Date: Wed, 5 Jul 2023 09:46:10 GMT From: Andrew Turner <andrew@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: df0d0fc99093 - main - Add helpers to allocate an arm64 VFP state struct Message-ID: <202307050946.3659kAkA039213@gitrepo.freebsd.org>
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The branch main has been updated by andrew: URL: https://cgit.FreeBSD.org/src/commit/?id=df0d0fc99093cbdcab9b84911376ee52e58ce7f2 commit df0d0fc99093cbdcab9b84911376ee52e58ce7f2 Author: Andrew Turner <andrew@FreeBSD.org> AuthorDate: 2023-05-16 10:09:11 +0000 Commit: Andrew Turner <andrew@FreeBSD.org> CommitDate: 2023-07-05 09:42:14 +0000 Add helpers to allocate an arm64 VFP state struct This will be used by bhyve and will allow the size to change, e.g. for SVE. Reviewed by: markj Sponsored by: Arm Ltd Differential Revision: https://reviews.freebsd.org/D40131 --- sys/arm64/arm64/mp_machdep.c | 2 +- sys/arm64/arm64/vfp.c | 57 +++++++++++++++++++++++++++++++++++++++++--- sys/arm64/include/vfp.h | 6 ++++- 3 files changed, 60 insertions(+), 5 deletions(-) diff --git a/sys/arm64/arm64/mp_machdep.c b/sys/arm64/arm64/mp_machdep.c index babeee331be0..9aef6a9a080f 100644 --- a/sys/arm64/arm64/mp_machdep.c +++ b/sys/arm64/arm64/mp_machdep.c @@ -274,7 +274,7 @@ init_secondary(uint64_t cpu) cpu_initclocks_ap(); #ifdef VFP - vfp_init(); + vfp_init_secondary(); #endif dbg_init(); diff --git a/sys/arm64/arm64/vfp.c b/sys/arm64/arm64/vfp.c index 22b15ee78596..46ae5d8e8fcd 100644 --- a/sys/arm64/arm64/vfp.c +++ b/sys/arm64/arm64/vfp.c @@ -38,6 +38,8 @@ __FBSDID("$FreeBSD$"); #include <sys/pcpu.h> #include <sys/proc.h> +#include <vm/uma.h> + #include <machine/armreg.h> #include <machine/md_var.h> #include <machine/pcb.h> @@ -57,6 +59,9 @@ struct fpu_kern_ctx { struct vfpstate state; }; +static uma_zone_t fpu_save_area_zone; +static struct vfpstate *fpu_initialstate; + void vfp_enable(void) { @@ -280,7 +285,7 @@ vfp_restore_state(void) } void -vfp_init(void) +vfp_init_secondary(void) { uint64_t pfr; @@ -291,9 +296,34 @@ vfp_init(void) /* Disable to be enabled when it's used */ vfp_disable(); +} + +static void +vfp_init(const void *dummy __unused) +{ + uint64_t pfr; + + /* Check if there is a vfp unit present */ + pfr = READ_SPECIALREG(id_aa64pfr0_el1); + if ((pfr & ID_AA64PFR0_FP_MASK) == ID_AA64PFR0_FP_NONE) + return; + + fpu_save_area_zone = uma_zcreate("VFP_save_area", + sizeof(struct vfpstate), NULL, NULL, NULL, NULL, + _Alignof(struct vfpstate) - 1, 0); + fpu_initialstate = uma_zalloc(fpu_save_area_zone, M_WAITOK | M_ZERO); - if (PCPU_GET(cpuid) == 0) - thread0.td_pcb->pcb_fpusaved->vfp_fpcr = VFPCR_INIT; + /* Ensure the VFP is enabled before accessing it in vfp_store */ + vfp_enable(); + vfp_store(fpu_initialstate); + + /* Disable to be enabled when it's used */ + vfp_disable(); + + /* Zero the VFP registers but keep fpcr and fpsr */ + bzero(fpu_initialstate->vfp_regs, sizeof(fpu_initialstate->vfp_regs)); + + thread0.td_pcb->pcb_fpusaved->vfp_fpcr = VFPCR_INIT; } SYSINIT(vfp, SI_SUB_CPU, SI_ORDER_ANY, vfp_init, NULL); @@ -433,4 +463,25 @@ is_fpu_kern_thread(u_int flags __unused) curpcb = curthread->td_pcb; return ((curpcb->pcb_fpflags & PCB_FP_KERN) != 0); } + +/* + * FPU save area alloc/free/init utility routines + */ +struct vfpstate * +fpu_save_area_alloc(void) +{ + return (uma_zalloc(fpu_save_area_zone, M_WAITOK)); +} + +void +fpu_save_area_free(struct vfpstate *fsa) +{ + uma_zfree(fpu_save_area_zone, fsa); +} + +void +fpu_save_area_reset(struct vfpstate *fsa) +{ + memcpy(fsa, fpu_initialstate, sizeof(*fsa)); +} #endif diff --git a/sys/arm64/include/vfp.h b/sys/arm64/include/vfp.h index 4f64b0396417..79e710694268 100644 --- a/sys/arm64/include/vfp.h +++ b/sys/arm64/include/vfp.h @@ -66,7 +66,7 @@ struct vfpstate { struct pcb; struct thread; -void vfp_init(void); +void vfp_init_secondary(void); void vfp_enable(void); void vfp_disable(void); void vfp_discard(struct thread *); @@ -94,6 +94,10 @@ int fpu_kern_leave(struct thread *, struct fpu_kern_ctx *); int fpu_kern_thread(u_int); int is_fpu_kern_thread(u_int); +struct vfpstate *fpu_save_area_alloc(void); +void fpu_save_area_free(struct vfpstate *fsa); +void fpu_save_area_reset(struct vfpstate *fsa); + /* Convert to and from Aarch32 FPSCR to Aarch64 FPCR/FPSR */ #define VFP_FPSCR_FROM_SRCR(vpsr, vpcr) ((vpsr) | ((vpcr) & 0x7c00000)) #define VFP_FPSR_FROM_FPSCR(vpscr) ((vpscr) &~ 0x7c00000)
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