The '==' expression itself is bool, no need to convert it to bool again.
This fixes the following coccicheck warning:
arch/x86/net/bpf_jit_comp32.c:1478:50-55: WARNING: conversion to bool not needed here
arch/x86/net/bpf_jit_comp32.c:1479:50-55: WARNING: conversion to bool not needed here
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200506140352.37154-1-yanaijie@huawei.com
Luke Nelson says:
====================
This patch series introduces a set of optimizations to the BPF JIT
on RV64. The optimizations are related to the verifier zero-extension
optimization and BPF_JMP BPF_K.
We tested the optimizations on a QEMU riscv64 virt machine, using
lib/test_bpf and test_verifier, and formally verified their correctness
using Serval.
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This patch optimizes BPF_JSET BPF_K by using a RISC-V andi instruction
when the BPF immediate fits in 12 bits, instead of first loading the
immediate to a temporary register.
Examples of generated code with and without this optimization:
BPF_JMP_IMM(BPF_JSET, R1, 2, 1) without optimization:
20: li t1,2
24: and t1,a0,t1
28: bnez t1,0x30
BPF_JMP_IMM(BPF_JSET, R1, 2, 1) with optimization:
20: andi t1,a0,2
24: bnez t1,0x2c
BPF_JMP32_IMM(BPF_JSET, R1, 2, 1) without optimization:
20: li t1,2
24: mv t2,a0
28: slli t2,t2,0x20
2c: srli t2,t2,0x20
30: slli t1,t1,0x20
34: srli t1,t1,0x20
38: and t1,t2,t1
3c: bnez t1,0x44
BPF_JMP32_IMM(BPF_JSET, R1, 2, 1) with optimization:
20: andi t1,a0,2
24: bnez t1,0x2c
In these examples, because the upper 32 bits of the sign-extended
immediate are 0, BPF_JMP BPF_JSET and BPF_JMP32 BPF_JSET are equivalent
and therefore the JIT produces identical code for them.
Co-developed-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Luke Nelson <luke.r.nels@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Björn Töpel <bjorn.topel@gmail.com>
Acked-by: Björn Töpel <bjorn.topel@gmail.com>
Link: https://lore.kernel.org/bpf/20200506000320.28965-5-luke.r.nels@gmail.com
This patch adds an optimization to BPF_JMP (32- and 64-bit) BPF_K for
when the BPF immediate is zero.
When the immediate is zero, the code can directly use the RISC-V zero
register instead of loading a zero immediate to a temporary register
first.
Co-developed-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Luke Nelson <luke.r.nels@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Björn Töpel <bjorn.topel@gmail.com>
Acked-by: Björn Töpel <bjorn.topel@gmail.com>
Link: https://lore.kernel.org/bpf/20200506000320.28965-4-luke.r.nels@gmail.com
This patch adds two optimizations for BPF_ALU BPF_END BPF_FROM_LE in
the RV64 BPF JIT.
First, it enables the verifier zero-extension optimization to avoid zero
extension when imm == 32. Second, it avoids generating code for imm ==
64, since it is equivalent to a no-op.
Co-developed-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Luke Nelson <luke.r.nels@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Björn Töpel <bjorn.topel@gmail.com>
Acked-by: Björn Töpel <bjorn.topel@gmail.com>
Link: https://lore.kernel.org/bpf/20200506000320.28965-3-luke.r.nels@gmail.com
Commit 66d0d5a854 ("riscv: bpf: eliminate zero extension code-gen")
added support for the verifier zero-extension optimization on RV64 and
commit 46dd3d7d28 ("bpf, riscv: Enable zext optimization for more
RV64G ALU ops") enabled it for more instruction cases.
However, BPF_LSH BPF_X and BPF_{LSH,RSH,ARSH} BPF_K are still missing
the optimization.
This patch enables the zero-extension optimization for these remaining
cases.
Co-developed-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Luke Nelson <luke.r.nels@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Björn Töpel <bjorn.topel@gmail.com>
Acked-by: Björn Töpel <bjorn.topel@gmail.com>
Link: https://lore.kernel.org/bpf/20200506000320.28965-2-luke.r.nels@gmail.com
The newly added bpf_stats_handler function has the wrong #ifdef
check around it, leading to an unused-function warning when
CONFIG_SYSCTL is disabled:
kernel/sysctl.c:205:12: error: unused function 'bpf_stats_handler' [-Werror,-Wunused-function]
static int bpf_stats_handler(struct ctl_table *table, int write,
Fix the check to match the reference.
