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authorHerbert Xu <herbert@gondor.apana.org.au>2010-05-03 05:28:58 +0200
committerHerbert Xu <herbert@gondor.apana.org.au>2010-05-03 05:28:58 +0200
commitdf2071bd081408318d659cd14a9cf6ff23d874c9 (patch)
treeb31291b5fd4b9f84c629833afbfaa8d431857475 /Documentation/networking
parentpadata: Dont scale the parallel objects with the cpus (diff)
parentMerge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6 (diff)
downloadlinux-df2071bd081408318d659cd14a9cf6ff23d874c9.tar.xz
linux-df2071bd081408318d659cd14a9cf6ff23d874c9.zip
Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'Documentation/networking')
-rw-r--r--Documentation/networking/Makefile2
-rw-r--r--Documentation/networking/skfp.txt2
-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.c12
6 files changed, 207 insertions, 39 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
# Tell kbuild to always build the programs
always := $(hostprogs-y)
+
+obj-m := timestamping/
diff --git a/Documentation/networking/skfp.txt b/Documentation/networking/skfp.txt
index abfddf81e34a..203ec66c9fb4 100644
--- a/Documentation/networking/skfp.txt
+++ b/Documentation/networking/skfp.txt
@@ -68,7 +68,7 @@ Compaq adapters (not tested):
=======================
From v2.01 on, the driver is integrated in the linux kernel sources.
-Therefor, the installation is the same as for any other adapter
+Therefore, the installation is the same as for any other adapter
supported by the kernel.
Refer to the manual of your distribution about the installation
of network adapters.
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 @@
+ STMicroelectronics 10/100/1000 Synopsys Ethernet driver
+
+Copyright (C) 2007-2010 STMicroelectronics Ltd
+Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
+
+This is the driver for the MAC 10/100/1000 on-chip Ethernet controllers
+(Synopsys IP blocks); it has been fully tested on STLinux platforms.
+
+Currently this network device driver is for all STM embedded MAC/GMAC
+(7xxx SoCs).
+
+DWC Ether MAC 10/100/1000 Universal version 3.41a and DWC Ether MAC 10/100
+Universal version 4.0 have been used for developing the first code
+implementation.
+
+Please, for more information also visit: www.stlinux.com
+
+1) Kernel Configuration
+The kernel configuration option is STMMAC_ETH:
+ Device Drivers ---> Network device support ---> Ethernet (1000 Mbit) --->
+ STMicroelectronics 10/100/1000 Ethernet driver (STMMAC_ETH)
+
+2) Driver parameters list:
+ debug: message level (0: no output, 16: all);
+ phyaddr: to manually provide the physical address to the PHY device;
+ dma_rxsize: DMA rx ring size;
+ dma_txsize: DMA tx ring size;
+ buf_sz: DMA buffer size;
+ tc: control the HW FIFO threshold;
+ tx_coe: Enable/Disable Tx Checksum Offload engine;
+ watchdog: transmit timeout (in milliseconds);
+ flow_ctrl: Flow control ability [on/off];
+ pause: Flow Control Pause Time;
+ tmrate: timer period (only if timer optimisation is configured).
+
+3) Command line options
+Driver parameters can be also passed in command line by using:
+ stmmaceth=dma_rxsize:128,dma_txsize:512
+
+4) Driver information and notes
+
+4.1) Transmit process
+The xmit method is invoked when the kernel needs to transmit a packet; it sets
+the descriptors in the ring and informs the DMA engine that there is a packet
+ready to be transmitted.
+Once the controller has finished transmitting the packet, an interrupt is
+triggered; So the driver will be able to release the socket buffers.
+By default, the driver sets the NETIF_F_SG bit in the features field of the
+net_device structure enabling the scatter/gather feature.
+
+4.2) Receive process
+When one or more packets are received, an interrupt happens. The interrupts
+are not queued so the driver has to scan all the descriptors in the ring during
+the receive process.
+This is based on NAPI so the interrupt handler signals only if there is work to be
+done, and it exits.
+Then the poll method will be scheduled at some future point.
+The incoming packets are stored, by the DMA, in a list of pre-allocated socket
+buffers in order to avoid the memcpy (Zero-copy).
+
+4.3) Timer-Driver Interrupt
+Instead of having the device that asynchronously notifies the frame receptions, the
+driver configures a timer to generate an interrupt at regular intervals.
+Based on the granularity of the timer, the frames that are received by the device
+will experience different levels of latency. Some NICs have dedicated timer
+device to perform this task. STMMAC can use either the RTC device or the TMU
+channel 2 on STLinux platforms.
+The timers frequency can be passed to the driver as parameter; when change it,
+take care of both hardware capability and network stability/performance impact.
+Several performance tests on STM platforms showed this optimisation allows to spare
+the CPU while having the maximum throughput.
