diff options
Diffstat (limited to 'arch/arm/vfp/vfphw.S')
| -rw-r--r-- | arch/arm/vfp/vfphw.S | 206 |
1 files changed, 14 insertions, 192 deletions
diff --git a/arch/arm/vfp/vfphw.S b/arch/arm/vfp/vfphw.S index 4d8478264d82..d5a03f3c10c5 100644 --- a/arch/arm/vfp/vfphw.S +++ b/arch/arm/vfp/vfphw.S @@ -4,12 +4,6 @@ * * 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> @@ -19,20 +13,6 @@ #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} @@ -48,179 +28,25 @@ #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 - 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. - - mov lr, r3 @ we think we have handled things -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 r2, sp @ nothing stacked - regdump is at TOS - mov lr, r3 @ 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 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 @@ -240,10 +66,6 @@ ENTRY(vfp_save_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 |