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459 lines
14 KiB
459 lines
14 KiB
/*
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* arch/m68k/atari/ataints.c -- Atari Linux interrupt handling code
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*
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* 5/2/94 Roman Hodek:
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* Added support for TT interrupts; setup for TT SCU (may someone has
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* twiddled there and we won't get the right interrupts :-()
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*
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* Major change: The device-independent code in m68k/ints.c didn't know
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* about non-autovec ints yet. It hardcoded the number of possible ints to
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* 7 (IRQ1...IRQ7). But the Atari has lots of non-autovec ints! I made the
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* number of possible ints a constant defined in interrupt.h, which is
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* 47 for the Atari. So we can call request_irq() for all Atari interrupts
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* just the normal way. Additionally, all vectors >= 48 are initialized to
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* call trap() instead of inthandler(). This must be changed here, too.
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*
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* 1995-07-16 Lars Brinkhoff <f93labr@dd.chalmers.se>:
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* Corrected a bug in atari_add_isr() which rejected all SCC
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* interrupt sources if there were no TT MFP!
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*
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* 12/13/95: New interface functions atari_level_triggered_int() and
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* atari_register_vme_int() as support for level triggered VME interrupts.
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*
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* 02/12/96: (Roman)
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* Total rewrite of Atari interrupt handling, for new scheme see comments
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* below.
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*
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* 1996-09-03 lars brinkhoff <f93labr@dd.chalmers.se>:
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* Added new function atari_unregister_vme_int(), and
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* modified atari_register_vme_int() as well as IS_VALID_INTNO()
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* to work with it.
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file COPYING in the main directory of this archive
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* for more details.
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*
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*/
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/kernel_stat.h>
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#include <linux/init.h>
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#include <linux/seq_file.h>
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#include <asm/system.h>
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#include <asm/traps.h>
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#include <asm/atarihw.h>
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#include <asm/atariints.h>
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#include <asm/atari_stdma.h>
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#include <asm/irq.h>
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#include <asm/entry.h>
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/*
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* Atari interrupt handling scheme:
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* --------------------------------
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*
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* All interrupt source have an internal number (defined in
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* <asm/atariints.h>): Autovector interrupts are 1..7, then follow ST-MFP,
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* TT-MFP, SCC, and finally VME interrupts. Vector numbers for the latter can
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* be allocated by atari_register_vme_int().
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*
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* Each interrupt can be of three types:
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*
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* - SLOW: The handler runs with all interrupts enabled, except the one it
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* was called by (to avoid reentering). This should be the usual method.
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* But it is currently possible only for MFP ints, since only the MFP
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* offers an easy way to mask interrupts.
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*
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* - FAST: The handler runs with all interrupts disabled. This should be used
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* only for really fast handlers, that just do actions immediately
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* necessary, and let the rest do a bottom half or task queue.
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*
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* - PRIORITIZED: The handler can be interrupted by higher-level ints
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* (greater IPL, no MFP priorities!). This is the method of choice for ints
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* which should be slow, but are not from a MFP.
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*
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* The feature of more than one handler for one int source is still there, but
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* only applicable if all handers are of the same type. To not slow down
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* processing of ints with only one handler by the chaining feature, the list
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* calling function atari_call_irq_list() is only plugged in at the time the
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* second handler is registered.
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*
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* Implementation notes: For fast-as-possible int handling, there are separate
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* entry points for each type (slow/fast/prio). The assembler handler calls
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* the irq directly in the usual case, no C wrapper is involved. In case of
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* multiple handlers, atari_call_irq_list() is registered as handler and calls
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* in turn the real irq's. To ease access from assembler level to the irq
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* function pointer and accompanying data, these two are stored in a separate
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* array, irq_handler[]. The rest of data (type, name) are put into a second
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* array, irq_param, that is accessed from C only. For each slow interrupt (32
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* in all) there are separate handler functions, which makes it possible to
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* hard-code the MFP register address and value, are necessary to mask the
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* int. If there'd be only one generic function, lots of calculations would be
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* needed to determine MFP register and int mask from the vector number :-(
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*
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* Furthermore, slow ints may not lower the IPL below its previous value
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* (before the int happened). This is needed so that an int of class PRIO, on
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* that this int may be stacked, cannot be reentered. This feature is
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* implemented as follows: If the stack frame format is 1 (throwaway), the int
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* is not stacked, and the IPL is anded with 0xfbff, resulting in a new level
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* 2, which still blocks the HSYNC, but no interrupts of interest. If the
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* frame format is 0, the int is nested, and the old IPL value can be found in
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* the sr copy in the frame.