+
+4.4) WOL
+Wake up on Lan feature through Magic Frame is only supported for the GMAC
+core.
+
+4.5) DMA descriptors
+Driver handles both normal and enhanced descriptors. The latter has been only
+tested on DWC Ether MAC 10/100/1000 Universal version 3.41a.
+
+4.6) Ethtool support
+Ethtool is supported. Driver statistics and internal errors can be taken using:
+ethtool -S ethX command. It is possible to dump registers etc.
+
+4.7) Jumbo and Segmentation Offloading
+Jumbo frames are supported and tested for the GMAC.
+The GSO has been also added but it's performed in software.
+LRO is not supported.
+
+4.8) Physical
+The driver is compatible with PAL to work with PHY and GPHY devices.
+
+4.9) Platform information
+Several information came from the platform; please refer to the
+driver's Header file in include/linux directory.
+
+struct plat_stmmacenet_data {
+ int bus_id;
+ int pbl;
+ int has_gmac;
+ void (*fix_mac_speed)(void *priv, unsigned int speed);
+ void (*bus_setup)(unsigned long ioaddr);
+#ifdef CONFIG_STM_DRIVERS
+ struct stm_pad_config *pad_config;
+#endif
+ void *bsp_priv;
+};
+
+Where:
+- pbl (Programmable Burst Length) is maximum number of
+ beats to be transferred in one DMA transaction.
+ GMAC also enables the 4xPBL by default.
+- fix_mac_speed and bus_setup are used to configure internal target
+ registers (on STM platforms);
+- has_gmac: GMAC core is on board (get it at run-time in the next step);
+- bus_id: bus identifier.
+
+struct plat_stmmacphy_data {
+ int bus_id;
+ int phy_addr;
+ unsigned int phy_mask;
+ int interface;
+ int (*phy_reset)(void *priv);
+ void *priv;
+};
+
+Where:
+- bus_id: bus identifier;
+- phy_addr: physical address used for the attached phy device;
+ set it to -1 to get it at run-time;
+- interface: physical MII interface mode;
+- phy_reset: hook to reset HW function.
+
+TODO:
+- Continue to make the driver more generic and suitable for other Synopsys
+ Ethernet controllers used on other architectures (i.e. ARM).
+- 10G controllers are not supported.
+- MAC uses Normal descriptors and GMAC uses enhanced ones.
+ This is a limit that should be reviewed. MAC could want to
+ use the enhanced structure.
+- Checksumming: Rx/Tx csum is done in HW in case of GMAC only.
+- Review the timer optimisation code to use an embedded device that seems to be
+ 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
SOF_TIMESTAMPING_TX/RX determine how time stamps are generated.
SOF_TIMESTAMPING_RAW/SYS determine how they are reported in the
following control message:
- struct scm_timestamping {
- struct timespec systime;
- struct timespec hwtimetrans;
- struct timespec hwtimeraw;
- };
+
+struct scm_timestamping {
+ struct timespec systime;
+ struct timespec hwtimetrans;
+ struct timespec hwtimeraw;
+};
recvmsg() can be used to get this control message for regular incoming
packets. 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.
SIOCSHWTSTAMP:
Hardware time stamping must also be initialized for each device driver
-that is expected to do hardware time stamping. The parameter is:
+that is expected to do hardware time stamping. The parameter is defined in
+/include/linux/net_tstamp.h as:
struct hwtstamp_config {
- int flags; /* no flags defined right now, must be zero */
- int tx_type; /* HWTSTAMP_TX_* */
- int rx_filter; /* HWTSTAMP_FILTER_* */
+ int flags; /* no flags defined right now, must be zero */
+ int tx_type; /* HWTSTAMP_TX_* */
+ int rx_filter; /* HWTSTAMP_FILTER_* */
};
Desired behavior is passed into the kernel and to a specific device by
@@ -139,42 +141,56 @@ enum {
/* time stamp any incoming packet */
HWTSTAMP_FILTER_ALL,
- /* return value: time stamp all packets requested plus some others */
- HWTSTAMP_FILTER_SOME,
+ /* return value: time stamp all packets requested plus some others */
+ HWTSTAMP_FILTER_SOME,
/* PTP v1, UDP, any kind of event packet */
HWTSTAMP_FILTER_PTP_V1_L4_EVENT,
- ...
+ /* for the complete list of values, please check
+ * the include file /include/linux/net_tstamp.h
+ */
};
DEVICE IMPLEMENTATION
A driver which supports hardware time stamping must support the
-SIOCSHWTSTAMP ioctl. Time stamps for received packets must be stored
-in the skb with skb_hwtstamp_set().
+SIOCSHWTSTAMP ioctl and update the supplied struct hwtstamp_config with
+the actual values as described in the section on SIOCSHWTSTAMP.
