Exercised with
"ip link set <PF intf> vf <vf_i> state {auto|enable|disable}"
Sets the reporting policy for VF link state to either
- mirror physical link state
- always up
- always down
get VF link state mode in efx_ef10_sriov_get_vf_config
Exercised by
"ip link show <PF intf>";
output will include a line like
vf 0 MAC 12:34:56:78:9a:bc, link-state auto
Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The max vlan tags that can be offloaded is 2, including any upstream VLAN
aggregator. Currently there is no way for the net driver to know whether
the upstream vswitch (if any) is using vlan tags, so there is no way to
know how many tags we can request.
Along with the implementation for the ndo_set_vf_vlan callback, this patch
also adds 2 VLAN tags for the driver created VEB switch if possible, that
way it is possible to offload as many tags as are allowed.
Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently we do an entity reset when we detect an MC reboot.
This messes up SRIOV because it leaves VFs orphaned. The extra
reset is rather redundant anyway, since the MC reboot will have
basically reset everything.
This change replaces the entity reset after MC reboot with a
simpler datapath reset that reallocates resources but doesn't
perform the entity reset.
Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
rtnetlink calls ndo_get_vf_config when compiling information
about a network interface, so that the VFs associated with a PF
can be listed (eg: ip link show).
Implement a response to this entry point and return PF-set MAC
address for VF in ndo_get_vf_config
Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Implement a response to this entrypoint.
The ndo_set_vf_mac() entrypoint is only exposed in the driver if
CONFIG_SFC_SRIOV is defined.
Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In order to avoid MC bugs the flags field needs to be set to 0.
Instead of explicitly clearing out the flags individually, a
better way to do this is to memset the MCDI_BUF to 0.
Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A VF's MAC address is set by its parent PF and added to its vport.
To get this MAC address, the VF must use MC_CMD_ VPORT_GET_MAC_ADDRESSES.
In the current scheme, a VF's vport should only have one MAC address,
so warn if this is not the case.
Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If MCDI timeouts are encountered during efx_ef10_filter_table_remove(),
an FLR will be queued, but efx->filter_state will still be kfree()d.
The queued FLR will then call efx_ef10_filter_table_restore(), which
will try to use efx->filter_state. This previously caused a panic.
This patch adds an rwsem to protect the existence of efx->filter_state,
separately from the spinlock protecting its contents. Users which can
race against efx_ef10_filter_table_remove() should down_read this rwsem.
Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Initialised in efx_probe_vf and removal is dealt with in
efx_ef10_remove.
vf->efx is needed in future patches to change the MAC address
of the VF via the parent PF, while the driver is bound to the
VF.
Example: ip link set dev vf NUM mac LLADDR
Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Otherwise the PF and VF can disagree on the VF's MAC address and
this leads to strange behaviour, up to and including kernel panics.
Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Added function efx_ef10_get_vf_index to store the vf_index
in nic_data during probe
vf_index is needed in future patches to access a particular
VF in the VF data structure.
Moved efx_ef10_probe_pf and efx_ef10_probe_vf in order to
used efx_ef10_remove
Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
MC_CMD_SET_MAC is privileged and can only by called by the link
control function.
This patch adds efx_ef10_mac_reconfigure_vf which avoids the call
to MC_CMD_SET_MAC by the Virtual function
Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is one primary function per adaptor, one link control function
per port and the rest as categorised as general.
This patch adds privileges to the MCDI commands based on which
functions are allowed to call them.
Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This also matches with the sibling call netdev_alloc_skb_ip_align() made in
rx fast path.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The clocks on the Arria 10 platform is a bit different than the
Cyclone/Arria 5 platform that it should just have it's own
driver.
Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
There are 5 possible parent clocks for the SoCFPGA Arria10. Move the define
SYSMGR_SDMMC_CTRL_SET and streq() to clk.h so that the Arria clock driver
can use.
Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Commit 5d3abf8ff6 ("libata: Fall back to unqueued READ LOG EXT if
the DMA variant fails") allowed us to fall back to the unqueued READ
LOG variant if the queued version failed. However, if the device did
not support the page at all we would end up looping due to a merge
snafu.
Ensure we only take the fallback path once.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This is cleary used after init time too for example for
configuring UART wake-up events during runtime. This fixes
section mismatch warnings for randconfig builds that happen
because __init_or_module.
