- 15 Feb, 2021 38 commits
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Eric Dumazet authored
My prior cleanup missed that tcp_data_ready() has to look at SOCK_DONE. Otherwise, an application using SO_RCVLOWAT will not get EPOLLIN event if a FIN is received in the middle of expected payload. The reason SOCK_DONE is not examined in tcp_epollin_ready() is that tcp_poll() catches the FIN because tcp_fin() is also setting RCV_SHUTDOWN into sk->sk_shutdown Fixes: 05dc72ab ("tcp: factorize logic into tcp_epollin_ready()") Signed-off-by:
Eric Dumazet <edumazet@google.com> Reported-by:
Wei Wang <weiwan@google.com> Cc: Arjun Roy <arjunroy@google.com> Reviewed-by:
David S. Miller <davem@davemloft.net>
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David S. Miller authored
Vladimir Oltean says: ==================== Fix buggy brport flags offload for SJA1105 DSA While testing the "Software fallback for bridging in DSA" on sja1105, I discovered that I managed to introduce two bugs in a single patch submitted recently to net-next. ==================== Signed-off-by: -
Vladimir Oltean authored
The prototype of br_vlan_filter_toggle was updated to include a netlink extack, but the stub definition wasn't, which results in a build error when CONFIG_BRIDGE_VLAN_FILTERING=n. Fixes: 9e781401 ("net: bridge: propagate extack through store_bridge_parm") Signed-off-by:
Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by:
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Vladimir Oltean authored
The switchdev_port_attr_set function prototype was updated only for the case where CONFIG_SWITCHDEV=y|m, leaving a prototype mismatch with the stub definition for the disabled case. This results in a build error, so update that function too. Fixes: dcbdf135 ("net: bridge: propagate extack through switchdev_port_attr_set") Signed-off-by:
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Vladimir Oltean authored
Smatch is confused by the fact that a 32-bit BIT(port) macro is passed as argument to the ocelot_ifh_set_dest function and warns: ocelot_xmit() warn: should '(((1))) << (dp->index)' be a 64 bit type? seville_xmit() warn: should '(((1))) << (dp->index)' be a 64 bit type? The destination port mask is copied into a 12-bit field of the packet, starting at bit offset 67 and ending at 56. So this DSA tagging protocol supports at most 12 bits, which is clearly less than 32. Attempting to send to a port number > 12 will cause the packing() call to truncate way before there will be 32-bit truncation due to type promotion of the BIT(port) argument towards u64. Therefore, smatch's fears that BIT(port) will do the wrong thing and cause unexpected truncation for "port" values >= 32 are unfounded. Nonetheless, let's silence the warning by explicitly passing an u64 value to ocelot_ifh_set_dest, such that the compiler does not need to do a questionable type promotion. Reported-by:
kernel test robot <lkp@intel.com> Reported-by:
Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
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Heiner Kallweit authored
Armin reported that after referenced commit his RTL8105e is dead when resuming from suspend and machine runs on battery. This patch has been confirmed to fix the issue. Fixes: e80bd76f ("r8169: work around power-saving bug on some chip versions") Reported-by:
Armin Wolf <W_Armin@gmx.de> Tested-by:
Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by:
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David S. Miller authored
Stefan Chulski says: ==================== net: mvpp2: Minor non functional driver code improvements The patch series contains minor code improvements and did not change any functionality. ==================== Signed-off-by: -
Stefan Chulski authored
GENCONF_CTRL0_PORTX naming improved. Non functional change. Signed-off-by:
Stefan Chulski <stefanc@marvell.com> Signed-off-by:
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Stefan Chulski authored
Use PTR_ERR_OR_ZERO instead of IS_ERR and PTR_ERR. Non functional change. Signed-off-by:
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Stefan Chulski authored
Use >= MVPP22 instead of != MVPP21. Non functional change. Signed-off-by:
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Stefan Chulski authored
PPv2.1 contain 0 in Version ID register, priv->hw_version check can be removed. Signed-off-by:
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David S. Miller authored
Vladimir Oltean says: ==================== Propagate extack for switchdev VLANs from DSA This series moves the restriction messages printed by the DSA core, and by some individual device drivers, into the netlink extended ack structure, to be communicated to user space where possible, or still printed to the kernel log from the bridge layer. ==================== Signed-off-by: -
