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author | 2023-02-21 18:24:12 -0800 | |
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committer | 2023-02-21 18:24:12 -0800 | |
commit | 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch) | |
tree | cc5c2d0a898769fd59549594fedb3ee6f84e59a0 /arch/x86/include/asm/alternative.h | |
download | linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip |
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski:
"Core:
- Add dedicated kmem_cache for typical/small skb->head, avoid having
to access struct page at kfree time, and improve memory use.
- Introduce sysctl to set default RPS configuration for new netdevs.
- Define Netlink protocol specification format which can be used to
describe messages used by each family and auto-generate parsers.
Add tools for generating kernel data structures and uAPI headers.
- Expose all net/core sysctls inside netns.
- Remove 4s sleep in netpoll if carrier is instantly detected on
boot.
- Add configurable limit of MDB entries per port, and port-vlan.
- Continue populating drop reasons throughout the stack.
- Retire a handful of legacy Qdiscs and classifiers.
Protocols:
- Support IPv4 big TCP (TSO frames larger than 64kB).
- Add IP_LOCAL_PORT_RANGE socket option, to control local port range
on socket by socket basis.
- Track and report in procfs number of MPTCP sockets used.
- Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
manager.
- IPv6: don't check net.ipv6.route.max_size and rely on garbage
collection to free memory (similarly to IPv4).
- Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).
- ICMP: add per-rate limit counters.
- Add support for user scanning requests in ieee802154.
- Remove static WEP support.
- Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
reporting.
- WiFi 7 EHT channel puncturing support (client & AP).
BPF:
- Add a rbtree data structure following the "next-gen data structure"
precedent set by recently added linked list, that is, by using
kfunc + kptr instead of adding a new BPF map type.
- Expose XDP hints via kfuncs with initial support for RX hash and
timestamp metadata.
- Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
better support decap on GRE tunnel devices not operating in collect
metadata.
- Improve x86 JIT's codegen for PROBE_MEM runtime error checks.
- Remove the need for trace_printk_lock for bpf_trace_printk and
bpf_trace_vprintk helpers.
- Extend libbpf's bpf_tracing.h support for tracing arguments of
kprobes/uprobes and syscall as a special case.
- Significantly reduce the search time for module symbols by
livepatch and BPF.
- Enable cpumasks to be used as kptrs, which is useful for tracing
programs tracking which tasks end up running on which CPUs in
different time intervals.
- Add support for BPF trampoline on s390x and riscv64.
- Add capability to export the XDP features supported by the NIC.
- Add __bpf_kfunc tag for marking kernel functions as kfuncs.
- Add cgroup.memory=nobpf kernel parameter option to disable BPF
memory accounting for container environments.
Netfilter:
- Remove the CLUSTERIP target. It has been marked as obsolete for
years, and we still have WARN splats wrt races of the out-of-band
/proc interface installed by this target.
- Add 'destroy' commands to nf_tables. They are identical to the
existing 'delete' commands, but do not return an error if the
referenced object (set, chain, rule...) did not exist.
Driver API:
- Improve cpumask_local_spread() locality to help NICs set the right
IRQ affinity on AMD platforms.
- Separate C22 and C45 MDIO bus transactions more clearly.
- Introduce new DCB table to control DSCP rewrite on egress.
- Support configuration of Physical Layer Collision Avoidance (PLCA)
Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
shared medium Ethernet.
- Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
preemption of low priority frames by high priority frames.
- Add support for controlling MACSec offload using netlink SET.
- Rework devlink instance refcounts to allow registration and
de-registration under the instance lock. Split the code into
multiple files, drop some of the unnecessarily granular locks and
factor out common parts of netlink operation handling.
- Add TX frame aggregation parameters (for USB drivers).
- Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
messages with notifications for debug.
- Allow offloading of UDP NEW connections via act_ct.
- Add support for per action HW stats in TC.
- Support hardware miss to TC action (continue processing in SW from
a specific point in the action chain).