Signed-off-by: Tony Lindgren <tony@atomide.com>
With the omap1 SPARSE_IRQ changes mach/irqs.h is no longer
automatically included. Turns out now we rely on ARCH_OMAP15XX
including hardware.h from memory.h, so without ARCH_OMAP15XX
we get build failures.
As we have legacy drivers still relying on these indirect
includes, let's not add more mach includes to the drivers.
Those have to be removed anyways for multiplatform support.
Let's fix up mach-omap1 to include soc.h where cpu_is_omap
checks are done, and common.h for board-*.c files.
But let's keep the indirect memory.h include for now to avoid
unnecessary churn in the drivers.
Signed-off-by: Tony Lindgren <tony@atomide.com>
gcc-5.x warns about a preexisting problem in the hpt36x pata driver:
drivers/ata/pata_hpt366.c: In function 'hpt36x_init_one':
drivers/ata/pata_hpt366.c:376:9: warning: assignment discards 'const' qualifier from pointer target type [-Wdiscarded-array-qualifiers]
Other ata drivers have the same problem, as ata_pci_bmdma_init_one
takes a non-const pointer, and they solve it by using a cast to
turn that pointer into a normal non-const pointer.
I also tried to change the ata core code to make host->private_data
a const pointer, but that quickly got out of hand, as some other
drivers expect it to be writable, so I ended up using the same
hack as the others here.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
rndis_get_nr() returns either a non-negative value on success
or a negative value on failure. In case of failure an error code
is returned to the caller of rndis_register().
If the "i" is unsigned, the information about error from rndis_get_nr()
is lost. If there is no error but rndis_get_nr() returns a value greater
than 256 the least significant bits of i are zero effectively limiting the
number of configs to 256.
This patch fixes that.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
If CONFIG_USB_GADGET_DEBUG_FILES is set then a block is opened and inside
it there is a local variable "i" which hides the "i" local to the
rndis_deregister(). Consequently, a random value is formatted
into the "name" buffer.
This patch removes the block-local i.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
The patch:
83210e59ee
usb: gadget: rndis: use rndis_params instead of configNr
should change all invocations of rndis_signal_(dis)connect().
This patch fixes that.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
flush_scheduled_work() is just a simple call to flush_work().
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reading to wq->unbound_attrs requires protection of either wq_pool_mutex
or wq->mutex, and wq_sysfs_prep_attrs() is called with wq_pool_mutex held,
so we don't need to grab wq->mutex here.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This pre-declaration was unneeded since a previous refactor patch
6ba94429c8 ("workqueue: Reorder sysfs code").
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Bspec says we should disable the FDI RX/TX before disabling the PCH
ports. Do so.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
30 usecs (or really, 1 jiffy) can go by pretty fast.
Move the set of the timeout immediately before the loop.
Remove the unnecessary max(1ul, usecs_to_jiffies(30)) as
usecs_to_jiffies with a non-zero constant is guaranteed
to be non-zero.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Follow the BSpec sequence for the CRT port as well on PCH platforms,
ie. disable the pipe before the port.
Didn't bother looking at DDI in detail yet, so leave that one be even
though the CRT is a PCH port there.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Original issue is that the id field in the dai is not same as the id
in dai_driver when dai driver count == 1. This is due to the legacy
dai naming check, which could possibly cause issues if the audio drivers
written in assumption that dai->id would be always equal to dai_driver->id.
This assumption is true only if the dai driver count is greater than 1,
and false if dai driver count is 1. On Qcom Lpass driver we hit such
issue while adding support to apq8016.
The code path which falls back to legacy naming for cases where num_dai
== 1 does not check if there is any valid information in the dai_driver.
This patch fixes that by checking if the dai_driver has valid id and
name before falling back to legacy dai naming
Although the drivers can work around this issue by only using
dai->driver->id, but this patch attempts to fix the actual issue.
Suggested-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Acked-by: Kenneth Westfield <kwestfie@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
While at it also remove the redundant/unneeded w/a like done for hdmi
already.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
[danvet: Mention that this also removes the unneeded w/a, as suggested
by Jesse.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
BSpec says we should disable all ports after the pipe on PCH
platforms. Do so. Fixes a pipe off timeout on ILK now caused by
the transcoder B workaround.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Simon Horman says:
====================
rocker: transaction fixes
this series addresses what appear to be errors in the handling of
prepare and then commit transactions in the rocker driver.
