cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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q40ints.c (8108B)


      1/*
      2 * arch/m68k/q40/q40ints.c
      3 *
      4 * Copyright (C) 1999,2001 Richard Zidlicky
      5 *
      6 * This file is subject to the terms and conditions of the GNU General Public
      7 * License.  See the file COPYING in the main directory of this archive
      8 * for more details.
      9 *
     10 * .. used to be loosely based on bvme6000ints.c
     11 *
     12 */
     13
     14#include <linux/types.h>
     15#include <linux/kernel.h>
     16#include <linux/errno.h>
     17#include <linux/interrupt.h>
     18#include <linux/irq.h>
     19
     20#include <asm/machdep.h>
     21#include <asm/ptrace.h>
     22#include <asm/traps.h>
     23
     24#include <asm/q40_master.h>
     25#include <asm/q40ints.h>
     26
     27/*
     28 * Q40 IRQs are defined as follows:
     29 *            3,4,5,6,7,10,11,14,15 : ISA dev IRQs
     30 *            16-31: reserved
     31 *            32   : keyboard int
     32 *            33   : frame int (50/200 Hz periodic timer)
     33 *            34   : sample int (10/20 KHz periodic timer)
     34 *
     35*/
     36
     37static void q40_irq_handler(unsigned int, struct pt_regs *fp);
     38static void q40_irq_enable(struct irq_data *data);
     39static void q40_irq_disable(struct irq_data *data);
     40
     41unsigned short q40_ablecount[35];
     42unsigned short q40_state[35];
     43
     44static unsigned int q40_irq_startup(struct irq_data *data)
     45{
     46	unsigned int irq = data->irq;
     47
     48	/* test for ISA ints not implemented by HW */
     49	switch (irq) {
     50	case 1: case 2: case 8: case 9:
     51	case 11: case 12: case 13:
     52		pr_warn("%s: ISA IRQ %d not implemented by HW\n", __func__,
     53			irq);
     54		/* FIXME return -ENXIO; */
     55	}
     56	return 0;
     57}
     58
     59static void q40_irq_shutdown(struct irq_data *data)
     60{
     61}
     62
     63static struct irq_chip q40_irq_chip = {
     64	.name		= "q40",
     65	.irq_startup	= q40_irq_startup,
     66	.irq_shutdown	= q40_irq_shutdown,
     67	.irq_enable	= q40_irq_enable,
     68	.irq_disable	= q40_irq_disable,
     69};
     70
     71/*
     72 * void q40_init_IRQ (void)
     73 *
     74 * Parameters:	None
     75 *
     76 * Returns:	Nothing
     77 *
     78 * This function is called during kernel startup to initialize
     79 * the q40 IRQ handling routines.
     80 */
     81
     82static int disabled;
     83
     84void __init q40_init_IRQ(void)
     85{
     86	m68k_setup_irq_controller(&q40_irq_chip, handle_simple_irq, 1,
     87				  Q40_IRQ_MAX);
     88
     89	/* setup handler for ISA ints */
     90	m68k_setup_auto_interrupt(q40_irq_handler);
     91
     92	m68k_irq_startup_irq(IRQ_AUTO_2);
     93	m68k_irq_startup_irq(IRQ_AUTO_4);
     94
     95	/* now enable some ints.. */
     96	master_outb(1, EXT_ENABLE_REG);  /* ISA IRQ 5-15 */
     97
     98	/* make sure keyboard IRQ is disabled */
     99	master_outb(0, KEY_IRQ_ENABLE_REG);
    100}
    101
    102
    103/*
    104 * this stuff doesn't really belong here..
