DECLARE_PER_CPU(struct task_struct *, __entry_task);
#include <asm/types.h>
+#include <asm/traps.h>
struct cpu_context_save {
__u32 r4;
__u32 cpu_domain; /* cpu domain */
struct cpu_context_save cpu_context; /* cpu context */
__u32 abi_syscall; /* ABI type and syscall nr */
- __u8 used_cp[16]; /* thread used copro */
unsigned long tp_value[2]; /* TLS registers */
union fp_state fpstate __attribute__((aligned(8)));
union vfp_state vfpstate;
extern void iwmmxt_task_release(struct thread_info *);
extern void iwmmxt_task_switch(struct thread_info *);
+extern int iwmmxt_undef_handler(struct pt_regs *, u32);
+
+static inline void register_iwmmxt_undef_handler(void)
+{
+ static struct undef_hook iwmmxt_undef_hook = {
+ .instr_mask = 0x0c000e00,
+ .instr_val = 0x0c000000,
+ .cpsr_mask = MODE_MASK | PSR_T_BIT,
+ .cpsr_val = USR_MODE,
+ .fn = iwmmxt_undef_handler,
+ };
+
+ register_undef_hook(&iwmmxt_undef_hook);
+}
+
extern void vfp_sync_hwstate(struct thread_info *);
extern void vfp_flush_hwstate(struct thread_info *);
DEFINE(TI_CPU_DOMAIN, offsetof(struct thread_info, cpu_domain));
DEFINE(TI_CPU_SAVE, offsetof(struct thread_info, cpu_context));
DEFINE(TI_ABI_SYSCALL, offsetof(struct thread_info, abi_syscall));
- DEFINE(TI_USED_CP, offsetof(struct thread_info, used_cp));
DEFINE(TI_TP_VALUE, offsetof(struct thread_info, tp_value));
DEFINE(TI_FPSTATE, offsetof(struct thread_info, fpstate));
#ifdef CONFIG_VFP
__und_usr:
usr_entry uaccess=0
- mov r2, r4
- mov r3, r5
-
- @ r2 = regs->ARM_pc, which is either 2 or 4 bytes ahead of the
- @ faulting instruction depending on Thumb mode.
- @ r3 = regs->ARM_cpsr
- @
- @ The emulation code returns using r9 if it has emulated the
- @ instruction, or the more conventional lr if we are to treat
- @ this as a real undefined instruction
- @
- badr r9, ret_from_exception
-
@ IRQs must be enabled before attempting to read the instruction from
@ user space since that could cause a page/translation fault if the
@ page table was modified by another CPU.
enable_irq
- tst r3, #PSR_T_BIT @ Thumb mode?
- bne __und_usr_thumb
- sub r4, r2, #4 @ ARM instr at LR - 4
-1: ldrt r0, [r4]
- ARM_BE8(rev r0, r0) @ little endian instruction
-
- uaccess_disable ip
-
- @ r0 = 32-bit ARM instruction which caused the exception
- @ r2 = PC value for the following instruction (:= regs->ARM_pc)
- @ r4 = PC value for the faulting instruction
- @ lr = 32-bit undefined instruction function
- badr lr, __und_usr_fault_32
- b call_fpe
-
-__und_usr_thumb:
- @ Thumb instruction
- sub r4, r2, #2 @ First half of thumb instr at LR - 2
-#if CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7
-/*
- * Thumb-2 instruction handling. Note that because pre-v6 and >= v6 platforms
- * can never be supported in a single kernel, this code is not applicable at
- * all when __LINUX_ARM_ARCH__ < 6. This allows simplifying assumptions to be
- * made about .arch directives.
- */
-#if __LINUX_ARM_ARCH__ < 7
-/* If the target CPU may not be Thumb-2-capable, a run-time check is needed: */
- ldr_va r5, cpu_architecture
- cmp r5, #CPU_ARCH_ARMv7
- blo __und_usr_fault_16 @ 16bit undefined instruction
-/*
- * The following code won't get run unless the running CPU really is v7, so
- * coding round the lack of ldrht on older arches is pointless. Temporarily
- * override the assembler target arch with the minimum required instead:
- */
- .arch armv6t2
+ tst r5, #PSR_T_BIT @ Thumb mode?