- Warn if old Wireless Extension user space interface is used with
modern cfg80211/mac80211 drivers. Do not support Wireless
Extensions for Wi-Fi 7 devices at all. Everyone should switch to
using nl80211 interface instead.
- Improve the CAN bit timing configuration. Use extack to return
error messages directly to user space, update the SJW handling,
including the definition of a new default value that will benefit
CAN-FD controllers, by increasing their oscillator tolerance.
New hardware / drivers:
- Ethernet:
- nVidia BlueField-3 support (control traffic driver)
- Ethernet support for imx93 SoCs
- Motorcomm yt8531 gigabit Ethernet PHY
- onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
- Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
- Amlogic gxl MDIO mux
- WiFi:
- RealTek RTL8188EU (rtl8xxxu)
- Qualcomm Wi-Fi 7 devices (ath12k)
- CAN:
- Renesas R-Car V4H
Drivers:
- Bluetooth:
- Set Per Platform Antenna Gain (PPAG) for Intel controllers.
- Ethernet NICs:
- Intel (1G, igc):
- support TSN / Qbv / packet scheduling features of i226 model
- Intel (100G, ice):
- use GNSS subsystem instead of TTY
- multi-buffer XDP support
- extend support for GPIO pins to E823 devices
- nVidia/Mellanox:
- update the shared buffer configuration on PFC commands
- implement PTP adjphase function for HW offset control
- TC support for Geneve and GRE with VF tunnel offload
- more efficient crypto key management method
- multi-port eswitch support
- Netronome/Corigine:
- add DCB IEEE support
- support IPsec offloading for NFP3800
- Freescale/NXP (enetc):
- support XDP_REDIRECT for XDP non-linear buffers
- improve reconfig, avoid link flap and waiting for idle
- support MAC Merge layer
- Other NICs:
- sfc/ef100: add basic devlink support for ef100
- ionic: rx_push mode operation (writing descriptors via MMIO)
- bnxt: use the auxiliary bus abstraction for RDMA
- r8169: disable ASPM and reset bus in case of tx timeout
- cpsw: support QSGMII mode for J721e CPSW9G
- cpts: support pulse-per-second output
- ngbe: add an mdio bus driver
- usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
- r8152: handle devices with FW with NCM support
- amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
- virtio-net: support multi buffer XDP
- virtio/vsock: replace virtio_vsock_pkt with sk_buff
- tsnep: XDP support
- Ethernet high-speed switches:
- nVidia/Mellanox (mlxsw):
- add support for latency TLV (in FW control messages)
- Microchip (sparx5):
- separate explicit and implicit traffic forwarding rules, make
the implicit rules always active
- add support for egress DSCP rewrite
- IS0 VCAP support (Ingress Classification)
- IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
etc.)
- ES2 VCAP support (Egress Access Control)
- support for Per-Stream Filtering and Policing (802.1Q,
8.6.5.1)
- Ethernet embedded switches:
- Marvell (mv88e6xxx):
- add MAB (port auth) offload support
- enable PTP receive for mv88e6390
- NXP (ocelot):
- support MAC Merge layer
- support for the the vsc7512 internal copper phys
- Microchip:
- lan9303: convert to PHYLINK
- lan966x: support TC flower filter statistics
- lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
- lan937x: support Credit Based Shaper configuration
- ksz9477: support Energy Efficient Ethernet
- other:
- qca8k: convert to regmap read/write API, use bulk operations
- rswitch: Improve TX timestamp accuracy
- Intel WiFi (iwlwifi):
- EHT (Wi-Fi 7) rate reporting
- STEP equalizer support: transfer some STEP (connection to radio
on platforms with integrated wifi) related parameters from the
BIOS to the firmware.