    105 */
    106
    107int ql_ticks;              /* 200Hz ticks since last jiffie */
    108static int sound_ticks;
    109
    110#define SVOL 45
    111
    112void q40_mksound(unsigned int hz, unsigned int ticks)
    113{
    114	/* for now ignore hz, except that hz==0 switches off sound */
    115	/* simply alternate the ampl (128-SVOL)-(128+SVOL)-..-.. at 200Hz */
    116	if (hz == 0) {
    117		if (sound_ticks)
    118			sound_ticks = 1;
    119
    120		*DAC_LEFT = 128;
    121		*DAC_RIGHT = 128;
    122
    123		return;
    124	}
    125	/* sound itself is done in q40_timer_int */
    126	if (sound_ticks == 0)
    127		sound_ticks = 1000; /* pretty long beep */
    128	sound_ticks = ticks << 1;
    129}
    130
    131static irqreturn_t q40_timer_int(int irq, void *dev_id)
    132{
    133	ql_ticks = ql_ticks ? 0 : 1;
    134	if (sound_ticks) {
    135		unsigned char sval=(sound_ticks & 1) ? 128-SVOL : 128+SVOL;
    136		sound_ticks--;
    137		*DAC_LEFT=sval;
    138		*DAC_RIGHT=sval;
    139	}
    140
    141	if (!ql_ticks) {
    142		unsigned long flags;
    143
    144		local_irq_save(flags);
    145		legacy_timer_tick(1);
    146		timer_heartbeat();
    147		local_irq_restore(flags);
    148	}
    149	return IRQ_HANDLED;
    150}
    151
    152void q40_sched_init (void)
    153{
    154	int timer_irq;
    155
    156	timer_irq = Q40_IRQ_FRAME;
    157
    158	if (request_irq(timer_irq, q40_timer_int, 0, "timer", NULL))
    159		panic("Couldn't register timer int");
    160
    161	master_outb(-1, FRAME_CLEAR_REG);
    162	master_outb( 1, FRAME_RATE_REG);
    163}
    164
    165
    166/*
    167 * tables to translate bits into IRQ numbers
    168 * it is a good idea to order the entries by priority
    169 *
    170*/
    171
    172struct IRQ_TABLE{ unsigned mask; int irq ;};
    173#if 0
    174static struct IRQ_TABLE iirqs[]={
    175  {Q40_IRQ_FRAME_MASK,Q40_IRQ_FRAME},
    176  {Q40_IRQ_KEYB_MASK,Q40_IRQ_KEYBOARD},
    177  {0,0}};
    178#endif
    179static struct IRQ_TABLE eirqs[] = {
    180  { .mask = Q40_IRQ3_MASK,	.irq = 3 },	/* ser 1 */
    181  { .mask = Q40_IRQ4_MASK,	.irq = 4 },	/* ser 2 */
    182  { .mask = Q40_IRQ14_MASK,	.irq = 14 },	/* IDE 1 */
    183  { .mask = Q40_IRQ15_MASK,	.irq = 15 },	/* IDE 2 */
    184  { .mask = Q40_IRQ6_MASK,	.irq = 6 },	/* floppy, handled elsewhere */
    185  { .mask = Q40_IRQ7_MASK,	.irq = 7 },	/* par */
    186  { .mask = Q40_IRQ5_MASK,	.irq = 5 },
    187  { .mask = Q40_IRQ10_MASK,	.irq = 10 },
    188  {0,0}
    189};
    190
    191/* complain only this many times about spurious ints : */
    192static int ccleirq=60;    /* ISA dev IRQs*/
    193/*static int cclirq=60;*/     /* internal */
    194
    195/* FIXME: add shared ints,mask,unmask,probing.... */
    196
    197#define IRQ_INPROGRESS 1
    198/*static unsigned short saved_mask;*/
    199//static int do_tint=0;
    200
    201#define DEBUG_Q40INT
    202/*#define IP_USE_DISABLE *//* would be nice, but crashes ???? */
    203
    204static int mext_disabled=0;  /* ext irq disabled by master chip? */
    205static int aliased_irq=0;  /* how many times inside handler ?*/
    206
    207
    208/* got interrupt, dispatch to ISA or keyboard/timer IRQs */
    209static void q40_irq_handler(unsigned int irq, struct pt_regs *fp)
    210{
    211	unsigned mir, mer;
    212	int i;
    213
    214//repeat:
    215	mir = master_inb(IIRQ_REG);
    216#ifdef CONFIG_BLK_DEV_FD
    217	if ((mir & Q40_IRQ_EXT_MASK) &&
    218	    (master_inb(EIRQ_REG) & Q40_IRQ6_MASK)) {
    219		floppy_hardint();
    220		return;
    221	}
    222#endif
    223	switch (irq) {
    224	case 4:
    225	case 6:
