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-rw-r--r--Documentation/DocBook/Makefile2
-rw-r--r--Documentation/DocBook/kernel-api.tmpl1
-rw-r--r--Documentation/acpi-hotkey.txt2
-rw-r--r--Documentation/fujitsu/frv/kernel-ABI.txt192
-rw-r--r--Documentation/kernel-parameters.txt34
-rw-r--r--Documentation/networking/packet_mmap.txt2
-rw-r--r--Documentation/networking/tuntap.txt2
7 files changed, 128 insertions, 107 deletions
diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile
index 7d87dd73cbe4..5a2882d275ba 100644
--- a/Documentation/DocBook/Makefile
+++ b/Documentation/DocBook/Makefile
@@ -2,7 +2,7 @@
2# This makefile is used to generate the kernel documentation, 2# This makefile is used to generate the kernel documentation,
3# primarily based on in-line comments in various source files. 3# primarily based on in-line comments in various source files.
4# See Documentation/kernel-doc-nano-HOWTO.txt for instruction in how 4# See Documentation/kernel-doc-nano-HOWTO.txt for instruction in how
5# to ducument the SRC - and how to read it. 5# to document the SRC - and how to read it.
6# To add a new book the only step required is to add the book to the 6# To add a new book the only step required is to add the book to the
7# list of DOCBOOKS. 7# list of DOCBOOKS.
8 8
diff --git a/Documentation/DocBook/kernel-api.tmpl b/Documentation/DocBook/kernel-api.tmpl
index 8c9c6704e85b..ca02e04a906c 100644
--- a/Documentation/DocBook/kernel-api.tmpl
+++ b/Documentation/DocBook/kernel-api.tmpl
@@ -322,7 +322,6 @@ X!Earch/i386/kernel/mca.c
322 <chapter id="sysfs"> 322 <chapter id="sysfs">
323 <title>The Filesystem for Exporting Kernel Objects</title> 323 <title>The Filesystem for Exporting Kernel Objects</title>
324!Efs/sysfs/file.c 324!Efs/sysfs/file.c
325!Efs/sysfs/dir.c
326!Efs/sysfs/symlink.c 325!Efs/sysfs/symlink.c
327!Efs/sysfs/bin.c 326!Efs/sysfs/bin.c
328 </chapter> 327 </chapter>
diff --git a/Documentation/acpi-hotkey.txt b/Documentation/acpi-hotkey.txt
index 744f1aec6553..38040fa37649 100644
--- a/Documentation/acpi-hotkey.txt
+++ b/Documentation/acpi-hotkey.txt
@@ -30,7 +30,7 @@ specific hotkey(event))
30echo "event_num:event_type:event_argument" > 30echo "event_num:event_type:event_argument" >
31 /proc/acpi/hotkey/action. 31 /proc/acpi/hotkey/action.
32The result of the execution of this aml method is 32The result of the execution of this aml method is
33attached to /proc/acpi/hotkey/poll_method, which is dnyamically 33attached to /proc/acpi/hotkey/poll_method, which is dynamically
34created. Please use command "cat /proc/acpi/hotkey/polling_method" 34created. Please use command "cat /proc/acpi/hotkey/polling_method"
35to retrieve it. 35to retrieve it.
36 36
diff --git a/Documentation/fujitsu/frv/kernel-ABI.txt b/Documentation/fujitsu/frv/kernel-ABI.txt
index 0ed9b0a779bc..8b0a5fc8bfd9 100644
--- a/Documentation/fujitsu/frv/kernel-ABI.txt
+++ b/Documentation/fujitsu/frv/kernel-ABI.txt
@@ -1,17 +1,19 @@
1 ================================= 1 =================================
2 INTERNAL KERNEL ABI FOR FR-V ARCH 2 INTERNAL KERNEL ABI FOR FR-V ARCH
3 ================================= 3 =================================
4 4
5The internal FRV kernel ABI is not quite the same as the userspace ABI. A number of the registers 5The internal FRV kernel ABI is not quite the same as the userspace ABI. A
6are used for special purposed, and the ABI is not consistent between modules vs core, and MMU vs 6number of the registers are used for special purposed, and the ABI is not
7no-MMU. 7consistent between modules vs core, and MMU vs no-MMU.