Vladimir Oltean authored
Some drivers can't dynamically change the VLAN filtering option, or impose some restrictions, it would be nice to propagate this info through netlink instead of printing it to a kernel log that might never be read. Also netlink extack includes the module that emitted the message, which means that it's easier to figure out which ones are driver-generated errors as opposed to command misuse. Signed-off-by:
Florian Fainelli <f.fainelli@gmail.com> Signed-off-by:
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Vladimir Oltean authored
Allow drivers to communicate their restrictions to user space directly, instead of printing to the kernel log. Where the conversion would have been lossy and things like VLAN ID could no longer be conveyed (due to the lack of support for printf format specifier in netlink extack), I chose to keep the messages in full form to the kernel log only, and leave it up to individual driver maintainers to move more messages to extack. Signed-off-by:
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Vladimir Oltean authored
The benefit is the ability to propagate errors from switchdev drivers for the SWITCHDEV_ATTR_ID_BRIDGE_VLAN_FILTERING and SWITCHDEV_ATTR_ID_BRIDGE_VLAN_PROTOCOL attributes. Signed-off-by:
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Vladimir Oltean authored
The bridge sysfs interface stores parameters for the STP, VLAN, multicast etc subsystems using a predefined function prototype. Sometimes the underlying function being called supports a netlink extended ack message, and we ignore it. Let's expand the store_bridge_parm function prototype to include the extack, and just print it to console, but at least propagate it where applicable. Where not applicable, create a shim function in the br_sysfs_br.c file that discards the extra function argument. This patch allows us to propagate the extack argument to br_vlan_set_default_pvid, br_vlan_set_proto and br_vlan_filter_toggle, and from there, further up in br_changelink from br_netlink.c. Signed-off-by:
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Vladimir Oltean authored
This function is identical with br_vlan_filter_toggle. Signed-off-by:
Nikolay Aleksandrov <nikolay@nvidia.com> Signed-off-by:
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David S. Miller authored
Vladimir Oltean says: ==================== PTP for DSA tag_ocelot_8021q Changes in v2: Add stub definition for ocelot_port_inject_frame when switch driver is not compiled in. This is part two of the errata workaround begun here: https://patchwork.kernel.org/project/netdevbpf/cover/20210129010009.3959398-1-olteanv@gmail.com/ Now that we have basic traffic support when we operate the Ocelot DSA switches without an NPI port, it would be nice to regain some of the features lost due to the lack of the NPI port functionality. An important one is PTP timestamping, which is intimately tied to the DSA frame header added by the NPI port: on TX, we put a "timestamp request ID" in the Injection Frame Header, while on RX, the Extraction Frame Header contains a partial 32-bit PTP timestamp. Get rid of the NPI port and replace it with a VLAN-based tagger, and you lose PTP, right? Well, not quite, this is what this patch series is about. The NPI port is basically a regular Ethernet port configured to service the packets in and out of the switch's CPU port module (which has other non-DSA I/O mechanisms too, such as register-based MMIO and DMA). If we disable the NPI port, we can in theory still access the packets delivered to the CPU port module by doing exactly what the ocelot switchdev driver does: extracting Ethernet packets through registers (yes, it is as icky as it sounds). However, there's a catch. The Felix switch was integrated into NXP LS1028A with the idea in mind that it will operate as DSA, i.e. using the CPU port module connected to the NPI port, not having I/O over register-based MMIO which is painfully slow and CPU intensive. So register-based packet I/O not supposed to work - those registers aren't even documented in the hardware reference manual for Felix. However they kinda do, with the exception of the fact that an RX interrupt was really not wired to the CPU cores - so we don't know when the CPU port module receives a new packet. But we can hack even around that, by replicating every packet that goes to the CPU port module and making it also go to a plain internal Ethernet port. Then drop the Ethernet packet and read the other copy of it from the CPU port module, this time annotated with the much-wanted RX timestamp. This is all fine and it works, but it does raise some questions about what DSA even is anymore, if we start having switches that inject