forked from luck/tmp_suning_uos_patched
c642846489
The current lazy saving of the VFP registers is no longer possible with thread migration on SMP. This patch implements a per-CPU vfp-state pointer and the saving of the VFP registers at every context switch. The registers restoring is still performed in a lazy way. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
234 lines
6.1 KiB
ArmAsm
234 lines
6.1 KiB
ArmAsm
/*
|
|
* linux/arch/arm/vfp/vfphw.S
|
|
*
|
|
* Copyright (C) 2004 ARM Limited.
|
|
* Written by Deep Blue Solutions Limited.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This code is called from the kernel's undefined instruction trap.
|
|
* r9 holds the return address for successful handling.
|
|
* lr holds the return address for unrecognised instructions.
|
|
* r10 points at the start of the private FP workspace in the thread structure
|
|
* sp points to a struct pt_regs (as defined in include/asm/proc/ptrace.h)
|
|
*/
|
|
#include <asm/thread_info.h>
|
|
#include <asm/vfpmacros.h>
|
|
#include "../kernel/entry-header.S"
|
|
|
|
.macro DBGSTR, str
|
|
#ifdef DEBUG
|
|
stmfd sp!, {r0-r3, ip, lr}
|
|
add r0, pc, #4
|
|
bl printk
|
|
b 1f
|
|
.asciz "<7>VFP: \str\n"
|
|
.balign 4
|
|
1: ldmfd sp!, {r0-r3, ip, lr}
|
|
#endif
|
|
.endm
|
|
|
|
.macro DBGSTR1, str, arg
|
|
#ifdef DEBUG
|
|
stmfd sp!, {r0-r3, ip, lr}
|
|
mov r1, \arg
|
|
add r0, pc, #4
|
|
bl printk
|
|
b 1f
|
|
.asciz "<7>VFP: \str\n"
|
|
.balign 4
|
|
1: ldmfd sp!, {r0-r3, ip, lr}
|
|
#endif
|
|
.endm
|
|
|
|
.macro DBGSTR3, str, arg1, arg2, arg3
|
|
#ifdef DEBUG
|
|
stmfd sp!, {r0-r3, ip, lr}
|
|
mov r3, \arg3
|
|
mov r2, \arg2
|
|
mov r1, \arg1
|
|
add r0, pc, #4
|
|
bl printk
|
|
b 1f
|
|
.asciz "<7>VFP: \str\n"
|
|
.balign 4
|
|
1: ldmfd sp!, {r0-r3, ip, lr}
|
|
#endif
|
|
.endm
|
|
|
|
|
|
@ VFP hardware support entry point.
|
|
@
|
|
@ r0 = faulted instruction
|
|
@ r2 = faulted PC+4
|
|
@ r9 = successful return
|
|
@ r10 = vfp_state union
|
|
@ r11 = CPU number
|
|
@ lr = failure return
|
|
|
|
.globl vfp_support_entry
|
|
vfp_support_entry:
|
|
DBGSTR3 "instr %08x pc %08x state %p", r0, r2, r10
|
|
|
|
VFPFMRX r1, FPEXC @ Is the VFP enabled?
|
|
DBGSTR1 "fpexc %08x", r1
|
|
tst r1, #FPEXC_ENABLE
|
|
bne look_for_VFP_exceptions @ VFP is already enabled
|
|
|
|
DBGSTR1 "enable %x", r10
|
|
ldr r3, last_VFP_context_address
|
|
orr r1, r1, #FPEXC_ENABLE @ user FPEXC has the enable bit set
|
|
ldr r4, [r3, r11, lsl #2] @ last_VFP_context pointer
|
|
bic r5, r1, #FPEXC_EXCEPTION @ make sure exceptions are disabled
|
|
cmp r4, r10
|
|
beq check_for_exception @ we are returning to the same
|
|
@ process, so the registers are
|
|
@ still there. In this case, we do
|
|
@ not want to drop a pending exception.
|
|
|
|
VFPFMXR FPEXC, r5 @ enable VFP, disable any pending
|
|
@ exceptions, so we can get at the
|
|
@ rest of it
|
|
|
|
#ifndef CONFIG_SMP
|
|
@ Save out the current registers to the old thread state
|
|
@ No need for SMP since this is not done lazily
|
|
|
|
DBGSTR1 "save old state %p", r4
|
|
cmp r4, #0
|
|
beq no_old_VFP_process
|
|
VFPFMRX r5, FPSCR @ current status
|
|
VFPFMRX r6, FPINST @ FPINST (always there, rev0 onwards)
|
|
tst r1, #FPEXC_FPV2 @ is there an FPINST2 to read?
|
|
VFPFMRX r8, FPINST2, NE @ FPINST2 if needed - avoids reading
|
|
@ nonexistant reg on rev0
|
|
VFPFSTMIA r4 @ save the working registers
|
|
stmia r4, {r1, r5, r6, r8} @ save FPEXC, FPSCR, FPINST, FPINST2
|
|
@ and point r4 at the word at the
|
|
@ start of the register dump
|
|
#endif
|
|
|
|
no_old_VFP_process:
|
|
DBGSTR1 "load state %p", r10
|
|
str r10, [r3, r11, lsl #2] @ update the last_VFP_context pointer
|
|
@ Load the saved state back into the VFP
|
|
VFPFLDMIA r10 @ reload the working registers while
|
|
@ FPEXC is in a safe state
|
|
ldmia r10, {r1, r5, r6, r8} @ load FPEXC, FPSCR, FPINST, FPINST2
|
|
tst r1, #FPEXC_FPV2 @ is there an FPINST2 to write?
