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authorJiri Kosina <jkosina@suse.cz>2010-04-22 20:08:44 -0400
committerJiri Kosina <jkosina@suse.cz>2010-04-22 20:08:44 -0400
commit6c9468e9eb1252eaefd94ce7f06e1be9b0b641b1 (patch)
tree797676a336b050bfa1ef879377c07e541b9075d6 /Documentation/networking
parent4cb3ca7cd7e2cae8d1daf5345ec99a1e8502cf3f (diff)
parentc81eddb0e3728661d1585fbc564449c94165cc36 (diff)
Merge branch 'master' into for-next
Diffstat (limited to 'Documentation/networking')
-rw-r--r--Documentation/networking/Makefile2
-rw-r--r--Documentation/networking/stmmac.txt143
-rw-r--r--Documentation/networking/timestamping.txt76
-rw-r--r--Documentation/networking/timestamping/Makefile11
-rw-r--r--Documentation/networking/timestamping/timestamping.c10
5 files changed, 205 insertions, 37 deletions
diff --git a/Documentation/networking/Makefile b/Documentation/networking/Makefile
index 6d8af1ac56c4..5aba7a33aeeb 100644
--- a/Documentation/networking/Makefile
+++ b/Documentation/networking/Makefile
@@ -6,3 +6,5 @@ hostprogs-y := ifenslave
6 6
7# Tell kbuild to always build the programs 7# Tell kbuild to always build the programs
8always := $(hostprogs-y) 8always := $(hostprogs-y)
9
10obj-m := timestamping/
diff --git a/Documentation/networking/stmmac.txt b/Documentation/networking/stmmac.txt
new file mode 100644
index 000000000000..7ee770b5ef5f
--- /dev/null
+++ b/Documentation/networking/stmmac.txt
@@ -0,0 +1,143 @@
1 STMicroelectronics 10/100/1000 Synopsys Ethernet driver
2
3Copyright (C) 2007-2010 STMicroelectronics Ltd
4Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
5
6This is the driver for the MAC 10/100/1000 on-chip Ethernet controllers
7(Synopsys IP blocks); it has been fully tested on STLinux platforms.
8
9Currently this network device driver is for all STM embedded MAC/GMAC
10(7xxx SoCs).
11
12DWC Ether MAC 10/100/1000 Universal version 3.41a and DWC Ether MAC 10/100
13Universal version 4.0 have been used for developing the first code
14implementation.
15
16Please, for more information also visit: www.stlinux.com
17
181) Kernel Configuration
19The kernel configuration option is STMMAC_ETH:
20 Device Drivers ---> Network device support ---> Ethernet (1000 Mbit) --->
21 STMicroelectronics 10/100/1000 Ethernet driver (STMMAC_ETH)
22
232) Driver parameters list:
24 debug: message level (0: no output, 16: all);
25 phyaddr: to manually provide the physical address to the PHY device;
26 dma_rxsize: DMA rx ring size;
27 dma_txsize: DMA tx ring size;
28 buf_sz: DMA buffer size;
29 tc: control the HW FIFO threshold;
30 tx_coe: Enable/Disable Tx Checksum Offload engine;
31 watchdog: transmit timeout (in milliseconds);
32 flow_ctrl: Flow control ability [on/off];
33 pause: Flow Control Pause Time;
34 tmrate: timer period (only if timer optimisation is configured).
35
363) Command line options
37Driver parameters can be also passed in command line by using:
38 stmmaceth=dma_rxsize:128,dma_txsize:512
39
404) Driver information and notes
41
424.1) Transmit process
43The xmit method is invoked when the kernel needs to transmit a packet; it sets
44the descriptors in the ring and informs the DMA engine that there is a packet
45ready to be transmitted.
46Once the controller has finished transmitting the packet, an interrupt is
47triggered; So the driver will be able to release the socket buffers.
48By default, the driver sets the NETIF_F_SG bit in the features field of the
49net_device structure enabling the scatter/gather feature.
50
514.2) Receive process
52When one or more packets are received, an interrupt happens. The interrupts
53are not queued so the driver has to scan all the descriptors in the ring during
54the receive process.
55This is based on NAPI so the interrupt handler signals only if there is work to be
56done, and it exits.
57Then the poll method will be scheduled at some future point.
58The incoming packets are stored, by the DMA, in a list of pre-allocated socket
59buffers in order to avoid the memcpy (Zero-copy).
