diff options
author | Catalin Marinas <catalin.marinas@arm.com> | 2020-07-31 18:09:57 +0100 |
---|---|---|
committer | Catalin Marinas <catalin.marinas@arm.com> | 2020-07-31 18:09:57 +0100 |
commit | 0e4cd9f2654915be8d09a1bd1b405ce5426e64c4 (patch) | |
tree | 0aeb119873c87509ff54cbc9c6946b271f3780bf /tools | |
parent | 18aa3bd58b1428d1927fe11f85ad444423d4fc59 (diff) | |
parent | 5f1f7f6c205a2e7f1d92229ac358254bd2826c2d (diff) |
Merge branch 'for-next/read-barrier-depends' into for-next/core
* for-next/read-barrier-depends:
: Allow architectures to override __READ_ONCE()
arm64: Reduce the number of header files pulled into vmlinux.lds.S
compiler.h: Move compiletime_assert() macros into compiler_types.h
checkpatch: Remove checks relating to [smp_]read_barrier_depends()
include/linux: Remove smp_read_barrier_depends() from comments
tools/memory-model: Remove smp_read_barrier_depends() from informal doc
Documentation/barriers/kokr: Remove references to [smp_]read_barrier_depends()
Documentation/barriers: Remove references to [smp_]read_barrier_depends()
locking/barriers: Remove definitions for [smp_]read_barrier_depends()
alpha: Replace smp_read_barrier_depends() usage with smp_[r]mb()
vhost: Remove redundant use of read_barrier_depends() barrier
asm/rwonce: Don't pull <asm/barrier.h> into 'asm-generic/rwonce.h'
asm/rwonce: Remove smp_read_barrier_depends() invocation
alpha: Override READ_ONCE() with barriered implementation
asm/rwonce: Allow __READ_ONCE to be overridden by the architecture
compiler.h: Split {READ,WRITE}_ONCE definitions out into rwonce.h
tools: bpf: Use local copy of headers including uapi/linux/filter.h
Diffstat (limited to 'tools')
-rw-r--r-- | tools/bpf/Makefile | 3 | ||||
-rw-r--r-- | tools/include/uapi/linux/filter.h | 90 | ||||
-rw-r--r-- | tools/memory-model/Documentation/explanation.txt | 26 |
3 files changed, 104 insertions, 15 deletions
diff --git a/tools/bpf/Makefile b/tools/bpf/Makefile index 6df1850f8353..8a69258fd8aa 100644 --- a/tools/bpf/Makefile +++ b/tools/bpf/Makefile @@ -9,7 +9,8 @@ MAKE = make INSTALL ?= install CFLAGS += -Wall -O2 -CFLAGS += -D__EXPORTED_HEADERS__ -I$(srctree)/include/uapi -I$(srctree)/include +CFLAGS += -D__EXPORTED_HEADERS__ -I$(srctree)/tools/include/uapi \ + -I$(srctree)/tools/include # This will work when bpf is built in tools env. where srctree # isn't set and when invoked from selftests build, where srctree diff --git a/tools/include/uapi/linux/filter.h b/tools/include/uapi/linux/filter.h new file mode 100644 index 000000000000..eaef459e7bd4 --- /dev/null +++ b/tools/include/uapi/linux/filter.h @@ -0,0 +1,90 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +/* + * Linux Socket Filter Data Structures + */ + +#ifndef __LINUX_FILTER_H__ +#define __LINUX_FILTER_H__ + + +#include <linux/types.h> +#include <linux/bpf_common.h> + +/* + * Current version of the filter code architecture. + */ +#define BPF_MAJOR_VERSION 1 +#define BPF_MINOR_VERSION 1 + +/* + * Try and keep these values and structures similar to BSD, especially + * the BPF code definitions which need to match so you can share filters + */ + +struct sock_filter { /* Filter block */ + __u16 code; /* Actual filter code */ + __u8 jt; /* Jump true */ + __u8 jf; /* Jump false */ + __u32 k; /* Generic multiuse field */ +}; + +struct sock_fprog { /* Required for SO_ATTACH_FILTER. */ + unsigned short len; /* Number of filter blocks */ + struct sock_filter *filter; +}; + +/* ret - BPF_K and BPF_X also apply */ +#define BPF_RVAL(code) ((code) & 0x18) +#define BPF_A 0x10 + +/* misc */ +#define BPF_MISCOP(code) ((code) & 0xf8) +#define BPF_TAX 0x00 +#define BPF_TXA 0x80 + +/* + * Macros for filter block array initializers. + */ +#ifndef BPF_STMT +#define BPF_STMT(code, k) { (unsigned short)(code), 0, 0, k } +#endif +#ifndef BPF_JUMP +#define BPF_JUMP(code, k, jt, jf) { (unsigned short)(code), jt, jf, k } +#endif + +/* + * Number of scratch memory words for: BPF_ST and BPF_STX + */ +#define BPF_MEMWORDS 16 + +/* RATIONALE. Negative offsets are invalid in BPF. + We use them to reference ancillary data. + Unlike introduction new instructions, it does not break + existing compilers/optimizers. + */ +#define SKF_AD_OFF (-0x1000) +#define SKF_AD_PROTOCOL 0 +#define SKF_AD_PKTTYPE 4 +#define SKF_AD_IFINDEX 8 +#define SKF_AD_NLATTR 12 +#define SKF_AD_NLATTR_NEST 16 +#define SKF_AD_MARK 20 +#define SKF_AD_QUEUE 24 +#define SKF_AD_HATYPE 28 +#define SKF_AD_RXHASH 32 +#define SKF_AD_CPU 36 +#define SKF_AD_ALU_XOR_X 40 +#define SKF_AD_VLAN_TAG 44 +#define SKF_AD_VLAN_TAG_PRESENT 48 +#define SKF_AD_PAY_OFFSET 52 +#define SKF_AD_RANDOM 56 +#define SKF_AD_VLAN_TPID 60 +#define SKF_AD_MAX 64 + +#define SKF_NET_OFF (-0x100000) +#define SKF_LL_OFF (-0x200000) + +#define BPF_NET_OFF SKF_NET_OFF +#define BPF_LL_OFF SKF_LL_OFF + +#endif /* __LINUX_FILTER_H__ */ diff --git a/tools/memory-model/Documentation/explanation.txt b/tools/memory-model/Documentation/explanation.txt index e91a2eb19592..01adf9e0ebac 100644 --- a/tools/memory-model/Documentation/explanation.txt +++ b/tools/memory-model/Documentation/explanation.txt @@ -1122,12 +1122,10 @@ maintain at least the appearance of FIFO order. In practice, this difficulty is solved by inserting a special fence between P1's two loads when the kernel is compiled for the Alpha architecture. In fact, as of version 4.15, the kernel automatically -adds this fence (called smp_read_barrier_depends() and defined as -nothing at all on non-Alpha builds) after every READ_ONCE() and atomic -load. The effect of the fence is to cause the CPU not to execute any -po-later instructions until after the local cache has finished -processing all the stores it has already received. Thus, if the code -was changed to: +adds this fence after every READ_ONCE() and atomic load on Alpha. The +effect of the fence is to cause the CPU not to execute any po-later +instructions until after the local cache has finished processing all +the stores it has already received. Thus, if the code was changed to: P1() { @@ -1146,14 +1144,14 @@ READ_ONCE() or another synchronization primitive rather than accessed directly. The LKMM requires that smp_rmb(), acquire fences, and strong fences -share this property with smp_read_barrier_depends(): They do not allow -the CPU to execute any po-later instructions (or po-later loads in the -case of smp_rmb()) until all outstanding stores have been processed by -the local cache. In the case of a strong fence, the CPU first has to -wait for all of its po-earlier stores to propagate to every other CPU -in the system; then it has to wait for the local cache to process all -the stores received as of that time -- not just the stores received -when the strong fence began. +share this property: They do not allow the CPU to execute any po-later +instructions (or po-later loads in the case of smp_rmb()) until all +outstanding stores have been processed by the local cache. In the +case of a strong fence, the CPU first has to wait for all of its +po-earlier stores to propagate to every other CPU in the system; then +it has to wait for the local cache to process all the stores received +as of that time -- not just the stores received when the strong fence +began. And of course, none of this matters for any architecture other than Alpha. |