- Qualcomm 802.11ax WiFi (ath11k):
- IPQ5018 support
- Fine Timing Measurement (FTM) responder role support
- channel 177 support
- MediaTek WiFi (mt76):
- per-PHY LED support
- mt7996: EHT (Wi-Fi 7) support
- Wireless Ethernet Dispatch (WED) reset support
- switch to using page pool allocator
- RealTek WiFi (rtw89):
- support new version of Bluetooth co-existance
- Mobile:
- rmnet: support TX aggregation"
* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
page_pool: add a comment explaining the fragment counter usage
net: ethtool: fix __ethtool_dev_mm_supported() implementation
ethtool: pse-pd: Fix double word in comments
xsk: add linux/vmalloc.h to xsk.c
sefltests: netdevsim: wait for devlink instance after netns removal
selftest: fib_tests: Always cleanup before exit
net/mlx5e: Align IPsec ASO result memory to be as required by hardware
net/mlx5e: TC, Set CT miss to the specific ct action instance
net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
net/mlx5: Refactor tc miss handling to a single function
net/mlx5: Kconfig: Make tc offload depend on tc skb extension
net/sched: flower: Support hardware miss to tc action
net/sched: flower: Move filter handle initialization earlier
net/sched: cls_api: Support hardware miss to tc action
net/sched: Rename user cookie and act cookie
sfc: fix builds without CONFIG_RTC_LIB
sfc: clean up some inconsistent indentings
net/mlx4_en: Introduce flexible array to silence overflow warning
net: lan966x: Fix possible deadlock inside PTP
net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
...
Diffstat (limited to '')
-rw-r--r-- | arch/x86/include/asm/alternative.h | 476 |
1 files changed, 476 insertions, 0 deletions
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h new file mode 100644 index 000000000..e2975a32d --- /dev/null +++ b/arch/x86/include/asm/alternative.h @@ -0,0 +1,476 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_ALTERNATIVE_H +#define _ASM_X86_ALTERNATIVE_H + +#include <linux/types.h> +#include <linux/stringify.h> +#include <asm/asm.h> + +#define ALT_FLAGS_SHIFT 16 + +#define ALT_FLAG_NOT BIT(0) +#define ALT_NOT(feature) ((ALT_FLAG_NOT << ALT_FLAGS_SHIFT) | (feature)) + +#ifndef __ASSEMBLY__ + +#include <linux/stddef.h> + +/* + * Alternative inline assembly for SMP. + * + * The LOCK_PREFIX macro defined here replaces the LOCK and + * LOCK_PREFIX macros used everywhere in the source tree. + * + * SMP alternatives use the same data structures as the other + * alternatives and the X86_FEATURE_UP flag to indicate the case of a + * UP system running a SMP kernel. The existing apply_alternatives() + * works fine for patching a SMP kernel for UP. + * + * The SMP alternative tables can be kept after boot and contain both + * UP and SMP versions of the instructions to allow switching back to + * SMP at runtime, when hotplugging in a new CPU, which is especially + * useful in virtualized environments. + * + * The very common lock prefix is handled as special case in a + * separate table which is a pure address list without replacement ptr + * and size information. That keeps the table sizes small. + */ + +#ifdef CONFIG_SMP +#define LOCK_PREFIX_HERE \ + ".pushsection .smp_locks,\"a\"\n" \ + ".balign 4\n" \ + ".long 671f - .