linux_dsm_epyc7002/arch/m68k/atari/ataints.c
Finn Thain 1efdd4bd25 m68k: Call timer_interrupt() with interrupts disabled
Some platforms execute their timer handler with the interrupt priority
level set below 6. That means the handler could be interrupted by another
driver and this could lead to re-entry of the timer core.

Avoid this by use of local_irq_save/restore for timer interrupt dispatch.
This provides mutual exclusion around the timer interrupt flag access
which is needed later in this series for the clocksource conversion.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1811131407120.2697@nanos.tec.linutronix.de
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2019-03-25 10:22:24 +01:00

392 lines
10 KiB
C

/*
* 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 <linux/module.h>
#include <linux/irq.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>
#include <asm/io.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().
*/
/*
* 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;
/* 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");
extern void atari_microwire_cmd(int cmd);
static unsigned int atari_irq_startup(struct irq_data *data)
{
unsigned int irq = data->irq;
m68k_irq_startup(data);
atari_turnon_irq(irq);
atari_enable_irq(irq);
return 0;
}
static void atari_irq_shutdown(struct irq_data *data)
{
unsigned int irq = data->irq;
atari_disable_irq(irq);
atari_turnoff_irq(irq);
m68k_irq_shutdown(data);
if (irq == IRQ_AUTO_4)
vectors[VEC_INT4] = falcon_hblhandler;
}
static void atari_irq_enable(struct irq_data *data)
{
atari_enable_irq(data->irq);
}
static void atari_irq_disable(struct irq_data *data)
{
atari_disable_irq(data->irq);
}
static struct irq_chip atari_irq_chip = {
.name = "atari",
.irq_startup = atari_irq_startup,
.irq_shutdown = atari_irq_shutdown,
.irq_enable = atari_irq_enable,
.irq_disable = atari_irq_disable,
};
/*
* ST-MFP timer D chained interrupts - each driver gets its own timer
* interrupt instance.
*/
struct mfptimerbase {
volatile struct MFP *mfp;
unsigned char mfp_mask, mfp_data;
unsigned short int_mask;
int handler_irq, mfptimer_irq, server_irq;
char *name;
} stmfp_base = {
.mfp = &st_mfp,
.int_mask = 0x0,
.handler_irq = IRQ_MFP_TIMD,
.mfptimer_irq = IRQ_MFP_TIMER1,
.name = "MFP Timer D"
};
static irqreturn_t mfp_timer_d_handler(int irq, void *dev_id)
{
struct mfptimerbase *base = dev_id;
int mach_irq;
unsigned char ints;
mach_irq = base->mfptimer_irq;
ints = base->int_mask;
for (; ints; mach_irq++, ints >>= 1) {
if (ints & 1)
generic_handle_irq(mach_irq);
}
return IRQ_HANDLED;
}
static void atari_mfptimer_enable(struct irq_data *data)
{
int mfp_num = data->irq - IRQ_MFP_TIMER1;
stmfp_base.int_mask |= 1 << mfp_num;
atari_enable_irq(IRQ_MFP_TIMD);
}
static void atari_mfptimer_disable(struct irq_data *data)
{
int mfp_num = data->irq - IRQ_MFP_TIMER1;
stmfp_base.int_mask &= ~(1 << mfp_num);
if (!stmfp_base.int_mask)
atari_disable_irq(IRQ_MFP_TIMD);
}
static struct irq_chip atari_mfptimer_chip = {
.name = "timer_d",
.irq_enable = atari_mfptimer_enable,
.irq_disable = atari_mfptimer_disable,
};
/*
* EtherNAT CPLD interrupt handling
* CPLD interrupt register is at phys. 0x80000023
* Need this mapped in at interrupt startup time
* Possibly need this mapped on demand anyway -
* EtherNAT USB driver needs to disable IRQ before
* startup!
*/
static unsigned char *enat_cpld;
static unsigned int atari_ethernat_startup(struct irq_data *data)
