/*
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* Copyright (C) 2005 Stelian Pop.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,
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* USA; either version 2 of the License, or (at your option) any later
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* version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#include <linux/linkage.h>
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#include <linux/version.h>
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#include <asm/assembler.h>
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#include <asm/asm-offsets.h>
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#include <asm/tls.h>
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#ifdef CONFIG_VFP
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#include <asm/vfpmacros.h>
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#endif
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.macro fpu_switch tmp
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#ifdef CONFIG_VFP
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#if __LINUX_ARM_ARCH__ <= 6
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#ifdef CONFIG_JUMP_LABEL
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9998: nop
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.pushsection __jump_table, "aw"
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.word 9998b, 9999f, __xeno_vfp_key
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.popsection
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#else
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ldr \tmp, =elf_hwcap
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ldr \tmp, [\tmp]
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tst \tmp, #HWCAP_VFP
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beq 9999f
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#endif
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#endif
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@ Always disable VFP so we can lazily save/restore the old
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@ state. This occurs in the context of the previous thread.
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VFPFMRX \tmp, FPEXC
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bic \tmp, \tmp, #FPEXC_EN
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VFPFMXR FPEXC, \tmp
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#if __LINUX_ARM_ARCH__ <= 6
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9999:
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#endif
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#endif
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.endm
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.text
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#if defined(CONFIG_VFP) && defined(CONFIG_XENO_ARCH_FPU)
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/* Copied from vfp_save_state in arch/arm/vfp/vfphw.S
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* r0 = pointer to union vfp_state, r1 = fpexc
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*/
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ENTRY(__asm_vfp_save)
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VFPFSTMIA r0, r2 @ save the working registers
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VFPFMRX r2, FPSCR @ current status
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tst r1, #FPEXC_EX @ is there additional state to save?
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beq 1f
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VFPFMRX r3, FPINST @ FPINST (only if FPEXC.EX is set)
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tst r1, #FPEXC_FP2V @ is there an FPINST2 to read?
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beq 1f
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VFPFMRX r12, FPINST2 @ FPINST2 if needed (and present)
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1:
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stmia r0, {r1, r2, r3, r12} @ save FPEXC, FPSCR, FPINST, FPINST2
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mov pc, lr
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ENDPROC(__asm_vfp_save)
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/* Copied from no_old_VFP_process in arch/arm/vfp/vfphw.S
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* r0 = pointer to union vfp_state
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* r1 = current cpu
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*/
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ENTRY(__asm_vfp_load)
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#ifdef CONFIG_SMP
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str r1, [r0, #VFP_CPU]
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#endif
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VFPFLDMIA r0, r2 @ reload the working registers while
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@ FPEXC is in a safe state
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ldmia r0, {r1, r2, r3, r12} @ load FPEXC, FPSCR, FPINST, FPINST2
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tst r1, #FPEXC_EX @ is there additional state to restore?
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beq 1f
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VFPFMXR FPINST, r3 @ restore FPINST (only if FPEXC.EX is set)
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tst r1, #FPEXC_FP2V @ is there an FPINST2 to write?
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beq 1f
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VFPFMXR FPINST2, r12 @ FPINST2 if needed (and present)
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1:
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VFPFMXR FPSCR, r2 @ restore status
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mov pc, lr
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ENDPROC(__asm_vfp_load)
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#endif
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#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 11, 0)
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.macro load_tls base, tp, tpuser
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ldr \tp, [\base, #TI_TP_VALUE]
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.endm
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.macro switch_tls base, tp, tpuser, tmp1, tmp2
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set_tls \tp, \tmp1, \tmp2
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.endm
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#else
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.macro load_tls base, tp, tpuser
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ldr \tp, [\base, #TI_TP_VALUE]
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ldr \tpuser, [\base, #TI_TP_VALUE + 4]
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.endm
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#endif
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/*
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* Switch context routine.
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*
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* Registers according to the ARM procedure call standard:
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* Reg Description
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* r0-r3 argument/scratch registers
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* r4-r9 variable register
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* r10=sl stack limit/variable register
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* r11=fp frame pointer/variable register
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* r12=ip intra-procedure-call scratch register
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* r13=sp stack pointer (auto preserved)
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* r14=lr link register
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* r15=pc program counter (auto preserved)
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*
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* Copied from __switch_to, arch/arm/kernel/entry-armv.S.