8 8
9This partly stems from the fact that FRV CPUs do not have a separate supervisor stack pointer, and 9This partly stems from the fact that FRV CPUs do not have a separate
10most of them do not have any scratch registers, thus requiring at least one general purpose 10supervisor stack pointer, and most of them do not have any scratch
11register to be clobbered in such an event. Also, within the kernel core, it is possible to simply 11registers, thus requiring at least one general purpose register to be
12jump or call directly between functions using a relative offset. This cannot be extended to modules 12clobbered in such an event. Also, within the kernel core, it is possible to
13for the displacement is likely to be too far. Thus in modules the address of a function to call 13simply jump or call directly between functions using a relative offset.
14must be calculated in a register and then used, requiring two extra instructions. 14This cannot be extended to modules for the displacement is likely to be too
15far. Thus in modules the address of a function to call must be calculated
16in a register and then used, requiring two extra instructions.
15 17
16This document has the following sections: 18This document has the following sections:
17 19
@@ -39,7 +41,8 @@ When a system call is made, the following registers are effective:
39CPU OPERATING MODES 41CPU OPERATING MODES
40=================== 42===================
41 43
42The FR-V CPU has three basic operating modes. In order of increasing capability: 44The FR-V CPU has three basic operating modes. In order of increasing
45capability:
43 46
44 (1) User mode. 47 (1) User mode.
45 48
@@ -47,42 +50,46 @@ The FR-V CPU has three basic operating modes. In order of increasing capability:
47 50
48 (2) Kernel mode. 51 (2) Kernel mode.
49 52
50 Normal kernel mode. There are many additional control registers available that may be 53 Normal kernel mode. There are many additional control registers
51 accessed in this mode, in addition to all the stuff available to user mode. This has two 54 available that may be accessed in this mode, in addition to all the
52 submodes: 55 stuff available to user mode. This has two submodes:
53 56
54 (a) Exceptions enabled (PSR.T == 1). 57 (a) Exceptions enabled (PSR.T == 1).
55 58
56 Exceptions will invoke the appropriate normal kernel mode handler. On entry to the 59 Exceptions will invoke the appropriate normal kernel mode
57 handler, the PSR.T bit will be cleared. 60 handler. On entry to the handler, the PSR.T bit will be cleared.
58 61
59 (b) Exceptions disabled (PSR.T == 0). 62 (b) Exceptions disabled (PSR.T == 0).
60 63
61 No exceptions or interrupts may happen. Any mandatory exceptions will cause the CPU to 64 No exceptions or interrupts may happen. Any mandatory exceptions
62 halt unless the CPU is told to jump into debug mode instead. 65 will cause the CPU to halt unless the CPU is told to jump into
66 debug mode instead.
63 67
64 (3) Debug mode. 68 (3) Debug mode.
65 69
66 No exceptions may happen in this mode. Memory protection and management exceptions will be 70 No exceptions may happen in this mode. Memory protection and
67 flagged for later consideration, but the exception handler won't be invoked. Debugging traps 71 management exceptions will be flagged for later consideration, but
68 such as hardware breakpoints and watchpoints will be ignored. This mode is entered only by 72 the exception handler won't be invoked. Debugging traps such as
69 debugging events obtained from the other two modes. 73 hardware breakpoints and watchpoints will be ignored. This mode is
74 entered only by debugging events obtained from the other two modes.
70 75
71 All kernel mode registers may be accessed, plus a few extra debugging specific registers. 76 All kernel mode registers may be accessed, plus a few extra debugging
77 specific registers.
72 78
73 79
74================================= 80=================================
75INTERNAL KERNEL-MODE REGISTER ABI 81INTERNAL KERNEL-MODE REGISTER ABI
76================================= 82=================================
77 83
78There are a number of permanent register assignments that are set up by entry.S in the exception 84There are a number of permanent register assignments that are set up by
79prologue. Note that there is a complete set of exception prologues for each of user->kernel 85entry.S in the exception prologue. Note that there is a complete set of
80transition and kernel->kernel transition. There are also user->debug and kernel->debug mode 86exception prologues for each of user->kernel transition and kernel->kernel
81transition prologues. 87transition. There are also user->debug and kernel->debug mode transition
88prologues.
82 89
83 90
84 REGISTER FLAVOUR USE 91 REGISTER FLAVOUR USE
85 =============== ======= ==================================================== 92 =============== ======= ==============================================
86 GR1 Supervisor stack pointer 93 GR1 Supervisor stack pointer
87 GR15 Current thread info pointer 94 GR15 Current thread info pointer
88 GR16 GP-Rel base register for small data 95 GR16 GP-Rel base register for small data
@@ -92,10 +99,12 @@ transition prologues.
