address_handler low_memory = {
.length = 0x000100000000ULL, .length = FW_MAX_PHYSICAL_RANGE,
.address_callback = handle_low_memory, .address_callback = handle_low_memory,
}; };

3
drivers/firewire/core.h
View File

@ -237,6 +237,9 @@ static inline bool is_next_generation(int new_generation, int old_generation)
#define LOCAL_BUS 0xffc0 #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_request(struct fw_card *card, struct fw_packet *request);
void fw_core_handle_response(struct fw_card *card, struct fw_packet *packet); void fw_core_handle_response(struct fw_card *card, struct fw_packet *packet);
int fw_get_response_length(struct fw_request *request); int fw_get_response_length(struct fw_request *request);

27
drivers/firewire/ohci.c
View File

@ -370,6 +370,10 @@ MODULE_PARM_DESC(debug, "Verbose logging (default = 0"
", busReset events = " __stringify(OHCI_PARAM_DEBUG_BUSRESETS) ", busReset events = " __stringify(OHCI_PARAM_DEBUG_BUSRESETS)
", or a combination, or all = -1)"); ", 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) static void log_irqs(struct fw_ohci *ohci, u32 evt)
{ {
if (likely(!(param_debug & if (likely(!(param_debug &
@ -2050,10 +2054,10 @@ static void bus_reset_work(struct work_struct *work)
be32_to_cpu(ohci->next_header)); be32_to_cpu(ohci->next_header));
} }
#ifdef CONFIG_FIREWIRE_OHCI_REMOTE_DMA if (param_remote_dma) {
reg_write(ohci, OHCI1394_PhyReqFilterHiSet, ~0); reg_write(ohci, OHCI1394_PhyReqFilterHiSet, ~0);
reg_write(ohci, OHCI1394_PhyReqFilterLoSet, ~0); reg_write(ohci, OHCI1394_PhyReqFilterLoSet, ~0);
#endif }
spin_unlock_irq(&ohci->lock); spin_unlock_irq(&ohci->lock);
@ -2363,7 +2367,7 @@ static int ohci_enable(struct fw_card *card,
reg_write(ohci, OHCI1394_FairnessControl, 0); reg_write(ohci, OHCI1394_FairnessControl, 0);
card->priority_budget_implemented = ohci->pri_req_max != 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_IntEventClear, ~0);
reg_write(ohci, OHCI1394_IntMaskClear, ~0); reg_write(ohci, OHCI1394_IntMaskClear, ~0);
@ -2587,13 +2591,13 @@ static int ohci_cancel_packet(struct fw_card *card, struct fw_packet *packet)
static int ohci_enable_phys_dma(struct fw_card *card, static int ohci_enable_phys_dma(struct fw_card *card,
int node_id, int generation) int node_id, int generation)
{ {
#ifdef CONFIG_FIREWIRE_OHCI_REMOTE_DMA
return 0;
#else
struct fw_ohci *ohci = fw_ohci(card); struct fw_ohci *ohci = fw_ohci(card);
unsigned long flags; unsigned long flags;
int n, ret = 0; int n, ret = 0;
if (param_remote_dma)
return 0;
/* /*
* FIXME: Make sure this bitmask is cleared when we clear the busReset * FIXME: Make sure this bitmask is cleared when we clear the busReset
* interrupt bit. Clear physReqResourceAllBuses on bus reset. * interrupt bit. Clear physReqResourceAllBuses on bus reset.
@ -2622,7 +2626,6 @@ static int ohci_enable_phys_dma(struct fw_card *card,
spin_unlock_irqrestore(&ohci->lock, flags); spin_unlock_irqrestore(&ohci->lock, flags);
return ret; return ret;
#endif /* CONFIG_FIREWIRE_OHCI_REMOTE_DMA */
} }
static u32 ohci_read_csr(struct fw_card *card, int csr_offset) static u32 ohci_read_csr(struct fw_card *card, int csr_offset)
@ -3720,9 +3723,11 @@ static int pci_probe(struct pci_dev *dev,
version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff; version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
ohci_notice(ohci, ohci_notice(ohci,
"added OHCI v%x.%x device as card %d, " "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, 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; return 0;

11
lib/Kconfig.debug
View File

@ -1556,17 +1556,6 @@ config PROVIDE_OHCI1394_DMA_INIT
See Documentation/debugging-via-ohci1394.txt for more information. 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 config BUILD_DOCSRC
bool "Build targets in Documentation/ tree" bool "Build targets in Documentation/ tree"
depends on HEADERS_CHECK depends on HEADERS_CHECK