diff options
Diffstat (limited to 'arch/m68k/atari/ataints.c')
| -rw-r--r-- | arch/m68k/atari/ataints.c | 648 |
1 files changed, 648 insertions, 0 deletions
diff --git a/arch/m68k/atari/ataints.c b/arch/m68k/atari/ataints.c new file mode 100644 index 0000000000000..076f479178425 --- /dev/null +++ b/arch/m68k/atari/ataints.c @@ -0,0 +1,648 @@ +/* + * arch/m68k/atari/ataints.c -- Atari Linux interrupt handling code + * + * 5/2/94 Roman Hodek: + * Added support for TT interrupts; setup for TT SCU (may someone has + * twiddled there and we won't get the right interrupts :-() + * + * Major change: The device-independent code in m68k/ints.c didn't know + * about non-autovec ints yet. It hardcoded the number of possible ints to + * 7 (IRQ1...IRQ7). But the Atari has lots of non-autovec ints! I made the + * number of possible ints a constant defined in interrupt.h, which is + * 47 for the Atari. So we can call request_irq() for all Atari interrupts + * just the normal way. Additionally, all vectors >= 48 are initialized to + * call trap() instead of inthandler(). This must be changed here, too. + * + * 1995-07-16 Lars Brinkhoff <f93labr@dd.chalmers.se>: + * Corrected a bug in atari_add_isr() which rejected all SCC + * interrupt sources if there were no TT MFP! + * + * 12/13/95: New interface functions atari_level_triggered_int() and + * atari_register_vme_int() as support for level triggered VME interrupts. + * + * 02/12/96: (Roman) + * Total rewrite of Atari interrupt handling, for new scheme see comments + * below. + * + * 1996-09-03 lars brinkhoff <f93labr@dd.chalmers.se>: + * Added new function atari_unregister_vme_int(), and + * modified atari_register_vme_int() as well as IS_VALID_INTNO() + * to work with it. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of this archive + * for more details. + * + */ + +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/kernel_stat.h> +#include <linux/init.h> +#include <linux/seq_file.h> + +#include <asm/system.h> +#include <asm/traps.h> + +#include <asm/atarihw.h> +#include <asm/atariints.h> +#include <asm/atari_stdma.h> +#include <asm/irq.h> +#include <asm/entry.h> + + +/* + * Atari interrupt handling scheme: + * -------------------------------- + * + * All interrupt source have an internal number (defined in + * <asm/atariints.h>): Autovector interrupts are 1..7, then follow ST-MFP, + * TT-MFP, SCC, and finally VME interrupts. Vector numbers for the latter can + * be allocated by atari_register_vme_int(). + * + * Each interrupt can be of three types: + * + * - SLOW: The handler runs with all interrupts enabled, except the one it + * was called by (to avoid reentering). This should be the usual method. + * But it is currently possible only for MFP ints, since only the MFP + * offers an easy way to mask interrupts. + * + * - FAST: The handler runs with all interrupts disabled. This should be used + * only for really fast handlers, that just do actions immediately + * necessary, and let the rest do a bottom half or task queue. + * + * - PRIORITIZED: The handler can be interrupted by higher-level ints + * (greater IPL, no MFP priorities!). This is the method of choice for ints + * which should be slow, but are not from a MFP. + * + * The feature of more than one handler for one int source is still there, but + * only applicable if all handers are of the same type. To not slow down + * processing of ints with only one handler by the chaining feature, the list + * calling function atari_call_irq_list() is only plugged in at the time the + * second handler is registered. + * + * Implementation notes: For fast-as-possible int handling, there are separate + * entry points for each type (slow/fast/prio). The assembler handler calls + * the irq directly in the usual case, no C wrapper is involved. In case of + * multiple handlers, atari_call_irq_list() is registered as handler and calls + * in turn the real irq's. To ease access from assembler level to the irq + * function pointer and accompanying data, these two are stored in a separate + * array, irq_handler[]. The rest of data (type, name) are put into a second + * array, irq_param, that is accessed from C only. For each slow interrupt (32 + * in all) there are separate handler functions, which makes it possible to + * hard-code the MFP register address and value, are necessary to mask the + * int. If there'd be only one generic function, lots of calculations would be + * needed to determine MFP register and int mask from the vector number :-( + * + * Furthermore, slow ints may not lower the IPL below its previous value + * (before the int happened). This is needed so that an int of class PRIO, on + * that this int may be stacked, cannot be reentered. This feature is + * implemented as follows: If the stack frame format is 1 (throwaway), the int + * is not stacked, and the IPL is anded with 0xfbff, resulting in a new level + * 2, which still blocks the HSYNC, but no interrupts of interest. If the + * frame format is 0, the int is nested, and the old IPL value can be found in + * the sr copy in the frame. + */ + + +#define NUM_INT_SOURCES (8 + NUM_ATARI_SOURCES) + +typedef void (*asm_irq_handler)(void); + +struct irqhandler { + irqreturn_t (*handler)(int, void *, struct pt_regs *); + void *dev_id; +}; + +struct irqparam { + unsigned long flags; + const char *devname; +}; + +/* + * Array with irq's and their parameter data. This array is accessed from low + * level assembler code, so an element size of 8 allows usage of index scaling + * addressing mode. + */ +static struct irqhandler irq_handler[NUM_INT_SOURCES]; + +/* + * This array hold the rest of parameters of int handlers: type + * (slow,fast,prio) and the name of the handler. These values are only + * accessed from C + */ +static struct irqparam irq_param[NUM_INT_SOURCES]; + +/* + * Bitmap for free interrupt vector numbers + * (new vectors starting from 0x70 can be allocated by + * atari_register_vme_int()) + */ +static int free_vme_vec_bitmap; + +/* check for valid int number (complex, sigh...) */ +#define IS_VALID_INTNO(n) \ + ((n) > 0 && \ + /* autovec and ST-MFP ok anyway */ \ + (((n) < TTMFP_SOURCE_BASE) || \ + /* TT-MFP ok if present */ \ + ((n) >= TTMFP_SOURCE_BASE && (n) < SCC_SOURCE_BASE && \ + ATARIHW_PRESENT(TT_MFP)) || \ + /* SCC ok if present and number even */ \ + ((n) >= SCC_SOURCE_BASE && (n) < VME_SOURCE_BASE && \ + !