\n" /* offset */ \ + ".popsection\n" \ + "671:" + +#define LOCK_PREFIX LOCK_PREFIX_HERE "\n\tlock; " + +#else /* ! CONFIG_SMP */ +#define LOCK_PREFIX_HERE "" +#define LOCK_PREFIX "" +#endif + +/* + * objtool annotation to ignore the alternatives and only consider the original + * instruction(s). + */ +#define ANNOTATE_IGNORE_ALTERNATIVE \ + "999:\n\t" \ + ".pushsection .discard.ignore_alts\n\t" \ + ".long 999b - .\n\t" \ + ".popsection\n\t" + +/* + * The patching flags are part of the upper bits of the @ft_flags parameter when + * specifying them. The split is currently like this: + * + * [31... flags ...16][15... CPUID feature bit ...0] + * + * but since this is all hidden in the macros argument being split, those fields can be + * extended in the future to fit in a u64 or however the need arises. + */ +struct alt_instr { + s32 instr_offset; /* original instruction */ + s32 repl_offset; /* offset to replacement instruction */ + + union { + struct { + u32 cpuid: 16; /* CPUID bit set for replacement */ + u32 flags: 16; /* patching control flags */ + }; + u32 ft_flags; + }; + + u8 instrlen; /* length of original instruction */ + u8 replacementlen; /* length of new instruction */ +} __packed; + +/* + * Debug flag that can be tested to see whether alternative + * instructions were patched in already: + */ +extern int alternatives_patched; + +extern void alternative_instructions(void); +extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end); +extern void apply_retpolines(s32 *start, s32 *end); +extern void apply_returns(s32 *start, s32 *end); +extern void apply_ibt_endbr(s32 *start, s32 *end); +extern void apply_fineibt(s32 *start_retpoline, s32 *end_retpoine, + s32 *start_cfi, s32 *end_cfi); + +struct module; +struct paravirt_patch_site; + +struct callthunk_sites { + s32 *call_start, *call_end; + struct paravirt_patch_site *pv_start, *pv_end; +}; + +#ifdef CONFIG_CALL_THUNKS +extern void callthunks_patch_builtin_calls(void); +extern void callthunks_patch_module_calls(struct callthunk_sites *sites, + struct module *mod); +extern void *callthunks_translate_call_dest(void *dest); +extern bool is_callthunk(void *addr); +extern int x86_call_depth_emit_accounting(u8 **pprog, void *func); +#else +static __always_inline void callthunks_patch_builtin_calls(void) {} +static __always_inline void +callthunks_patch_module_calls(struct callthunk_sites *sites, + struct module *mod) {} +static __always_inline void *callthunks_translate_call_dest(void *dest) +{ + return dest; +} +static __always_inline bool is_callthunk(void *addr) +{ + return false; +} +static __always_inline int x86_call_depth_emit_accounting(u8 **pprog, + void *func) +{ + return 0; +} +#endif + +#ifdef CONFIG_SMP +extern void alternatives_smp_module_add(struct module *mod, char *name, + void *locks, void *locks_end, + void *text, void *text_end); +extern void alternatives_smp_module_del(struct module *mod); +extern void alternatives_enable_smp(void); +extern int alternatives_text_reserved(void *start, void *end); +extern bool skip_smp_alternatives; +#else +static inline void alternatives_smp_module_add(struct module *mod, char *name, + void *locks, void *locks_end, + void *text, void *text_end) {} +static inline void alternatives_smp_module_del(struct module *mod) {} +static inline void alternatives_enable_smp(void) {} +static inline int alternatives_text_reserved(void *start, void *end) +{ + return 0; +} +#endif /* CONFIG_SMP */ + +#define b_replacement(num) "664"#num +#define e_replacement(num) "665"#num + +#define