In all cases the problem is that data structures visible outside of
the transaction are modified during the prepare phase.
In the case of the first two patches this results in the kernel reporting a
BUG. I have noted test-cases in the change logs.
The third patch is also a bug fix, as noted by Toshiaki Makita,
however I have not been able to reliably reproduce the problem and
thus have not provided a test case.
The last patch is a correctness fix that does not fix a bug
that manifests as far as I can tell.
Changes: v3->v4
* All patches
- Add Jiri Pirko's ack
* "rocker: do not make neighbour entry changes when preparing transactions"
- Setting of entry values in all transaction phases
as suggested by Toshiaki Makita
* "rocker: make rocker_port_internal_vlan_id_{get,put}() non-transactional"
- Remove Fixes tag as I believe this is a correctness rather than a bug fix
Changes: v2->v3
* "rocker: do not make neighbour entry changes when preparing transactions"
- Correct inverted logic
- Added ack from Scott Feldman
Changes: v1->v2
* "rocker: do not make neighbour entry changes when preparing transactions"
- Revised changelog to reflect information from Toshiaki Makita
that there is a bug that can manifest
- Update address and ttl regardless of the value of the transaction state
* All other patches
- Added acks from Scott Feldman
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
The motivation for this is that rocker_port_internal_vlan_id_{get,put} appear
to only partially implement the transaction model: memory allocation
and freeing is transactional, but hash and bitmap manipulation is not.
The latter could be fixed, however, as it is not currently exercised
due to trans always being SWITCHDEV_TRANS_NONE it seems cleaner
to make rocker_port_internal_vlan_id_get non-transactional.
This problem was introduced by c4f20321d9 ("rocker: support
prepare-commit transaction model").
Found by inspection.
I do not believe that this change should have any run-time effect.
Acked-by: Scott Feldman <sfeldma@gmail.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
rocker_port_ipv4_nh() and in turn rocker_port_ipv4_neigh() may be
be called with trans == SWITCHDEV_TRANS_PREPARE and then
trans == SWITCHDEV_TRANS_COMMIT from switchdev_port_obj_set() via
fib_table_insert().
The first time that rocker_port_ipv4_nh() is called, with
trans == SWITCHDEV_TRANS_PREPARE, _rocker_neigh_add() adds a new entry to
the neigh table.
And the second time rocker_port_ipv4_nh() is called, with
trans == SWITCHDEV_TRANS_COMMIT, that entry is found. This causes
rocker_port_ipv4_nh() to believe it is not adding an entry and thus it
frees "entry", which is still present in rocker driver's neigh table.
This problem does not appear to affect deletion as my analysis is that
deletion is always performed with trans == SWITCHDEV_TRANS_NONE.
For completeness _rocker_neigh_{add,del,prepare} are updated not to
manipulate fib table entries if trans == SWITCHDEV_TRANS_PREPARE.
Fixes: c4f20321d9 ("rocker: support prepare-commit transaction model")
Reported-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Incorrect condition is used in spin_event_timeout(). When the TX is
done, the SPIE_NF bit in ESPI_SPIE register is set to 1 to indicate the
Tx FIFO is not full. If the bit is 0, it indicates the Tx FIFO is full.
Due to this error, if the Tx FIFO is full at the beginning, but becomes
not full after handling the Rx FIFO (the SPIE_NF bit is set), the
spin_event_timeout() returns with timeout occurred. It causes the
interrupt handler not to send completion notification to the thread that
called wait_for_complete() waiting for the notification.
Signed-off-by: Jane Wan <Jane.Wan@gainspeed.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Use the generic mechanism to declare a bitmap instead of unsigned long.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
To find that dvs-gpio is valid or not, gpio API gpio_is_valid()
can be directly used instead of intermediate variable.
Removing the extra variable and using the gpio_is_valid().
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
If platform data has dvs-gpio value 0 as default/unset then
make this as invalid gpio so that function gpio_is_valid()
can return false on this case.
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Alexei Starovoitov says:
====================
bpf: introduce bpf_tail_call() helper
introduce bpf_tail_call(ctx, &jmp_table, index) helper function
which can be used from BPF programs like:
int bpf_prog(struct pt_regs *ctx)
{
...
bpf_tail_call(ctx, &jmp_table, index);
...
