/*
* 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 add_isr() 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.
*
* 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/ptrace.h>
#include <linux/kernel_stat.h>
#include <asm/system.h>
#include <asm/traps.h>
#include <asm/atarihw.h>
#include <asm/atariints.h>
#include <asm/atari_stdma.h>
#include <asm/bootinfo.h>
#include <asm/irq.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(). Currently, all int source numbers
* have the IRQ_MACHSPEC bit set, to keep the general int handling functions
* in kernel/ints.c from them.
*
* 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_isr_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 isr directly in the usual case, no C wrapper is involved. In case of
* multiple handlers, atari_call_isr_list() is registered as handler and calls
* in turn the real isr's. To ease access from assembler level to the isr
* 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 {
isrfunc isr;
void *data;
};
struct irqparam {
int type;
char *name;
};
/*
* Array with isr'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];
/*
* Counter for next free interrupt vector number
* (new vectors starting from 0x70 can be allocated by
* atari_register_vme_int())
*/
static int next_free_vme_vec = VME_SOURCE_BASE;
/* 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 less than #registered VME vectors */ \
((n) >= VME_SOURCE_BASE && (n) < next_free_vme_vec)))
/*
* Here start the assembler entry points for interrupts
*/
#define IRQ_NAME(nr) atari_slow_irq_##nr##_handler(void)
#define MFP_MK_BASE "0xfa13"
/* This must agree with head.S. */
#define ORIG_DO "0x20"
#define FORMATVEC "0x2E"
#define SR "0x28"
#define SAVE_ALL \
"clrl %%sp@-;" /* stk_adj */ \
"clrl %%sp@-;" \
"subql #1,%%sp@;" /* orig d0 = -1 */ \
"movel %%d0,%%sp@-;" /* d0 */ \
"moveml %%d1-%%d5/%%a0-%%a1,%%sp@-"
#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" \
SYMBOL_NAME_STR(atari_slow_irq_) #n "_handler:\t" \
SAVE_ALL "\n" \
" addql #1,"SYMBOL_NAME_STR(intr_count)"\n" \
" andb #~(1<<(" #n "&7))," /* mask this interrupt */ \
"("MFP_MK_BASE"+(((" #n "&8)^8)>>2)+((" #n "&16)<<3)):w\n" \
" movew %%sp@("SR"),%%d0\n" /* get old IPL from stack frame */ \
" movew %%sr,%%d1\n" \
" andw #0x0700,%%d0\n" \
" andw #0xf8ff,%%d1\n" \
" orw %%d0,%%d1\n" \
" movew %%d1,%%sr\n" /* set IPL = previous value */ \
" addql #1,%a0\n" \
" lea "SYMBOL_NAME_STR(irq_handler)"+("#n"+8)*8,%%a0\n" \
" movel %%a0@(4),%%sp@-\n" /* push handler data */ \
" pea %%sp@(4)\n" /* push addr of frame */ \
" pea (" #n "+8):w\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<<(" #n "&7))," /* now unmask the int again */ \
"("MFP_MK_BASE"+(((" #n "&8)^8)>>2)+((" #n "&16)<<3)):w\n" \
" jbra "SYMBOL_NAME_STR(ret_from_interrupt)"\n" \
: : "i" (&kstat.interrupts[n+8]) \
); \
}
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] = {
atari_slow_irq_0_handler,
atari_slow_irq_1_handler,
atari_slow_irq_2_handler,
atari_slow_irq_3_handler,
atari_slow_irq_4_handler,
atari_slow_irq_5_handler,
atari_slow_irq_6_handler,
atari_slow_irq_7_handler,
atari_slow_irq_8_handler,
atari_slow_irq_9_handler,
atari_slow_irq_10_handler,
atari_slow_irq_11_handler,
atari_slow_irq_12_handler,
atari_slow_irq_13_handler,
atari_slow_irq_14_handler,
atari_slow_irq_15_handler,
atari_slow_irq_16_handler,