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*/
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#if 0
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#define NUM_INT_SOURCES (8 + NUM_ATARI_SOURCES)
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typedef void (*asm_irq_handler)(void);
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struct irqhandler {
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irqreturn_t (*handler)(int, void *, struct pt_regs *);
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void *dev_id;
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};
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struct irqparam {
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unsigned long flags;
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const char *devname;
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};
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/*
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* Array with irq's and their parameter data. This array is accessed from low
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* level assembler code, so an element size of 8 allows usage of index scaling
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* addressing mode.
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*/
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static struct irqhandler irq_handler[NUM_INT_SOURCES];
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/*
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* This array hold the rest of parameters of int handlers: type
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* (slow,fast,prio) and the name of the handler. These values are only
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* accessed from C
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*/
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static struct irqparam irq_param[NUM_INT_SOURCES];
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/* check for valid int number (complex, sigh...) */
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#define IS_VALID_INTNO(n) \
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((n) > 0 && \
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/* autovec and ST-MFP ok anyway */ \
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(((n) < TTMFP_SOURCE_BASE) || \
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/* TT-MFP ok if present */ \
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((n) >= TTMFP_SOURCE_BASE && (n) < SCC_SOURCE_BASE && \
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ATARIHW_PRESENT(TT_MFP)) || \
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/* SCC ok if present and number even */ \
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((n) >= SCC_SOURCE_BASE && (n) < VME_SOURCE_BASE && \
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!((n) & 1) && ATARIHW_PRESENT(SCC)) || \
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/* greater numbers ok if they are registered VME vectors */ \
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((n) >= VME_SOURCE_BASE && (n) < VME_SOURCE_BASE + VME_MAX_SOURCES && \
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free_vme_vec_bitmap & (1 << ((n) - VME_SOURCE_BASE)))))
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/*
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* Here start the assembler entry points for interrupts
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*/
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#define IRQ_NAME(nr) atari_slow_irq_##nr##_handler(void)
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#define BUILD_SLOW_IRQ(n) \
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asmlinkage void IRQ_NAME(n); \
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/* Dummy function to allow asm with operands. */ \
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void atari_slow_irq_##n##_dummy (void) { \
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__asm__ (__ALIGN_STR "\n" \
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"atari_slow_irq_" #n "_handler:\t" \
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" addl %6,%5\n" /* preempt_count() += HARDIRQ_OFFSET */ \
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SAVE_ALL_INT "\n" \
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GET_CURRENT(%%d0) "\n" \
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" andb #~(1<<(%c3&7)),%a4:w\n" /* mask this interrupt */ \
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/* get old IPL from stack frame */ \
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" bfextu %%sp@(%c2){#5,#3},%%d0\n" \
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" movew %%sr,%%d1\n" \
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" bfins %%d0,%%d1{#21,#3}\n" \
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" movew %%d1,%%sr\n" /* set IPL = previous value */ \
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" addql #1,%a0\n" \
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" lea %a1,%%a0\n" \
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" pea %%sp@\n" /* push addr of frame */ \
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" movel %%a0@(4),%%sp@-\n" /* push handler data */ \
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" pea (%c3+8)\n" /* push int number */ \
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" movel %%a0@,%%a0\n" \
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" jbsr %%a0@\n" /* call the handler */ \
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" addql #8,%%sp\n" \
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" addql #4,%%sp\n" \
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" orw #0x0600,%%sr\n" \
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" andw #0xfeff,%%sr\n" /* set IPL = 6 again */ \
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" orb #(1<<(%c3&7)),%a4:w\n" /* now unmask the int again */ \
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" jbra ret_from_interrupt\n" \
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: : "i" (&kstat_cpu(0).irqs[n+8]), "i" (&irq_handler[n+8]), \
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"n" (PT_OFF_SR), "n" (n), \
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"i" (n & 8 ? (n & 16 ? &tt_mfp.int_mk_a : &mfp.int_mk_a) \
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: (n & 16 ? &tt_mfp.int_mk_b : &mfp.int_mk_b)), \
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"m" (preempt_count()), "di" (HARDIRQ_OFFSET) \
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); \
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for (;;); /* fake noreturn */ \
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}
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BUILD_SLOW_IRQ(0);
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BUILD_SLOW_IRQ(1);
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BUILD_SLOW_IRQ(2);
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BUILD_SLOW_IRQ(3);
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BUILD_SLOW_IRQ(4);
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BUILD_SLOW_IRQ(5);
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BUILD_SLOW_IRQ(6);
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BUILD_SLOW_IRQ(7);
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BUILD_SLOW_IRQ(8);
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BUILD_SLOW_IRQ(9);
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BUILD_SLOW_IRQ(10);
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BUILD_SLOW_IRQ(11);
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BUILD_SLOW_IRQ(12);
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BUILD_SLOW_IRQ(13);