    226		do_IRQ(Q40_IRQ_SAMPLE, fp);
    227		return;
    228	}
    229	if (mir & Q40_IRQ_FRAME_MASK) {
    230		do_IRQ(Q40_IRQ_FRAME, fp);
    231		master_outb(-1, FRAME_CLEAR_REG);
    232	}
    233	if ((mir & Q40_IRQ_SER_MASK) || (mir & Q40_IRQ_EXT_MASK)) {
    234		mer = master_inb(EIRQ_REG);
    235		for (i = 0; eirqs[i].mask; i++) {
    236			if (mer & eirqs[i].mask) {
    237				irq = eirqs[i].irq;
    238/*
    239 * There is a little mess wrt which IRQ really caused this irq request. The
    240 * main problem is that IIRQ_REG and EIRQ_REG reflect the state when they
    241 * are read - which is long after the request came in. In theory IRQs should
    242 * not just go away but they occasionally do
    243 */
    244				if (irq > 4 && irq <= 15 && mext_disabled) {
    245					/*aliased_irq++;*/
    246					goto iirq;
    247				}
    248				if (q40_state[irq] & IRQ_INPROGRESS) {
    249					/* some handlers do local_irq_enable() for irq latency reasons, */
    250					/* however reentering an active irq handler is not permitted */
    251#ifdef IP_USE_DISABLE
    252					/* in theory this is the better way to do it because it still */
    253					/* lets through eg the serial irqs, unfortunately it crashes */
    254					disable_irq(irq);
    255					disabled = 1;
    256#else
    257					/*pr_warn("IRQ_INPROGRESS detected for irq %d, disabling - %s disabled\n",
    258						irq, disabled ? "already" : "not yet"); */
    259					fp->sr = (((fp->sr) & (~0x700))+0x200);
    260					disabled = 1;
    261#endif
    262					goto iirq;
    263				}
    264				q40_state[irq] |= IRQ_INPROGRESS;
    265				do_IRQ(irq, fp);
    266				q40_state[irq] &= ~IRQ_INPROGRESS;
    267
    268				/* naively enable everything, if that fails than    */
    269				/* this function will be reentered immediately thus */
    270				/* getting another chance to disable the IRQ        */
    271
    272				if (disabled) {
    273#ifdef IP_USE_DISABLE
    274					if (irq > 4) {
    275						disabled = 0;
    276						enable_irq(irq);
    277					}
    278#else
    279					disabled = 0;
    280					/*pr_info("reenabling irq %d\n", irq); */
    281#endif
    282				}
    283// used to do 'goto repeat;' here, this delayed bh processing too long
    284				return;
    285			}
    286		}
    287		if (mer && ccleirq > 0 && !aliased_irq) {
    288			pr_warn("ISA interrupt from unknown source? EIRQ_REG = %x\n",
    289				mer);
    290			ccleirq--;
    291		}
    292	}
    293 iirq:
    294	mir = master_inb(IIRQ_REG);
    295	/* should test whether keyboard irq is really enabled, doing it in defhand */
    296	if (mir & Q40_IRQ_KEYB_MASK)
    297		do_IRQ(Q40_IRQ_KEYBOARD, fp);
    298
    299	return;
    300}
    301
    302void q40_irq_enable(struct irq_data *data)
    303{
    304	unsigned int irq = data->irq;
    305
    306	if (irq >= 5 && irq <= 15) {
    307		mext_disabled--;
    308		if (mext_disabled > 0)
    309			pr_warn("q40_irq_enable : nested disable/enable\n");
    310		if (mext_disabled == 0)
    311			master_outb(1, EXT_ENABLE_REG);
    312	}
    313}
    314
    315
    316void q40_irq_disable(struct irq_data *data)
    317{
    318	unsigned int irq = data->irq;
    319
    320	/* disable ISA iqs : only do something if the driver has been
    321	 * verified to be Q40 "compatible" - right now IDE, NE2K
    322	 * Any driver should not attempt to sleep across disable_irq !!
    323	 */
    324
    325	if (irq >= 5 && irq <= 15) {
    326		master_outb(0, EXT_ENABLE_REG);
    327		mext_disabled++;
    328		if (mext_disabled > 1)
    329			pr_info("disable_irq nesting count %d\n",
    330				mext_disabled);
    331	}
    332}