60
614.3) Timer-Driver Interrupt
62Instead of having the device that asynchronously notifies the frame receptions, the
63driver configures a timer to generate an interrupt at regular intervals.
64Based on the granularity of the timer, the frames that are received by the device
65will experience different levels of latency. Some NICs have dedicated timer
66device to perform this task. STMMAC can use either the RTC device or the TMU
67channel 2 on STLinux platforms.
68The timers frequency can be passed to the driver as parameter; when change it,
69take care of both hardware capability and network stability/performance impact.
70Several performance tests on STM platforms showed this optimisation allows to spare
71the CPU while having the maximum throughput.
72
734.4) WOL
74Wake up on Lan feature through Magic Frame is only supported for the GMAC
75core.
76
774.5) DMA descriptors
78Driver handles both normal and enhanced descriptors. The latter has been only
79tested on DWC Ether MAC 10/100/1000 Universal version 3.41a.
80
814.6) Ethtool support
82Ethtool is supported. Driver statistics and internal errors can be taken using:
83ethtool -S ethX command. It is possible to dump registers etc.
84
854.7) Jumbo and Segmentation Offloading
86Jumbo frames are supported and tested for the GMAC.
87The GSO has been also added but it's performed in software.
88LRO is not supported.
89
904.8) Physical
91The driver is compatible with PAL to work with PHY and GPHY devices.
92
934.9) Platform information
94Several information came from the platform; please refer to the
95driver's Header file in include/linux directory.
96
97struct plat_stmmacenet_data {
98 int bus_id;
99 int pbl;
100 int has_gmac;
101 void (*fix_mac_speed)(void *priv, unsigned int speed);
102 void (*bus_setup)(unsigned long ioaddr);
103#ifdef CONFIG_STM_DRIVERS
104 struct stm_pad_config *pad_config;
105#endif
106 void *bsp_priv;
107};
108
109Where:
110- pbl (Programmable Burst Length) is maximum number of
111 beats to be transferred in one DMA transaction.
112 GMAC also enables the 4xPBL by default.
113- fix_mac_speed and bus_setup are used to configure internal target
114 registers (on STM platforms);
115- has_gmac: GMAC core is on board (get it at run-time in the next step);
116- bus_id: bus identifier.
117
118struct plat_stmmacphy_data {
119 int bus_id;
120 int phy_addr;
121 unsigned int phy_mask;
122 int interface;
123 int (*phy_reset)(void *priv);
124 void *priv;
125};
126
127Where:
128- bus_id: bus identifier;
129- phy_addr: physical address used for the attached phy device;
130 set it to -1 to get it at run-time;
131- interface: physical MII interface mode;
132- phy_reset: hook to reset HW function.
133
134TODO:
135- Continue to make the driver more generic and suitable for other Synopsys
136 Ethernet controllers used on other architectures (i.e. ARM).
137- 10G controllers are not supported.
138- MAC uses Normal descriptors and GMAC uses enhanced ones.
139 This is a limit that should be reviewed. MAC could want to
140 use the enhanced structure.
141- Checksumming: Rx/Tx csum is done in HW in case of GMAC only.
142- Review the timer optimisation code to use an embedded device that seems to be
143 available in new chip generations.
diff --git a/Documentation/networking/timestamping.txt b/Documentation/networking/timestamping.txt
index 0e58b4539176..e8c8f4f06c67 100644
--- a/Documentation/networking/timestamping.txt
+++ b/Documentation/networking/timestamping.txt
@@ -41,11 +41,12 @@ SOF_TIMESTAMPING_SOFTWARE: return system time stamp generated in
41SOF_TIMESTAMPING_TX/RX determine how time stamps are generated. 41SOF_TIMESTAMPING_TX/RX determine how time stamps are generated.
42SOF_TIMESTAMPING_RAW/SYS determine how they are reported in the 42SOF_TIMESTAMPING_RAW/SYS determine how they are reported in the
43following control message: 43following control message:
44 struct scm_timestamping { 44
45 struct timespec systime; 45struct scm_timestamping {
46 struct timespec hwtimetrans; 46 struct timespec systime;
47 struct timespec hwtimeraw; 47 struct timespec hwtimetrans;
48 }; 48 struct timespec hwtimeraw;
49};
49 50
50recvmsg() can be used to get this control message for regular incoming 51recvmsg() can be used to get this control message for regular incoming
51packets. For send time stamps the outgoing packet is looped back to 52packets. For send time stamps the outgoing packet is looped back to
@@ -87,12 +88,13 @@ by the network device and will be empty without that support.