92 GR31 NOMMU Destroyed by debug mode entry 99 GR31 NOMMU Destroyed by debug mode entry
93 GR31 MMU Destroyed by TLB miss kernel mode entry 100 GR31 MMU Destroyed by TLB miss kernel mode entry
94 CCR.ICC2 Virtual interrupt disablement tracking 101 CCR.ICC2 Virtual interrupt disablement tracking
95 CCCR.CC3 Cleared by exception prologue (atomic op emulation) 102 CCCR.CC3 Cleared by exception prologue
103 (atomic op emulation)
96 SCR0 MMU See mmu-layout.txt. 104 SCR0 MMU See mmu-layout.txt.
97 SCR1 MMU See mmu-layout.txt. 105 SCR1 MMU See mmu-layout.txt.
98 SCR2 MMU Save for EAR0 (destroyed by icache insns in debug mode) 106 SCR2 MMU Save for EAR0 (destroyed by icache insns
107 in debug mode)
99 SCR3 MMU Save for GR31 during debug exceptions 108 SCR3 MMU Save for GR31 during debug exceptions
100 DAMR/IAMR NOMMU Fixed memory protection layout. 109 DAMR/IAMR NOMMU Fixed memory protection layout.
101 DAMR/IAMR MMU See mmu-layout.txt. 110 DAMR/IAMR MMU See mmu-layout.txt.
@@ -104,18 +113,21 @@ transition prologues.
104Certain registers are also used or modified across function calls: 113Certain registers are also used or modified across function calls:
105 114
106 REGISTER CALL RETURN 115 REGISTER CALL RETURN
107 =============== =============================== =============================== 116 =============== =============================== ======================
108 GR0 Fixed Zero - 117 GR0 Fixed Zero -
109 GR2 Function call frame pointer 118 GR2 Function call frame pointer
110 GR3 Special Preserved 119 GR3 Special Preserved
111 GR3-GR7 - Clobbered 120 GR3-GR7 - Clobbered
112 GR8 Function call arg #1 Return value (or clobbered) 121 GR8 Function call arg #1 Return value
113 GR9 Function call arg #2 Return value MSW (or clobbered) 122 (or clobbered)
123 GR9 Function call arg #2 Return value MSW
124 (or clobbered)
114 GR10-GR13 Function call arg #3-#6 Clobbered 125 GR10-GR13 Function call arg #3-#6 Clobbered
115 GR14 - Clobbered 126 GR14 - Clobbered
116 GR15-GR16 Special Preserved 127 GR15-GR16 Special Preserved
117 GR17-GR27 - Preserved 128 GR17-GR27 - Preserved
118 GR28-GR31 Special Only accessed explicitly 129 GR28-GR31 Special Only accessed
130 explicitly
119 LR Return address after CALL Clobbered 131 LR Return address after CALL Clobbered
120 CCR/CCCR - Mostly Clobbered 132 CCR/CCCR - Mostly Clobbered
121 133
@@ -124,46 +136,53 @@ Certain registers are also used or modified across function calls:
124INTERNAL DEBUG-MODE REGISTER ABI 136INTERNAL DEBUG-MODE REGISTER ABI
125================================ 137================================
126 138
127This is the same as the kernel-mode register ABI for functions calls. The difference is that in 139This is the same as the kernel-mode register ABI for functions calls. The
128debug-mode there's a different stack and a different exception frame. Almost all the global 140difference is that in debug-mode there's a different stack and a different
129registers from kernel-mode (including the stack pointer) may be changed. 141exception frame. Almost all the global registers from kernel-mode
142(including the stack pointer) may be changed.
130 143
131 REGISTER FLAVOUR USE 144 REGISTER FLAVOUR USE
132 =============== ======= ==================================================== 145 =============== ======= ==============================================
133 GR1 Debug stack pointer 146 GR1 Debug stack pointer
134 GR16 GP-Rel base register for small data 147 GR16 GP-Rel base register for small data
135 GR31 Current debug exception frame pointer (__debug_frame) 148 GR31 Current debug exception frame pointer
149 (__debug_frame)
136 SCR3 MMU Saved value of GR31 150 SCR3 MMU Saved value of GR31
137 151
138 152
139Note that debug mode is able to interfere with the kernel's emulated atomic ops, so it must be 153Note that debug mode is able to interfere with the kernel's emulated atomic
140exceedingly careful not to do any that would interact with the main kernel in this regard. Hence 154ops, so it must be exceedingly careful not to do any that would interact
141the debug mode code (gdbstub) is almost completely self-contained. The only external code used is 155with the main kernel in this regard. Hence the debug mode code (gdbstub) is
142the sprintf family of functions. 156almost completely self-contained. The only external code used is the
157sprintf family of functions.
