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rewrite wbinvd_on_all_cpus_acked() using cpu_xcall(9)
hshoexer <hshoexer@yerbouti.franken.de> writes:
> Hi,
>
> I'd like to simplify the implementation of amd64's
> wbinvd_on_all_cpus_acked() by using cpu_xcall(9).
>
> The diff below rewrites wbinvd_on_all_cpus_acked() accordingly.
>
> The required xcall glue code for amd64 is from this [1] mail by
> dlg@. If the wbinvd_on_all_cpus_acked() is ok, I'm fine with
> splitting this diff.
>
> Thoughts?
>
I believe dlg@ has some changes he may not have shared that are not in
tree that shuffle a bit of how things split across MI/MD.
Given we're post-release, I think it's a good time to start that
conversation again.
> Take care,
> HJ.
>
> [1] https://marc.info/?l=openbsd-tech&m=175246988124240
> -----------------------------------------------------------------
> commit 394bdebb36b1c9699343896fa2091cd1f52be6e3
> Author: hshoexer <hshoexer@yerbouti.franken.de>
> Date: Thu Nov 6 15:01:52 2025 +0100
>
> rewrite wbinvd_on_all_cpus_acked() using cpu_xcall(9)
>
> change includes required amd64 glue code by dlg@ as seen here:
> https://marc.info/?l=openbsd-tech&m=175246988124240
>
> diff --git a/sys/arch/amd64/amd64/cpu.c b/sys/arch/amd64/amd64/cpu.c
> index 5baf179a398..93f554cb652 100644
> --- a/sys/arch/amd64/amd64/cpu.c
> +++ b/sys/arch/amd64/amd64/cpu.c
> @@ -79,6 +79,7 @@
> #include <sys/memrange.h>
> #include <sys/atomic.h>
> #include <sys/user.h>
> +#include <sys/xcall.h>
>
> #include <uvm/uvm_extern.h>
>
> @@ -642,6 +643,8 @@ cpu_attach(struct device *parent, struct device *self, void *aux)
> #endif
>
> #if defined(MULTIPROCESSOR)
> + cpu_xcall_establish(ci);
> +
> /*
> * Allocate UPAGES contiguous pages for the idle PCB and stack.
> */
> @@ -1475,44 +1478,23 @@ wbinvd_on_all_cpus(void)
> return 0;
> }
>
> -volatile long wbinvd_wait __attribute__((section(".kudata")));
> +static void
> +xcwbinvd(void *arg)
> +{
> + wbinvd();
> +}
>
> void
> wbinvd_on_all_cpus_acked(void)
> {
> - struct cpu_info *ci, *self = curcpu();;
> - CPU_INFO_ITERATOR cii;
> - long wait = 0;
> - u_int64_t mask = 0;
> - int s;
> + struct cpu_info *ci;
> + CPU_INFO_ITERATOR cii;
>
> CPU_INFO_FOREACH(cii, ci) {
> - if (ci == self || !(ci->ci_flags & CPUF_RUNNING))
> + if (!(ci->ci_flags & CPUF_RUNNING))
> continue;
> - mask |= (1ULL << ci->ci_cpuid);
> - wait++;
> - }
> -
> - if (wait > 0) {
> - s = splvm();
> - while (atomic_cas_ulong(&wbinvd_wait, 0 , wait) != 0) {
> - while (wbinvd_wait != 0)
> - CPU_BUSY_CYCLE();
> - }
> -
> - CPU_INFO_FOREACH(cii, ci) {
> - if ((mask & (1ULL << ci->ci_cpuid)) == 0)
> - continue;
> - if (x86_fast_ipi(ci, LAPIC_IPI_WBINVD) != 0)
> - panic("%s: ipi failed", __func__);
> - }
> - splx(s);
> + cpu_xcall_sync(ci, xcwbinvd, NULL, "xcwbinvd");
> }
> -
> - wbinvd();
> -
> - while (wbinvd_wait != 0)
> - CPU_BUSY_CYCLE();
> }
> #endif /* MULTIPROCESSOR */
>
> diff --git a/sys/arch/amd64/amd64/ipifuncs.c b/sys/arch/amd64/amd64/ipifuncs.c
> index 482fc9eebb4..8a068278fc2 100644
> --- a/sys/arch/amd64/amd64/ipifuncs.c
> +++ b/sys/arch/amd64/amd64/ipifuncs.c
> @@ -108,6 +108,7 @@ void (*ipifunc[X86_NIPI])(struct cpu_info *) =
> NULL,
> #endif
> x86_64_ipi_wbinvd,
> + cpu_xcall_dispatch,
> };
>
> void
> diff --git a/sys/arch/amd64/amd64/lapic.c b/sys/arch/amd64/amd64/lapic.c
> index f7fdb81ccca..ccf743303f2 100644
> --- a/sys/arch/amd64/amd64/lapic.c
> +++ b/sys/arch/amd64/amd64/lapic.c
> @@ -364,8 +364,6 @@ lapic_boot_init(paddr_t lapic_base)
> idt_vec_set(LAPIC_IPI_INVLPG, Xipi_invlpg_pcid);
> idt_vec_set(LAPIC_IPI_INVLRANGE, Xipi_invlrange_pcid);
> }
> - idt_allocmap[LAPIC_IPI_WBINVD] = 1;
> - idt_vec_set(LAPIC_IPI_WBINVD, Xipi_wbinvd);
> #if NVMM > 0
> idt_allocmap[LAPIC_IPI_INVEPT] = 1;
> idt_vec_set(LAPIC_IPI_INVEPT, Xipi_invept);