87SIOCSHWTSTAMP: 88SIOCSHWTSTAMP:
88 89
89Hardware time stamping must also be initialized for each device driver 90Hardware time stamping must also be initialized for each device driver
90that is expected to do hardware time stamping. The parameter is: 91that is expected to do hardware time stamping. The parameter is defined in
92/include/linux/net_tstamp.h as:
91 93
92struct hwtstamp_config { 94struct hwtstamp_config {
93 int flags; /* no flags defined right now, must be zero */ 95 int flags; /* no flags defined right now, must be zero */
94 int tx_type; /* HWTSTAMP_TX_* */ 96 int tx_type; /* HWTSTAMP_TX_* */
95 int rx_filter; /* HWTSTAMP_FILTER_* */ 97 int rx_filter; /* HWTSTAMP_FILTER_* */
96}; 98};
97 99
98Desired behavior is passed into the kernel and to a specific device by 100Desired behavior is passed into the kernel and to a specific device by
@@ -139,42 +141,56 @@ enum {
139 /* time stamp any incoming packet */ 141 /* time stamp any incoming packet */
140 HWTSTAMP_FILTER_ALL, 142 HWTSTAMP_FILTER_ALL,
141 143
142 /* return value: time stamp all packets requested plus some others */ 144 /* return value: time stamp all packets requested plus some others */
143 HWTSTAMP_FILTER_SOME, 145 HWTSTAMP_FILTER_SOME,
144 146
145 /* PTP v1, UDP, any kind of event packet */ 147 /* PTP v1, UDP, any kind of event packet */
146 HWTSTAMP_FILTER_PTP_V1_L4_EVENT, 148 HWTSTAMP_FILTER_PTP_V1_L4_EVENT,
147 149
148 ... 150 /* for the complete list of values, please check
151 * the include file /include/linux/net_tstamp.h
152 */
149}; 153};
150 154
151 155
152DEVICE IMPLEMENTATION 156DEVICE IMPLEMENTATION
153 157
154A driver which supports hardware time stamping must support the 158A driver which supports hardware time stamping must support the
155SIOCSHWTSTAMP ioctl. Time stamps for received packets must be stored 159SIOCSHWTSTAMP ioctl and update the supplied struct hwtstamp_config with
156in the skb with skb_hwtstamp_set(). 160the actual values as described in the section on SIOCSHWTSTAMP.
161
162Time stamps for received packets must be stored in the skb. To get a pointer
163to the shared time stamp structure of the skb call skb_hwtstamps(). Then
164set the time stamps in the structure:
165
166struct skb_shared_hwtstamps {
167 /* hardware time stamp transformed into duration
168 * since arbitrary point in time
169 */
170 ktime_t hwtstamp;
171 ktime_t syststamp; /* hwtstamp transformed to system time base */
172};
157 173
158Time stamps for outgoing packets are to be generated as follows: 174Time stamps for outgoing packets are to be generated as follows:
159- In hard_start_xmit(), check if skb_hwtstamp_check_tx_hardware() 175- In hard_start_xmit(), check if skb_tx(skb)->hardware is set no-zero.
160 returns non-zero. If yes, then the driver is expected 176 If yes, then the driver is expected to do hardware time stamping.
161 to do hardware time stamping.
162- If this is possible for the skb and requested, then declare 177- If this is possible for the skb and requested, then declare
163 that the driver is doing the time stamping by calling 178 that the driver is doing the time stamping by setting the field
164 skb_hwtstamp_tx_in_progress(). A driver not supporting 179 skb_tx(skb)->in_progress non-zero. You might want to keep a pointer
165 hardware time stamping doesn't do that. A driver must never 180 to the associated skb for the next step and not free the skb. A driver
166 touch sk_buff::tstamp! It is used to store how time stamping 181 not supporting hardware time stamping doesn't do that. A driver must
167 for an outgoing packets is to be done. 182 never touch sk_buff::tstamp! It is used to store software generated
183 time stamps by the network subsystem.
168- As soon as the driver has sent the packet and/or obtained a 184- As soon as the driver has sent the packet and/or obtained a
169 hardware time stamp for it, it passes the time stamp back by 185 hardware time stamp for it, it passes the time stamp back by
170 calling skb_hwtstamp_tx() with the original skb, the raw 186 calling skb_hwtstamp_tx() with the original skb, the raw
171 hardware time stamp and a handle to the device (necessary 187 hardware time stamp. skb_hwtstamp_tx() clones the original skb and
172 to convert the hardware time stamp to system time). If obtaining 188 adds the timestamps, therefore the original skb has to be freed now.
