diff --git a/arch/arm/vfp/vfphw.S b/arch/arm/vfp/vfphw.S index 0ac022f800a13578d97db2a6236f2cc16e86ef03..53d9f8e8fac37f5964ccd9a24f588ec5df9ecb0a 100644 --- a/arch/arm/vfp/vfphw.S +++ b/arch/arm/vfp/vfphw.S @@ -100,10 +100,10 @@ vfp_support_entry: 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 + tst r1, #FPEXC_EX @ is there additional state to save? + VFPFMRX r6, FPINST, NE @ FPINST (only if FPEXC.EX is set) + tstne r1, #FPEXC_FP2V @ is there an FPINST2 to read? + VFPFMRX r8, FPINST2, NE @ FPINST2 if needed (and present) 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 @@ -117,10 +117,10 @@ no_old_VFP_process: 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 + tst r1, #FPEXC_EX @ is there additional state to restore? + VFPFMXR FPINST, r6, NE @ restore FPINST (only if FPEXC.EX is set) + tstne r1, #FPEXC_FP2V @ is there an FPINST2 to write? + VFPFMXR FPINST2, r8, NE @ FPINST2 if needed (and present) VFPFMXR FPSCR, r5 @ restore status check_for_exception: @@ -136,10 +136,14 @@ check_for_exception: look_for_VFP_exceptions: - tst r1, #FPEXC_EX + @ 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 @ IXE doesn't set FPEXC_EX ! + tst r5, #FPSCR_IXE bne process_exception @ Fall into hand on to next handler - appropriate coproc instr @@ -150,10 +154,6 @@ look_for_VFP_exceptions: 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. @@ -161,7 +161,7 @@ process_exception: @ r0 holds the trigger instruction @ r1 holds the FPEXC value @ r2 pointer to register dump - b VFP9_bounce @ we have handled this - the support + 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 @@ -175,10 +175,10 @@ vfp_save_state: @ 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 + tst r1, #FPEXC_EX @ is there additional state to save? + VFPFMRX r3, FPINST, NE @ FPINST (only if FPEXC.EX is set) + tstne r1, #FPEXC_FP2V @ is there an FPINST2 to read? + VFPFMRX r12, FPINST2, NE @ FPINST2 if needed (and present) VFPFSTMIA r0 @ save the working registers stmia r0, {r1, r2, r3, r12} @ save FPEXC, FPSCR, FPINST, FPINST2 mov pc, lr diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c index b4e210df92f2a37084c9dff73ae07b24ce73f725..32455c633f1c389039d455e10f990399c7c16e28 100644 --- a/arch/arm/vfp/vfpmodule.c +++ b/arch/arm/vfp/vfpmodule.c @@ -125,13 +125,13 @@ void vfp_raise_sigfpe(unsigned int sicode, struct pt_regs *regs) send_sig_info(SIGFPE, &info, current); } -static void vfp_panic(char *reason) +static void vfp_panic(char *reason, u32 inst) { int i; printk(KERN_ERR "VFP: Error: %s\n", reason); printk(KERN_ERR "VFP: EXC 0x%08x SCR 0x%08x INST 0x%08x\n", - fmrx(FPEXC), fmrx(FPSCR), fmrx(FPINST)); + fmrx(FPEXC), fmrx(FPSCR), inst); for (i = 0; i < 32; i += 2) printk(KERN_ERR "VFP: s%2u: 0x%08x s%2u: 0x%08x\n", i, vfp_get_float(i), i+1, vfp_get_float(i+1)); @@ -147,19 +147,16 @@ static void vfp_raise_exceptions(u32 exceptions, u32 inst, u32 fpscr, struct pt_ pr_debug("VFP: raising exceptions %08x\n", exceptions); if (exceptions == VFP_EXCEPTION_ERROR) { - vfp_panic("unhandled bounce"); + vfp_panic("unhandled bounce", inst); vfp_raise_sigfpe(0, regs); return; } /* - * If any of the status