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BUILD_SLOW_IRQ(14);
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BUILD_SLOW_IRQ(15);
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BUILD_SLOW_IRQ(16);
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BUILD_SLOW_IRQ(17);
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BUILD_SLOW_IRQ(18);
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BUILD_SLOW_IRQ(19);
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BUILD_SLOW_IRQ(20);
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BUILD_SLOW_IRQ(21);
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BUILD_SLOW_IRQ(22);
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BUILD_SLOW_IRQ(23);
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BUILD_SLOW_IRQ(24);
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BUILD_SLOW_IRQ(25);
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BUILD_SLOW_IRQ(26);
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BUILD_SLOW_IRQ(27);
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BUILD_SLOW_IRQ(28);
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BUILD_SLOW_IRQ(29);
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BUILD_SLOW_IRQ(30);
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BUILD_SLOW_IRQ(31);
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asm_irq_handler slow_handlers[32] = {
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[0] = atari_slow_irq_0_handler,
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[1] = atari_slow_irq_1_handler,
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[2] = atari_slow_irq_2_handler,
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[3] = atari_slow_irq_3_handler,
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[4] = atari_slow_irq_4_handler,
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[5] = atari_slow_irq_5_handler,
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[6] = atari_slow_irq_6_handler,
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[7] = atari_slow_irq_7_handler,
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[8] = atari_slow_irq_8_handler,
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[9] = atari_slow_irq_9_handler,
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[10] = atari_slow_irq_10_handler,
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[11] = atari_slow_irq_11_handler,
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[12] = atari_slow_irq_12_handler,
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[13] = atari_slow_irq_13_handler,
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[14] = atari_slow_irq_14_handler,
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[15] = atari_slow_irq_15_handler,
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[16] = atari_slow_irq_16_handler,
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[17] = atari_slow_irq_17_handler,
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[18] = atari_slow_irq_18_handler,
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[19] = atari_slow_irq_19_handler,
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[20] = atari_slow_irq_20_handler,
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[21] = atari_slow_irq_21_handler,
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[22] = atari_slow_irq_22_handler,
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[23] = atari_slow_irq_23_handler,
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[24] = atari_slow_irq_24_handler,
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[25] = atari_slow_irq_25_handler,
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[26] = atari_slow_irq_26_handler,
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[27] = atari_slow_irq_27_handler,
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[28] = atari_slow_irq_28_handler,
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[29] = atari_slow_irq_29_handler,
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[30] = atari_slow_irq_30_handler,
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[31] = atari_slow_irq_31_handler
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};
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asmlinkage void atari_fast_irq_handler( void );
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asmlinkage void atari_prio_irq_handler( void );
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/* Dummy function to allow asm with operands. */
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void atari_fast_prio_irq_dummy (void) {
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__asm__ (__ALIGN_STR "\n"
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"atari_fast_irq_handler:\n\t"
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"orw #0x700,%%sr\n" /* disable all interrupts */
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"atari_prio_irq_handler:\n\t"
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"addl %3,%2\n\t" /* preempt_count() += HARDIRQ_OFFSET */
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SAVE_ALL_INT "\n\t"
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GET_CURRENT(%%d0) "\n\t"
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/* get vector number from stack frame and convert to source */
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"bfextu %%sp@(%c1){#4,#10},%%d0\n\t"
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"subw #(0x40-8),%%d0\n\t"
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"jpl 1f\n\t"
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"addw #(0x40-8-0x18),%%d0\n"
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"1:\tlea %a0,%%a0\n\t"
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"addql #1,%%a0@(%%d0:l:4)\n\t"
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"lea irq_handler,%%a0\n\t"
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"lea %%a0@(%%d0:l:8),%%a0\n\t"
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"pea %%sp@\n\t" /* push frame address */
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"movel %%a0@(4),%%sp@-\n\t" /* push handler data */
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"movel %%d0,%%sp@-\n\t" /* push int number */
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"movel %%a0@,%%a0\n\t"
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"jsr %%a0@\n\t" /* and call the handler */
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"addql #8,%%sp\n\t"
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"addql #4,%%sp\n\t"
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"jbra ret_from_interrupt"
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: : "i" (&kstat_cpu(0).irqs), "n" (PT_OFF_FORMATVEC),
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"m" (preempt_count()), "di" (HARDIRQ_OFFSET)
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);
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for (;;);
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}
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#endif
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/*
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* Bitmap for free interrupt vector numbers
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* (new vectors starting from 0x70 can be allocated by
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* atari_register_vme_int())
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*/
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static int free_vme_vec_bitmap;
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/* GK:
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* HBL IRQ handler for Falcon. Nobody needs it :-)
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* ++andreas: raise ipl to disable further HBLANK interrupts.