alt_end_marker "663" +#define alt_slen "662b-661b" +#define alt_total_slen alt_end_marker"b-661b" +#define alt_rlen(num) e_replacement(num)"f-"b_replacement(num)"f" + +#define OLDINSTR(oldinstr, num) \ + "# ALT: oldnstr\n" \ + "661:\n\t" oldinstr "\n662:\n" \ + "# ALT: padding\n" \ + ".skip -(((" alt_rlen(num) ")-(" alt_slen ")) > 0) * " \ + "((" alt_rlen(num) ")-(" alt_slen ")),0x90\n" \ + alt_end_marker ":\n" + +/* + * gas compatible max based on the idea from: + * http://graphics.stanford.edu/~seander/bithacks.html#IntegerMinOrMax + * + * The additional "-" is needed because gas uses a "true" value of -1. + */ +#define alt_max_short(a, b) "((" a ") ^ (((" a ") ^ (" b ")) & -(-((" a ") < (" b ")))))" + +/* + * Pad the second replacement alternative with additional NOPs if it is + * additionally longer than the first replacement alternative. + */ +#define OLDINSTR_2(oldinstr, num1, num2) \ + "# ALT: oldinstr2\n" \ + "661:\n\t" oldinstr "\n662:\n" \ + "# ALT: padding2\n" \ + ".skip -((" alt_max_short(alt_rlen(num1), alt_rlen(num2)) " - (" alt_slen ")) > 0) * " \ + "(" alt_max_short(alt_rlen(num1), alt_rlen(num2)) " - (" alt_slen ")), 0x90\n" \ + alt_end_marker ":\n" + +#define OLDINSTR_3(oldinsn, n1, n2, n3) \ + "# ALT: oldinstr3\n" \ + "661:\n\t" oldinsn "\n662:\n" \ + "# ALT: padding3\n" \ + ".skip -((" alt_max_short(alt_max_short(alt_rlen(n1), alt_rlen(n2)), alt_rlen(n3)) \ + " - (" alt_slen ")) > 0) * " \ + "(" alt_max_short(alt_max_short(alt_rlen(n1), alt_rlen(n2)), alt_rlen(n3)) \ + " - (" alt_slen ")), 0x90\n" \ + alt_end_marker ":\n" + +#define ALTINSTR_ENTRY(ft_flags, num) \ + " .long 661b - .\n" /* label */ \ + " .long " b_replacement(num)"f - .\n" /* new instruction */ \ + " .4byte " __stringify(ft_flags) "\n" /* feature + flags */ \ + " .byte " alt_total_slen "\n" /* source len */ \ + " .byte " alt_rlen(num) "\n" /* replacement len */ + +#define ALTINSTR_REPLACEMENT(newinstr, num) /* replacement */ \ + "# ALT: replacement " #num "\n" \ + b_replacement(num)":\n\t" newinstr "\n" e_replacement(num) ":\n" + +/* alternative assembly primitive: */ +#define ALTERNATIVE(oldinstr, newinstr, ft_flags) \ + OLDINSTR(oldinstr, 1) \ + ".pushsection .altinstructions,\"a\"\n" \ + ALTINSTR_ENTRY(ft_flags, 1) \ + ".popsection\n" \ + ".pushsection .altinstr_replacement, \"ax\"\n" \ + ALTINSTR_REPLACEMENT(newinstr, 1) \ + ".popsection\n" + +#define ALTERNATIVE_2(oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2) \ + OLDINSTR_2(oldinstr, 1, 2) \ + ".pushsection .altinstructions,\"a\"\n" \ + ALTINSTR_ENTRY(ft_flags1, 1) \ + ALTINSTR_ENTRY(ft_flags2, 2) \ + ".popsection\n" \ + ".pushsection .altinstr_replacement, \"ax\"\n" \ + ALTINSTR_REPLACEMENT(newinstr1, 1) \ + ALTINSTR_REPLACEMENT(newinstr2, 2) \ + ".popsection\n" + +/* If @feature is set, patch in @newinstr_yes, otherwise @newinstr_no. */ +#define ALTERNATIVE_TERNARY(oldinstr, ft_flags, newinstr_yes, newinstr_no) \ + ALTERNATIVE_2(oldinstr, newinstr_no, X86_FEATURE_ALWAYS, \ + newinstr_yes, ft_flags) + +#define ALTERNATIVE_3(oldinsn, newinsn1, ft_flags1, newinsn2, ft_flags2, \ + newinsn3, ft_flags3) \ + OLDINSTR_3(oldinsn, 1, 2, 3) \ + ".pushsection .altinstructions,\"a\"\n" \ + ALTINSTR_ENTRY(ft_flags1, 1) \ + ALTINSTR_ENTRY(ft_flags2, 2) \ + ALTINSTR_ENTRY(ft_flags3, 3) \ + ".popsection\n" \ + ".pushsection .altinstr_replacement, \"ax\"\n" \ + ALTINSTR_REPLACEMENT(newinsn1, 1) \ + ALTINSTR_REPLACEMENT(newinsn2, 2) \ + ALTINSTR_REPLACEMENT(newinsn3, 3) \ + ".popsection\n" + +/* + * Alternative instructions for different CPU types or capabilities. + * + * This allows to use optimized instructions even on generic binary + * kernels. + * + * length of oldinstr must be longer or equal the length of newinstr + * It can be padded with nops as needed. + * + * For non barrier like inlines please define new variants + * without volatile and memory clobber. + */ +#define alternative(oldinstr, newinstr, ft_flags) \ + asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, ft_flags) : : : "memory") + +#define alternative_2(oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2) \ + asm_inline volatile(ALTERNATIVE_2(oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2) ::: "memory") + +#define alternative_ternary(oldinstr, ft_flags, newinstr_yes, newinstr_no) \ + asm_inline volatile(ALTERNATIVE_TERNARY(oldinstr, ft_flags, newinstr_yes, newinstr_no) ::: "memory") + +/* + * Alternative inline assembly with input. + * + * Peculiarities: + * No memory clobber here. + * Argument numbers start with 1. + * Leaving an unused argument 0 to keep API compatibility. + */ +#define alternative_input(oldinstr, newinstr, ft_flags, input...) \ + asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, ft_flags) \ + : : "i" (0), ## input) + +/* + * This is similar to alternative_input. But it has two features and + * respective instructions. + * + * If CPU has feature2, newinstr2 is used. + * Otherwise, if CPU has feature1, newinstr1 is used. + * Otherwise, oldinstr is used. + */ +#define alternative_input_2(oldinstr, newinstr1, ft_flags1, newinstr2, \ + ft_flags2, input...) \ + asm_inline volatile(ALTERNATIVE_2(oldinstr, newinstr1, ft_flags1, \ + newinstr2, ft_flags2) \ + : : "i" (0), ## input) + +/* Like alternative_input, but with a single output argument */ +#define alternative_io(oldinstr, newinstr, ft_flags, output, input...) \ + asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, ft_flags) \ + : output : "i" (0), ## input) + +/* Like alternative_io, but for replacing a direct call with another one. */ +#define alternative_call(oldfunc, newfunc, ft_flags, output, input...) \ + asm_inline volatile (ALTERNATIVE("call %P[old]", "call %P[new]", ft_flags) \ + : output : [old] "i" (oldfunc), [new] "i" (newfunc), ## input) + +/* + * Like alternative_call, but there are two features and respective functions. + * If CPU has feature2, function2 is used. + * Otherwise, if CPU has feature1, function1 is used. + * Otherwise, old function is used. + */ +#define alternative_call_2(oldfunc, newfunc1, ft_flags1, newfunc2, ft_flags2, \ + output, input...) \ + asm_inline volatile (ALTERNATIVE_2("call %P[old]", "call %P[new1]", ft_flags1,\ + "call %P[new2]", ft_flags2) \ + : output, ASM_CALL_CONSTRAINT \ + : [old] "i" (oldfunc), [new1] "i" (newfunc1), \ + [new2] "i" (newfunc2), ## input) + +/* + * use this macro(s) if you need more than one output parameter + * in alternative_io + */ +#define ASM_OUTPUT2(a...) a + +/* + * use this macro if you need clobbers but no inputs in + * alternative_{input,io,call}() + */ +#define ASM_NO_INPUT_CLOBBER(clbr...) "i" (0) : clbr + +#else /* __ASSEMBLY__ */ + +#ifdef CONFIG_SMP + .macro LOCK_PREFIX +672: lock + .pushsection .smp_locks,"a" + .balign 4 + .long 672b - . + .popsection + .endm +#else + .macro