+ mov r1, #2 @ set insn size to 2 for Thumb
+ bne 0f @ handle as Thumb undef exception
+#ifdef CONFIG_FPE_NWFPE
+ adr r9, ret_from_exception
+ bl call_fpe @ returns via R9 on success
#endif
-2: ldrht r5, [r4]
-ARM_BE8(rev16 r5, r5) @ little endian instruction
- cmp r5, #0xe800 @ 32bit instruction if xx != 0
- blo __und_usr_fault_16_pan @ 16bit undefined instruction
-3: ldrht r0, [r2]
-ARM_BE8(rev16 r0, r0) @ little endian instruction
+ mov r1, #4 @ set insn size to 4 for ARM
+0: mov r0, sp
uaccess_disable ip
- add r2, r2, #2 @ r2 is PC + 2, make it PC + 4
- str r2, [sp, #S_PC] @ it's a 2x16bit instr, update
- orr r0, r0, r5, lsl #16
- badr lr, __und_usr_fault_32
- @ r0 = the two 16-bit Thumb instructions which caused the exception
- @ r2 = PC value for the following Thumb instruction (:= regs->ARM_pc)
- @ r4 = PC value for the first 16-bit Thumb instruction
- @ lr = 32bit undefined instruction function
-
-#if __LINUX_ARM_ARCH__ < 7
-/* If the target arch was overridden, change it back: */
-#ifdef CONFIG_CPU_32v6K
- .arch armv6k
-#else
- .arch armv6
-#endif
-#endif /* __LINUX_ARM_ARCH__ < 7 */
-#else /* !(CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7) */
- b __und_usr_fault_16
-#endif
+ bl __und_fault
+ b ret_from_exception
UNWIND(.fnend)
ENDPROC(__und_usr)
-/*
- * The out of line fixup for the ldrt instructions above.
- */
- .pushsection .text.fixup, "ax"
- .align 2
-4: str r4, [sp, #S_PC] @ retry current instruction
- ret r9
- .popsection
- .pushsection __ex_table,"a"
- .long 1b, 4b
-#if CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7
- .long 2b, 4b
- .long 3b, 4b
-#endif
- .popsection
-
-/*
- * Check whether the instruction is a co-processor instruction.
- * If yes, we need to call the relevant co-processor handler.
- *
- * Note that we don't do a full check here for the co-processor
- * instructions; all instructions with bit 27 set are well
- * defined. The only instructions that should fault are the
- * co-processor instructions. However, we have to watch out
- * for the ARM6/ARM7 SWI bug.
- *
- * NEON is a special case that has to be handled here. Not all
- * NEON instructions are co-processor instructions, so we have
- * to make a special case of checking for them. Plus, there's
- * five groups of them, so we have a table of mask/opcode pairs
- * to check against, and if any match then we branch off into the
- * NEON handler code.
- *
- * Emulators may wish to make use of the following registers:
- * r0 = instruction opcode (32-bit ARM or two 16-bit Thumb)
- * r2 = PC value to resume execution after successful emulation
- * r9 = normal "successful" return address
- * r10 = this threads thread_info structure
- * lr = unrecognised instruction return address
- * IRQs enabled, FIQs enabled.
- */
- @
- @ Fall-through from Thumb-2 __und_usr
- @
-#ifdef CONFIG_NEON
- get_thread_info r10 @ get current thread
- adr r6, .LCneon_thumb_opcodes
- b 2f
-#endif
-call_fpe:
- get_thread_info r10 @ get current thread
-#ifdef CONFIG_NEON
- adr r6, .LCneon_arm_opcodes
-2: ldr r5, [r6], #4 @ mask value
- ldr r7, [r6], #4 @ opcode bits matching in mask
- cmp r5, #0 @ end mask?
- beq 1f
- and r8, r0, r5
- cmp r8, r7 @ NEON instruction?
- bne 2b
- mov r7, #1
- strb r7, [r10, #TI_USED_CP + 10] @ mark CP#10 as used
- strb r7, [r10, #TI_USED_CP + 11] @ mark CP#11 as used
- b do_vfp @ let VFP handler handle this
-1:
-#endif
- tst r0, #0x08000000 @ only CDP/CPRT/LDC/STC have bit 27
- tstne r0, #0x04000000 @ bit 26 set on both ARM and Thumb-2
- reteq lr
- and r8, r0, #0x00000f00 @ mask out CP number
- mov r7, #1
- add r6, r10, r8, lsr #8 @ add used_cp[] array offset first
- strb r7, [r6, #TI_USED_CP] @ set appropriate used_cp[]
-#ifdef CONFIG_IWMMXT
- @ Test if we need to give access to iWMMXt coprocessors
- ldr r5, [r10, #TI_FLAGS]
- rsbs r7, r8, #(1 << 8) @ CP 0 or 1 only