{
int enat_num = 140 - data->irq + 1;
m68k_irq_startup(data);
/*
* map CPLD interrupt register
*/
if (!enat_cpld)
enat_cpld = (unsigned char *)ioremap((ATARI_ETHERNAT_PHYS_ADDR+0x23), 0x2);
/*
* do _not_ enable the USB chip interrupt here - causes interrupt storm
* and triggers dead interrupt watchdog
* Need to reset the USB chip to a sane state in early startup before
* removing this hack
*/
if (enat_num == 1)
*enat_cpld |= 1 << enat_num;
return 0;
}
static void atari_ethernat_enable(struct irq_data *data)
{
int enat_num = 140 - data->irq + 1;
/*
* map CPLD interrupt register
*/
if (!enat_cpld)
enat_cpld = (unsigned char *)ioremap((ATARI_ETHERNAT_PHYS_ADDR+0x23), 0x2);
*enat_cpld |= 1 << enat_num;
}
static void atari_ethernat_disable(struct irq_data *data)
{
int enat_num = 140 - data->irq + 1;
/*
* map CPLD interrupt register
*/
if (!enat_cpld)
enat_cpld = (unsigned char *)ioremap((ATARI_ETHERNAT_PHYS_ADDR+0x23), 0x2);
*enat_cpld &= ~(1 << enat_num);
}
static void atari_ethernat_shutdown(struct irq_data *data)
{
int enat_num = 140 - data->irq + 1;
if (enat_cpld) {
*enat_cpld &= ~(1 << enat_num);
iounmap(enat_cpld);
enat_cpld = NULL;
}
}
static struct irq_chip atari_ethernat_chip = {
.name = "ethernat",
.irq_startup = atari_ethernat_startup,
.irq_shutdown = atari_ethernat_shutdown,
.irq_enable = atari_ethernat_enable,
.irq_disable = atari_ethernat_disable,
};
/*
* 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)
{
m68k_setup_user_interrupt(VEC_USER, NUM_ATARI_SOURCES - IRQ_USER);
m68k_setup_irq_controller(&atari_irq_chip, handle_simple_irq, 1,
NUM_ATARI_SOURCES - 1);
/* Initialize the MFP(s) */
#ifdef ATARI_USE_SOFTWARE_EOI
st_mfp.vec_adr = 0x48; /* Software EOI-Mode */
#else
st_mfp.vec_adr = 0x40; /* Automatic EOI-Mode */
#endif
st_mfp.int_en_a = 0x00; /* turn off MFP-Ints */
st_mfp.int_en_b = 0x00;
st_mfp.int_mk_a = 0xff; /* no Masking */
st_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) {
atari_scc.cha_a_ctrl = 9;
MFPDELAY();
atari_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)
*/
vectors[VEC_INT2] = falcon_hblhandler;
vectors[VEC_INT4] = 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;
m68k_setup_irq_controller(&atari_mfptimer_chip, handle_simple_irq,
IRQ_MFP_TIMER1, 8);
irq_set_status_flags(IRQ_MFP_TIMER1, IRQ_IS_POLLED);
irq_set_status_flags(IRQ_MFP_TIMER2, IRQ_IS_POLLED);
/* prepare timer D data for use as poll interrupt */
/* set Timer D data Register - needs to be > 0 */
st_mfp.tim_dt_d = 254; /* < 100 Hz */
/* start timer D, div = 1:100 */
st_mfp.tim_ct_cd = (st_mfp.tim_ct_cd & 0xf0) | 0x6;
/* request timer D dispatch handler */
if (request_irq(IRQ_MFP_TIMD, mfp_timer_d_handler, IRQF_SHARED,
stmfp_base.name, &stmfp_base))
pr_err("Couldn't register %s interrupt\n", stmfp_base.name);
/*
* EtherNAT ethernet / USB interrupt handlers
*/
m68k_setup_irq_controller(&atari_ethernat_chip, handle_simple_irq,
139, 2);
}
/*
* atari_register_vme_int() returns the number of a free interrupt vector for
* hardware with a programmable int vector (probably a VME board).
*/
unsigned int 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;
}
EXPORT_SYMBOL(atari_register_vme_int);
void atari_unregister_vme_int(unsigned int irq)
{
if (irq >= VME_SOURCE_BASE && irq < VME_SOURCE_BASE + VME_MAX_SOURCES) {
irq -= VME_SOURCE_BASE;
free_vme_vec_bitmap &= ~(1 << irq);
}
}
EXPORT_SYMBOL(atari_unregister_vme_int);