some of their packets over Ethernet and some through registers, where do we draw the line. In principle I believe these concerns are founded, but at the same time, the way that the Felix driver uses register MMIO based packet I/O is fundamentally the same as any other DSA driver capable of PTP makes use of a side-channel for timestamps like a FIFO (just that this one is a lot more complicated, and comes with the entire actual packet, not just the timestamp). Nonetheless, I tried to keep the extra pressure added by this ERR workaround upon the DSA subsystem as small as possible, so some of the patches are just a revisit of some of Andrew's complaints w.r.t. the fact that tag_ocelot already violates any driver <-> tagger boundary, and as a consequence, is not able to be used on testbeds such as dsa_loop (which it now can). So now, the tag_ocelot and tag_ocelot_8021q drivers should be dsa_loop-clean, and have the ERR workarounds as self-contained as possible, using all the designated features for PTP timestamping and nothing more. Comments appreciated. ==================== Signed-off-by:
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Vladimir Oltean authored
For TX timestamping, we use the felix_txtstamp method which is common with the regular (non-8021q) ocelot tagger. This method says that skb deferral is needed, prepares a timestamp request ID, and puts a clone of the skb in a queue waiting for the timestamp IRQ. felix_txtstamp is called by dsa_skb_tx_timestamp() just before the tagger's xmit method. In the tagger xmit, we divert the packets classified by dsa_skb_tx_timestamp() as PTP towards the MMIO-based injection registers, and we declare them as dead towards dsa_slave_xmit. If not PTP, we proceed with normal tag_8021q stuff. Then the timestamp IRQ fires, the clone queued up from felix_txtstamp is matched to the TX timestamp retrieved from the switch's FIFO based on the timestamp request ID, and the clone is delivered to the stack. On RX, thanks to the VCAP IS2 rule that redirects the frames with an EtherType for 1588 towards two destinations: - the CPU port module (for MMIO based extraction) and - if the "no XTR IRQ" workaround is in place, the dsa_8021q CPU port the relevant data path processing starts in the ptp_classify_raw BPF classifier installed by DSA in the RX data path (post tagger, which is completely unaware that it saw a PTP packet). This time we can't reuse the same implementation of .port_rxtstamp that also works with the default ocelot tagger. That is because felix_rxtstamp is given an skb with a freshly stripped DSA header, and it says "I don't need deferral for its RX timestamp, it's right in it, let me show you"; and it just points to the header right behind skb->data, from where it unpacks the timestamp and annotates the skb with it. The same thing cannot happen with tag_ocelot_8021q, because for one thing, the skb did not have an extraction frame header in the first place, but a VLAN tag with no timestamp information. So the code paths in felix_rxtstamp for the regular and 8021q tagger are completely independent. With tag_8021q, the timestamp must come from the packet's duplicate delivered to the CPU port module, but there is potentially complex logic to be handled [ and prone to reordering ] if we were to just start reading packets from the CPU port module, and try to match them to the one we received over Ethernet and which needs an RX timestamp. So we do something simple: we tell DSA "give me some time to think" (we request skb deferral by returning false from .port_rxtstamp) and we just drop the frame we got over Ethernet with no attempt to match it to anything - we just treat it as a notification that there's data to be processed from the CPU port module's queues. Then we proceed to read the packets from those, one by one, which we deliver up the stack, timestamped, using netif_rx - the same function that any driver would use anyway if it needed RX timestamp deferral. So the assumption is that we'll come across the PTP packet that triggered the CPU extraction notification eventually, but we don't know when exactly. Thanks to the VCAP IS2 trap/redirect rule and the exclusion of the CPU port module from the flooding replicators, only PTP frames should be present in the CPU port module's RX queues anyway. There is just one conflict between the VCAP IS2 trapping rule and the semantics of the BPF classifier. Namely, ptp_classify_raw() deems general messages as non-timestampable, but still, those are trapped to the CPU port module since they have an EtherType of ETH_P_1588. So, if the "no XTR IRQ" workaround is in place, we need to run another BPF classifier on the frames extracted over MMIO, to avoid duplicates being sent to the stack (once over Ethernet, once over MMIO). It doesn't look like it's possible to install VCAP IS2 rules based on keys extracted from the 1588 frame headers. Signed-off-by:
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Vladimir Oltean authored
Since the tag_8021q tagger is software-defined, it has no means by itself for retrieving hardware timestamps of PTP event messages. Because we do want to support PTP on ocelot even with tag_8021q, we need to use the CPU port module for that. The RX timestamp is present in the Extraction Frame Header. And because we can't use NPI mode which redirects the CPU queues to an "external CPU" (meaning the ARM CPU running Linux), then we need to poll the CPU port module through the MMIO registers to retrieve TX and RX timestamps. Sadly, on NXP LS1028A, the Felix switch was integrated into the SoC without wiring the extraction IRQ line to the ARM GIC. So, if we want to be notified of any PTP packets received on the CPU port module, we have a problem. There is a possible workaround, which is to use the Ethernet CPU port as a notification channel that packets are available on the CPU port module as well. When a PTP packet is received by the DSA tagger (without timestamp, of course), we go to the CPU extraction queues, poll for it there, then we drop the original Ethernet packet and masquerade the packet retrieved over MMIO (plus the timestamp) as the original when we inject it up the stack. Create a quirk in struct felix is selected by the Felix driver (but not by Seville, since that doesn't support PTP at all). We want to do this such that the workaround is minimally invasive for future switches that don't require this workaround. The only traffic for which we need timestamps is PTP traffic, so add a redirection rule to the CPU port module for this. Currently we only have the need for PTP over L2, so redirection rules for UDP ports 319 and 320 are TBD for now. Note that for the workaround of matching of PTP-over-Ethernet-port with PTP-over-MMIO queues to work properly, both channels need to be absolutely lossless. There are two parts to achieving that: - We keep flow control enabled on the tag_8021q CPU port - We put the DSA master interface in promiscuous mode, so it will never drop a PTP frame (for the profiles we are interested in, these are sent to the multicast MAC addresses of 01-80-c2-00-00-0e and 01-1b-19-00-00-00). Signed-off-by:
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Vladimir Oltean authored
Since the felix DSA driver will need to poll the CPU port module for extracted frames as well, let's create some common functions that read an Extraction Frame Header, and then an skb, from a CPU extraction group. We abuse the struct ocelot_ops :: port_to_netdev function a little bit, in order to retrieve the DSA port net_device or the ocelot switchdev net_device based on the source port information from the Extraction Frame Header, but it's all in the benefit of code simplification - netdev_alloc_skb needs it. Originally, the port_to_netdev method was intended for parsing act->dev from tc flower offload code. Signed-off-by:
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Vladimir Oltean authored
The ocelot tagger is a hot mess currently, it relies on memory initialized by the attached driver for basic frame transmission. This is against all that DSA tagging protocols stand for, which is that the transmission and reception of a DSA-tagged frame, the data path, should be independent from the switch control path, because the tag protocol is in principle hot-pluggable and reusable across switches (even if in practice it wasn't until very recently). But if another driver like dsa_loop wants to make use of tag_ocelot, it couldn't. This was done to have common code between Felix and Ocelot, which have one bit difference in the frame header format. Quoting from commit 67c24049 ("net: dsa: felix: create a template for the DSA tags on xmit"): Other alternatives have been analyzed, such as: - Create a separate tag_seville.c: too much code duplication for just 1 bit field difference. - Create a separate DSA_TAG_PROTO_SEVILLE under tag_ocelot.c, just like tag_brcm.c, which would have a separate .xmit function. Again, too much code duplication for just 1 bit field difference. - Allocate the template from the init function of the tag_ocelot.c module, instead of from the driver: couldn't figure out a method of accessing the correct port template corresponding to the correct tagger in the .xmit function. The really interesting part is that Seville should have had its own tagging protocol defined - it is not compatible on the wire with Ocelot, even for that single bit. In principle, a packet generated by DSA_TAG_PROTO_OCELOT when booted on NXP LS1028A would look in a certain way, but when booted on NXP T1040 it would look