143 158
144Futhermore, break.S is so complicated because single-step mode does not switch off on entry to an 159Futhermore, break.S is so complicated because single-step mode does not
145exception. That means unless manually disabled, single-stepping will blithely go on stepping into 160switch off on entry to an exception. That means unless manually disabled,
146things like interrupts. See gdbstub.txt for more information. 161single-stepping will blithely go on stepping into things like interrupts.
162See gdbstub.txt for more information.
147 163
148 164
149========================== 165==========================
150VIRTUAL INTERRUPT HANDLING 166VIRTUAL INTERRUPT HANDLING
151========================== 167==========================
152 168
153Because accesses to the PSR is so slow, and to disable interrupts we have to access it twice (once 169Because accesses to the PSR is so slow, and to disable interrupts we have
154to read and once to write), we don't actually disable interrupts at all if we don't have to. What 170to access it twice (once to read and once to write), we don't actually
155we do instead is use the ICC2 condition code flags to note virtual disablement, such that if we 171disable interrupts at all if we don't have to. What we do instead is use
156then do take an interrupt, we note the flag, really disable interrupts, set another flag and resume 172the ICC2 condition code flags to note virtual disablement, such that if we
157execution at the point the interrupt happened. Setting condition flags as a side effect of an 173then do take an interrupt, we note the flag, really disable interrupts, set
158arithmetic or logical instruction is really fast. This use of the ICC2 only occurs within the 174another flag and resume execution at the point the interrupt happened.
175Setting condition flags as a side effect of an arithmetic or logical
176instruction is really fast. This use of the ICC2 only occurs within the
159kernel - it does not affect userspace. 177kernel - it does not affect userspace.
160 178
161The flags we use are: 179The flags we use are:
162 180
163 (*) CCR.ICC2.Z [Zero flag] 181 (*) CCR.ICC2.Z [Zero flag]
164 182
165 Set to virtually disable interrupts, clear when interrupts are virtually enabled. Can be 183 Set to virtually disable interrupts, clear when interrupts are
166 modified by logical instructions without affecting the Carry flag. 184 virtually enabled. Can be modified by logical instructions without
185 affecting the Carry flag.
167 186
168 (*) CCR.ICC2.C [Carry flag] 187 (*) CCR.ICC2.C [Carry flag]
169 188
@@ -176,8 +195,9 @@ What happens is this:
176 195
177 ICC2.Z is 0, ICC2.C is 1. 196 ICC2.Z is 0, ICC2.C is 1.
178 197
179 (2) An interrupt occurs. The exception prologue examines ICC2.Z and determines that nothing needs 198 (2) An interrupt occurs. The exception prologue examines ICC2.Z and
180 doing. This is done simply with an unlikely BEQ instruction. 199 determines that nothing needs doing. This is done simply with an
200 unlikely BEQ instruction.
181 201
182 (3) The interrupts are disabled (local_irq_disable) 202 (3) The interrupts are disabled (local_irq_disable)
183 203
@@ -187,48 +207,56 @@ What happens is this:
187 207
188 ICC2.Z would be set to 0. 208 ICC2.Z would be set to 0.
189 209
190 A TIHI #2 instruction (trap #2 if condition HI - Z==0 && C==0) would be used to trap if 210 A TIHI #2 instruction (trap #2 if condition HI - Z==0 && C==0) would
191 interrupts were now virtually enabled, but physically disabled - which they're not, so the 211 be used to trap if interrupts were now virtually enabled, but
192 trap isn't taken. The kernel would then be back to state (1). 212 physically disabled - which they're not, so the trap isn't taken. The
213 kernel would then be back to state (1).