((n) & 1) && ATARIHW_PRESENT(SCC)) || \ + /* greater numbers ok if they are registered VME vectors */ \ + ((n) >= VME_SOURCE_BASE && (n) < VME_SOURCE_BASE + VME_MAX_SOURCES && \ + free_vme_vec_bitmap & (1 << ((n) - VME_SOURCE_BASE))))) + + +/* + * Here start the assembler entry points for interrupts + */ + +#define IRQ_NAME(nr) atari_slow_irq_##nr##_handler(void) + +#define BUILD_SLOW_IRQ(n) \ +asmlinkage void IRQ_NAME(n); \ +/* Dummy function to allow asm with operands. */ \ +void atari_slow_irq_##n##_dummy (void) { \ +__asm__ (__ALIGN_STR "\n" \ +"atari_slow_irq_" #n "_handler:\t" \ +" addl %6,%5\n" /* preempt_count() += HARDIRQ_OFFSET */ \ + SAVE_ALL_INT "\n" \ + GET_CURRENT(%%d0) "\n" \ +" andb #~(1<<(%c3&7)),%a4:w\n" /* mask this interrupt */ \ + /* get old IPL from stack frame */ \ +" bfextu %%sp@(%c2){#5,#3},%%d0\n" \ +" movew %%sr,%%d1\n" \ +" bfins %%d0,%%d1{#21,#3}\n" \ +" movew %%d1,%%sr\n" /* set IPL = previous value */ \ +" addql #1,%a0\n" \ +" lea %a1,%%a0\n" \ +" pea %%sp@\n" /* push addr of frame */ \ +" movel %%a0@(4),%%sp@-\n" /* push handler data */ \ +" pea (%c3+8)\n" /* push int number */ \ +" movel %%a0@,%%a0\n" \ +" jbsr %%a0@\n" /* call the handler */ \ +" addql #8,%%sp\n" \ +" addql #4,%%sp\n" \ +" orw #0x0600,%%sr\n" \ +" andw #0xfeff,%%sr\n" /* set IPL = 6 again */ \ +" orb #(1<<(%c3&7)),%a4:w\n" /* now unmask the int again */ \ +" jbra ret_from_interrupt\n" \ + : : "i" (&kstat_cpu(0).irqs[n+8]), "i" (&irq_handler[n+8]), \ + "n" (PT_OFF_SR), "n" (n), \ + "i" (n & 8 ? (n & 16 ? &tt_mfp.int_mk_a : &mfp.int_mk_a) \ + : (n & 16 ? &tt_mfp.int_mk_b : &mfp.int_mk_b)), \ + "m" (preempt_count()), "di" (HARDIRQ_OFFSET) \ +); \ + for (;;); /* fake noreturn */ \ +} + +BUILD_SLOW_IRQ(0); +BUILD_SLOW_IRQ(1); +BUILD_SLOW_IRQ(2); +BUILD_SLOW_IRQ(3); +BUILD_SLOW_IRQ(4); +BUILD_SLOW_IRQ(5); +BUILD_SLOW_IRQ(6); +BUILD_SLOW_IRQ(7); +BUILD_SLOW_IRQ(8); +BUILD_SLOW_IRQ(9); +BUILD_SLOW_IRQ(10); +BUILD_SLOW_IRQ(11); +BUILD_SLOW_IRQ(12); +BUILD_SLOW_IRQ(13); +BUILD_SLOW_IRQ(14); +BUILD_SLOW_IRQ(15); +BUILD_SLOW_IRQ(16); +BUILD_SLOW_IRQ(17); +BUILD_SLOW_IRQ(18); +BUILD_SLOW_IRQ(19); +BUILD_SLOW_IRQ(20); +BUILD_SLOW_IRQ(21); +BUILD_SLOW_IRQ(22); +BUILD_SLOW_IRQ(23); +BUILD_SLOW_IRQ(24); +BUILD_SLOW_IRQ(25); +BUILD_SLOW_IRQ(26); +BUILD_SLOW_IRQ(27); +BUILD_SLOW_IRQ(28); +BUILD_SLOW_IRQ(29); +BUILD_SLOW_IRQ(30); +BUILD_SLOW_IRQ(31); + +asm_irq_handler slow_handlers[32] = { + [0] = atari_slow_irq_0_handler, + [1] = atari_slow_irq_1_handler, + [2] = atari_slow_irq_2_handler, + [3] = atari_slow_irq_3_handler, + [4] = atari_slow_irq_4_handler, + [5] = atari_slow_irq_5_handler, + [6] = atari_slow_irq_6_handler, + [7] = atari_slow_irq_7_handler, + [8] = atari_slow_irq_8_handler, + [9] = atari_slow_irq_9_handler, + [10] = atari_slow_irq_10_handler, + [11] = atari_slow_irq_11_handler, + [12] = atari_slow_irq_12_handler, + [13] = atari_slow_irq_13_handler, + [14] = atari_slow_irq_14_handler, + [15] = atari_slow_irq_15_handler, + [16] = atari_slow_irq_16_handler, + [17] = atari_slow_irq_17_handler, + [18] = atari_slow_irq_18_handler, + [19] = atari_slow_irq_19_handler, + [20] = atari_slow_irq_20_handler, + [21] = atari_slow_irq_21_handler, + [22] = atari_slow_irq_22_handler, + [23] = atari_slow_irq_23_handler, + [24] = atari_slow_irq_24_handler, + [25] = atari_slow_irq_25_handler, + [26] = atari_slow_irq_26_handler, + [27] = atari_slow_irq_27_handler, + [28] = atari_slow_irq_28_handler, + [29] = atari_slow_irq_29_handler, + [30] = atari_slow_irq_30_handler, + [31] = atari_slow_irq_31_handler +}; + +asmlinkage void atari_fast_irq_handler( void ); +asmlinkage void atari_prio_irq_handler( void ); + +/* Dummy function to allow asm with operands. */ +void atari_fast_prio_irq_dummy (void) { +__asm__ (__ALIGN_STR "\n" +"atari_fast_irq_handler:\n\t" + "orw #0x700,%%sr\n" /* disable all interrupts */ +"atari_prio_irq_handler:\n\t" + "addl %3,%2\n\t" /* preempt_count() += HARDIRQ_OFFSET */ + SAVE_ALL_INT "\n\t" + GET_CURRENT(%%d0) "\n\t" + /* get vector number from stack frame and convert to source */ + "bfextu %%sp@(%c1){#4,#10},%%d0\n\t" + "subw #(0x40-8),%%d0\n\t" + "jpl 1f\n\t" + "addw #(0x40-8-0x18),%%d0\n" + "1:\tlea %a0,%%a0\n\t" + "addql #1,%%a0@(%%d0:l:4)\n\t" + "lea irq_handler,%%a0\n\t" + "lea %%a0@(%%d0:l:8),%%a0\n\t" + "pea %%sp@\n\t" /* push frame address */ + "movel %%a0@(4),%%sp@-\n\t" /* push handler data */ + "movel %%d0,%%sp@-\n\t" /* push int number */ + "movel %%a0@,%%a0\n\t" + "jsr %%a0@\n\t" /* and call the handler */ + "addql #8,%%sp\n\t" + "addql #4,%%sp\n\t" + "jbra ret_from_interrupt" + : : "i" (&kstat_cpu(0).irqs), "n" (PT_OFF_FORMATVEC), + "m" (preempt_count()), "di" (HARDIRQ_OFFSET) +); + for (;;); +} + +/* GK: + * HBL IRQ handler for Falcon. Nobody needs it :-) + * ++andreas: raise ipl to disable further HBLANK interrupts. + */ +asmlinkage void falcon_hblhandler(void); +asm(".text\n" +__ALIGN_STR "\n\t" +"falcon_hblhandler:\n\t" + "orw #0x200,%sp@\n\t" /* set saved ipl to 2 */ + "rte"); + +/* Defined in entry.S; only increments 'num_spurious' */ +asmlinkage void bad_interrupt(void); + +extern void atari_microwire_cmd( int cmd ); + +extern int atari_SCC_reset_done; + +/* + * void atari_init_IRQ (void) + * + * Parameters: None + * + * Returns: Nothing + * + * This function should be called during kernel startup to initialize + * the atari IRQ handling routines. + */ + +void __init atari_init_IRQ(void) +{ + int i; + + /* initialize the vector table */ + for (i = 0; i < NUM_INT_SOURCES; ++i) { + vectors[IRQ_SOURCE_TO_VECTOR(i)] = bad_interrupt; + } + + /* Initialize the MFP(s) */ + +#ifdef ATARI_USE_SOFTWARE_EOI + mfp.vec_adr = 0x48; /* Software EOI-Mode */ +#else + mfp.vec_adr = 0x40; /* Automatic EOI-Mode */ +#endif + mfp.int_en_a = 0x00; /* turn off MFP-Ints */ + mfp.int_en_b = 0x00; + mfp.int_mk_a = 0xff; /* no Masking */ + mfp.int_mk_b = 0xff; + + if (ATARIHW_PRESENT(TT_MFP)) { +#ifdef ATARI_USE_SOFTWARE_EOI + tt_mfp.vec_adr = 0x58; /* Software EOI-Mode */ +#else + tt_mfp.vec_adr = 0x50; /* Automatic EOI-Mode */ +#endif + tt_mfp.int_en_a = 0x00; /* turn off MFP-Ints */ + tt_mfp.int_en_b = 0x00; + tt_mfp.int_mk_a = 0xff; /* no Masking */ + tt_mfp.int_mk_b = 0xff; + } + + if (ATARIHW_PRESENT(SCC) && !atari_SCC_reset_done) { + scc.cha_a_ctrl = 9; + MFPDELAY(); + scc.cha_a_ctrl = (char) 0xc0; /* hardware reset */ + } + + if (ATARIHW_PRESENT(SCU)) { + /* init the SCU if present */ + tt_scu.sys_mask = 0x10; /* enable VBL (for the cursor) and + * disable HSYNC interrupts (who + * needs them?) MFP and SCC are + * enabled in VME mask + */ + tt_scu.vme_mask = 0x60; /* enable MFP and SCC ints */ + } + else { + /* If no SCU and no Hades, the HSYNC interrupt needs to be + * disabled this way. (Else _inthandler in kernel/sys_call.S + * gets overruns) + */ + + if (!MACH_IS_HADES) + vectors[VEC_INT2] = falcon_hblhandler; + } + + if (ATARIHW_PRESENT(PCM_8BIT) && ATARIHW_PRESENT(MICROWIRE)) { + /* Initialize the LM1992 Sound Controller to enable + the PSG sound. This is misplaced here, it should + be in an atasound_init(), that doesn't exist yet. */ + atari_microwire_cmd(MW_LM1992_PSG_HIGH); + } + + stdma_init(); + + /* Initialize the PSG: all sounds off, both ports output */ + sound_ym.rd_data_reg_sel = 7; + sound_ym.wd_data = 0xff; +} + + +static irqreturn_t atari_call_irq_list( int irq, void *dev_id, struct pt_regs *fp ) +{ + irq_node_t *node; + + for (node = (irq_node_t *)dev_id; node; node = node->next) + node->handler(irq, node->dev_id, fp); + return IRQ_HANDLED; +} + + +/* + * atari_request_irq : add an interrupt service routine for a particular + * machine specific interrupt source. + * If the addition was successful, it returns 0. + */ + +int atari_request_irq(unsigned int irq, irqreturn_t (*handler)(int, void *, struct pt_regs *), + unsigned long flags, const char *devname, void *dev_id) +{ + int vector; + unsigned long oflags = flags; + + /* + * The following is a hack to make some PCI card drivers work, + * which set the SA_SHIRQ flag. + */ + + flags &= ~SA_SHIRQ; + + if (flags == SA_INTERRUPT) { + printk ("%s: SA_INTERRUPT changed to IRQ_TYPE_SLOW for %s\n", + __FUNCTION__, devname); + flags = IRQ_TYPE_SLOW; + } + if (flags < IRQ_TYPE_SLOW || flags > IRQ_TYPE_PRIO) { + printk ("%s: Bad irq type 0x%lx <0x%lx> requested from %s\n", + __FUNCTION__, flags, oflags, devname); + return -EINVAL; + } + if (!IS_VALID_INTNO(irq)) { + printk ("%s: Unknown irq %d requested from %s\n", + __FUNCTION__, irq, devname); + return -ENXIO; + } + vector = IRQ_SOURCE_TO_VECTOR(irq); + + /* + * Check type/source combination: slow ints are (currently) + * only possible for MFP-interrupts. + */ + if (flags == IRQ_TYPE_SLOW && + (irq < STMFP_SOURCE_BASE || irq >= SCC_SOURCE_BASE)) { + printk ("%s: Slow irq requested for non-MFP source %d from %s\n", + __FUNCTION__, irq, devname); + return -EINVAL; + } + + if (vectors[vector] == bad_interrupt) { + /* int has no handler yet */ + irq_handler[irq].handler = handler; + irq_handler[irq].dev_id = dev_id; + irq_param[irq].flags = flags; + irq_param[irq].devname = devname; + vectors[vector] = + (flags == IRQ_TYPE_SLOW) ? slow_handlers[irq-STMFP_SOURCE_BASE] : + (flags == IRQ_TYPE_FAST) ? atari_fast_irq_handler : + atari_prio_irq_handler; + /* If MFP int, also enable and umask it */ + atari_turnon_irq(irq); + atari_enable_irq(irq); + + return 0; + } + else if (irq_param[irq].flags == flags) { + /* old handler is of same type -> handlers can be chained */ + irq_node_t *node; + unsigned long flags; + + local_irq_save(flags); + + if (irq_handler[irq].handler != atari_call_irq_list) { + /* Only one handler yet, make a node for this first one */ + if (!(node = new_irq_node())) + return -ENOMEM; + node->handler = irq_handler[irq].handler; + node->dev_id = irq_handler[irq].dev_id; + node->devname = irq_param[irq].devname; + node->next = NULL; + + irq_handler[irq].handler = atari_call_irq_list; + irq_handler[irq].dev_id = node; + irq_param[irq].devname = "chained"; + } + + if (!