> diff --git a/sys/arch/amd64/amd64/vector.S b/sys/arch/amd64/amd64/vector.S
> index 8b82db6b4f6..c531c9f827c 100644
> --- a/sys/arch/amd64/amd64/vector.S
> +++ b/sys/arch/amd64/amd64/vector.S
> @@ -816,17 +816,6 @@ IDTVEC(ipi_invlrange_pcid)
> iretq
> END(Xipi_invlrange_pcid)
>
> -IDTVEC(ipi_wbinvd)
> - ioapic_asm_ack()
> -
> - wbinvd
> -
> - lock
> - decq wbinvd_wait
> -
> - iretq
> -END(Xipi_wbinvd)
> -
> #endif /* MULTIPROCESSOR */
>
> /*
> diff --git a/sys/arch/amd64/conf/files.amd64 b/sys/arch/amd64/conf/files.amd64
> index 630de36a01d..38d5796f650 100644
> --- a/sys/arch/amd64/conf/files.amd64
> +++ b/sys/arch/amd64/conf/files.amd64
> @@ -95,7 +95,7 @@ file arch/amd64/amd64/mpbios.c mpbios needs-flag
> file arch/amd64/amd64/mpbios_intr_fixup.c mpbios & pci
>
> define cpu {[apid = -1]}
> -device cpu
> +device cpu: xcall
> attach cpu at mainbus
> file arch/amd64/amd64/cpu.c cpu
>
> diff --git a/sys/arch/amd64/include/cpu.h b/sys/arch/amd64/include/cpu.h
> index b125f1c4d50..f3b8ec80d96 100644
> --- a/sys/arch/amd64/include/cpu.h
> +++ b/sys/arch/amd64/include/cpu.h
> @@ -53,6 +53,7 @@
> #include <sys/sched.h>
> #include <sys/sensors.h>
> #include <sys/srp.h>
> +#include <sys/xcall.h>
> #include <uvm/uvm_percpu.h>
>
> #ifdef _KERNEL
> @@ -215,6 +216,7 @@ struct cpu_info {
>
> #ifdef MULTIPROCESSOR
> struct srp_hazard ci_srp_hazards[SRP_HAZARD_NUM];
> + struct xcall_cpu ci_xcall;
> #define __HAVE_UVM_PERCPU
> struct uvm_pmr_cache ci_uvm; /* [o] page cache */
> #endif
> diff --git a/sys/arch/amd64/include/i82489var.h b/sys/arch/amd64/include/i82489var.h
> index 561efa3fbd7..95dfff5173d 100644
> --- a/sys/arch/amd64/include/i82489var.h
> +++ b/sys/arch/amd64/include/i82489var.h
> @@ -72,8 +72,7 @@ extern void Xresume_lapic_ipi(void);
> #define LAPIC_IPI_INVLTLB (LAPIC_IPI_OFFSET + 0)
> #define LAPIC_IPI_INVLPG (LAPIC_IPI_OFFSET + 1)
> #define LAPIC_IPI_INVLRANGE (LAPIC_IPI_OFFSET + 2)
> -#define LAPIC_IPI_WBINVD (LAPIC_IPI_OFFSET + 3)
> -#define LAPIC_IPI_INVEPT (LAPIC_IPI_OFFSET + 4)
> +#define LAPIC_IPI_INVEPT (LAPIC_IPI_OFFSET + 3)
>
> extern void Xipi_invltlb(void);
> extern void Xipi_invltlb_pcid(void);
> @@ -81,7 +80,6 @@ extern void Xipi_invlpg(void);
> extern void Xipi_invlpg_pcid(void);
> extern void Xipi_invlrange(void);
> extern void Xipi_invlrange_pcid(void);
> -extern void Xipi_wbinvd(void);
> #if NVMM > 0
> extern void Xipi_invept(void);
> #endif /* NVMM > 0 */
> diff --git a/sys/arch/amd64/include/intr.h b/sys/arch/amd64/include/intr.h
> index c0e12824c2d..ffdff36ca38 100644
> --- a/sys/arch/amd64/include/intr.h
> +++ b/sys/arch/amd64/include/intr.h
> @@ -222,7 +222,9 @@ void x86_ipi_handler(void);
> void x86_setperf_ipi(struct cpu_info *);
>
> extern void (*ipifunc[X86_NIPI])(struct cpu_info *);
> -#endif
> +
> +#define cpu_xcall_ipi(_ci) x86_send_ipi((_ci), X86_IPI_XCALL)
> +#endif /* MULTIPROCESSOR */
>
> #endif /* !_LOCORE */
>
> diff --git a/sys/arch/amd64/include/intrdefs.h b/sys/arch/amd64/include/intrdefs.h
> index 048d0202b88..69238b46155 100644
> --- a/sys/arch/amd64/include/intrdefs.h
> +++ b/sys/arch/amd64/include/intrdefs.h
> @@ -85,8 +85,9 @@
> #define X86_IPI_START_VMM 0x00000100
> #define X86_IPI_STOP_VMM 0x00000200
> #define X86_IPI_WBINVD 0x00000400
> +#define X86_IPI_XCALL 0x00000800
>
> -#define X86_NIPI 12
> +#define X86_NIPI 13
>
> #define IREENT_MAGIC 0x18041969
>
> diff --git a/sys/conf/files b/sys/conf/files
> index 59df8c6fd1b..1e00c25cb6c 100644
> --- a/sys/conf/files
> +++ b/sys/conf/files
> @@ -751,7 +751,7 @@ file kern/kern_uuid.c
> file kern/kern_watchdog.c !small_kernel
> file kern/kern_task.c
> file kern/kern_srp.c
> -file kern/kern_xcall.c xcall needs-flag
> +file kern/kern_xcall.c xcall
> file kern/kern_xxx.c
> file kern/sched_bsd.c
> file kern/subr_autoconf.c
rewrite wbinvd_on_all_cpus_acked() using cpu_xcall(9)