- movscs r7, r5, lsr #(TIF_USING_IWMMXT + 1)
- bcs iwmmxt_task_enable
-#endif
- ARM( add pc, pc, r8, lsr #6 )
- THUMB( lsr r8, r8, #6 )
- THUMB( add pc, r8 )
- nop
-
- ret.w lr @ CP#0
- W(b) do_fpe @ CP#1 (FPE)
- W(b) do_fpe @ CP#2 (FPE)
- ret.w lr @ CP#3
- ret.w lr @ CP#4
- ret.w lr @ CP#5
- ret.w lr @ CP#6
- ret.w lr @ CP#7
- ret.w lr @ CP#8
- ret.w lr @ CP#9
-#ifdef CONFIG_VFP
- W(b) do_vfp @ CP#10 (VFP)
- W(b) do_vfp @ CP#11 (VFP)
-#else
- ret.w lr @ CP#10 (VFP)
- ret.w lr @ CP#11 (VFP)
-#endif
- ret.w lr @ CP#12
- ret.w lr @ CP#13
- ret.w lr @ CP#14 (Debug)
- ret.w lr @ CP#15 (Control)
-
-#ifdef CONFIG_NEON
- .align 6
-
-.LCneon_arm_opcodes:
- .word 0xfe000000 @ mask
- .word 0xf2000000 @ opcode
-
- .word 0xff100000 @ mask
- .word 0xf4000000 @ opcode
-
- .word 0x00000000 @ mask
- .word 0x00000000 @ opcode
-
-.LCneon_thumb_opcodes:
- .word 0xef000000 @ mask
- .word 0xef000000 @ opcode
-
- .word 0xff100000 @ mask
- .word 0xf9000000 @ opcode
-
- .word 0x00000000 @ mask
- .word 0x00000000 @ opcode
-#endif
-
-do_fpe:
- add r10, r10, #TI_FPSTATE @ r10 = workspace
- ldr_va pc, fp_enter, tmp=r4 @ Call FP module USR entry point
-
-/*
- * The FP module is called with these registers set:
- * r0 = instruction
- * r2 = PC+4
- * r9 = normal "successful" return address
- * r10 = FP workspace
- * lr = unrecognised FP instruction return address
- */
-
- .pushsection .data
- .align 2
-ENTRY(fp_enter)
- .word no_fp
- .popsection
-
-ENTRY(no_fp)
- ret lr
-ENDPROC(no_fp)
-
-__und_usr_fault_32:
- mov r1, #4
- b 1f
-__und_usr_fault_16_pan:
- uaccess_disable ip
-__und_usr_fault_16:
- mov r1, #2
-1: mov r0, sp
- badr lr, ret_from_exception
- b __und_fault
-ENDPROC(__und_usr_fault_32)
-ENDPROC(__und_usr_fault_16)
-
.align 5
__pabt_usr:
usr_entry
.text
.arm
+ENTRY(iwmmxt_undef_handler)
+ push {r9, r10, lr}
+ get_thread_info r10
+ mov r9, pc
+ b iwmmxt_task_enable
+ mov r0, #0
+ pop {r9, r10, pc}
+ENDPROC(iwmmxt_undef_handler)
+
/*
* Lazy switching of Concan coprocessor context
*
+ * r0 = struct pt_regs pointer
* r10 = struct thread_info pointer
* r9 = ret_from_exception
* lr = undefined instr exit
PJ4(mcr p15, 0, r2, c1, c0, 2)
ldr r3, =concan_owner
- add r0, r10, #TI_IWMMXT_STATE @ get task Concan save area
- ldr r2, [sp, #60] @ current task pc value
+ ldr r2, [r0, #S_PC] @ current task pc value
ldr r1, [r3] @ get current Concan owner
- str r0, [r3] @ this task now owns Concan regs
sub r2, r2, #4 @ adjust pc back
- str r2, [sp, #60]
+ str r2, [r0, #S_PC]
+ add r0, r10, #TI_IWMMXT_STATE @ get task Concan save area
+ str r0, [r3] @ this task now owns Concan regs
mrc p15, 0, r2, c2, c0, 0
mov r2, r2 @ cpwait
pr_info("PJ4 iWMMXt v%d coprocessor enabled.\n", vers);
elf_hwcap |= HWCAP_IWMMXT;
thread_register_notifier(&iwmmxt_notifier_block);
+ register_iwmmxt_undef_handler();
#endif
return 0;
flush_ptrace_hw_breakpoint(tsk);
- memset(thread->used_cp, 0, sizeof(thread->used_cp));
memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
memset(&thread->fpstate, 0, sizeof(union fp_state));
{
struct thread_info *thread = task_thread_info(target);
- thread->used_cp[1] = thread->used_cp[2] = 1;
-
return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
&thread->fpstate,
0, sizeof(struct user_fp));
pr_info("XScale iWMMXt coprocessor detected.\n");
elf_hwcap |= HWCAP_IWMMXT;
thread_register_notifier(&iwmmxt_notifier_block);
+ register_iwmmxt_undef_handler();
#endif
} else {
pr_info("XScale DSP coprocessor detected.\n");
movne r2, r2, lsr #2 @ turned into # of sets
sub r2, r2, #(1 << 5)
stmia r1, {r2, r3}
+#ifdef CONFIG_VFP
+ mov r1, #1 @ disable quirky VFP
+ str_l r1, VFP_arch_feroceon, r2
+#endif
ret lr
/*
Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
*/
+#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/opcodes.h>
@ plain LDR instruction. Weird, but it seems harmless.