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* Right now it is identical, but who knows what the
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* future reserves us...
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*
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* XXX: All the following config options are NOT tested:
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* CONFIG_IWMMXT
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*
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* Calling args:
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* r0 = previous thread_info, r1 = next thread_info
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*
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* FIXME: this is ugly, at some point we should stop duplicating
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* what __switch_to() does, dropping specific fpu management from
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* Cobalt in the same move; this will have to wait until Dovetail
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* is substituted to the I-pipe though, since the former already
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* provides the support we need for this. --rpm
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*/
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ENTRY(__asm_thread_switch)
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#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 19, 0)
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add ip, r0, #TI_CPU_SAVE
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ARM( stmia ip!, {r4 - sl, fp, sp, lr} ) @ Store most regs on stack
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THUMB( stmia ip!, {r4 - sl, fp} ) @ Store most regs on stack
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THUMB( str sp, [ip], #4 )
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THUMB( str lr, [ip], #4 )
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load_tls r1, r4, r5
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#ifdef CONFIG_CPU_USE_DOMAINS
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ldr r6, [r1, #TI_CPU_DOMAIN]
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#endif
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switch_tls r0, r4, r5, r3, r7
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#if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
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ldr r7, [r1, #TI_TASK]
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ldr r8, =__stack_chk_guard
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ldr r7, [r7, #TSK_STACK_CANARY]
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#endif
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#ifdef CONFIG_CPU_USE_DOMAINS
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mcr p15, 0, r6, c3, c0, 0 @ Set domain register
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#endif
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fpu_switch r4
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#if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
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str r7, [r8]
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#endif
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ARM( add r4, r1, #TI_CPU_SAVE )
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ARM( ldmia r4, {r4 - sl, fp, sp, pc} ) @ Load all regs saved previously
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THUMB( add ip, r1, #TI_CPU_SAVE )
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THUMB( ldmia ip!, {r4 - sl, fp} ) @ Load all regs saved previously
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THUMB( ldr sp, [ip], #4 )
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THUMB( ldr pc, [ip] )
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ENDPROC(__asm_thread_switch)
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#else /* LINUX_VERSION_CODE >= KERNEL_VERSION(4, 19, 0) */
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#include <asm/unwind.h>
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UNWIND(.fnstart )
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UNWIND(.cantunwind )
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add ip, r0, #TI_CPU_SAVE
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ARM( stmia ip!, {r4 - sl, fp, sp, lr} ) @ Store most regs on stack
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THUMB( stmia ip!, {r4 - sl, fp} ) @ Store most regs on stack
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THUMB( str sp, [ip], #4 )
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THUMB( str lr, [ip], #4 )
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ldr r4, [r1, #TI_TP_VALUE]
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ldr r5, [r1, #TI_TP_VALUE + 4]
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#ifdef CONFIG_CPU_USE_DOMAINS
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mrc p15, 0, r6, c3, c0, 0 @ Get domain register
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str r6, [r0, #TI_CPU_DOMAIN] @ Save old domain register
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ldr r6, [r1, #TI_CPU_DOMAIN]
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#endif
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switch_tls r0, r4, r5, r3, r7
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#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP)
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ldr r7, [r1, #TI_TASK]
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ldr r8, =__stack_chk_guard
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.if (TSK_STACK_CANARY > IMM12_MASK)
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add r7, r7, #TSK_STACK_CANARY & ~IMM12_MASK
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.endif
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ldr r7, [r7, #TSK_STACK_CANARY & IMM12_MASK]
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#endif
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#ifdef CONFIG_CPU_USE_DOMAINS
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mcr p15, 0, r6, c3, c0, 0 @ Set domain register
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#endif
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mov r5, r0
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fpu_switch r4
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add r4, r1, #TI_CPU_SAVE
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#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP)
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str r7, [r8]
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#endif
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THUMB( mov ip, r4 )
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mov r0, r5
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ARM( ldmia r4, {r4 - sl, fp, sp, pc} ) @ Load all regs saved previously
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THUMB( ldmia ip!, {r4 - sl, fp} ) @ Load all regs saved previously
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THUMB( ldr sp, [ip], #4 )
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THUMB( ldr pc, [ip] )
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UNWIND(.fnend )
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#endif /* LINUX_VERSION_CODE >= KERNEL_VERSION(4, 19, 0) */
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