flags are set, update the FPSCR. + * Update the FPSCR with the additional exception flags. * Comparison instructions always return at least one of * these flags set. */ - if (exceptions & (FPSCR_N|FPSCR_Z|FPSCR_C|FPSCR_V)) - fpscr &= ~(FPSCR_N|FPSCR_Z|FPSCR_C|FPSCR_V); - fpscr |= exceptions; fmxr(FPSCR, fpscr); @@ -220,35 +217,64 @@ static u32 vfp_emulate_instruction(u32 inst, u32 fpscr, struct pt_regs *regs) /* * Package up a bounce condition. */ -void VFP9_bounce(u32 trigger, u32 fpexc, struct pt_regs *regs) +void VFP_bounce(u32 trigger, u32 fpexc, struct pt_regs *regs) { - u32 fpscr, orig_fpscr, exceptions, inst; + u32 fpscr, orig_fpscr, fpsid, exceptions; pr_debug("VFP: bounce: trigger %08x fpexc %08x\n", trigger, fpexc); /* - * Enable access to the VFP so we can handle the bounce. + * At this point, FPEXC can have the following configuration: + * + * EX DEX IXE + * 0 1 x - synchronous exception + * 1 x 0 - asynchronous exception + * 1 x 1 - sychronous on VFP subarch 1 and asynchronous on later + * 0 0 1 - synchronous on VFP9 (non-standard subarch 1 + * implementation), undefined otherwise + * + * Clear various bits and enable access to the VFP so we can + * handle the bounce. */ - fmxr(FPEXC, fpexc & ~(FPEXC_EX|FPEXC_FPV2|FPEXC_INV|FPEXC_UFC|FPEXC_OFC|FPEXC_IOC)); + fmxr(FPEXC, fpexc & ~(FPEXC_EX|FPEXC_DEX|FPEXC_FP2V|FPEXC_VV|FPEXC_TRAP_MASK)); + fpsid = fmrx(FPSID); orig_fpscr = fpscr = fmrx(FPSCR); /* - * If we are running with inexact exceptions enabled, we need to - * emulate the trigger instruction. Note that as we're emulating - * the trigger instruction, we need to increment PC. + * Check for the special VFP subarch 1 and FPSCR.IXE bit case */ - if (fpscr & FPSCR_IXE) { - regs->ARM_pc += 4; + if ((fpsid & FPSID_ARCH_MASK) == (1 << FPSID_ARCH_BIT) + && (fpscr & FPSCR_IXE)) { + /* + * Synchronous exception, emulate the trigger instruction + */ goto emulate; } - barrier(); + if (fpexc & FPEXC_EX) { + /* + * Asynchronous exception. The instruction is read from FPINST + * and the interrupted instruction has to be restarted. + */ + trigger = fmrx(FPINST); + regs->ARM_pc -= 4; + } else if (!(fpexc & FPEXC_DEX)) { + /* + * Illegal combination of bits. It can be caused by an + * unallocated VFP instruction but with FPSCR.IXE set and not + * on VFP subarch 1. + */ + vfp_raise_exceptions(VFP_EXCEPTION_ERROR, trigger, fpscr, regs); + return; + } /* - * Modify fpscr to indicate the number of iterations remaining + * Modify fpscr to indicate the number of iterations remaining. + * If FPEXC.EX is 0, FPEXC.DEX is 1 and the FPEXC.VV bit indicates + * whether FPEXC.VECITR or FPSCR.LEN is used. */ - if (fpexc & FPEXC_EX) { + if (fpexc & (FPEXC_EX | FPEXC_VV)) { u32 len; len = fpexc + (1 << FPEXC_LENGTH_BIT); @@ -262,15 +288,15 @@ void VFP9_bounce(u32 trigger, u32 fpexc, struct pt_regs *regs) * FPEXC bounce reason, but this appears to be unreliable. * Emulate the bounced instruction instead. */ - inst = fmrx(FPINST); - exceptions = vfp_emulate_instruction(inst, fpscr, regs); + exceptions = vfp_emulate_instruction(trigger, fpscr, regs); if (exceptions) - vfp_raise_exceptions(exceptions, inst, orig_fpscr, regs); + vfp_raise_exceptions(exceptions, trigger, orig_fpscr, regs); /* - * If there isn't a second FP instruction, exit now. + * If there isn't a second FP instruction, exit now. Note that + * the FPEXC.FP2V bit is valid only if FPEXC.EX is 1. */ - if (!