.pushsection .text.fixup,"ax"
.align 2
+.Lrep: str r4, [sp, #S_PC] @ retry current instruction
.Lfix: ret r9 @ let the user eat segfaults
.popsection
.align 3
.long .Lx1, .Lfix
.popsection
+
+ @
+ @ Check whether the instruction is a co-processor instruction.
+ @ If yes, we need to call the relevant co-processor handler.
+ @ Only FPE instructions are dispatched here, everything else
+ @ is handled by undef hooks.
+ @
+ @ Emulators may wish to make use of the following registers:
+ @ r4 = PC value to resume execution after successful emulation
+ @ r9 = normal "successful" return address
+ @ lr = unrecognised instruction return address
+ @ IRQs enabled, FIQs enabled.
+ @
+ENTRY(call_fpe)
+ mov r2, r4
+ sub r4, r4, #4 @ ARM instruction at user PC - 4
+USERL( .Lrep, ldrt r0, [r4]) @ load opcode from user space
+ARM_BE8(rev r0, r0) @ little endian instruction
+
+ uaccess_disable ip
+
+ get_thread_info r10 @ get current thread
+ tst r0, #0x08000000 @ only CDP/CPRT/LDC/STC have bit 27
+ reteq lr
+ and r8, r0, #0x00000f00 @ mask out CP number
+#ifdef CONFIG_IWMMXT
+ @ Test if we need to give access to iWMMXt coprocessors
+ ldr r5, [r10, #TI_FLAGS]
+ rsbs r7, r8, #(1 << 8) @ CP 0 or 1 only
+ movscs r7, r5, lsr #(TIF_USING_IWMMXT + 1)
+ movcs r0, sp @ pass struct pt_regs
+ bcs iwmmxt_task_enable
+#endif
+ add pc, pc, r8, lsr #6
+ nop
+
+ ret lr @ CP#0
+ b do_fpe @ CP#1 (FPE)
+ b do_fpe @ CP#2 (FPE)
+ ret lr @ CP#3
+ ret lr @ CP#4
+ ret lr @ CP#5
+ ret lr @ CP#6
+ ret lr @ CP#7
+ ret lr @ CP#8
+ ret lr @ CP#9
+ ret lr @ CP#10 (VFP)
+ ret lr @ CP#11 (VFP)
+ ret lr @ CP#12
+ ret lr @ CP#13
+ ret lr @ CP#14 (Debug)
+ ret lr @ CP#15 (Control)
+
+do_fpe:
+ add r10, r10, #TI_FPSTATE @ r10 = workspace
+ ldr_va pc, fp_enter, tmp=r4 @ Call FP module USR entry point
+
+ @
+ @ The FP module is called with these registers set:
+ @ r0 = instruction
+ @ r2 = PC+4
+ @ r9 = normal "successful" return address
+ @ r10 = FP workspace
+ @ lr = unrecognised FP instruction return address
+ @
+
+ .pushsection .data
+ .align 2
+ENTRY(fp_enter)
+ .word no_fp
+ .popsection
+
+no_fp:
+ ret lr
+ENDPROC(no_fp)
# ccflags-y := -DDEBUG
# asflags-y := -DDEBUG
-obj-y += vfpmodule.o entry.o vfphw.o vfpsingle.o vfpdouble.o
+obj-y += vfpmodule.o vfphw.o vfpsingle.o vfpdouble.o
+++ /dev/null
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * linux/arch/arm/vfp/entry.S
- *
- * Copyright (C) 2004 ARM Limited.
- * Written by Deep Blue Solutions Limited.
- */
-#include <linux/init.h>
-#include <linux/linkage.h>
-#include <asm/thread_info.h>
-#include <asm/vfpmacros.h>
-#include <asm/assembler.h>
-#include <asm/asm-offsets.h>
-
-@ VFP entry point.
-@
-@ r0 = instruction opcode (32-bit ARM or two 16-bit Thumb)
-@ r2 = PC value to resume execution after successful emulation
-@ r9 = normal "successful" return address
-@ r10 = this threads thread_info structure
-@ lr = unrecognised instruction return address
-@ IRQs enabled.
-@
-ENTRY(do_vfp)
- mov r1, r10
- str lr, [sp, #-8]!
- add r3, sp, #4
- str r9, [r3]
- bl vfp_entry
- ldr pc, [sp], #8
-ENDPROC(do_vfp)
};
asmlinkage void vfp_save_state(void *location, u32 fpexc);
+asmlinkage u32 vfp_load_state(const void *location);
*
* Copyright (C) 2004 ARM Limited.