Fixes: d46edd671a ("bpf: Sharing bpf runtime stats with BPF_ENABLE_STATS")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200505140734.503701-1-arnd@arndb.de
Remove the unnecessary member of address in struct xdp_umem as it is
only used during the umem registration. No need to carry this around
as it is not used during run-time nor when unregistering the umem.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Link: https://lore.kernel.org/bpf/1588599232-24897-3-git-send-email-magnus.karlsson@intel.com
Change two variables names so that it is clearer what they
represent. The first one is xsk_list that in fact only contains the
list of AF_XDP sockets with a Tx component. Change this to xsk_tx_list
for improved clarity. The second variable is size in the ring
structure. One might think that this is the size of the ring, but it
is in fact the size of the umem, copied into the ring structure to
improve performance. Rename this variable umem_size to avoid any
confusion.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Link: https://lore.kernel.org/bpf/1588599232-24897-2-git-send-email-magnus.karlsson@intel.com
gcc-10 warns about accesses to zero-length arrays:
kernel/bpf/core.c: In function 'bpf_patch_insn_single':
cc1: warning: writing 8 bytes into a region of size 0 [-Wstringop-overflow=]
In file included from kernel/bpf/core.c:21:
include/linux/filter.h:550:20: note: at offset 0 to object 'insnsi' with size 0 declared here
550 | struct bpf_insn insnsi[0];
| ^~~~~~
In this case, we really want to have two flexible-array members,
but that is not possible. Removing the union to make insnsi a
flexible-array member while leaving insns as a zero-length array
fixes the warning, as nothing writes to the other one in that way.
This trick only works on linux-3.18 or higher, as older versions
had additional members in the union.
Fixes: 60a3b2253c ("net: bpf: make eBPF interpreter images read-only")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200430213101.135134-6-arnd@arndb.de
This patch adds an optimization that uses the asr immediate instruction
for BPF_ALU BPF_ARSH BPF_K, rather than loading the immediate to
a temporary register. This is similar to existing code for handling
BPF_ALU BPF_{LSH,RSH} BPF_K. This optimization saves two instructions
and is more consistent with LSH and RSH.
Example of the code generated for BPF_ALU32_IMM(BPF_ARSH, BPF_REG_0, 5)
before the optimization:
2c: mov r8, #5
30: mov r9, #0
34: asr r0, r0, r8
and after optimization:
2c: asr r0, r0, #5
Tested on QEMU using lib/test_bpf and test_verifier.
Co-developed-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Luke Nelson <luke.r.nels@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200501020210.32294-3-luke.r.nels@gmail.com
This patch optimizes the code generated by emit_a32_arsh_r64, which
handles the BPF_ALU64 BPF_ARSH BPF_X instruction.
The original code uses a conditional B followed by an unconditional ORR.
The optimization saves one instruction by removing the B instruction
and using a conditional ORR (with an inverted condition).
Example of the code generated for BPF_ALU64_REG(BPF_ARSH, BPF_REG_0,
BPF_REG_1), before optimization:
34: rsb ip, r2, #32
38: subs r9, r2, #32
3c: lsr lr, r0, r2
40: orr lr, lr, r1, lsl ip
44: bmi 0x4c
48: orr lr, lr, r1, asr r9
4c: asr ip, r1, r2
50: mov r0, lr
54: mov r1, ip
and after optimization:
34: rsb ip, r2, #32
38: subs r9, r2, #32
3c: lsr lr, r0, r2
40: orr lr, lr, r1, lsl ip
44: orrpl lr, lr, r1, asr r9
48: asr ip, r1, r2
4c: mov r0, lr
50: mov r1, ip
Tested on QEMU using lib/test_bpf and test_verifier.
Co-developed-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Luke Nelson <luke.r.nels@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200501020210.32294-2-luke.r.nels@gmail.com
Karsten Graul says:
====================
net/smc: add and delete link processing
These patches add the 'add link' and 'delete link' processing as
SMC server and client. This processing allows to establish and
remove links of a link group dynamically.
v2: Fix mess up with unused static functions. Merge patch 8 into patch 4.
Postpone patch 13 to next series.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
As SMC server, when a second link was deleted, trigger the setup of an
asymmetric link. Do this by enqueueing a local ADD_LINK message which
is processed by the LLC layer as if it were received from peer. Do the
same when a new IB port became active and a new link could be created.
smc_llc_srv_add_link_local() enqueues a local ADD_LINK message.
And smc_llc_srv_delete_link_local() is used the same way to enqueue a
local DELETE_LINK message. This is used when an IB port is no longer
active.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add smc_llc_process_srv_delete_link() to process a DELETE_LINK request
as SMC server. When the request is to delete ALL links then terminate
the whole link group. If not, find the link to delete by its link_id,
send the DELETE_LINK request LLC message and wait for the response.
