mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-31 16:38:12 +00:00
ARM: vfp: Use undef hook for handling VFP exceptions
Now that the VFP support code has been reimplemented as a C function that takes a struct pt_regs pointer and an opcode, we can use the existing undef_hook framework to deal with undef exceptions triggered by VFP instructions instead of having special handling in assembler. Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
This commit is contained in:
parent
6ee1e6772e
commit
cdd87465ad
4 changed files with 54 additions and 141 deletions
|
@ -557,13 +557,6 @@ ENDPROC(__und_usr)
|
|||
* 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
|
||||
|
@ -575,25 +568,8 @@ ENDPROC(__und_usr)
|
|||
@
|
||||
@ 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
|
||||
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
|
||||
|
@ -620,42 +596,13 @@ call_fpe:
|
|||
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
|
||||
|
|
|
@ -8,4 +8,4 @@
|
|||
# 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
|
||||
|
|
|
@ -1,31 +0,0 @@
|
|||
/* 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, r0 @ pass trigger opcode via R1
|
||||
mov r0, sp @ pass struct pt_regs via R0
|
||||
bl vfp_support_entry @ dispatch the VFP exception
|
||||
cmp r0, #0 @ handled successfully?
|
||||
reteq r9 @ then use R9 as return address
|
||||
ret lr @ pass to undef handler
|
||||
ENDPROC(do_vfp)
|
|
@ -641,15 +641,37 @@ static int vfp_starting_cpu(unsigned int unused)
|
|||
return 0;
|
||||
}
|
||||
|
||||
static int vfp_kmode_exception(struct pt_regs *regs, unsigned int instr)
|
||||
{
|
||||
/*
|
||||
* If we reach this point, a floating point exception has been raised
|
||||
* while running in kernel mode. If the NEON/VFP unit was enabled at the
|
||||
* time, it means a VFP instruction has been issued that requires
|
||||
* software assistance to complete, something which is not currently
|
||||
* supported in kernel mode.
|
||||
* If the NEON/VFP unit was disabled, and the location pointed to below
|
||||
* is properly preceded by a call to kernel_neon_begin(), something has
|
||||
* caused the task to be scheduled out and back in again. In this case,
|
||||
* rebuilding and running with CONFIG_DEBUG_ATOMIC_SLEEP enabled should
|
||||
* be helpful in localizing the problem.
|
||||
*/
|
||||
if (fmrx(FPEXC) & FPEXC_EN)
|
||||
pr_crit("BUG: unsupported FP instruction in kernel mode\n");
|
||||
else
|
||||
pr_crit("BUG: FP instruction issued in kernel mode with FP unit disabled\n");
|
||||
pr_crit("FPEXC == 0x%08x\n", fmrx(FPEXC));
|
||||
return 1;
|
||||
}
|
||||
|
||||
/*
|
||||
* vfp_support_entry - Handle VFP exception from user mode
|
||||
* 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.
|
||||
*/
|
||||
asmlinkage int vfp_support_entry(struct pt_regs *regs, u32 trigger)
|
||||
static int vfp_support_entry(struct pt_regs *regs, u32 trigger)
|
||||
{
|
||||
struct thread_info *ti = current_thread_info();
|
||||
u32 fpexc;
|
||||
|
@ -657,6 +679,9 @@ asmlinkage int vfp_support_entry(struct pt_regs *regs, u32 trigger)
|
|||
if (unlikely(!have_vfp))
|
||||
return -ENODEV;
|
||||
|
||||
if (!user_mode(regs))
|
||||
return vfp_kmode_exception(regs, trigger);
|
||||
|
||||
local_bh_disable();
|
||||
fpexc = fmrx(FPEXC);
|
||||
|
||||
|
@ -722,7 +747,6 @@ asmlinkage int vfp_support_entry(struct pt_regs *regs, u32 trigger)
|
|||
* replay the instruction that trapped.
|
||||
*/
|
||||
fmxr(FPEXC, fpexc);
|
||||
regs->ARM_pc -= 4;
|
||||
} else {
|
||||
/* Check for synchronous or asynchronous exceptions */
|
||||
if (!(fpexc & (FPEXC_EX | FPEXC_DEX))) {
|
||||
|
@ -743,78 +767,47 @@ asmlinkage int vfp_support_entry(struct pt_regs *regs, u32 trigger)
|
|||
fpexc |= FPEXC_DEX;
|
||||
}
|
||||
}
|
||||
bounce: VFP_bounce(trigger, fpexc, regs);
|
||||
bounce: regs->ARM_pc += 4;
|
||||
VFP_bounce(trigger, fpexc, regs);
|
||||
}
|
||||
|
||||
local_bh_enable();
|
||||
return 0;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_KERNEL_MODE_NEON
|
||||
|
||||
static int vfp_kmode_exception(struct pt_regs *regs, unsigned int instr)
|
||||
{
|
||||
/*
|
||||
* If we reach this point, a floating point exception has been raised
|
||||
* while running in kernel mode. If the NEON/VFP unit was enabled at the
|
||||
* time, it means a VFP instruction has been issued that requires
|
||||
* software assistance to complete, something which is not currently
|
||||
* supported in kernel mode.
|
||||
* If the NEON/VFP unit was disabled, and the location pointed to below
|
||||
* is properly preceded by a call to kernel_neon_begin(), something has
|
||||
* caused the task to be scheduled out and back in again. In this case,
|
||||
* rebuilding and running with CONFIG_DEBUG_ATOMIC_SLEEP enabled should
|
||||
* be helpful in localizing the problem.
|
||||
*/
|
||||
if (fmrx(FPEXC) & FPEXC_EN)
|
||||
pr_crit("BUG: unsupported FP instruction in kernel mode\n");
|
||||
else
|
||||
pr_crit("BUG: FP instruction issued in kernel mode with FP unit disabled\n");
|
||||
pr_crit("FPEXC == 0x%08x\n", fmrx(FPEXC));
|
||||
return 1;
|
||||
}
|
||||
|
||||
static struct undef_hook vfp_kmode_exception_hook[] = {{
|
||||
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
|
||||
|
@ -919,8 +912,11 @@ static int __init vfp_init(void)
|
|||
* 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);
|
||||
|
@ -989,6 +985,7 @@ static int __init vfp_init(void)
|
|||
|
||||
have_vfp = true;
|
||||
|
||||
register_undef_hook(&vfp_support_hook);
|
||||
thread_register_notifier(&vfp_notifier_block);
|
||||
vfp_pm_init();
|
||||
|
||||
|
|
Loading…
Reference in a new issue