173 the hardware time stamp somehow fails, then the driver should 189 If obtaining the hardware time stamp somehow fails, then the driver
174 not fall back to software time stamping. The rationale is that 190 should not fall back to software time stamping. The rationale is that
175 this would occur at a later time in the processing pipeline 191 this would occur at a later time in the processing pipeline than other
176 than other software time stamping and therefore could lead 192 software time stamping and therefore could lead to unexpected deltas
177 to unexpected deltas between time stamps. 193 between time stamps.
178- If the driver did not call skb_hwtstamp_tx_in_progress(), then 194- If the driver did not call set skb_tx(skb)->in_progress, then
179 dev_hard_start_xmit() checks whether software time stamping 195 dev_hard_start_xmit() checks whether software time stamping
180 is wanted as fallback and potentially generates the time stamp. 196 is wanted as fallback and potentially generates the time stamp.
diff --git a/Documentation/networking/timestamping/Makefile b/Documentation/networking/timestamping/Makefile
index 2a1489fdc036..e79973443e9f 100644
--- a/Documentation/networking/timestamping/Makefile
+++ b/Documentation/networking/timestamping/Makefile
@@ -1,6 +1,13 @@
1CPPFLAGS = -I../../../include 1# kbuild trick to avoid linker error. Can be omitted if a module is built.
2obj- := dummy.o
2 3
3timestamping: timestamping.c 4# List of programs to build
5hostprogs-y := timestamping
6
7# Tell kbuild to always build the programs
8always := $(hostprogs-y)
9
10HOSTCFLAGS_timestamping.o += -I$(objtree)/usr/include
4 11
5clean: 12clean:
6 rm -f timestamping 13 rm -f timestamping
diff --git a/Documentation/networking/timestamping/timestamping.c b/Documentation/networking/timestamping/timestamping.c
index bab619a48214..8ba82bfe6a33 100644
--- a/Documentation/networking/timestamping/timestamping.c
+++ b/Documentation/networking/timestamping/timestamping.c
@@ -41,9 +41,9 @@
41#include <arpa/inet.h> 41#include <arpa/inet.h>
42#include <net/if.h> 42#include <net/if.h>
43 43
44#include "asm/types.h" 44#include <asm/types.h>
45#include "linux/net_tstamp.h" 45#include <linux/net_tstamp.h>
46#include "linux/errqueue.h" 46#include <linux/errqueue.h>
47 47
48#ifndef SO_TIMESTAMPING 48#ifndef SO_TIMESTAMPING
49# define SO_TIMESTAMPING 37 49# define SO_TIMESTAMPING 37
@@ -164,7 +164,7 @@ static void printpacket(struct msghdr *msg, int res,
164 164
165 gettimeofday(&now, 0); 165 gettimeofday(&now, 0);
166 166
167 printf("%ld.%06ld: received %s data, %d bytes from %s, %d bytes control messages\n", 167 printf("%ld.%06ld: received %s data, %d bytes from %s, %zu bytes control messages\n",
168 (long)now.tv_sec, (long)now.tv_usec, 168 (long)now.tv_sec, (long)now.tv_usec,
169 (recvmsg_flags & MSG_ERRQUEUE) ? "error" : "regular", 169 (recvmsg_flags & MSG_ERRQUEUE) ? "error" : "regular",
170 res, 170 res,
@@ -173,7 +173,7 @@ static void printpacket(struct msghdr *msg, int res,
173 for (cmsg = CMSG_FIRSTHDR(msg); 173 for (cmsg = CMSG_FIRSTHDR(msg);
174 cmsg; 174 cmsg;
175 cmsg = CMSG_NXTHDR(msg, cmsg)) { 175 cmsg = CMSG_NXTHDR(msg, cmsg)) {
176 printf(" cmsg len %d: ", cmsg->cmsg_len); 176 printf(" cmsg len %zu: ", cmsg->cmsg_len);
177 switch (cmsg->cmsg_level) { 177 switch (cmsg->cmsg_level) {
178 case SOL_SOCKET: 178 case SOL_SOCKET:
179 printf("SOL_SOCKET "); 179 printf("SOL_SOCKET ");