/* $NetBSD: isa_irq.S,v 1.2 1998/06/12 23:08:52 tv Exp $ */ /* * Copyright 1997 * Digital Equipment Corporation. All rights reserved. * * This software is furnished under license and may be used and * copied only in accordance with the following terms and conditions. * Subject to these conditions, you may download, copy, install, * use, modify and distribute this software in source and/or binary * form. No title or ownership is transferred hereby. * * 1) Any source code used, modified or distributed must reproduce * and retain this copyright notice and list of conditions as * they appear in the source file. * * 2) No right is granted to use any trade name, trademark, or logo of * Digital Equipment Corporation. Neither the "Digital Equipment * Corporation" name nor any trademark or logo of Digital Equipment * Corporation may be used to endorse or promote products derived * from this software without the prior written permission of * Digital Equipment Corporation. * * 3) This software is provided "AS-IS" and any express or implied * warranties, including but not limited to, any implied warranties * of merchantability, fitness for a particular purpose, or * non-infringement are disclaimed. In no event shall DIGITAL be * liable for any damages whatsoever, and in particular, DIGITAL * shall not be liable for special, indirect, consequential, or * incidental damages or damages for lost profits, loss of * revenue or loss of use, whether such damages arise in contract, * negligence, tort, under statute, in equity, at law or otherwise, * even if advised of the possibility of such damage. */ /* * Copyright (c) 1994-1997 Mark Brinicombe. * Copyright (c) 1994 Brini. * All rights reserved. * * This code is derived from software written for Brini by Mark Brinicombe * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Brini. * 4. The name of the company nor the name of the author may be used to * endorse or promote products derived from this software without specific * prior written permission. * * THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL BRINI OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * RiscBSD kernel project * * irq.S * * Low level irq and fiq handlers * * Created : 27/09/94 */ #include "assym.h" #include #include #include #include #include #include #include "opt_uvm.h" sp .req r13 lr .req r14 pc .req r15 .text /* * * irq_entry * * Main entry point for the IRQ vector * * This function reads the irq request bits in the IOMD registers * IRQRQA, IRQRQB and DMARQ * It then calls an installed handler for each bit that is set. * The function stray_irqhandler is called if a handler is not defined * for a particular interrupt. * If a interrupt handler is found then it is called with r0 containing * the argument defined in the handler structure. If the field ih_arg * is zero then a pointer to the IRQ frame on the stack is passed instead. */ Ldisabled_mask: .word _disabled_mask Lcurrent_spl_level: .word _current_spl_level Lcurrent_intr_depth: .word _current_intr_depth Lvam_io_data: .word _isa_io_bs_tag .text .global irq_entry /* * Register usage * * r6 - Address of current handler * r7 - Pointer to handler pointer list * r8 - Current IRQ requests. * r9 - Used to count through possible IRQ bits. * r10 - Base address of IOMD */ /* Some documentation