193 214
194 (5) An interrupt occurs. The exception prologue examines ICC2.Z and determines that the interrupt 215 (5) An interrupt occurs. The exception prologue examines ICC2.Z and
195 shouldn't actually have happened. It jumps aside, and there disabled interrupts by setting 216 determines that the interrupt shouldn't actually have happened. It
196 PSR.PIL to 14 and then it clears ICC2.C. 217 jumps aside, and there disabled interrupts by setting PSR.PIL to 14
218 and then it clears ICC2.C.
197 219
198 (6) If interrupts were then saved and disabled again (local_irq_save): 220 (6) If interrupts were then saved and disabled again (local_irq_save):
199 221
200 ICC2.Z would be shifted into the save variable and masked off (giving a 1). 222 ICC2.Z would be shifted into the save variable and masked off
223 (giving a 1).
201 224
202 ICC2.Z would then be set to 1 (thus unchanged), and ICC2.C would be unaffected (ie: 0). 225 ICC2.Z would then be set to 1 (thus unchanged), and ICC2.C would be
226 unaffected (ie: 0).
203 227
204 (7) If interrupts were then restored from state (6) (local_irq_restore): 228 (7) If interrupts were then restored from state (6) (local_irq_restore):
205 229
206 ICC2.Z would be set to indicate the result of XOR'ing the saved value (ie: 1) with 1, which 230 ICC2.Z would be set to indicate the result of XOR'ing the saved
207 gives a result of 0 - thus leaving ICC2.Z set. 231 value (ie: 1) with 1, which gives a result of 0 - thus leaving
232 ICC2.Z set.
208 233
209 ICC2.C would remain unaffected (ie: 0). 234 ICC2.C would remain unaffected (ie: 0).
210 235
211 A TIHI #2 instruction would be used to again assay the current state, but this would do 236 A TIHI #2 instruction would be used to again assay the current state,
212 nothing as Z==1. 237 but this would do nothing as Z==1.
213 238
214 (8) If interrupts were then enabled (local_irq_enable): 239 (8) If interrupts were then enabled (local_irq_enable):
215 240
216 ICC2.Z would be cleared. ICC2.C would be left unaffected. Both flags would now be 0. 241 ICC2.Z would be cleared. ICC2.C would be left unaffected. Both
242 flags would now be 0.
217 243
218 A TIHI #2 instruction again issued to assay the current state would then trap as both Z==0 244 A TIHI #2 instruction again issued to assay the current state would
219 [interrupts virtually enabled] and C==0 [interrupts really disabled] would then be true. 245 then trap as both Z==0 [interrupts virtually enabled] and C==0
246 [interrupts really disabled] would then be true.
220 247
221 (9) The trap #2 handler would simply enable hardware interrupts (set PSR.PIL to 0), set ICC2.C to 248 (9) The trap #2 handler would simply enable hardware interrupts
222 1 and return. 249 (set PSR.PIL to 0), set ICC2.C to 1 and return.
223 250
224(10) Immediately upon returning, the pending interrupt would be taken. 251(10) Immediately upon returning, the pending interrupt would be taken.
225 252
226(11) The interrupt handler would take the path of actually processing the interrupt (ICC2.Z is 253(11) The interrupt handler would take the path of actually processing the
227 clear, BEQ fails as per step (2)). 254 interrupt (ICC2.Z is clear, BEQ fails as per step (2)).
228 255
229(12) The interrupt handler would then set ICC2.C to 1 since hardware interrupts are definitely 256(12) The interrupt handler would then set ICC2.C to 1 since hardware
230 enabled - or else the kernel wouldn't be here. 257 interrupts are definitely enabled - or else the kernel wouldn't be here.
231 258
232(13) On return from the interrupt handler, things would be back to state (1). 259(13) On return from the interrupt handler, things would be back to state (1).
233 260
234This trap (#2) is only available in kernel mode. In user mode it will result in SIGILL. 261This trap (#2) is only available in kernel mode. In user mode it will
262result in SIGILL.
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index f8cb55c30b0f..b3a6187e5305 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1,4 +1,4 @@
1February 2003 Kernel Parameters v2.5.59 1 Kernel Parameters
2 ~~~~~~~~~~~~~~~~~ 2 ~~~~~~~~~~~~~~~~~
3 3
4The following is a consolidated list of the kernel parameters as implemented 4The following is a consolidated list of the kernel parameters as implemented
@@ -17,9 +17,17 @@ are specified on the kernel command line with the module name plus
17 17
18 usbcore.blinkenlights=1 18 usbcore.blinkenlights=1
19 19
20The text in square brackets at the beginning of the description states the 20This document may not be entirely up to date and comprehensive. The command
21restrictions on the kernel for the said kernel parameter to be valid. The 21"modinfo -p ${modulename}" shows a current list of all parameters of a loadable
22restrictions referred to are that the relevant option is valid if: 22module. Loadable modules, after being loaded into the running kernel, also
23reveal their parameters in /sys/module/${modulename}/parameters/. Some of these
24parameters may be changed at runtime by the command
25"echo -n ${value} > /sys/module/${modulename}/parameters/${parm}".
