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authorLubomir Rintel <lkundrak@v3.sk>2013-12-22 11:34:22 +0100
committerStefan Richter <stefanr@s5r6.in-berlin.de>2014-01-12 18:54:38 +0100
commit8bc588e0e585bc9085df75e84d4d5635f45cf360 (patch)
tree8dc98f31ce6330b1bd8670a42f60061e94481c68
parenta9954ce769e2c8b450b00ab2a4e208f447996b2d (diff)
downloadlinux-8bc588e0e585bc9085df75e84d4d5635f45cf360.tar.bz2
firewire: ohci: Turn remote DMA support into a module parameter
This makes it possible to debug kernel over FireWire without the need to recompile it. [Stefan R: changed description from "...0" to "...N"] Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
-rw-r--r--Documentation/debugging-via-ohci1394.txt4
-rw-r--r--drivers/firewire/ohci.c19
-rw-r--r--lib/Kconfig.debug11
3 files changed, 12 insertions, 22 deletions
diff --git a/Documentation/debugging-via-ohci1394.txt b/Documentation/debugging-via-ohci1394.txt
index 14d194496490..73473aa8d861 100644
--- a/Documentation/debugging-via-ohci1394.txt
+++ b/Documentation/debugging-via-ohci1394.txt
@@ -38,9 +38,7 @@ Drivers
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 the firewire-ohci driver depends on the PCI enumeration to be
completed, an initialization routine which runs pretty early has been
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 6aa8a86cb83b..036fb3bd5659 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -370,6 +370,10 @@ MODULE_PARM_DESC(debug, "Verbose logging (default = 0"
", 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 &
@@ -2050,10 +2054,10 @@ static void bus_reset_work(struct work_struct *work)
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);
@@ -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,
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.
@@ -2622,7 +2626,6 @@ static int ohci_enable_phys_dma(struct fw_card *card,
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)
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index db25707aa41b..dc30284a3b07 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1547,17 +1547,6 @@ config PROVIDE_OHCI1394_DMA_INIT
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