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*/
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asmlinkage void falcon_hblhandler(void);
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asm(".text\n"
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__ALIGN_STR "\n\t"
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"falcon_hblhandler:\n\t"
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"orw #0x200,%sp@\n\t" /* set saved ipl to 2 */
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"rte");
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extern void atari_microwire_cmd(int cmd);
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extern int atari_SCC_reset_done;
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static int atari_startup_irq(unsigned int irq)
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{
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m68k_irq_startup(irq);
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atari_turnon_irq(irq);
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atari_enable_irq(irq);
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return 0;
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}
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static void atari_shutdown_irq(unsigned int irq)
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{
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atari_disable_irq(irq);
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atari_turnoff_irq(irq);
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m68k_irq_shutdown(irq);
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if (irq == IRQ_AUTO_4)
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vectors[VEC_INT4] = falcon_hblhandler;
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}
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static struct irq_controller atari_irq_controller = {
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.name = "atari",
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.lock = SPIN_LOCK_UNLOCKED,
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.startup = atari_startup_irq,
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.shutdown = atari_shutdown_irq,
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.enable = atari_enable_irq,
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.disable = atari_disable_irq,
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};
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/*
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* void atari_init_IRQ (void)
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*
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* Parameters: None
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*
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* Returns: Nothing
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*
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* This function should be called during kernel startup to initialize
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* the atari IRQ handling routines.
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*/
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void __init atari_init_IRQ(void)
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{
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m68k_setup_user_interrupt(VEC_USER, NUM_ATARI_SOURCES - IRQ_USER, NULL);
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m68k_setup_irq_controller(&atari_irq_controller, 1, NUM_ATARI_SOURCES - 1);
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/* Initialize the MFP(s) */
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#ifdef ATARI_USE_SOFTWARE_EOI
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mfp.vec_adr = 0x48; /* Software EOI-Mode */
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#else
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mfp.vec_adr = 0x40; /* Automatic EOI-Mode */
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#endif
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mfp.int_en_a = 0x00; /* turn off MFP-Ints */
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mfp.int_en_b = 0x00;
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mfp.int_mk_a = 0xff; /* no Masking */
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mfp.int_mk_b = 0xff;
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if (ATARIHW_PRESENT(TT_MFP)) {
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#ifdef ATARI_USE_SOFTWARE_EOI
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tt_mfp.vec_adr = 0x58; /* Software EOI-Mode */
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#else
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tt_mfp.vec_adr = 0x50; /* Automatic EOI-Mode */
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#endif
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tt_mfp.int_en_a = 0x00; /* turn off MFP-Ints */
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tt_mfp.int_en_b = 0x00;
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tt_mfp.int_mk_a = 0xff; /* no Masking */
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tt_mfp.int_mk_b = 0xff;
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}
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if (ATARIHW_PRESENT(SCC) && !atari_SCC_reset_done) {
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scc.cha_a_ctrl = 9;
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MFPDELAY();
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scc.cha_a_ctrl = (char) 0xc0; /* hardware reset */
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}
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if (ATARIHW_PRESENT(SCU)) {
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/* init the SCU if present */
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tt_scu.sys_mask = 0x10; /* enable VBL (for the cursor) and
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* disable HSYNC interrupts (who
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* needs them?) MFP and SCC are
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* enabled in VME mask
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*/
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tt_scu.vme_mask = 0x60; /* enable MFP and SCC ints */
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} else {
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/* If no SCU and no Hades, the HSYNC interrupt needs to be
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* disabled this way. (Else _inthandler in kernel/sys_call.S
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* gets overruns)
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*/
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if (!MACH_IS_HADES) {
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vectors[VEC_INT2] = falcon_hblhandler;
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vectors[VEC_INT4] = falcon_hblhandler;
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}
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}
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if (ATARIHW_PRESENT(PCM_8BIT) && ATARIHW_PRESENT(MICROWIRE)) {
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/* Initialize the LM1992 Sound Controller to enable
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the PSG sound. This is misplaced here, it should
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be in an atasound_init(), that doesn't exist yet. */
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atari_microwire_cmd(MW_LM1992_PSG_HIGH);
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}
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stdma_init();
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/* Initialize the PSG: all sounds off, both ports output */
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sound_ym.rd_data_reg_sel = 7;
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sound_ym.wd_data = 0xff;
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}
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/*
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* atari_register_vme_int() returns the number of a free interrupt vector for
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* hardware with a programmable int vector (probably a VME board).
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*/
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unsigned long atari_register_vme_int(void)
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{
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int i;
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for (i = 0; i < 32; i++)
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if ((free_vme_vec_bitmap & (1 << i)) == 0)
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break;
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if (i == 16)
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return 0;
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free_vme_vec_bitmap |= 1 << i;
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return VME_SOURCE_BASE + i;
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}
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void atari_unregister_vme_int(unsigned long irq)
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|
{
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if (irq >= VME_SOURCE_BASE && irq < VME_SOURCE_BASE + VME_MAX_SOURCES) {
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|
irq -= VME_SOURCE_BASE;
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|
free_vme_vec_bitmap &= ~(1 << irq);
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|
}
|
|
}
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