* Written by Deep Blue Solutions Limited.
- *
- * This code is called from the kernel's undefined instruction trap.
- * r1 holds the thread_info pointer
- * r3 holds the return address for successful handling.
- * lr holds the return address for unrecognised instructions.
- * sp points to a struct pt_regs (as defined in include/asm/proc/ptrace.h)
*/
#include <linux/init.h>
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/asm-offsets.h>
- .macro DBGSTR, str
-#ifdef DEBUG
- stmfd sp!, {r0-r3, ip, lr}
- ldr r0, =1f
- bl _printk
- ldmfd sp!, {r0-r3, ip, lr}
-
- .pushsection .rodata, "a"
-1: .ascii KERN_DEBUG "VFP: \str\n"
- .byte 0
- .previous
-#endif
- .endm
-
.macro DBGSTR1, str, arg
#ifdef DEBUG
stmfd 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
- ldr r0, =1f
- bl _printk
- ldmfd sp!, {r0-r3, ip, lr}
-
- .pushsection .rodata, "a"
-1: .ascii KERN_DEBUG "VFP: \str\n"
- .byte 0
- .previous
-#endif
- .endm
-
-
-@ VFP hardware support entry point.
-@
-@ r0 = instruction opcode (32-bit ARM or two 16-bit Thumb)
-@ r1 = thread_info pointer
-@ r2 = PC value to resume execution after successful emulation
-@ r3 = normal "successful" return address
-@ lr = unrecognised instruction return address
-@ IRQs enabled.
-ENTRY(vfp_support_entry)
- ldr r11, [r1, #TI_CPU] @ CPU number
- add r10, r1, #TI_VFPSTATE @ r10 = workspace
-
- DBGSTR3 "instr %08x pc %08x state %p", r0, r2, r10
-
- .fpu vfpv2
- VFPFMRX r1, FPEXC @ Is the VFP enabled?
- DBGSTR1 "fpexc %08x", r1
- tst r1, #FPEXC_EN
- bne look_for_VFP_exceptions @ VFP is already enabled
-
- DBGSTR1 "enable %x", r10
- ldr r9, vfp_current_hw_state_address
- orr r1, r1, #FPEXC_EN @ user FPEXC has the enable bit set
- ldr r4, [r9, r11, lsl #2] @ vfp_current_hw_state pointer
- bic r5, r1, #FPEXC_EX @ make sure exceptions are disabled
- cmp r4, r10 @ this thread owns the hw context?
-#ifndef CONFIG_SMP
- @ For UP, checking that this thread owns the hw context is
- @ sufficient to determine that the hardware state is valid.
- beq vfp_hw_state_valid
-
- @ On UP, we lazily save the VFP context. As a different
- @ thread wants ownership of the VFP hardware, save the old
- @ state if there was a previous (valid) owner.
-
- VFPFMXR FPEXC, r5 @ enable VFP, disable any pending
- @ exceptions, so we can get at the
- @ rest of it
-
- DBGSTR1 "save old state %p", r4
- cmp r4, #0 @ if the vfp_current_hw_state is NULL
- beq vfp_reload_hw @ then the hw state needs reloading
- VFPFSTMIA r4, r5 @ save the working registers
- VFPFMRX r5, FPSCR @ current status
-#ifndef CONFIG_CPU_FEROCEON
- tst r1, #FPEXC_EX @ is there additional state to save?
- beq 1f
- VFPFMRX r6, FPINST @ FPINST (only if FPEXC.EX is set)
- tst r1, #FPEXC_FP2V @ is there an FPINST2 to read?
- beq 1f
- VFPFMRX r8, FPINST2 @ FPINST2 if needed (and present)
-1:
-#endif
- stmia r4, {r1, r5, r6, r8} @ save FPEXC, FPSCR, FPINST, FPINST2
-vfp_reload_hw:
-
-#else
- @ For SMP, if this thread does not own the hw context, then we
- @ need to reload it. No need to save the old state as on SMP,
- @ we always save the state when we switch away from a thread.
- bne vfp_reload_hw
-
- @ This thread has ownership of the current hardware context.
- @ However, it may have been migrated to another CPU, in which
- @ case the saved state is newer than the hardware context.
- @ Check this by looking at the CPU number which the state was
- @ last loaded onto.
- ldr ip, [r10, #VFP_CPU]
- teq ip, r11
- beq vfp_hw_state_valid
-
-vfp_reload_hw:
- @ We're loading this threads state into the VFP hardware. Update
- @ the CPU number which contains the most up to date VFP context.
