/* SPDX-License-Identifier: GPL-2.0 */ #include <linux/export.h> #include <linux/linkage.h> #include <asm/processor.h> #include <asm/ppc_asm.h> #include <asm/reg.h> #include <asm/asm-offsets.h> #include <asm/cputable.h> #include <asm/thread_info.h> #include <asm/page.h> #include <asm/ptrace.h> #include <asm/asm-compat.h> /* * Load state from memory into VMX registers including VSCR. * Assumes the caller has enabled VMX in the MSR. */ _GLOBAL(load_vr_state) li r4,VRSTATE_VSCR lvx v0,r4,r3 mtvscr v0 REST_32VRS(0,r4,r3) blr EXPORT_SYMBOL(load_vr_state) _ASM_NOKPROBE_SYMBOL(load_vr_state); /* used by restore_math */ /* * Store VMX state into memory, including VSCR. * Assumes the caller has enabled VMX in the MSR. */ _GLOBAL(store_vr_state) SAVE_32VRS(0, r4, r3) mfvscr v0 li r4, VRSTATE_VSCR stvx v0, r4, r3 blr EXPORT_SYMBOL(store_vr_state) /* * Disable VMX for the task which had it previously, * and save its vector registers in its thread_struct. * Enables the VMX for use in the kernel on return. * On SMP we know the VMX is free, since we give it up every * switch (ie, no lazy save of the vector registers). * * Note that on 32-bit this can only use registers that will be * restored by fast_exception_return, i.e. r3 - r6, r10 and r11. */ _GLOBAL(load_up_altivec) mfmsr r5 /* grab the current MSR */ #ifdef CONFIG_PPC_BOOK3S_64 /* interrupt doesn't set MSR[RI] and HPT can fault on current access */ ori r5,r5,MSR_RI #endif oris r5,r5,MSR_VEC@h MTMSRD(r5) /* enable use of AltiVec now */ isync /* * While userspace in general ignores VRSAVE, glibc uses it as a boolean * to optimise userspace context save/restore. Whenever we take an * altivec unavailable exception we must set VRSAVE to something non * zero. Set it to all 1s. See also the programming note in the ISA. */ mfspr r4,SPRN_VRSAVE cmpwi 0,r4,0 bne+ 1f li r4,-1 mtspr SPRN_VRSAVE,r4 1: /* enable use of VMX after return */ #ifdef CONFIG_PPC32 addi r5,r2,THREAD oris r9,r9,MSR_VEC@h #else ld r4,PACACURRENT(r13) addi r5,r4,THREAD /* Get THREAD */ oris r12,r12,MSR_VEC@h std r12,_MSR(r1) #ifdef CONFIG_PPC_BOOK3S_64 li r4,0 stb r4,PACASRR_VALID(r13) #endif #endif li r4,1 stb r4,THREAD_LOAD_VEC(r5) addi r6,r5,THREAD_VRSTATE li r10,VRSTATE_VSCR stw r4,THREAD_USED_VR(r5) lvx v0,r10,r6 mtvscr v0 REST_32VRS(0,r4,r6) /* restore registers and return */ blr _ASM_NOKPROBE_SYMBOL(load_up_altivec) /* * save_altivec(tsk) * Save the vector registers to its thread_struct */ _GLOBAL(save_altivec) addi r3,r3,THREAD /* want THREAD of task */ PPC_LL r7,THREAD_VRSAVEAREA(r3) PPC_LL r5,PT_REGS(r3) PPC_LCMPI 0,r7,0 bne 2f addi r7,r3,THREAD_VRSTATE 2: SAVE_32VRS(0,r4,r7) mfvscr v0 li r4,VRSTATE_VSCR stvx v0,r4,r7 blr #ifdef CONFIG_VSX #ifdef CONFIG_PPC32 #error This asm code isn't ready for 32-bit kernels #endif /* * load_up_vsx(unused, unused, tsk) * Disable VSX for the task which had it previously, * and save its vector registers in its thread_struct. * Reuse the fp and vsx saves, but first check to see if they have * been saved already. */ _GLOBAL(load_up_vsx) /* Load FP and VSX registers if they haven't been done yet */ andi. r5,r12,MSR_FP beql+ load_up_fpu /* skip if already loaded */ andis. r5,r12,MSR_VEC@h beql+ load_up_altivec /* skip if already loaded */ #ifdef CONFIG_PPC_BOOK3S_64 /* interrupt doesn't set MSR[RI] and HPT can fault on current access */ li r5,MSR_RI mtmsrd r5,1 #endif ld r4,PACACURRENT(r13) addi r4,r4,THREAD /* Get THREAD */ li r6,1 stw r6,THREAD_USED_VSR(r4) /* ... also set thread