LOCK_PREFIX + .endm +#endif + +/* + * objtool annotation to ignore the alternatives and only consider the original + * instruction(s). + */ +.macro ANNOTATE_IGNORE_ALTERNATIVE + .Lannotate_\@: + .pushsection .discard.ignore_alts + .long .Lannotate_\@ - . + .popsection +.endm + +/* + * Issue one struct alt_instr descriptor entry (need to put it into + * the section .altinstructions, see below). This entry contains + * enough information for the alternatives patching code to patch an + * instruction. See apply_alternatives(). + */ +.macro altinstr_entry orig alt ft_flags orig_len alt_len + .long \orig - . + .long \alt - . + .4byte \ft_flags + .byte \orig_len + .byte \alt_len +.endm + +/* + * Define an alternative between two instructions. If @feature is + * present, early code in apply_alternatives() replaces @oldinstr with + * @newinstr. ".skip" directive takes care of proper instruction padding + * in case @newinstr is longer than @oldinstr. + */ +.macro ALTERNATIVE oldinstr, newinstr, ft_flags +140: + \oldinstr +141: + .skip -(((144f-143f)-(141b-140b)) > 0) * ((144f-143f)-(141b-140b)),0x90 +142: + + .pushsection .altinstructions,"a" + altinstr_entry 140b,143f,\ft_flags,142b-140b,144f-143f + .popsection + + .pushsection .altinstr_replacement,"ax" +143: + \newinstr +144: + .popsection +.endm + +#define old_len 141b-140b +#define new_len1 144f-143f +#define new_len2 145f-144f +#define new_len3 146f-145f + +/* + * gas compatible max based on the idea from: + * http://graphics.stanford.edu/~seander/bithacks.html#IntegerMinOrMax + * + * The additional "-" is needed because gas uses a "true" value of -1. + */ +#define alt_max_2(a, b) ((a) ^ (((a) ^ (b)) & -(-((a) < (b))))) +#define alt_max_3(a, b, c) (alt_max_2(alt_max_2(a, b), c)) + + +/* + * Same as ALTERNATIVE macro above but for two alternatives. If CPU + * has @feature1, it replaces @oldinstr with @newinstr1. If CPU has + * @feature2, it replaces @oldinstr with @feature2. + */ +.macro ALTERNATIVE_2 oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2 +140: + \oldinstr +141: + .skip -((alt_max_2(new_len1, new_len2) - (old_len)) > 0) * \ + (alt_max_2(new_len1, new_len2) - (old_len)),0x90 +142: + + .pushsection .altinstructions,"a" + altinstr_entry 140b,143f,\ft_flags1,142b-140b,144f-143f + altinstr_entry 140b,144f,\ft_flags2,142b-140b,145f-144f + .popsection + + .pushsection .altinstr_replacement,"ax" +143: + \newinstr1 +144: + \newinstr2 +145: + .popsection +.endm + +.macro ALTERNATIVE_3 oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2, newinstr3, ft_flags3 +140: + \oldinstr +141: + .skip -((alt_max_3(new_len1, new_len2, new_len3) - (old_len)) > 0) * \ + (alt_max_3(new_len1, new_len2, new_len3) - (old_len)),0x90 +142: + + .pushsection .altinstructions,"a" + altinstr_entry 140b,143f,\ft_flags1,142b-140b,144f-143f + altinstr_entry 140b,144f,\ft_flags2,142b-140b,145f-144f + altinstr_entry 140b,145f,\ft_flags3,142b-140b,146f-145f + .popsection + + .pushsection .altinstr_replacement,"ax" +143: + \newinstr1 +144: + \newinstr2 +145: + \newinstr3 +146: + .popsection +.endm + +/* If @feature is set, patch in @newinstr_yes, otherwise @newinstr_no. */ +#define ALTERNATIVE_TERNARY(oldinstr, ft_flags, newinstr_yes, newinstr_no) \ + ALTERNATIVE_2 oldinstr, newinstr_no, X86_FEATURE_ALWAYS, \ + newinstr_yes, ft_flags + +#endif /* __ASSEMBLY__ */ + +#endif /* _ASM_X86_ALTERNATIVE_H */ |