}
that is roughly equivalent to:
int bpf_prog(struct pt_regs *ctx)
{
...
if (jmp_table[index])
return (*jmp_table[index])(ctx);
...
}
The important detail that it's not a normal call, but a tail call.
The kernel stack is precious, so this helper reuses the current
stack frame and jumps into another BPF program without adding
extra call frame.
It's trivially done in interpreter and a bit trickier in JITs.
Use cases:
- simplify complex programs
- dispatch into other programs
(for example: index in jump table can be syscall number or network protocol)
- build dynamic chains of programs
The chain of tail calls can form unpredictable dynamic loops therefore
tail_call_cnt is used to limit the number of calls and currently is set to 32.
patch 1 - support bpf_tail_call() in interpreter
patch 2 - support in x64 JIT
We've discussed what's neccessary to support it in arm64/s390 JITs
and it looks fine.
patch 3 - sample example for tracing
patch 4 - sample example for networking
More details in every patch.
This set went through several iterations of reviews/fixes and older
attempts can be seen:
https://git.kernel.org/cgit/linux/kernel/git/ast/bpf.git/log/?h=tail_call_v[123456]
- tail_call_v1 does it without touching JITs but introduces overhead
for all programs that don't use this helper function.
- tail_call_v2 still has some overhead and x64 JIT does full stack
unwind (prologue skipping optimization wasn't there)
- tail_call_v3 reuses 'call' instruction encoding and has interpreter
overhead for every normal call
- tail_call_v4 fixes above architectural shortcomings and v5,v6 fix few
more bugs
This last tail_call_v6 approach seems to be the best.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Usage:
$ sudo ./sockex3
IP src.port -> dst.port bytes packets
127.0.0.1.42010 -> 127.0.0.1.12865 1568 8
127.0.0.1.59526 -> 127.0.0.1.33778 11422636 173070
127.0.0.1.33778 -> 127.0.0.1.59526 11260224828 341974
127.0.0.1.12865 -> 127.0.0.1.42010 1832 12
IP src.port -> dst.port bytes packets
127.0.0.1.42010 -> 127.0.0.1.12865 1568 8
127.0.0.1.59526 -> 127.0.0.1.33778 23198092 351486
127.0.0.1.33778 -> 127.0.0.1.59526 22972698518 698616
127.0.0.1.12865 -> 127.0.0.1.42010 1832 12
this example is similar to sockex2 in a way that it accumulates per-flow
statistics, but it does packet parsing differently.
sockex2 inlines full packet parser routine into single bpf program.
This sockex3 example have 4 independent programs that parse vlan, mpls, ip, ipv6
and one main program that starts the process.
bpf_tail_call() mechanism allows each program to be small and be called
on demand potentially multiple times, so that many vlan, mpls, ip in ip,
gre encapsulations can be parsed. These and other protocol parsers can
be added or removed at runtime. TLVs can be parsed in similar manner.
Note, tail_call_cnt dynamic check limits the number of tail calls to 32.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bpf_tail_call() arguments:
ctx - context pointer
jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table
index - index in the jump table
In this implementation x64 JIT bypasses stack unwind and jumps into the
callee program after prologue, so the callee program reuses the same stack.
The logic can be roughly expressed in C like:
u32 tail_call_cnt;
void *jumptable[2] = { &&label1, &&label2 };
int bpf_prog1(void *ctx)
{
label1:
...
}
int bpf_prog2(void *ctx)
{
label2:
...
}
int bpf_prog1(void *ctx)
{
...
if (tail_call_cnt++ < MAX_TAIL_CALL_CNT)
goto *jumptable[index]; ... and pass my 'ctx' to callee ...
... fall through if no entry in jumptable ...
}
Note that 'skip current program epilogue and next program prologue' is
an optimization. Other JITs don't have to do it the same way.
>From safety point of view it's valid as well, since programs always
initialize the stack before use, so any residue in the stack left by
the current program is not going be read. The same verifier checks are
done for the calls from the kernel into all bpf programs.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
introduce bpf_tail_call(ctx, &jmp_table, index) helper function
which can be used from BPF programs like:
int bpf_prog(struct pt_regs *ctx)
{
...
bpf_tail_call(ctx, &jmp_table, index);
...