differently. The reverse is also true: a packet generated by a Seville switch would be interpreted incorrectly by Wireshark if it was told it was generated by an Ocelot switch. Actually things are a bit more nuanced. If we concentrate only on the DSA tag, what I said above is true, but Ocelot/Seville also support an optional DSA tag prefix, which can be short or long, and it is possible to distinguish the two taggers based on an integer constant put in that prefix. Nonetheless, creating a separate tagger is still justified, since the tag prefix is optional, and without it, there is again no way to distinguish. Claiming backwards binary compatibility is a bit more tough, since I've already changed the format of tag_ocelot once, in commit 5124197c ("net: dsa: tag_ocelot: use a short prefix on both ingress and egress"). Therefore I am not very concerned with treating this as a bugfix and backporting it to stable kernels (which would be another mess due to the fact that there would be lots of conflicts with the other DSA_TAG_PROTO* definitions). It's just simpler to say that the string values of the taggers have ABI value starting with kernel 5.12, which will be when the changing of tag protocol via /sys/class/net/<dsa-master>/dsa/tagging goes live. Signed-off-by:
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Vladimir Oltean authored
There is one place where we cannot avoid accessing driver data, and that is 2-step PTP TX timestamping, since the switch wants us to provide a timestamp request ID through the injection header, which naturally must come from a sequence number kept by the driver (it is generated by the .port_txtstamp method prior to the tagger's xmit). However, since other drivers like dsa_loop do not claim PTP support anyway, the DSA_SKB_CB(skb)->clone will always be NULL anyway, so if we move all PTP-related dereferences of struct ocelot and struct ocelot_port into a separate function, we can effectively ensure that this is dead code when the ocelot tagger is attached to non-ocelot switches, and the stateful portion of the tagger is more self-contained. Signed-off-by:
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Vladimir Oltean authored
The Injection Frame Header and Extraction Frame Header that the switch prepends to frames over the NPI port is also prepended to frames delivered over the CPU port module's queues. Let's unify the handling of the frame headers by making the ocelot driver call some helpers exported by the DSA tagger. Among other things, this allows us to get rid of the strange cpu_to_be32 when transmitting the Injection Frame Header on ocelot, since the packing API uses network byte order natively (when "quirks" is 0). The comments above ocelot_gen_ifh talk about setting pop_cnt to 3, and the cpu extraction queue mask to something, but the code doesn't do it, so we don't do it either. Signed-off-by:
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Vladimir Oltean authored
Taggers should be written to do something valid irrespective of the switch driver that they are attached to. This is even more true now, because since the introduction of the .change_tag_protocol method, a certain tagger is not necessarily strictly associated with a driver any longer, and I would like to be able to test all taggers with dsa_loop in the future. In the case of ocelot, it needs to move the classified VLAN from the DSA tag into the skb if the port is VLAN-aware. We can allow it to do that by looking at the dp->vlan_filtering property, no need to invoke structures which are specific to ocelot. Signed-off-by:
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Vladimir Oltean authored
The felix DSA driver will inject some frames through register MMIO, same as ocelot switchdev currently does. So we need to be able to reuse the common code. Also create some shim definitions, since the DSA tagger can be compiled without support for the switch driver. Signed-off-by:
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Vladimir Oltean authored
This looks a bit nicer than the open-coded "(x + 3) % 4" idiom. Signed-off-by:
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Vladimir Oltean authored
The ocelot_rx_frame_word() function can return a negative error code, however this isn't being checked for consistently. Errors being ignored have not been seen in practice though. Also, some constructs can be simplified by using "goto" instead of repeated "break" statements. Signed-off-by:
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Vladimir Oltean authored
