The branch main has been updated by kevans: URL: https://cgit.FreeBSD.org/src/commit/?id=86c31aca33ff771b845acbbed3b3659fde7e710f
commit 86c31aca33ff771b845acbbed3b3659fde7e710f Author: Kyle Evans <[email protected]> AuthorDate: 2023-05-11 18:23:03 +0000 Commit: Kyle Evans <[email protected]> CommitDate: 2023-05-11 18:23:14 +0000 arm64: add swapueword8/32 Much like casueword*, except just a plain old swap. Maintains a similar interface to casu(9)- return value -1 (fault), 0 (success), or 1 (fail), and also both ll/sc and LSE variants are implemented. These will be used to implement 32-bit swp/swpb emulation on aarch64. Reveiwed by: andrew Sponsored by: Stormshield Sponsored by: Klara, Inc. Differential Revision: https://reviews.freebsd.org/D39837 --- sys/arm64/arm64/support.S | 92 +++++++++++++++++++++++++++++++++++++++++ sys/arm64/arm64/support_ifunc.c | 24 +++++++++++ sys/arm64/include/md_var.h | 11 +++++ 3 files changed, 127 insertions(+) diff --git a/sys/arm64/arm64/support.S b/sys/arm64/arm64/support.S index 28ac1d553fbc..f7e9abcd910c 100644 --- a/sys/arm64/arm64/support.S +++ b/sys/arm64/arm64/support.S @@ -55,6 +55,98 @@ fsu_fault_nopcb: ret END(fsu_fault) +/* + * int swapueword8_llsc(volatile uint8_t *, uint8_t *) + */ +ENTRY(swapueword8_llsc) + check_user_access 0, (VM_MAXUSER_ADDRESS-3), fsu_fault_nopcb + adr x6, fsu_fault /* Load the fault handler */ + SET_FAULT_HANDLER(x6, x4) /* And set it */ + ENTER_USER_ACCESS(w6, x4) + + ldrb w7, [x1] + + ldxrb w2, [x0] + stxrb w3, w7, [x0] + cbnz w3, 1f + + strb w2, [x1] /* Stash old value in *val */ + +1: EXIT_USER_ACCESS(w6) + SET_FAULT_HANDLER(xzr, x6) + mov w0, w3 + ret +END(swapueword8_llsc) + +/* + * int swapueword8_lse(volatile uint8_t *, uint8_t *) + */ +ENTRY(swapueword8_lse) + check_user_access 0, (VM_MAXUSER_ADDRESS-3), fsu_fault_nopcb + adr x6, fsu_fault /* Load the fault handler */ + SET_FAULT_HANDLER(x6, x4) /* And set it */ + ENTER_USER_ACCESS(w6, x4) + + ldrb w7, [x1] + + .arch_extension lse + swpb w7, w2, [x0] + .arch_extension nolse + + strb w2, [x1] /* Stash old value in *val */ + + EXIT_USER_ACCESS(w6) + SET_FAULT_HANDLER(xzr, x6) + mov w0, #0 + ret +END(swapueword8_lse) + +/* + * int swapueword32_llsc(volatile uint32_t *, uint32_t *) + */ +ENTRY(swapueword32_llsc) + check_user_access 0, (VM_MAXUSER_ADDRESS-3), fsu_fault_nopcb + adr x6, fsu_fault /* Load the fault handler */ + SET_FAULT_HANDLER(x6, x4) /* And set it */ + ENTER_USER_ACCESS(w6, x4) + + ldr w7, [x1] + + ldxr w2, [x0] /* Stash the old value in w2 */ + stxr w3, w7, [x0] /* Store new value */ + cbnz w3, 1f + + str w2, [x1] /* Stash old value in *val */ + +1: EXIT_USER_ACCESS(w6) + SET_FAULT_HANDLER(xzr, x6) + mov w0, w3 + ret +END(swapueword32_llsc) + +/* + * int swapueword32_lse(volatile uint32_t *, uint32_t *) + */ +ENTRY(swapueword32_lse) + check_user_access 