- str r11, [r10, #VFP_CPU]
-
- VFPFMXR FPEXC, r5 @ enable VFP, disable any pending
- @ exceptions, so we can get at the
- @ rest of it
-#endif
-
- DBGSTR1 "load state %p", r10
- str r10, [r9, r11, lsl #2] @ update the vfp_current_hw_state pointer
+ENTRY(vfp_load_state)
+ @ Load the current VFP state
+ @ r0 - load location
+ @ returns FPEXC
+ DBGSTR1 "load VFP state %p", r0
@ Load the saved state back into the VFP
- VFPFLDMIA r10, r5 @ reload the working registers while
+ VFPFLDMIA r0, r1 @ reload the working registers while
@ FPEXC is in a safe state
- ldmia r10, {r1, r5, r6, r8} @ load FPEXC, FPSCR, FPINST, FPINST2
-#ifndef CONFIG_CPU_FEROCEON
- tst r1, #FPEXC_EX @ is there additional state to restore?
+ ldmia r0, {r0-r3} @ load FPEXC, FPSCR, FPINST, FPINST2
+ tst r0, #FPEXC_EX @ is there additional state to restore?
beq 1f
- VFPFMXR FPINST, r6 @ restore FPINST (only if FPEXC.EX is set)
- tst r1, #FPEXC_FP2V @ is there an FPINST2 to write?
+ VFPFMXR FPINST, r2 @ restore FPINST (only if FPEXC.EX is set)
+ tst r0, #FPEXC_FP2V @ is there an FPINST2 to write?
beq 1f
- VFPFMXR FPINST2, r8 @ FPINST2 if needed (and present)
+ VFPFMXR FPINST2, r3 @ FPINST2 if needed (and present)
1:
-#endif
- VFPFMXR FPSCR, r5 @ restore status
-
-@ The context stored in the VFP hardware is up to date with this thread
-vfp_hw_state_valid:
- tst r1, #FPEXC_EX
- 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
- mov sp, r3 @ we think we have handled things
- pop {lr}
- sub r2, r2, #4 @ Retry current instruction - if Thumb
- str r2, [sp, #S_PC] @ mode it's two 16-bit instructions,
- @ else it's one 32-bit instruction, so
- @ always subtract 4 from the following
- @ instruction address.
-
-local_bh_enable_and_ret:
- adr r0, .
- mov r1, #SOFTIRQ_DISABLE_OFFSET
- b __local_bh_enable_ip @ tail call
-
-look_for_VFP_exceptions:
- @ Check for synchronous or asynchronous exception
- tst r1, #FPEXC_EX | FPEXC_DEX
- bne process_exception
- @ On some implementations of the VFP subarch 1, setting FPSCR.IXE
- @ causes all the CDP instructions to be bounced synchronously without
- @ setting the FPEXC.EX bit
- VFPFMRX r5, FPSCR
- tst r5, #FPSCR_IXE
- bne process_exception
-
- tst r5, #FPSCR_LENGTH_MASK
- beq skip
- orr r1, r1, #FPEXC_DEX
- b process_exception
-skip:
-
- @ Fall into hand on to next handler - appropriate coproc instr
- @ not recognised by VFP
-
- DBGSTR "not VFP"
- b local_bh_enable_and_ret
-
-process_exception:
- DBGSTR "bounce"
- mov sp, r3 @ setup for a return to the user code.
- pop {lr}
- mov r2, sp @ nothing stacked - regdump is at TOS
-
- @ 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 VFP_bounce @ we have handled this - the support
- @ code will raise an exception if
- @ required. If not, the user code will
- @ retry the faulted instruction
-ENDPROC(vfp_support_entry)
+ VFPFMXR FPSCR, r1 @ restore status
+ ret lr
+ENDPROC(vfp_load_state)
ENTRY(vfp_save_state)
@ Save the current VFP state
ret lr
ENDPROC(vfp_save_state)
- .align
-vfp_current_hw_state_address:
- .word vfp_current_hw_state
-
.macro tbl_branch, base, tmp, shift
#ifdef CONFIG_THUMB2_KERNEL
adr \tmp, 1f
#include <linux/uaccess.h>
#include <linux/user.h>
#include <linux/export.h>
+#include <linux/perf_event.h>
#include <asm/cp15.h>
#include <asm/cputype.h>
#include "vfpinstr.h"
#include "vfp.h"
-/*
- * Our undef handlers (in entry.S)
- */
-asmlinkage void vfp_support_entry(u32, void *, u32, u32);
-
static bool have_vfp __ro_after_init;
/*
* Used in startup: set to non-zero if VFP checks fail
* After startup, holds VFP architecture
*/
-static unsigned int __initdata VFP_arch;
+static unsigned int VFP_arch;
+
+#ifdef CONFIG_CPU_FEROCEON
+extern unsigned int VFP_arch_feroceon __alias(VFP_arch);
+#endif
/*
* The pointer to the vfpstate structure of the thread which currently
* emulate it.
*/
}
+ perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, regs->ARM_pc);
return exceptions & ~VFP_NAN_FLAG;
}
/*
* Package up a bounce condition.