+
+Time stamps for received packets must be stored in the skb. To get a pointer
+to the shared time stamp structure of the skb call skb_hwtstamps(). Then
+set the time stamps in the structure:
+
+struct skb_shared_hwtstamps {
+ /* hardware time stamp transformed into duration
+ * since arbitrary point in time
+ */
+ ktime_t hwtstamp;
+ ktime_t syststamp; /* hwtstamp transformed to system time base */
+};
Time stamps for outgoing packets are to be generated as follows:
-- In hard_start_xmit(), check if skb_hwtstamp_check_tx_hardware()
- returns non-zero. If yes, then the driver is expected
- to do hardware time stamping.
+- In hard_start_xmit(), check if skb_tx(skb)->hardware is set no-zero.
+ If yes, then the driver is expected to do hardware time stamping.
- If this is possible for the skb and requested, then declare
- that the driver is doing the time stamping by calling
- skb_hwtstamp_tx_in_progress(). A driver not supporting
- hardware time stamping doesn't do that. A driver must never
- touch sk_buff::tstamp! It is used to store how time stamping
- for an outgoing packets is to be done.
+ that the driver is doing the time stamping by setting the field
+ skb_tx(skb)->in_progress non-zero. You might want to keep a pointer
+ to the associated skb for the next step and not free the skb. A driver
+ not supporting hardware time stamping doesn't do that. A driver must
+ never touch sk_buff::tstamp! It is used to store software generated
+ time stamps by the network subsystem.
- As soon as the driver has sent the packet and/or obtained a
hardware time stamp for it, it passes the time stamp back by
calling skb_hwtstamp_tx() with the original skb, the raw
- hardware time stamp and a handle to the device (necessary
- to convert the hardware time stamp to system time). If obtaining
- the hardware time stamp somehow fails, then the driver should
- not fall back to software time stamping. The rationale is that
- this would occur at a later time in the processing pipeline
- than other software time stamping and therefore could lead
- to unexpected deltas between time stamps.
-- If the driver did not call skb_hwtstamp_tx_in_progress(), then
+ hardware time stamp. skb_hwtstamp_tx() clones the original skb and
+ adds the timestamps, therefore the original skb has to be freed now.
+ If obtaining the hardware time stamp somehow fails, then the driver
+ should not fall back to software time stamping. The rationale is that
+ this would occur at a later time in the processing pipeline than other
+ software time stamping and therefore could lead to unexpected deltas
+ between time stamps.
+- If the driver did not call set skb_tx(skb)->in_progress, then
dev_hard_start_xmit() checks whether software time stamping
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 @@
-CPPFLAGS = -I../../../include
+# kbuild trick to avoid linker error. Can be omitted if a module is built.
+obj- := dummy.o
-timestamping: timestamping.c
+# List of programs to build
+hostprogs-y := timestamping
+
+# Tell kbuild to always build the programs
+always := $(hostprogs-y)
+
+HOSTCFLAGS_timestamping.o += -I$(objtree)/usr/include
clean:
rm -f timestamping
diff --git a/Documentation/networking/timestamping/timestamping.c b/Documentation/networking/timestamping/timestamping.c
index a7936fe8444a..8ba82bfe6a33 100644
--- a/Documentation/networking/timestamping/timestamping.c
+++ b/Documentation/networking/timestamping/timestamping.c
@@ -41,9 +41,9 @@
#include <arpa/inet.h>
#include <net/if.h>
-#include "asm/types.h"
-#include "linux/net_tstamp.h"
-#include "linux/errqueue.h"
+#include <asm/types.h>
+#include <linux/net_tstamp.h>
+#include <linux/errqueue.h>
#ifndef SO_TIMESTAMPING
# define SO_TIMESTAMPING 37
@@ -164,7 +164,7 @@ static void printpacket(struct msghdr *msg, int res,
gettimeofday(&now, 0);
- printf("%ld.%06ld: received %s data, %d bytes from %s, %d bytes control messages\n",
+ printf("%ld.%06ld: received %s data, %d bytes from %s, %zu bytes control messages\n",
(long)now.tv_sec, (long)now.tv_usec,
(recvmsg_flags & MSG_ERRQUEUE) ? "error" : "regular",
res,
@@ -173,7 +173,7 @@ static void printpacket(struct msghdr *msg, int res,
for (cmsg = CMSG_FIRSTHDR(msg);
cmsg;
cmsg = CMSG_NXTHDR(msg, cmsg)) {
- printf(" cmsg len %d: ", cmsg->cmsg_len);
+ printf(" cmsg len %zu: ", cmsg->cmsg_len);
switch (cmsg->cmsg_level) {
case SOL_SOCKET:
printf("SOL_SOCKET ");
@@ -370,7 +370,7 @@ int main(int argc, char **argv)
}
sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
- if (socket < 0)
+ if (sock < 0)
bail("socket");
memset(&device, 0, sizeof(device));