used vsr */ /* enable use of VSX after return */ oris r12,r12,MSR_VSX@h std r12,_MSR(r1) li r4,0 stb r4,PACASRR_VALID(r13) b fast_interrupt_return_srr #endif /* CONFIG_VSX */ /* * The routines below are in assembler so we can closely control the * usage of floating-point registers. These routines must be called * with preempt disabled. */ .data #ifdef CONFIG_PPC32 fpzero: .long 0 fpone: .long 0x3f800000 /* 1.0 in single-precision FP */ fphalf: .long 0x3f000000 /* 0.5 in single-precision FP */ #define LDCONST(fr, name) \ lis r11,name@ha; \ lfs fr,name@l(r11) #else fpzero: .quad 0 fpone: .quad 0x3ff0000000000000 /* 1.0 */ fphalf: .quad 0x3fe0000000000000 /* 0.5 */ #ifdef CONFIG_PPC_KERNEL_PCREL #define LDCONST(fr, name) \ pla r11,name@pcrel; \ lfd fr,0(r11) #else #define LDCONST(fr, name) \ addis r11,r2,name@toc@ha; \ lfd fr,name@toc@l(r11) #endif #endif .text /* * Internal routine to enable floating point and set FPSCR to 0. * Don't call it from C; it doesn't use the normal calling convention. */ SYM_FUNC_START_LOCAL(fpenable) #ifdef CONFIG_PPC32 stwu r1,-64(r1) #else stdu r1,-64(r1) #endif mfmsr r10 ori r11,r10,MSR_FP mtmsr r11 isync stfd fr0,24(r1) stfd fr1,16(r1) stfd fr31,8(r1) LDCONST(fr1, fpzero) mffs fr31 MTFSF_L(fr1) blr SYM_FUNC_END(fpenable) fpdisable: mtlr r12 MTFSF_L(fr31) lfd fr31,8(r1) lfd fr1,16(r1) lfd fr0,24(r1) mtmsr r10 isync addi r1,r1,64 blr /* * Vector add, floating point. */ _GLOBAL(vaddfp) mflr r12 bl fpenable li r0,4 mtctr r0 li r6,0 1: lfsx fr0,r4,r6 lfsx fr1,r5,r6 fadds fr0,fr0,fr1 stfsx fr0,r3,r6 addi r6,r6,4 bdnz 1b b fpdisable /* * Vector subtract, floating point. */ _GLOBAL(vsubfp) mflr r12 bl fpenable li r0,4 mtctr r0 li r6,0 1: lfsx fr0,r4,r6 lfsx fr1,r5,r6 fsubs fr0,fr0,fr1 stfsx fr0,r3,r6 addi r6,r6,4 bdnz 1b b fpdisable /* * Vector multiply and add, floating point. */ _GLOBAL(vmaddfp) mflr r12 bl fpenable stfd fr2,32(r1) li r0,4 mtctr r0 li r7,0 1: lfsx fr0,r4,r7 lfsx fr1,r5,r7 lfsx fr2,r6,r7 fmadds fr0,fr0,fr2,fr1 stfsx fr0,r3,r7 addi r7,r7,4 bdnz 1b lfd fr2,32(r1) b fpdisable /* * Vector negative multiply and subtract, floating point. */ _GLOBAL(vnmsubfp) mflr r12 bl fpenable stfd fr2,32(r1) li r0,4 mtctr r0 li r7,0 1: lfsx fr0,r4,r7 lfsx fr1,r5,r7 lfsx fr2,r6,r7 fnmsubs fr0,fr0,fr2,fr1 stfsx fr0,r3,r7 addi r7,r7,4 bdnz 1b lfd fr2,32(r1) b fpdisable /* * Vector reciprocal estimate. We just compute 1.0/x. * r3 -> destination, r4 -> source. */ _GLOBAL(vrefp) mflr r12 bl fpenable li r0,4 LDCONST(fr1, fpone) mtctr r0 li r6,0 1: lfsx fr0,r4,r6 fdivs fr0,fr1,fr0 stfsx fr0,r3,r6 addi r6,r6,4 bdnz 1b b fpdisable /* * Vector reciprocal square-root estimate, floating point. * We use the frsqrte instruction for the initial estimate followed * by 2 iterations of Newton-Raphson to get sufficient accuracy. * r3 -> destination, r4 -> source. */ _GLOBAL(vrsqrtefp) mflr r12 bl fpenable stfd fr2,32(r1) stfd fr3,40(r1) stfd fr4,48(r1) stfd fr5,56(r1) li r0,4 LDCONST(fr4, fpone) LDCONST(fr5, fphalf) mtctr r0 li r6,0 1: lfsx fr0,r4,r6 frsqrte fr1,fr0 /* r = frsqrte(s) */ fmuls fr3,fr1,fr0 /* r * s */ fmuls fr2,fr1,fr5 /* r * 0.5 */ fnmsubs fr3,fr1,fr3,fr4 /* 1 - s * r * r */ fmadds fr1,fr2,fr3,fr1 /* r = r + 0.5 * r * (1 - s * r * r) */ fmuls fr3,fr1,fr0 /* r * s */ fmuls fr2,fr1,fr5 /* r * 0.5 */ fnmsubs fr3,fr1,fr3,fr4 /* 1 - s * r * r */ fmadds fr1,fr2,fr3,fr1 /* r = r + 0.5 * r * (1 - s * r * r) */ stfsx fr1,r3,r6 addi r6,r6,4 bdnz 1b lfd fr5,56(r1) lfd fr4,48(r1) lfd fr3,40(r1) lfd fr2,32(r1) b fpdisable