*/
-void VFP_bounce(u32 trigger, u32 fpexc, struct pt_regs *regs)
+static void VFP_bounce(u32 trigger, u32 fpexc, struct pt_regs *regs)
{
u32 fpscr, orig_fpscr, fpsid, exceptions;
}
if (fpexc & FPEXC_EX) {
-#ifndef CONFIG_CPU_FEROCEON
/*
* Asynchronous exception. The instruction is read from FPINST
* and the interrupted instruction has to be restarted.
*/
trigger = fmrx(FPINST);
regs->ARM_pc -= 4;
-#endif
} else if (!(fpexc & FPEXC_DEX)) {
/*
* Illegal combination of bits. It can be caused by an
* on VFP subarch 1.
*/
vfp_raise_exceptions(VFP_EXCEPTION_ERROR, trigger, fpscr, regs);
- goto exit;
+ return;
}
/*
* the FPEXC.FP2V bit is valid only if FPEXC.EX is 1.
*/
if ((fpexc & (FPEXC_EX | FPEXC_FP2V)) != (FPEXC_EX | FPEXC_FP2V))
- goto exit;
+ return;
/*
* The barrier() here prevents fpinst2 being read
exceptions = vfp_emulate_instruction(trigger, orig_fpscr, regs);
if (exceptions)
vfp_raise_exceptions(exceptions, trigger, orig_fpscr, regs);
- exit:
- local_bh_enable();
}
static void vfp_enable(void *unused)
return 0;
}
-/*
- * Entered with:
- *
- * r0 = instruction opcode (32-bit ARM or two 16-bit Thumb)
- * r1 = thread_info pointer
- * r2 = PC value to resume execution after successful emulation
- * r3 = normal "successful" return address
- * lr = unrecognised instruction return address
- */
-asmlinkage void vfp_entry(u32 trigger, struct thread_info *ti, u32 resume_pc,
- u32 resume_return_address)
-{
- if (unlikely(!have_vfp))
- return;
-
- local_bh_disable();
- vfp_support_entry(trigger, ti, resume_pc, resume_return_address);
-}
-
-#ifdef CONFIG_KERNEL_MODE_NEON
-
static int vfp_kmode_exception(struct pt_regs *regs, unsigned int instr)
{
/*
return 1;
}
-static struct undef_hook vfp_kmode_exception_hook[] = {{
+/*
+ * vfp_support_entry - Handle VFP exception
+ *
+ * @regs: pt_regs structure holding the register state at exception entry
+ * @trigger: The opcode of the instruction that triggered the exception
+ *
+ * Returns 0 if the exception was handled, or an error code otherwise.
+ */
+static int vfp_support_entry(struct pt_regs *regs, u32 trigger)
+{
+ struct thread_info *ti = current_thread_info();
+ u32 fpexc;
+
+ if (unlikely(!have_vfp))
+ return -ENODEV;
+
+ if (!user_mode(regs))
+ return vfp_kmode_exception(regs, trigger);
+
+ local_bh_disable();
+ fpexc = fmrx(FPEXC);
+
+ /*
+ * If the VFP unit was not enabled yet, we have to check whether the
+ * VFP state in the CPU's registers is the most recent VFP state
+ * associated with the process. On UP systems, we don't save the VFP
+ * state eagerly on a context switch, so we may need to save the
+ * VFP state to memory first, as it may belong to another process.
+ */
+ if (!(fpexc & FPEXC_EN)) {
+ /*
+ * Enable the VFP unit but mask the FP exception flag for the
+ * time being, so we can access all the registers.
+ */
+ fpexc |= FPEXC_EN;
+ fmxr(FPEXC, fpexc & ~FPEXC_EX);
+
+ /*
+ * Check whether or not the VFP state in the CPU's registers is
+ * the most recent VFP state associated with this task. On SMP,
+ * migration may result in multiple CPUs holding VFP states
+ * that belong to the same task, but only the most recent one
+ * is valid.
+ */
+ if (!vfp_state_in_hw(ti->cpu, ti)) {
+ if (!IS_ENABLED(CONFIG_SMP) &&
+ vfp_current_hw_state[ti->cpu] != NULL) {
+ /*
+ * This CPU is currently holding the most
+ * recent VFP state associated with another
+ * task, and we must save that to memory first.
+ */
+ vfp_save_state(vfp_current_hw_state[ti->cpu],
+ fpexc);
+ }
+
+ /*
+ * We can now proceed with loading the task's VFP state
+ * from memory into the CPU registers.
+ */
+ fpexc = vfp_load_state(&ti->vfpstate);
+ vfp_current_hw_state[ti->cpu] = &ti->vfpstate;
+#ifdef CONFIG_SMP
+ /*
+ * Record that this CPU is now the one holding the most
+ * recent VFP state of the task.