It appears that the intention of this snippet of code is to not exit ocelot_xtr_irq_handler() while in the middle of extracting a frame. The problem in extracting it word by word is that future extraction attempts are really easy to get desynchronized, since the IRQ handler assumes that the first 16 bytes are the IFH, which give further information about the frame, such as frame length. But during normal operation, "err" will not be 0, but 4, set from here: for (i = 0; i < OCELOT_TAG_LEN / 4; i++) { err = ocelot_rx_frame_word(ocelot, grp, true, &ifh[i]); if (err != 4) break; } if (err != 4) break; In that case, draining the extraction queue is a no-op. So explicitly make this code execute only on negative err. Signed-off-by: -
Vladimir Oltean authored
Since the xtr (extraction) IRQ of the ocelot switch is not shared, then if it fired, it means that some data must be present in the queues of the CPU port module. So simplify the code. Signed-off-by:
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David S. Miller authored
Michael Chan says: ==================== bnxt_en: Error recovery optimizations. This series implements some optimizations to error recovery. One patch adds an echo/reply mechanism with firmware to enhance error detection. The other patches speed up the recovery process by polling config space earlier and to selectively initialize context memory during re-initialization. ==================== Signed-off-by: -
Michael Chan authored
We currently only log the error recovery settings if it is enabled. In some cases, firmware disables error recovery after it was initially enabled. Without logging anything, the user will not be aware of this change in setting. Log it when error recovery is disabled. Also, change the reset count value from hexadecimal to decimal. Reviewed-by:
Edwin Peer <edwin.peer@broadcom.com> Reviewed-by:
Pavan Chebbi <pavan.chebbi@broadcom.com> Signed-off-by:
Michael Chan <michael.chan@broadcom.com> Signed-off-by:
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Michael Chan authored
This is a new async message that the firmware can send to check if it can communicate with the driver. This is an added error detection scheme that firmware can use if it suspects errors in the PCIe interface. When the driver receives this async message, it will reply back echoing some data in the async message. If the firmware is not getting the reply with the proper data after some retries, error recovery will kick in. Reviewed-by:
Andy Gospodarek <gospo@broadcom.com> Reviewed-by:
Vasundhara Volam <vasundhara-v.volam@broadcom.com> Signed-off-by:
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Michael Chan authored
If firmware provides the offset to the "context kind" field of the relevant context memory blocks, we'll initialize just that field for each block instead of initializing all of context memory. Populate the bnxt_mem_init structure with the proper offset returned by firmware. If it is older firmware and the information is not available, we set the offset to an invalid value and fall back to the old behavior of initializing every byte. Otherwise, we initialize only the "context kind" byte at the offset. Reviewed-by:
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Michael Chan authored
Currently, the driver calls memset() to set all relevant context memory used by the chip to the initial value. This can take many milliseconds with the potentially large number of context pages allocated for the chip. To make this faster, we only need to initialize the "context kind" field of each block of context memory. This patch sets up the infrastructure to do that with the bnxt_mem_init structure. In the next patch, we'll add the logic to obtain the offset of the "context kind" from the firmware. This patch is not changing the current behavior of calling memset() to initialize all relevant context memory. Reviewed-by:
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Michael Chan authored
During some fatal firmware error conditions, the PCI config space register 0x2e which normally contains the subsystem ID will become 0xffff. This register will revert back to the normal value after the chip has completed core reset. If we detect this condition, we can poll this config register immediately for the value to revert. Because we use config read cycles to poll this register, there is no possibility of Master Abort if we happen to read it during core reset. This speeds up recovery significantly as we don't have to wait for the conservative min_time before polling MMIO to see if the firmware has come out of reset. As soon as this register changes value we can proceed to re-initialize the device. Reviewed-by:
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Edwin Peer authored
Newer devices may have local context memory instead of relying on the host for backing store. In these cases, HWRM_FUNC_BACKING_STORE_QCAPS will return a zero entry size to indicate contexts for which the host should not allocate backing store. Selectively allocate context memory based on device capabilities and only enable backing store for the appropriate contexts. Signed-off-by:
