Commit-ID: 59d3daafa17265f01149df8eab3fb69b9b42cb2e
Gitweb: http://git.kernel.org/tip/59d3daafa17265f01149df8eab3fb69b9b42cb2e
Author: Joerg Roedel <joerg.roedel@xxxxxxx>
AuthorDate: Fri, 9 Jan 2009 13:01:56 +0100
Commit: Joerg Roedel <joerg.roedel@xxxxxxx>
CommitDate: Thu, 5 Mar 2009 20:35:16 +0100
dma-debug: add kernel command line parameters
Impact: add dma_debug= and dma_debug_entries= kernel parameters
Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
---
Documentation/kernel-parameters.txt | 10 +++++++++
lib/dma-debug.c | 38 +++++++++++++++++++++++++++++++++++
2 files changed, 48 insertions(+), 0 deletions(-)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 54f21a5..0fa3c05 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -491,6 +491,16 @@ and is between 256 and 4096 characters. It is defined in the file
Range: 0 - 8192
Default: 64
+ dma_debug=off If the kernel is compiled with DMA_API_DEBUG support
+ this option disables the debugging code at boot.
+
+ dma_debug_entries=<number>
+ This option allows to tune the number of preallocated
+ entries for DMA-API debugging code. One entry is
+ required per DMA-API allocation. Use this if the
+ DMA-API debugging code disables itself because the
+ architectural default is too low.
+
hpet= [X86-32,HPET] option to control HPET usage
Format: { enable (default) | disable | force }
disable: disable HPET and use PIT instead
diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index 5b50bb3..2ede463 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -64,6 +64,9 @@ static bool global_disable __read_mostly;
static u32 num_free_entries;
static u32 min_free_entries;
+/* number of preallocated entries requested by kernel cmdline */
+static u32 req_entries;
+
/*
* Hash related functions
*
@@ -253,6 +256,9 @@ void dma_debug_init(u32 num_entries)
dma_entry_hash[i].lock = SPIN_LOCK_UNLOCKED;
}
+ if (req_entries)
+ num_entries = req_entries;
+
if (prealloc_memory(num_entries) != 0) {
printk(KERN_ERR "DMA-API: debugging out of memory error "
"- disabled\n");
@@ -264,3 +270,35 @@ void dma_debug_init(u32 num_entries)
printk(KERN_INFO "DMA-API: debugging enabled by kernel config\n");
}
+static __init int dma_debug_cmdline(char *str)
+{
+ if (!str)
+ return -EINVAL;
+
+ if (strncmp(str, "off", 3) == 0) {
+ printk(KERN_INFO "DMA-API: debugging disabled on kernel "
+ "command line\n");
+ global_disable = true;
+ }
+
+ return 0;
+}
+
+static __init int dma_debug_entries_cmdline(char *str)
+{
+ int res;
+
+ if (!str)
+ return -EINVAL;
+
+ res = get_option(&str, &req_entries);
+
+ if (!res)
+ req_entries = 0;
+
+ return 0;
+}
+
+__setup("dma_debug=", dma_debug_cmdline);
+__setup("dma_debug_entries=", dma_debug_entries_cmdline);
+
--
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