0, (VM_MAXUSER_ADDRESS-3), fsu_fault_nopcb + adr x6, fsu_fault /* Load the fault handler */ + SET_FAULT_HANDLER(x6, x4) /* And set it */ + ENTER_USER_ACCESS(w6, x4) + + ldr w7, [x1] + + .arch_extension lse + swp w7, w2, [x0] + .arch_extension nolse + + str w2, [x1] /* Stash old value in *val */ + + EXIT_USER_ACCESS(w6) + SET_FAULT_HANDLER(xzr, x6) + mov w0, #0 + ret +END(swapueword32_llsc) + /* * int casueword32_llsc(volatile uint32_t *, uint32_t, uint32_t *, uint32_t) */ diff --git a/sys/arm64/arm64/support_ifunc.c b/sys/arm64/arm64/support_ifunc.c index 8abf3f3c75af..8cbe1c97b0a1 100644 --- a/sys/arm64/arm64/support_ifunc.c +++ b/sys/arm64/arm64/support_ifunc.c @@ -32,6 +32,8 @@ #include <machine/atomic.h> #include <machine/ifunc.h> +#define _MD_WANT_SWAPWORD +#include <machine/md_var.h> int casueword32_llsc(volatile uint32_t *, uint32_t, uint32_t *, uint32_t); int casueword32_lse(volatile uint32_t *, uint32_t, uint32_t *, uint32_t); @@ -39,6 +41,12 @@ int casueword32_lse(volatile uint32_t *, uint32_t, uint32_t *, uint32_t); int casueword_llsc(volatile u_long *, u_long, u_long *, u_long); int casueword_lse(volatile u_long *, u_long, u_long *, u_long); +int swapueword8_llsc(volatile uint8_t *, uint8_t *); +int swapueword8_lse(volatile uint8_t *, uint8_t *); + +int swapueword32_llsc(volatile uint32_t *, uint32_t *); +int swapueword32_lse(volatile uint32_t *, uint32_t *); + DEFINE_IFUNC(, int, casueword32, (volatile uint32_t *base, uint32_t oldval, uint32_t *oldvalp, uint32_t newval)) { @@ -56,3 +64,19 @@ DEFINE_IFUNC(, int, casueword, (volatile u_long *base, u_long oldval, return (casueword_llsc); } + +DEFINE_IFUNC(, int, swapueword8, (volatile uint8_t *base, uint8_t *val)) +{ + if (lse_supported) + return (swapueword8_lse); + + return (swapueword8_llsc); +} + +DEFINE_IFUNC(, int, swapueword32, (volatile uint32_t *base, uint32_t *val)) +{ + if (lse_supported) + return (swapueword32_lse); + + return (swapueword32_llsc); +} diff --git a/sys/arm64/include/md_var.h b/sys/arm64/include/md_var.h index 6c78317c830c..d6c1b4ca2764 100644 --- a/sys/arm64/include/md_var.h +++ b/sys/arm64/include/md_var.h @@ -57,4 +57,15 @@ void generic_bs_poke_2(void) __asm(__STRING(generic_bs_poke_2)); void generic_bs_poke_4(void) __asm(__STRING(generic_bs_poke_4)); void generic_bs_poke_8(void) __asm(__STRING(generic_bs_poke_8)); +#ifdef _MD_WANT_SWAPWORD +/* + * XXX These are implemented primarily for swp/swpb emulation at the moment, and + * should be used sparingly with consideration -- they aren't implemented for + * any other platform. If we use them anywhere else, at a minimum they need + * KASAN/KMSAN interceptors added. + */ +int swapueword8(volatile uint8_t *base, uint8_t *val); +int swapueword32(volatile uint32_t *base, uint32_t *val); +#endif + #endif /* !_MACHINE_MD_VAR_H_ */