No matter if a response was received, clear the deleted link and update
the link group state.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add smc_llc_process_cli_delete_link() to process a DELETE_LINK request
as SMC client. When the request is to delete ALL links then terminate
the whole link group. If not, find the link to delete by its link_id,
send the DELETE_LINK response LLC message and then clear the deleted
link. Finally determine and update the link group state.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce a work that is scheduled when a new DELETE_LINK LLC request is
received. The work will call either the SMC client or SMC server
DELETE_LINK processing.
And use the LLC flow framework to process incoming DELETE_LINK LLC
messages, scheduling the llc_del_link_work for those events.
With these changes smc_lgr_forget() is only called by one function and
can be migrated into smc_lgr_cleanup_early().
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a link group moved from asymmetric to symmetric state then the
dangling asymmetric link can be deleted. Add smc_llc_find_asym_link() to
find the respective link and add smc_llc_delete_asym_link() to delete
it.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch finalizes the ADD_LINK processing of new links. Send the
CONFIRM_LINK request to the peer, receive the response and set link
state to ACTIVE.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Part of SMC server new link establishment is the exchange of rkeys for
used buffers.
Loop over all used RMB buffers and send ADD_LINK_CONTINUE LLC messages
to the peer.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
First set of functions to process an ADD_LINK LLC request as an SMC
server. Find an alternate IB device, determine the new link group type
and get the index for the new link. Then initialize the link and send
the ADD_LINK LLC message to the peer. Save the contents of the response,
ready the link, map all used buffers and register the buffers with the
IB device. If any error occurs, stop the processing and clear the link.
And call smc_llc_srv_add_link() in af_smc.c to start second link
establishment after the initial link of a link group was created.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch finalizes the ADD_LINK processing of new links. Receive the
CONFIRM_LINK request from peer, complete the link initialization,
register all used buffers with the IB device and finally send the
CONFIRM_LINK response, which completes the ADD_LINK processing.
And activate smc_llc_cli_add_link() in af_smc.c.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Part of the SMC client new link establishment process is the exchange of
rkeys for all used buffers.
Add new LLC message type ADD_LINK_CONTINUE which is used to exchange
rkeys of all current RMB buffers. Add functions to iterate over all
used RMB buffers of the link group, and implement the ADD_LINK_CONTINUE
processing.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
First set of functions to process an ADD_LINK LLC request as an SMC
client. Find an alternate IB device, determine the new link group type
and get the index for the new link. Then ready the link, map the buffers
and send an ADD_LINK LLC response. If any error occurs, send a reject
LLC message and terminate the processing.
Add smc_llc_alloc_alt_link() to find a free link index for a new link,
depending on the new link group type.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Sameeh Jubran says:
====================
Enhance current features in ena driver
Difference from v2:
* dropped patch "net: ena: move llq configuration from ena_probe to ena_device_init()"
* reworked patch ""net: ena: implement ena_com_get_admin_polling_mode() to drop the prototype
Difference from v1:
* reodered paches #01 and #02.
* dropped adding Rx/Tx drops to ethtool in patch #08
V1:
This patchset introduces the following:
* minor changes to RSS feature
* add total rx and tx drop counter
* add unmask_interrupt counter for ethtool statistics
* add missing implementation for ena_com_get_admin_polling_mode()
* some minor code clean-up and cosmetics
* use SHUTDOWN as reset reason when closing interface
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Extract code to ena_indirection_table_set() to make
the code cleaner.
Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The macros in ena_com.h have inconsistent spaces between
the macro name and it's value.
This commit sets all the macros to have a single space between
the name and value.
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The 'ENA_REGS_RESET_SHUTDOWN' enum indicates a normal driver
shutdown / removal procedure.
Also, a comment is added to one of the reset reason assignments for
code clarity.
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Before this commit there was a function prototype named
ena_com_get_ena_admin_polling_mode() that was never implemented.
This patch simply deletes it.
Signed-off-by: Igor Chauskin <igorch@amazon.com>
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1. Add support for getting tx drops from the device and saving them
in the driver.
2. Report tx via netdev stats.
Signed-off-by: Igor Chauskin <igorch@amazon.com>
Signed-off-by: Guy Tzalik <gtzalik@amazon.com>
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add unmask interrupts statistics to ethtool.
Signed-off-by: Netanel Belgazal <netanel@amazon.com>
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Both key and func parameters are pointers on the stack.
Setting them to NULL does nothing.
The original intent was to leave the key and func unset in this case,
but for this to happen nothing needs to be done as the calling
function ethtool_get_rxfh() already clears key and func.
This commit removes the above described useless code.
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit contains 2 cosmetic changes:
1. Use ena_com_check_supported_feature_id() in
ena_com_hash_key_fill_default_key() instead of rewriting
its implementation. This also saves us a superfluous admin
command by using the cached value.