(node = new_irq_node())) + return -ENOMEM; + node->handler = handler; + node->dev_id = dev_id; + node->devname = devname; + /* new handlers are put in front of the queue */ + node->next = irq_handler[irq].dev_id; + irq_handler[irq].dev_id = node; + + local_irq_restore(flags); + return 0; + } else { + printk ("%s: Irq %d allocated by other type int (call from %s)\n", + __FUNCTION__, irq, devname); + return -EBUSY; + } +} + +void atari_free_irq(unsigned int irq, void *dev_id) +{ + unsigned long flags; + int vector; + irq_node_t **list, *node; + + if (!IS_VALID_INTNO(irq)) { + printk("%s: Unknown irq %d\n", __FUNCTION__, irq); + return; + } + + vector = IRQ_SOURCE_TO_VECTOR(irq); + if (vectors[vector] == bad_interrupt) + goto not_found; + + local_irq_save(flags); + + if (irq_handler[irq].handler != atari_call_irq_list) { + /* It's the only handler for the interrupt */ + if (irq_handler[irq].dev_id != dev_id) { + local_irq_restore(flags); + goto not_found; + } + irq_handler[irq].handler = NULL; + irq_handler[irq].dev_id = NULL; + irq_param[irq].devname = NULL; + vectors[vector] = bad_interrupt; + /* If MFP int, also disable it */ + atari_disable_irq(irq); + atari_turnoff_irq(irq); + + local_irq_restore(flags); + return; + } + + /* The interrupt is chained, find the irq on the list */ + for(list = (irq_node_t **)&irq_handler[irq].dev_id; *list; list = &(*list)->next) { + if ((*list)->dev_id == dev_id) break; + } + if (!*list) { + local_irq_restore(flags); + goto not_found; + } + + (*list)->handler = NULL; /* Mark it as free for reallocation */ + *list = (*list)->next; + + /* If there's now only one handler, unchain the interrupt, i.e. plug in + * the handler directly again and omit atari_call_irq_list */ + node = (irq_node_t *)irq_handler[irq].dev_id; + if (node && !node->next) { + irq_handler[irq].handler = node->handler; + irq_handler[irq].dev_id = node->dev_id; + irq_param[irq].devname = node->devname; + node->handler = NULL; /* Mark it as free for reallocation */ + } + + local_irq_restore(flags); + return; + +not_found: + printk("%s: tried to remove invalid irq\n", __FUNCTION__); + return; +} + + +/* + * atari_register_vme_int() returns the number of a free interrupt vector for + * hardware with a programmable int vector (probably a VME board). + */ + +unsigned long atari_register_vme_int(void) +{ + int i; + + for(i = 0; i < 32; i++) + if((free_vme_vec_bitmap & (1 << i)) == 0) + break; + + if(i == 16) + return 0; + + free_vme_vec_bitmap |= 1 << i; + return (VME_SOURCE_BASE + i); +} + + +void atari_unregister_vme_int(unsigned long irq) +{ + if(irq >= VME_SOURCE_BASE && irq < VME_SOURCE_BASE + VME_MAX_SOURCES) { + irq -= VME_SOURCE_BASE; + free_vme_vec_bitmap &= ~(1 << irq); + } +} + + +int show_atari_interrupts(struct seq_file *p, void *v) +{ + int i; + + for (i = 0; i < NUM_INT_SOURCES; ++i) { + if (vectors[IRQ_SOURCE_TO_VECTOR(i)] == bad_interrupt) + continue; + if (i < STMFP_SOURCE_BASE) + seq_printf(p, "auto %2d: %10u ", + i, kstat_cpu(0).irqs[i]); + else + seq_printf(p, "vec $%02x: %10u ", + IRQ_SOURCE_TO_VECTOR(i), + kstat_cpu(0).irqs[i]); + + if (irq_handler[i].handler != atari_call_irq_list) { + seq_printf(p, "%s\n", irq_param[i].devname); + } + else { + irq_node_t *n; + for( n = (irq_node_t *)irq_handler[i].dev_id; n; n = n->next ) { + seq_printf(p, "%s\n", n->devname); + if (n->next) + seq_puts(p, " " ); + } + } + } + if (num_spurious) + seq_printf(p, "spurio.: %10u\n", num_spurious); + + return 0; +} + + |