+ */
+ ti->vfpstate.hard.cpu = ti->cpu;
+#endif
+ }
+
+ if (fpexc & FPEXC_EX)
+ /*
+ * Might as well handle the pending exception before
+ * retrying branch out before setting an FPEXC that
+ * stops us reading stuff.
+ */
+ goto bounce;
+
+ /*
+ * No FP exception is pending: just enable the VFP and
+ * replay the instruction that trapped.
+ */
+ fmxr(FPEXC, fpexc);
+ } else {
+ /* Check for synchronous or asynchronous exceptions */
+ if (!(fpexc & (FPEXC_EX | FPEXC_DEX))) {
+ u32 fpscr = fmrx(FPSCR);
+
+ /*
+ * On some implementations of the VFP subarch 1,
+ * setting FPSCR.IXE causes all the CDP instructions to
+ * be bounced synchronously without setting the
+ * FPEXC.EX bit
+ */
+ if (!(fpscr & FPSCR_IXE)) {
+ if (!(fpscr & FPSCR_LENGTH_MASK)) {
+ pr_debug("not VFP\n");
+ local_bh_enable();
+ return -ENOEXEC;
+ }
+ fpexc |= FPEXC_DEX;
+ }
+ }
+bounce: regs->ARM_pc += 4;
+ VFP_bounce(trigger, fpexc, regs);
+ }
+
+ local_bh_enable();
+ return 0;
+}
+
+static struct undef_hook neon_support_hook[] = {{
.instr_mask = 0xfe000000,
.instr_val = 0xf2000000,
- .cpsr_mask = MODE_MASK | PSR_T_BIT,
- .cpsr_val = SVC_MODE,
- .fn = vfp_kmode_exception,
+ .cpsr_mask = PSR_T_BIT,
+ .cpsr_val = 0,
+ .fn = vfp_support_entry,
}, {
.instr_mask = 0xff100000,
.instr_val = 0xf4000000,
- .cpsr_mask = MODE_MASK | PSR_T_BIT,
- .cpsr_val = SVC_MODE,
- .fn = vfp_kmode_exception,
+ .cpsr_mask = PSR_T_BIT,
+ .cpsr_val = 0,
+ .fn = vfp_support_entry,
}, {
.instr_mask = 0xef000000,
.instr_val = 0xef000000,
- .cpsr_mask = MODE_MASK | PSR_T_BIT,
- .cpsr_val = SVC_MODE | PSR_T_BIT,
- .fn = vfp_kmode_exception,
+ .cpsr_mask = PSR_T_BIT,
+ .cpsr_val = PSR_T_BIT,
+ .fn = vfp_support_entry,
}, {
.instr_mask = 0xff100000,
.instr_val = 0xf9000000,
- .cpsr_mask = MODE_MASK | PSR_T_BIT,
- .cpsr_val = SVC_MODE | PSR_T_BIT,
- .fn = vfp_kmode_exception,
-}, {
- .instr_mask = 0x0c000e00,
- .instr_val = 0x0c000a00,
- .cpsr_mask = MODE_MASK,
- .cpsr_val = SVC_MODE,
- .fn = vfp_kmode_exception,
+ .cpsr_mask = PSR_T_BIT,
+ .cpsr_val = PSR_T_BIT,
+ .fn = vfp_support_entry,
}};
-static int __init vfp_kmode_exception_hook_init(void)
-{
- int i;
+static struct undef_hook vfp_support_hook = {
+ .instr_mask = 0x0c000e00,
+ .instr_val = 0x0c000a00,
+ .fn = vfp_support_entry,
+};
- for (i = 0; i < ARRAY_SIZE(vfp_kmode_exception_hook); i++)
- register_undef_hook(&vfp_kmode_exception_hook[i]);
- return 0;
-}
-subsys_initcall(vfp_kmode_exception_hook_init);
+#ifdef CONFIG_KERNEL_MODE_NEON
/*
* Kernel-side NEON support functions
* for NEON if the hardware has the MVFR registers.
*/
if (IS_ENABLED(CONFIG_NEON) &&
- (fmrx(MVFR1) & 0x000fff00) == 0x00011100)
+ (fmrx(MVFR1) & 0x000fff00) == 0x00011100) {
elf_hwcap |= HWCAP_NEON;
+ for (int i = 0; i < ARRAY_SIZE(neon_support_hook); i++)
+ register_undef_hook(&neon_support_hook[i]);
+ }
if (IS_ENABLED(CONFIG_VFPv3)) {
u32 mvfr0 = fmrx(MVFR0);
have_vfp = true;
+ register_undef_hook(&vfp_support_hook);
thread_register_notifier(&vfp_notifier_block);
vfp_pm_init();
projects / linux-2.6-microblaze.git / commitdiff