2. Change if conditions in ena_com_rss_init() to be clearer.
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently in the driver we are setting the hash function to be CRC32.
Starting with this commit we want to change the default behaviour so that
we set the hash function to be Toeplitz instead.
Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Current code does not allow setting the hash function without
changing the key. This commit enables it.
To achieve this we separate ena_com_get_hash_function() to 2 functions:
ena_com_get_hash_function() - which gets only the hash function, and
ena_com_get_hash_key() - which gets only the hash key.
Also return 0 instead of rc at the end of ena_get_rxfh() since all
previous operations succeeded.
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In case the "func" parameter is NULL we now return "-EINVAL".
This shouldn't happen in general, but when it does happen, this is the
proper way to handle it.
We also check func for NULL in the beginning of the function, as there
is no reason to do all the work and realize in the end of the function
it was useless.
Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently when ena_set_hash_function() fails the hash function is
restored to the previous value by calling an admin command to get
the hash function from the device.
In this commit we avoid the admin command, by saving the previous
hash function before calling ena_set_hash_function() and using this
previous value to restore the hash function in case of failure of
ena_set_hash_function().
Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazet says:
====================
net_sched: sch_fq: round of optimizations
This series is focused on better layout of struct fq_flow to
reduce number of cache line misses in fq_enqueue() and dequeue operations.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
The prefetch() done in fq_dequeue() can be done a bit earlier
after the refactoring of the code done in the prior patch.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This refactors the code to not call fq_peek() from fq_dequeue_head()
since the caller can provide the skb.
Also rename fq_dequeue_head() to fq_dequeue_skb() because 'head' is
a bit vague, given the skb could come from t_root rb-tree.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
fq_gc() already builds a small array of pointers, so using
kmem_cache_free_bulk() needs very little change.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
sizeof(struct fq_flow) is 112 bytes on 64bit arches.
This means that half of them use two cache lines, but 50% use
three cache lines.
This patch adds cache line alignment, and makes sure that only
the first cache line is touched by fq_enqueue(), which is more
expensive that fq_dequeue() in general.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A significant amount of cpu cycles is spent in fq_gc()
When fq_gc() does its lookup in the rb-tree, it needs the
following fields from struct fq_flow :
f->sk (lookup key in the rb-tree)
f->fq_node (anchor in the rb-tree)
f->next (used to determine if the flow is detached)
f->age (used to determine if the flow is candidate for gc)
This unfortunately spans two cache lines (assuming 64 bytes cache lines)
We can avoid using f->next, if we use the low order bit of f->{age|tail}
This low order bit is 0, if f->tail points to an sk_buff.
We set the low order bit to 1, if the union contains a jiffies value.
Combined with the following patch, this makes sure we only need
to bring into cpu caches one cache line per flow.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Measurements of the MDIO bus have shown that driving the MDIO bus
using interrupts is slow. Back to back MDIO transactions take about
90us, with 25us spent performing the transaction, and the remainder of
the time the bus is idle.
Replacing the completion interrupt with polled IO results in back to
back transactions of 40us. The polling loop waiting for the hardware
to complete the transaction takes around 28us. Which suggests
interrupt handling has an overhead of 50us, and polled IO nearly
halves this overhead, and doubles the MDIO performance.
Care has to be taken when setting the MII_SPEED register, or it can
trigger an MII event> That then upsets the polling, due to an
unexpected pending event.
Suggested-by: Chris Heally <cphealy@gmail.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/smc/smc_llc.c:544:12: warning: ‘smc_llc_alloc_alt_link’ defined but not used [-Wunused-function]
static int smc_llc_alloc_alt_link(struct smc_link_group *lgr,
^~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: David S. Miller <davem@davemloft.net>
Vincent Cheng says:
====================
ptp: Add adjust phase to support phase offset.
This series adds adjust phase to the PTP Hardware Clock device interface.
Some PTP hardware clocks have a write phase mode that has
a built-in hardware filtering capability. The write phase mode
utilizes a phase offset control word instead of a frequency offset
control word. Add adjust phase function to take advantage of this
capability.
Changes since v1:
- As suggested by Richard Cochran:
1. ops->adjphase is new so need to check for non-null function pointer.
2. Kernel coding style uses lower_case_underscores.
3. Use existing PTP clock API for delayed worker.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Add idtcm_adjphase() to support PHC write phase mode.
Signed-off-by: Vincent Cheng <vincent.cheng.xh@renesas.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add adjust_phase to ptp_clock_caps capability to allow
user to query if a PHC driver supports adjust phase with
ioctl PTP_CLOCK_GETCAPS command.
Signed-off-by: Vincent Cheng <vincent.cheng.xh@renesas.com>
Reviewed-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Jason Yan