|
|
VFPFMXR FPINST2, r8, NE @ FPINST2 if needed - avoids writing
|
|
@ nonexistant reg on rev0
|
|
VFPFMXR FPINST, r6
|
|
VFPFMXR FPSCR, r5 @ restore status
|
|
|
|
check_for_exception:
|
|
tst r1, #FPEXC_EXCEPTION
|
|
bne process_exception @ might as well handle the pending
|
|
@ exception before retrying branch
|
|
@ out before setting an FPEXC that
|
|
@ stops us reading stuff
|
|
VFPFMXR FPEXC, r1 @ restore FPEXC last
|
|
sub r2, r2, #4
|
|
str r2, [sp, #S_PC] @ retry the instruction
|
|
mov pc, r9 @ we think we have handled things
|
|
|
|
|
|
look_for_VFP_exceptions:
|
|
tst r1, #FPEXC_EXCEPTION
|
|
bne process_exception
|
|
VFPFMRX r5, FPSCR
|
|
tst r5, #FPSCR_IXE @ IXE doesn't set FPEXC_EXCEPTION !
|
|
bne process_exception
|
|
|
|
@ Fall into hand on to next handler - appropriate coproc instr
|
|
@ not recognised by VFP
|
|
|
|
DBGSTR "not VFP"
|
|
mov pc, lr
|
|
|
|
process_exception:
|
|
DBGSTR "bounce"
|
|
sub r2, r2, #4
|
|
str r2, [sp, #S_PC] @ retry the instruction on exit from
|
|
@ the imprecise exception handling in
|
|
@ the support code
|
|
mov r2, sp @ nothing stacked - regdump is at TOS
|
|
mov lr, r9 @ setup for a return to the user code.
|
|
|
|
@ Now call the C code to package up the bounce to the support code
|
|
@ r0 holds the trigger instruction
|
|
@ r1 holds the FPEXC value
|
|
@ r2 pointer to register dump
|
|
b VFP9_bounce @ we have handled this - the support
|
|
@ code will raise an exception if
|
|
@ required. If not, the user code will
|
|
@ retry the faulted instruction
|
|
|
|
#ifdef CONFIG_SMP
|
|
.globl vfp_save_state
|
|
.type vfp_save_state, %function
|
|
vfp_save_state:
|
|
@ Save the current VFP state
|
|
@ r0 - save location
|
|
@ r1 - FPEXC
|
|
DBGSTR1 "save VFP state %p", r0
|
|
VFPFMRX r2, FPSCR @ current status
|
|
VFPFMRX r3, FPINST @ FPINST (always there, rev0 onwards)
|
|
tst r1, #FPEXC_FPV2 @ is there an FPINST2 to read?
|
|
VFPFMRX r12, FPINST2, NE @ FPINST2 if needed - avoids reading
|
|
@ nonexistant reg on rev0
|
|
VFPFSTMIA r0 @ save the working registers
|
|
stmia r0, {r1, r2, r3, r12} @ save FPEXC, FPSCR, FPINST, FPINST2
|
|
mov pc, lr
|
|
#endif
|
|
|
|
last_VFP_context_address:
|
|
.word last_VFP_context
|
|
|
|
.globl vfp_get_float
|
|
vfp_get_float:
|
|
add pc, pc, r0, lsl #3
|
|
mov r0, r0
|
|
.irp dr,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
|
|
mrc p10, 0, r0, c\dr, c0, 0 @ fmrs r0, s0
|
|
mov pc, lr
|
|
mrc p10, 0, r0, c\dr, c0, 4 @ fmrs r0, s1
|
|
mov pc, lr
|
|
.endr
|
|
|
|
.globl vfp_put_float
|
|
vfp_put_float:
|
|
add pc, pc, r1, lsl #3
|
|
mov r0, r0
|
|
.irp dr,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
|
|
mcr p10, 0, r0, c\dr, c0, 0 @ fmsr r0, s0
|
|
mov pc, lr
|
|
mcr p10, 0, r0, c\dr, c0, 4 @ fmsr r0, s1
|
|
mov pc, lr
|
|
.endr
|
|
|
|
.globl vfp_get_double
|
|
vfp_get_double:
|
|
add pc, pc, r0, lsl #3
|
|
mov r0, r0
|
|
.irp dr,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
|
|
fmrrd r0, r1, d\dr
|
|
mov pc, lr
|
|
.endr
|
|
|
|
@ virtual register 16 for compare with zero
|
|
mov r0, #0
|
|
mov r1, #0
|
|
mov pc, lr
|
|
|
|
.globl vfp_put_double
|
|
vfp_put_double:
|
|
add pc, pc, r2, lsl #3
|
|
mov r0, r0
|
|
.irp dr,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
|
|
fmdrr d\dr, r0, r1
|
|
mov pc, lr
|
|
.endr
|