26
27The parameters listed below are only valid if certain kernel build options were
28enabled and if respective hardware is present. The text in square brackets at
29the beginning of each description states the restrictions within which a
30parameter is applicable:
23 31
24 ACPI ACPI support is enabled. 32 ACPI ACPI support is enabled.
25 ALSA ALSA sound support is enabled. 33 ALSA ALSA sound support is enabled.
@@ -1046,10 +1054,10 @@ running once the system is up.
1046 noltlbs [PPC] Do not use large page/tlb entries for kernel 1054 noltlbs [PPC] Do not use large page/tlb entries for kernel
1047 lowmem mapping on PPC40x. 1055 lowmem mapping on PPC40x.
1048 1056
1049 nomce [IA-32] Machine Check Exception
1050
1051 nomca [IA-64] Disable machine check abort handling 1057 nomca [IA-64] Disable machine check abort handling
1052 1058
1059 nomce [IA-32] Machine Check Exception
1060
1053 noresidual [PPC] Don't use residual data on PReP machines. 1061 noresidual [PPC] Don't use residual data on PReP machines.
1054 1062
1055 noresume [SWSUSP] Disables resume and restores original swap 1063 noresume [SWSUSP] Disables resume and restores original swap
@@ -1682,20 +1690,6 @@ running once the system is up.
1682 1690
1683 1691
1684______________________________________________________________________ 1692______________________________________________________________________
1685Changelog:
1686
16872000-06-?? Mr. Unknown
1688 The last known update (for 2.4.0) - the changelog was not kept before.
1689
16902002-11-24 Petr Baudis <pasky@ucw.cz>
1691 Randy Dunlap <randy.dunlap@verizon.net>
1692 Update for 2.5.49, description for most of the options introduced,
1693 references to other documentation (C files, READMEs, ..), added S390,
1694 PPC, SPARC, MTD, ALSA and OSS category. Minor corrections and
1695 reformatting.
1696
16972005-10-19 Randy Dunlap <rdunlap@xenotime.net>
1698 Lots of typos, whitespace, some reformatting.
1699 1693
1700TODO: 1694TODO:
1701 1695
diff --git a/Documentation/networking/packet_mmap.txt b/Documentation/networking/packet_mmap.txt
index 4fc8e9874320..aaf99d5f0dad 100644
--- a/Documentation/networking/packet_mmap.txt
+++ b/Documentation/networking/packet_mmap.txt
@@ -254,7 +254,7 @@ and, the number of frames be
254 254
255 <block number> * <block size> / <frame size> 255 <block number> * <block size> / <frame size>
256 256
257Suposse the following parameters, which apply for 2.6 kernel and an 257Suppose the following parameters, which apply for 2.6 kernel and an
258i386 architecture: 258i386 architecture:
259 259
260 <size-max> = 131072 bytes 260 <size-max> = 131072 bytes
diff --git a/Documentation/networking/tuntap.txt b/Documentation/networking/tuntap.txt
index ec3d109d787a..76750fb9151a 100644
--- a/Documentation/networking/tuntap.txt
+++ b/Documentation/networking/tuntap.txt
@@ -138,7 +138,7 @@ This means that you have to read/write IP packets when you are using tun and
138ethernet frames when using tap. 138ethernet frames when using tap.
139 139
1405. What is the difference between BPF and TUN/TAP driver? 1405. What is the difference between BPF and TUN/TAP driver?
141BFP is an advanced packet filter. It can be attached to existing 141BPF is an advanced packet filter. It can be attached to existing
142network interface. It does not provide a virtual network interface. 142network interface. It does not provide a virtual network interface.
143A TUN/TAP driver does provide a virtual network interface and it is possible 143A TUN/TAP driver does provide a virtual network interface and it is possible
144to attach BPF to this interface. 144to attach BPF to this interface.