is in isa_machdep.c */ irq_entry: sub lr, lr, #0x00000004 /* Adjust the lr */ PUSHFRAMEINSVC /* Push an interrupt frame */ /* mov r11, #0x00000000*/ /* Trace back stops here */ /* Load r8 with the ISA 8259 irqs */ /* r8 <- irq's pending [15:0] */ /* address of 8259 #1 */ ldr r0, Lvam_io_data ldr r0, [r0] ldrb r8, [r0, #IO_ICU1] /* ocw3 = irr */ /* clear the IRR bits that are currently masked. */ ldr r2, Li8259_mask ldr r2, [r2] mvn r2, r2 /* disabled -> enabled */ /* address of 8259 #2 */ tst r2, #(1 << IRQ_SLAVE) /* if slave is enabled */ tstne r8, #(1 << IRQ_SLAVE) /* anything from slave? */ ldrneb r1, [r0, #IO_ICU2] /* ocw3 = irr */ orrne r8, r8, r1, lsl #8 and r8, r8, r2 /* clear disabled */ /* clear IRQ 2, which is only used for slave 8259 */ bic r8, r8, #(1 << IRQ_SLAVE) /* * Note that we have entered the IRQ handler. * We are in SVC mode so we cannot use the processor mode * to determine if we are in an IRQ. Instead we will count the * each time the interrupt handler is nested. */ ldr r0, Lcurrent_intr_depth ldr r1, [r0] add r1, r1, #1 str r1, [r0] /* Block the current requested interrupts */ ldr r1, Ldisabled_mask ldr r0, [r1] stmfd sp!, {r0} orr r0, r0, r8 str r0, [r1] /* * Need to block all interrupts at the IPL or lower for * all asserted interrupts. * This basically emulates hardware interrupt priority levels. * Means we need to go through the interrupt mask and for * every asserted interrupt we need to mask out all other * interrupts at the same or lower IPL. * If only we could wait until the main loop but we need to sort * this out first so interrupts can be re-enabled. * * This would benefit from a special ffs type routine */ mov r9, #0x00000001 ldr r7, Lirqblock emulate_hwipl_loop: tst r8, r9 ldrne r6, [r7] orrne r0, r0, r6 add r7, r7, #4 mov r9, r9, lsl #1 /* move on to next bit */ #ifdef CPU_ARM7500 teq r9, #0 /* done the last bit ? */ #else teq r9, #(1 << 24) /* done the last bit ? */ #endif /* CPU_ARM7500 */ bne emulate_hwipl_loop /* no - loop back. */ str r0, [r1] /* Update the IOMD irq masks */ bl _irq_setmasks mrs r0, cpsr_all /* Enable IRQ's */ bic r0, r0, #I32_bit msr cpsr_all, r0 ldr r7, [pc, #irqhandlers - . - 8] mov r9, #0x00000001 stmfd sp!, {r8} irqloop: /* This would benefit from a special ffs type routine */ tst r8, r9 /* Is a bit set ? */ beq nextirq /* No ? try next bit */ ldr r6, [r7] /* Get address of first handler structure */ teq r6, #0x00000000 /* Do we have a handler */ moveq r0, r8 /* IRQ requests as arg 0 */ beq _stray_irqhandler /* call special handler */ ldr r0, Lcnt ldr r1, [r0, #(V_INTR)] add r1, r1, #0x00000001 str r1, [r0, #(V_INTR)] irqchainloop: add lr, pc, #nextinchain - . - 8 /* return address */ /* * XXX: Should stats be accumlated for every interrupt routine called * or for every physical interrupt that is serviced. */ #ifdef IRQSTATS ldr r0, Lintrcnt ldr r1, [r6, #(IH_NUM)] add r0, r0, r1, lsl #2 ldr r1, [r0] add r1, r1, #0x00000001 str r1, [r0] #endif /* IRQSTATS */ ldr r0, [r6, #(IH_ARG)] /* Get argument pointer */ teq r0, #0x00000000 /* If arg is zero pass stack frame */ addeq r0, sp, #8 /* ... stack frame */ ldr pc, [r6, #(IH_FUNC)] /* Call handler */ nextinchain: teq r0, #0x00000001 /* Was the irq serviced ? */ beq irqdone ldr r6, [r6, #(IH_NEXT)] teq r6, #0x00000000 bne irqchainloop irqdone: nextirq: add r7, r7, #0x00000004 /* update pointer to handlers */ mov r9, r9, lsl #1 /* move on to next bit */ #ifdef CPU_ARM7500 teq r9, #0 /* done the last bit ? */ #else teq r9, #(1 << 24) /* done the last bit ? */ #endif /* CPU_ARM7500 */ bne irqloop /* no - loop back. */ ldmfd sp!, {r8} /* Restore previous disabled mask */ ldmfd sp!, {r2} ldr r1, Ldisabled_mask str r2, [r1] bl _irq_setmasks bl _dosoftints /* Handle the soft interrupts */ /* Manage AST's. Maybe this should be done as a soft interrupt ? */ ldr r0, [sp] /* Get the SPSR from stack */ and r0, r0, #(PSR_MODE) /* Test for USR32 mode before the IRQ */ teq r0, #(PSR_USR32_MODE) ldreq r0, Lastpending /* Do we have an AST pending ? */ ldreq r1, [r0] teqeq r1, #0x00000001 beq irqast /* call the AST handler */ /* Kill IRQ's in preparation for exit */ mrs r0, cpsr_all orr r0, r0, #(I32_bit) msr cpsr_all, r0 /* Decrement the nest count */ ldr r0, Lcurrent_intr_depth ldr r1, [r0] sub r1, r1, #1 str r1, [r0] PULLFRAMEFROMSVCANDEXIT movs pc, lr /* Exit */ /* * Ok, snag with current intr depth ... * If ast() calls mi_sleep() the current_intr_depth will not be * decremented until the process is woken up. This can result * in the system believing it is still in the interrupt handler. * If we are calling ast() then correct the current_intr_depth * before the call. */ irqast: mov r1, #0x00000000 /* Clear ast_pending */ str r1, [r0] /* Kill IRQ's so we atomically decrement current_intr_depth */ mrs r2, cpsr_all orr r3, r2, #(I32_bit) msr cpsr_all, r3 /* Decrement the nest count */ ldr r0, Lcurrent_intr_depth ldr r1, [r0] sub r1, r1, #1 str r1, [r0] /* Restore IRQ's */ msr cpsr_all, r2 mov r0, sp bl _ast /* Kill IRQ's in preparation for exit */ mrs r0, cpsr_all orr r0, r0, #(I32_bit) msr cpsr_all, r0 PULLFRAMEFROMSVCANDEXIT movs pc, lr /* Exit */ Lspl_mask: .word _spl_mask /* irq's allowed at current spl level */ Lcurrent_mask: .word _current_mask /* irq's that are usable */ Lirqblock: .word _irqblock ENTRY(irq_setmasks) /* Disable interrupts */ mrs r3, cpsr_all orr r1, r3, #(I32_bit) msr cpsr_all, r1 /* Calculate interrupt mask */ ldr r1, Lcurrent_mask /* All the enabled interrupts */ #ifdef LDRH ldrh r1, [r1] /* get hardware bits of mask */ #else .word 0xe0d110b0 /* hand-assembled ldrh r1, [r1] */ #endif ldr r2, Lspl_mask /* Block due to current spl level */ ldr r2, [r2] and r1, r1, r2 ldr r2, Ldisabled_mask /* Block due to active interrupts */ ldr r2, [r2] bic r1, r1, r2 /* since 8259's are so slow to access, this code does everything possible to avoid them */ /* get current mask: these are the bits */ ldr r0, Li8259_mask ldr r2, [r0] /* r2 = 0000.0000.0000.0000.ZZZZ.ZZZZ.ZZZZ.ZZZZ */ /* see if there's anything enabled on 8259 #2 */ tst r1, #0xff00 biceq r1, r1, #(1 << IRQ_SLAVE) /* no, so disable it */ orrne r1, r1, #(1 << IRQ_SLAVE) /* yes, so enable it */ /* eq => r1 = 0000.0000.0000.0000.0000.0000.MMMM.M0MM ne => r1 = 0000.0000.0000.0000.MMMM.MMMM.MMMM.M1MM */ /* 8259 bit high => disable */ mvn r1, r1 /* eq => r1 = 1111.1111.1111.1111.1111.1111.YYYY.Y1YY ne => r1 = 1111.1111.1111.1111.YYYY.YYYY.YYYY.Y0YY (for each bit position Y = !M) */ orreq r1, r2, r1, lsl #16 /* eq => r1 = 1111.1111.YYYY.Y1YY.ZZZZ.ZZZZ.ZZZZ.ZZZZ ne => r1 = 1111.1111.1111.1111.YYYY.YYYY.YYYY.Y0YY */ orreq r1, r1, #0x000000FF /* eq => r1 = 1111.1111.YYYY.Y1YY.ZZZZ.ZZZZ.1111.1111 ne => r1 = 1111.1111.1111.1111.YYYY.YYYY.YYYY.Y0YY */ and r1, r1, r1, lsr #16 /* eq => r1 = 0000.0000.0000.0000.ZZZZ.ZZZZ.YYYY.Y1YY ne => r1 = 0000.0000.0000.0000.YYYY.YYYY.YYYY.Y0YY */ /* if old = new, don't bother to set again. fast path to exit, since 8259's are so slow anyway */ eors r2, r1, r2 /* which bits are different? */ msreq cpsr_all, r3 /* no bits are different, return */ moveq pc, lr /* have to set at least one of the 8259's, store new mask */ str r1, [r0] ldr r0, Lvam_io_data ldr r0, [r0] /* see if there's any change for 8259 #1 (master) */ tst r2, #0x00FF /* bottom 8 bits different? */ strneb r1, [r0, #(IO_ICU1 + 1)] /* icu1 / ocw1 */ /* anything for 8259 #2? */ tst r2, #0xFF00 mov r1, r1, lsr #8 /* next byte */ strneb r1, [r0, #(IO_ICU2 + 1)] /* icu2 / ocw1 */ /* Restore old cpsr and exit */ msr cpsr_all, r3 mov pc, lr Lcnt: #if defined(UVM) .word _uvmexp #else .word _cnt #endif Lintrcnt: .word _intrcnt Li8259_mask: .word _i8259_mask irqhandlers: .word _irqhandlers /* Pointer to array of irqhandlers */ Lastpending: .word _astpending #ifdef IRQSTATS /* These symbols are used by vmstat */ .text .global __intrnames __intrnames: .word _intrnames .data /* XXX fix */ .globl _intrnames, _eintrnames, _intrcnt, _eintrcnt _intrnames: .asciz "interrupt 0 " .asciz "softnet " /* reserved0 */ .asciz "interrupt 2 " .asciz "interrupt 3 " .asciz "interrupt 4 " .asciz "interrupt 5 " .asciz "interrupt 6 " .asciz "softclock " /* reserved1 */ .asciz "softplip " /* reserved2 */ .asciz "interrupt 9 " .asciz "interrupt 10 " .asciz "interrupt 11 " .asciz "interrupt 12 " .asciz "interrupt 13 " .asciz "interrupt 14 " .asciz "interrupt 15 " .asciz "dma channel 0" .asciz "dma channel 1" .asciz "dma channel 2" .asciz "dma channel 3" .asciz "interrupt 20 " .asciz "interrupt 21 " .asciz "reserved 3 " .asciz "reserved 4 " .asciz "exp card 0 " .asciz "exp card 1 " .asciz "exp card 2 " .asciz "exp card 3 " .asciz "exp card 4 " .asciz "exp card 5 " .asciz "exp card 6 " .asciz "exp card 7 " _eintrnames: .bss .align 0 _intrcnt: .space 32*4 /* XXX Should be linked to number of interrupts */ _eintrcnt: #else /* IRQSTATS */ /* Dummy entries to keep vmstat happy */ .text .globl _intrnames, _eintrnames, _intrcnt, _eintrcnt _intrnames: .long 0 _eintrnames: _intrcnt: .long 0 _eintrcnt: #endif /* IRQSTATS */ /* FIQ code */ .text .align 0 .global _fiq_setregs /* Sets up the FIQ handler */ _fiq_setregs: mrs r2, cpsr_all mov r3, r2 bic r2, r2, #(PSR_MODE) orr r2, r2, #(PSR_FIQ32_MODE) orr r2, r2, #(I32_bit | F32_bit) /* IRQs/FIQs definitely off */ msr cpsr_all, r2 ldr r8, [r0, #FH_R8] /* Update FIQ registers*/ ldr r9, [r0, #FH_R9] ldr r10, [r0, #FH_R10] ldr r11, [r0, #FH_R11] ldr r12, [r0, #FH_R12] ldr r13, [r0, #FH_R13] msr cpsr_all, r3 /* Back to old mode */ mov pc, lr /* Exit */ .global _fiq_getregs /* Gets the FIQ registers */ _fiq_getregs: mrs r2, cpsr_all mov r3, r2 bic r2, r2, #(PSR_MODE) orr r2, r2, #(PSR_FIQ32_MODE) orr r2, r2, #(I32_bit | F32_bit) /* IRQs/FIQs definitely off */ msr cpsr_all, r2 str r8, [r0, #FH_R8] /* Update FIQ registers*/ str r9, [r0, #FH_R9] str r10, [r0, #FH_R10] str r11, [r0, #FH_R11] str r12, [r0, #FH_R12] str r13, [r0, #FH_R13] msr cpsr_all, r3 /* Back to old mode */ mov pc, lr /* Exit */ /* End of irq.S */