atari_slow_irq_17_handler,
atari_slow_irq_18_handler,
atari_slow_irq_19_handler,
atari_slow_irq_20_handler,
atari_slow_irq_21_handler,
atari_slow_irq_22_handler,
atari_slow_irq_23_handler,
atari_slow_irq_24_handler,
atari_slow_irq_25_handler,
atari_slow_irq_26_handler,
atari_slow_irq_27_handler,
atari_slow_irq_28_handler,
atari_slow_irq_29_handler,
atari_slow_irq_30_handler,
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"
SYMBOL_NAME_STR(atari_fast_irq_handler) ":
orw #0x700,%%sr /* disable all interrupts */
"SYMBOL_NAME_STR(atari_prio_irq_handler) ":\t"
SAVE_ALL "
addql #1,"SYMBOL_NAME_STR(intr_count)"
movew %%sp@(" FORMATVEC "),%%d0 /* get vector number from stack frame */
andil #0xfff,%%d0 /* mask off format nibble */
lsrl #2,%%d0 /* convert vector to source */
subl #(0x40-8),%%d0
jpl 1f
addl #(0x40-8-0x18),%%d0
1: lea %a0,%%a0
addql #1,%%a0@(%%d0:l:4)
lea "SYMBOL_NAME_STR(irq_handler)",%%a0
lea %%a0@(%%d0:l:8),%%a0
movel %%a0@(4),%%sp@- /* push handler data */
pea %%sp@(4) /* push frame address */
movel %%d0,%%sp@- /* push int number */
movel %%a0@,%%a0
jsr %%a0@ /* and call the handler */
addql #8,%%sp
addql #4,%%sp
jbra "SYMBOL_NAME_STR(ret_from_interrupt)
: : "i" (&kstat.interrupts)
);
}
/* 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"
SYMBOL_NAME_STR(falcon_hblhandler) ":
movel %d0,%sp@-
movew %sp@(4),%d0
andw #0xf8ff,%d0
orw #0x0200,%d0 /* set saved ipl to 2 */
movew %d0,%sp@(4)
movel %sp@+,%d0
rte");
/* Defined in entry.S; only increments 'num_spurious' */
asmlinkage void bad_interrupt(void);
extern void atari_microwire_cmd( int cmd );
/*
* void atari_init_INTS (void)
*
* Parameters: None
*
* Returns: Nothing
*
* This function should be called during kernel startup to initialize
* the atari IRQ handling routines.
*/
void atari_init_INTS(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 = /* turn off MFP-Ints */
mfp.int_en_b = 0x00;
mfp.int_mk_a = /* 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 = /* turn off MFP-Ints */
tt_mfp.int_en_b = 0x00;
tt_mfp.int_mk_a = /* no Masking */
tt_mfp.int_mk_b = 0xff;
}
if (ATARIHW_PRESENT(SCC)) {
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, the HSYNC interrupt needs to be disabled this
* way. (Else _inthandler in kernel/sys_call.S gets overruns)
*/
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 a 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 void atari_call_isr_list( int irq, struct pt_regs *fp, void *_p )
{
isr_node_t *p;
for( p = (isr_node_t *)_p; p; p = p->next )
p->isr( irq, fp, p->data );
}
/*
* atari_add_isr : add an interrupt service routine for a particular
* machine specific interrupt source.
* If the addition was successful, it returns 1, otherwise
* it returns 0. It will fail if the interrupt is already
* occupied of another handler with different type
*/
int atari_add_isr(unsigned long source, isrfunc isr, int type, void
*data, char *name)
{
int vector;
source &= ~IRQ_MACHSPEC;
if (type < IRQ_TYPE_SLOW || type > IRQ_TYPE_PRIO) {
printk ("atari_add_isr: Bad irq type %d requested from %s\n",
type, name );
return( 0 );
}
if (!IS_VALID_INTNO(source)) {
printk ("atari_add_isr: Unknown irq %ld requested from %s\n",
source, name );
return( 0 );
}
vector = IRQ_SOURCE_TO_VECTOR(source);
/*
* Check type/source combination: slow ints are (currently)
* only possible for MFP-interrupts.