}
that is roughly equivalent to:
int bpf_prog(struct pt_regs *ctx)
{
...
if (jmp_table[index])
return (*jmp_table[index])(ctx);
...
}
The important detail that it's not a normal call, but a tail call.
The kernel stack is precious, so this helper reuses the current
stack frame and jumps into another BPF program without adding
extra call frame.
It's trivially done in interpreter and a bit trickier in JITs.
In case of x64 JIT the bigger part of generated assembler prologue
is common for all programs, so it is simply skipped while jumping.
Other JITs can do similar prologue-skipping optimization or
do stack unwind before jumping into the next program.
bpf_tail_call() arguments:
ctx - context pointer
jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table
index - index in the jump table
Since all BPF programs are idenitified by file descriptor, user space
need to populate the jmp_table with FDs of other BPF programs.
If jmp_table[index] is empty the bpf_tail_call() doesn't jump anywhere
and program execution continues as normal.
New BPF_MAP_TYPE_PROG_ARRAY map type is introduced so that user space can
populate this jmp_table array with FDs of other bpf programs.
Programs can share the same jmp_table array or use multiple jmp_tables.
The chain of tail calls can form unpredictable dynamic loops therefore
tail_call_cnt is used to limit the number of calls and currently is set to 32.
Use cases:
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
==========
- simplify complex programs by splitting them into a sequence of small programs
- dispatch routine
For tracing and future seccomp the program may be triggered on all system
calls, but processing of syscall arguments will be different. It's more
efficient to implement them as:
int syscall_entry(struct seccomp_data *ctx)
{
bpf_tail_call(ctx, &syscall_jmp_table, ctx->nr /* syscall number */);
... default: process unknown syscall ...
}
int sys_write_event(struct seccomp_data *ctx) {...}
int sys_read_event(struct seccomp_data *ctx) {...}
syscall_jmp_table[__NR_write] = sys_write_event;
syscall_jmp_table[__NR_read] = sys_read_event;
For networking the program may call into different parsers depending on
packet format, like:
int packet_parser(struct __sk_buff *skb)
{
... parse L2, L3 here ...
__u8 ipproto = load_byte(skb, ... offsetof(struct iphdr, protocol));
bpf_tail_call(skb, &ipproto_jmp_table, ipproto);
... default: process unknown protocol ...
}
int parse_tcp(struct __sk_buff *skb) {...}
int parse_udp(struct __sk_buff *skb) {...}
ipproto_jmp_table[IPPROTO_TCP] = parse_tcp;
ipproto_jmp_table[IPPROTO_UDP] = parse_udp;
- for TC use case, bpf_tail_call() allows to implement reclassify-like logic
- bpf_map_update_elem/delete calls into BPF_MAP_TYPE_PROG_ARRAY jump table
are atomic, so user space can build chains of BPF programs on the fly
Implementation details:
=======================
- high performance of bpf_tail_call() is the goal.
It could have been implemented without JIT changes as a wrapper on top of
BPF_PROG_RUN() macro, but with two downsides:
. all programs would have to pay performance penalty for this feature and
tail call itself would be slower, since mandatory stack unwind, return,
stack allocate would be done for every tailcall.
. tailcall would be limited to programs running preempt_disabled, since
generic 'void *ctx' doesn't have room for 'tail_call_cnt' and it would
need to be either global per_cpu variable accessed by helper and by wrapper
or global variable protected by locks.
In this implementation x64 JIT bypasses stack unwind and jumps into the
callee program after prologue.
- bpf_prog_array_compatible() ensures that prog_type of callee and caller
are the same and JITed/non-JITed flag is the same, since calling JITed
program from non-JITed is invalid, since stack frames are different.
Similarly calling kprobe type program from socket type program is invalid.
- jump table is implemented as BPF_MAP_TYPE_PROG_ARRAY to reuse 'map'
abstraction, its user space API and all of verifier logic.
It's in the existing arraymap.c file, since several functions are
shared with regular array map.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently the IBX transcoder B workarounds are not working correctly.
Well, the HDMI one seems to be working somewhat, but the DP one is
definitely busted.
After a bit of experimentation it looks like the best way to make this
work is first disable the port on transcoder B, and then re-enable it
transcoder A, and immediately disable it again.
We can also clean up the code by noting that we can't be called without
a valid crtc. And also note that port A on ILK does not need the
workaround, so let's check for that one too.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