(fpexc & FPEXC_FPV2)) + if (fpexc ^ (FPEXC_EX | FPEXC_FP2V)) return; /* @@ -279,10 +305,9 @@ void VFP9_bounce(u32 trigger, u32 fpexc, struct pt_regs *regs) */ barrier(); trigger = fmrx(FPINST2); - orig_fpscr = fpscr = fmrx(FPSCR); emulate: - exceptions = vfp_emulate_instruction(trigger, fpscr, regs); + exceptions = vfp_emulate_instruction(trigger, orig_fpscr, regs); if (exceptions) vfp_raise_exceptions(exceptions, trigger, orig_fpscr, regs); } @@ -306,16 +331,9 @@ static int __init vfp_init(void) { unsigned int vfpsid; unsigned int cpu_arch = cpu_architecture(); - u32 access = 0; - if (cpu_arch >= CPU_ARCH_ARMv6) { - access = get_copro_access(); - - /* - * Enable full access to VFP (cp10 and cp11) - */ - set_copro_access(access | CPACC_FULL(10) | CPACC_FULL(11)); - } + if (cpu_arch >= CPU_ARCH_ARMv6) + vfp_enable(NULL); /* * First check that there is a VFP that we can use. @@ -329,15 +347,9 @@ static int __init vfp_init(void) vfp_vector = vfp_null_entry; printk(KERN_INFO "VFP support v0.3: "); - if (VFP_arch) { + if (VFP_arch) printk("not present\n"); - - /* - * Restore the copro access register. - */ - if (cpu_arch >= CPU_ARCH_ARMv6) - set_copro_access(access); - } else if (vfpsid & FPSID_NODOUBLE) { + else if (vfpsid & FPSID_NODOUBLE) { printk("no double precision support\n"); } else { smp_call_function(vfp_enable, NULL, 1, 1); diff --git a/include/asm-arm/vfp.h b/include/asm-arm/vfp.h index bd6be9d7f7729a467a509c956505b9d6c6f1bc08..9d474d47b26612fb69c9cd130da2d8e537401576 100644 --- a/include/asm-arm/vfp.h +++ b/include/asm-arm/vfp.h @@ -8,6 +8,8 @@ #define FPSID cr0 #define FPSCR cr1 #define FPEXC cr8 +#define FPINST cr9 +#define FPINST2 cr10 /* FPSID bits */ #define FPSID_IMPLEMENTER_BIT (24) @@ -28,6 +30,19 @@ /* FPEXC bits */ #define FPEXC_EX (1 << 31) #define FPEXC_EN (1 << 30) +#define FPEXC_DEX (1 << 29) +#define FPEXC_FP2V (1 << 28) +#define FPEXC_VV (1 << 27) +#define FPEXC_TFV (1 << 26) +#define FPEXC_LENGTH_BIT (8) +#define FPEXC_LENGTH_MASK (7 << FPEXC_LENGTH_BIT) +#define FPEXC_IDF (1 << 7) +#define FPEXC_IXF (1 << 4) +#define FPEXC_UFF (1 << 3) +#define FPEXC_OFF (1 << 2) +#define FPEXC_DZF (1 << 1) +#define FPEXC_IOF (1 << 0) +#define FPEXC_TRAP_MASK (FPEXC_IDF|FPEXC_IXF|FPEXC_UFF|FPEXC_OFF|FPEXC_DZF|FPEXC_IOF) /* FPSCR bits */ #define FPSCR_DEFAULT_NAN (1<<25) @@ -55,21 +70,6 @@ #define FPSCR_IXC (1<<4) #define FPSCR_IDC (1<<7) -/* - * VFP9-S specific. - */ -#define FPINST cr9 -#define FPINST2 cr10 - -/* FPEXC bits */ -#define FPEXC_FPV2 (1<<28) -#define FPEXC_LENGTH_BIT (8) -#define FPEXC_LENGTH_MASK (7 << FPEXC_LENGTH_BIT) -#define FPEXC_INV (1 << 7) -#define FPEXC_UFC (1 << 3) -#define FPEXC_OFC (1 << 2) -#define FPEXC_IOC (1 << 0) - /* Bit patterns for decoding the packaged operation descriptors */ #define VFPOPDESC_LENGTH_BIT (9) #define VFPOPDESC_LENGTH_MASK (0x07 << VFPOPDESC_LENGTH_BIT)