*/
if (type == IRQ_TYPE_SLOW &&
(source < STMFP_SOURCE_BASE || source >= SCC_SOURCE_BASE)) {
printk ("atari_add_isr: Slow irq requested for non-MFP source %ld from %s\n",
source, name );
return( 0 );
}
if (vectors[vector] == bad_interrupt) {
/* int has no handler yet */
irq_handler[source].isr = isr;
irq_handler[source].data = data;
irq_param[source].type = type;
irq_param[source].name = name;
vectors[vector] =
(type == IRQ_TYPE_SLOW) ? slow_handlers[source-STMFP_SOURCE_BASE] :
(type == IRQ_TYPE_FAST) ? atari_fast_irq_handler :
atari_prio_irq_handler;
/* If MFP int, also enable and umask it */
atari_turnon_irq(source);
atari_enable_irq(source);
return 1;
}
else if (irq_param[source].type == type) {
/* old handler is of same type -> handlers can be chained */
isr_node_t *p;
unsigned long flags;
save_flags(flags);
cli();
if (irq_handler[source].isr != atari_call_isr_list) {
/* Only one handler yet, make a node for this first one */
p = new_isr_node();
if (p == NULL) return 0;
p->isr = irq_handler[source].isr;
p->data = irq_handler[source].data;
p->name = irq_param[source].name;
p->next = NULL;
irq_handler[source].isr = atari_call_isr_list;
irq_handler[source].data = p;
irq_param[source].name = "chained";
}
p = new_isr_node();
if (p == NULL) return 0;
p->isr = isr;
p->data = data;
p->name = name;
/* new handlers are put in front of the queue */
p->next = irq_handler[source].data;
irq_handler[source].data = p;
restore_flags(flags);
return 1;
}
else {
printk ("atari_add_isr: Irq %ld allocated by other type int (call from %s)\n",
source, name );
return( 0 );
}
}
int atari_remove_isr(unsigned long source, isrfunc isr, void *data)
{
unsigned long flags;
int vector;
isr_node_t **p, *q;
source &= ~IRQ_MACHSPEC;
if (!IS_VALID_INTNO(source)) {
printk("atari_remove_isr: Unknown irq %ld\n", source);
return 0;
}
vector = IRQ_SOURCE_TO_VECTOR(source);
if (vectors[vector] == bad_interrupt)
goto not_found;
save_flags(flags);
cli();
if (irq_handler[source].isr != atari_call_isr_list) {
/* It's the only handler for the interrupt */
if (irq_handler[source].isr != isr &&
irq_handler[source].data != data) {
restore_flags(flags);
goto not_found;
}
irq_handler[source].isr = NULL;
irq_handler[source].data = NULL;
irq_param[source].name = NULL;
vectors[vector] = bad_interrupt;
/* If MFP int, also disable it */
atari_disable_irq(source);
atari_turnoff_irq(source);
restore_flags(flags);
return 1;
}
/* The interrupt is chained, find the isr on the list */
for( p = (isr_node_t **)&irq_handler[source].data; *p; p = &(*p)->next ) {
if ((*p)->isr == isr) break;
}
if (!*p) {
restore_flags(flags);
goto not_found;
}
(*p)->isr = NULL; /* Mark it as free for reallocation */
*p = (*p)->next;
/* If there's now only one handler, unchain the interrupt, i.e. plug in
* the handler directly again and omit atari_call_isr_list */
q = (isr_node_t *)irq_handler[source].data;
if (q && !q->next) {
irq_handler[source].isr = q->isr;
irq_handler[source].data = q->data;
irq_param[source].name = q->name;
q->isr = NULL; /* Mark it as free for reallocation */
}
restore_flags(flags);
return 1;
not_found:
printk("atari_remove_isr: isr %p not found on list!\n", isr);
return 0;
}
/*
* 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)
{
unsigned long source;
if (next_free_vme_vec == NUM_ATARI_SOURCES)
return 0;
source = next_free_vme_vec | IRQ_MACHSPEC;
next_free_vme_vec++;
return source;
}
int atari_get_irq_list(char *buf, int len)
{
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)
len += sprintf(buf+len, "auto %2d: %8d ",
i, kstat.interrupts[i]);
else
len += sprintf(buf+len, "vec $%02x: %8d ",
IRQ_SOURCE_TO_VECTOR(i),
kstat.interrupts[i]);
if (irq_handler[i].isr != atari_call_isr_list) {
len += sprintf(buf+len, "%s\n", irq_param[i].name);
}
else {
isr_node_t *p;
for( p = (isr_node_t *)irq_handler[i].data; p; p = p->next ) {
len += sprintf(buf+len, "%s\n", p->name);
if (p->next)
len += sprintf( buf+len, " " );
}
}
}
if (num_spurious)
len += sprintf(buf+len, "spurio.: %8ld\n", num_spurious);
return len;
}