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Michael Chan authored
The main changes are the echo request/response from firmware for error detection and the NO_FCS feature to transmit frames without FCS. Signed-off-by:
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- 13 Feb, 2021 2 commits
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David S. Miller authored
Alexander Lobakin says: ==================== skbuff: introduce skbuff_heads bulking and reusing Currently, all sorts of skb allocation always do allocate skbuff_heads one by one via kmem_cache_alloc(). On the other hand, we have percpu napi_alloc_cache to store skbuff_heads queued up for freeing and flush them by bulks. We can use this cache not only for bulk-wiping, but also to obtain heads for new skbs and avoid unconditional allocations, as well as for bulk-allocating (like XDP's cpumap code and veth driver already do). As this might affect latencies, cache pressure and lots of hardware and driver-dependent stuff, this new feature is mostly optional and can be issued via: - a new napi_build_skb() function (as a replacement for build_skb()); - existing {,__}napi_alloc_skb() and napi_get_frags() functions; - __alloc_skb() with passing SKB_ALLOC_NAPI in flags. iperf3 showed 35-70 Mbps bumps for both TCP and UDP while performing VLAN NAT on 1.2 GHz MIPS board. The boost is likely to be bigger on more powerful hosts and NICs with tens of Mpps. Note on skbuff_heads from distant slabs or pfmemalloc'ed slabs: - kmalloc()/kmem_cache_alloc() itself allows by default allocating memory from the remote nodes to defragment their slabs. This is controlled by sysctl, but according to this, skbuff_head from a remote node is an OK case; - The easiest way to check if the slab of skbuff_head is remote or pfmemalloc'ed is: if (!dev_page_is_reusable(virt_to_head_page(skb))) /* drop it */; ...*but*, regarding that most slabs are built of compound pages, virt_to_head_page() will hit unlikely-branch every single call. This check costed at least 20 Mbps in test scenarios and seems like it'd be better to _not_ do this. Since v5 [4]: - revert flags-to-bool conversion and simplify flags testing in __alloc_skb() (Alexander Duyck). Since v4 [3]: - rebase on top of net-next and address kernel build robot issue; - reorder checks a bit in __alloc_skb() to make new condition even more harmless. Since v3 [2]: - make the feature mostly optional, so driver developers could decide whether to use it or not (Paolo Abeni). This reuses the old flag for __alloc_skb() and introduces a new napi_build_skb(); - reduce bulk-allocation size from 32 to 16 elements (also Paolo). This equals to the value of XDP's devmap and veth batch processing (which were tested a lot) and should be sane enough; - don't waste cycles on explicit in_serving_softirq() check. Since v2 [1]: - also cover {,__}alloc_skb() and {,__}build_skb() cases (became handy after the changes that pass tiny skbs requests to kmalloc layer); - cover the cache with KASAN instrumentation (suggested by Eric Dumazet, help of Dmitry Vyukov); - completely drop redundant __kfree_skb_flush() (also Eric); - lots of code cleanups; - expand the commit message with NUMA and pfmemalloc points (Jakub). Since v1 [0]: - use one unified cache instead of two separate to greatly simplify the logics and reduce hotpath overhead (Edward Cree); - new: recycle also GRO_MERGED_FREE skbs instead of immediate freeing; - correct performance numbers after optimizations and performing lots of tests for different use cases. [0] https://lore.kernel.org/netdev/20210111182655.12159-1-alobakin@pm.me [1] https://lore.kernel.org/netdev/20210113133523.39205-1-alobakin@pm.me [2] https://lore.kernel.org/netdev/20210209204533.327360-1-alobakin@pm.me [3] https://lore.kernel.org/netdev/20210210162732.80467-1-alobakin@pm.me [4] https://lore.kernel.org/netdev/20210211185220.9753-1-alobakin@pm.me ==================== Reviewed-by:Alexander Duyck <alexanderduyck@fb.com> Signed-off-by:
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Alexander Lobakin authored
napi_frags_finish() and napi_skb_finish() can only be called inside NAPI Rx context, so we can feed NAPI cache with skbuff_heads that got NAPI_MERGED_FREE verdict instead of immediate freeing. Replace __kfree_skb() with __kfree_skb_defer() in napi_skb_finish() and move napi_skb_free_stolen_head() to skbuff.c, so it can drop skbs to NAPI cache. As many drivers call napi_alloc_skb()/napi_get_frags() on their receive path, this becomes especially useful. Signed-off-by:
Alexander Lobakin <alobakin@pm.me> Signed-off-by:
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