Ripped out everything except the ability to send EOI to the PIC.
This commit is contained in:
Michael Brown
parent
de2fc50f4c
commit
b12cd68726
|
|
@ -1,263 +1,37 @@
|
|||
/*
|
||||
* Basic support for controlling the 8259 Programmable Interrupt Controllers.
|
||||
* Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
|
||||
*
|
||||
* Initially written by Michael Brown (mcb30).
|
||||
*/
|
||||
|
||||
#include <etherboot.h>
|
||||
#include "pic8259.h"
|
||||
#include "old_realmode.h"
|
||||
|
||||
/* State of trivial IRQ handler */
|
||||
irq_t trivial_irq_installed_on = IRQ_NONE;
|
||||
static uint16_t trivial_irq_previous_trigger_count = 0;
|
||||
|
||||
/* The actual trivial IRQ handler
|
||||
* This program is free software; you can redistribute it and/or
|
||||
* modify it under the terms of the GNU General Public License as
|
||||
* published by the Free Software Foundation; either version 2 of the
|
||||
* License, or any later version.
|
||||
*
|
||||
* Note: we depend on the C compiler not realising that we're putting
|
||||
* variables in the ".text16" section and therefore not forcing them
|
||||
* back to the ".data" section. I don't see any reason to expect this
|
||||
* behaviour to change.
|
||||
* This program is distributed in the hope that it will be useful, but
|
||||
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||||
* General Public License for more details.
|
||||
*
|
||||
* These must *not* be the first variables to appear in this file; the
|
||||
* first variable to appear gets the ".data" directive.
|
||||
*/
|
||||
RM_FRAGMENT(_trivial_irq_handler,
|
||||
"pushw %bx\n\t"
|
||||
"call 1f\n1:\tpopw %bx\n\t" /* PIC access to variables */
|
||||
"incw %cs:(_trivial_irq_trigger_count-1b)(%bx)\n\t"
|
||||
"popw %bx\n\t"
|
||||
"iret\n\t"
|
||||
"\n\t"
|
||||
".globl _trivial_irq_trigger_count\n\t"
|
||||
"_trivial_irq_trigger_count: .short 0\n\t"
|
||||
"\n\t"
|
||||
".globl _trivial_irq_chain_to\n\t"
|
||||
"_trivial_irq_chain_to: .short 0,0\n\t"
|
||||
"\n\t"
|
||||
".globl _trivial_irq_chain\n\t"
|
||||
"_trivial_irq_chain: .byte 0\n\t"
|
||||
);
|
||||
extern volatile uint16_t _trivial_irq_trigger_count;
|
||||
extern segoff_t _trivial_irq_chain_to;
|
||||
extern int8_t _trivial_irq_chain;
|
||||
|
||||
/* Current locations of trivial IRQ handler. These will change at
|
||||
* runtime when relocation is used; the handler needs to be copied to
|
||||
* base memory before being installed.
|
||||
*/
|
||||
void (*trivial_irq_handler)P((void)) = _trivial_irq_handler;
|
||||
uint16_t volatile *trivial_irq_trigger_count = &_trivial_irq_trigger_count;
|
||||
segoff_t *trivial_irq_chain_to = &_trivial_irq_chain_to;
|
||||
uint8_t *trivial_irq_chain = &_trivial_irq_chain;
|
||||
|
||||
/* Install a handler for the specified IRQ. Address of previous
|
||||
* handler will be stored in previous_handler. Enabled/disabled state
|
||||
* of IRQ will be preserved across call, therefore if the handler does
|
||||
* chaining, ensure that either (a) IRQ is disabled before call, or
|
||||
* (b) previous_handler points directly to the place that the handler
|
||||
* picks up its chain-to address.
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program; if not, write to the Free Software
|
||||
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
||||
*/
|
||||
|
||||
int install_irq_handler ( irq_t irq, segoff_t *handler,
|
||||
uint8_t *previously_enabled,
|
||||
segoff_t *previous_handler ) {
|
||||
segoff_t *irq_vector = IRQ_VECTOR ( irq );
|
||||
*previously_enabled = irq_enabled ( irq );
|
||||
#include <pic8259.h>
|
||||
|
||||
if ( irq > IRQ_MAX ) {
|
||||
DBG ( "Invalid IRQ number %d\n" );
|
||||
return 0;
|
||||
}
|
||||
|
||||
previous_handler->segment = irq_vector->segment;
|
||||
previous_handler->offset = irq_vector->offset;
|
||||
if ( *previously_enabled ) disable_irq ( irq );
|
||||
DBG ( "Installing handler at %hx:%hx for IRQ %d (vector 0000:%hx),"
|
||||
" leaving %s\n",
|
||||
handler->segment, handler->offset, irq, virt_to_phys(irq_vector),
|
||||
( *previously_enabled ? "enabled" : "disabled" ) );
|
||||
DBG ( "...(previous handler at %hx:%hx)\n",
|
||||
previous_handler->segment, previous_handler->offset );
|
||||
irq_vector->segment = handler->segment;
|
||||
irq_vector->offset = handler->offset;
|
||||
if ( *previously_enabled ) enable_irq ( irq );
|
||||
return 1;
|
||||
}
|
||||
|
||||
/* Remove handler for the specified IRQ. Routine checks that another
|
||||
* handler has not been installed that chains to handler before
|
||||
* uninstalling handler. Enabled/disabled state of the IRQ will be
|
||||
* restored to that specified by previously_enabled.
|
||||
*/
|
||||
|
||||
int remove_irq_handler ( irq_t irq, segoff_t *handler,
|
||||
uint8_t *previously_enabled,
|
||||
segoff_t *previous_handler ) {
|
||||
segoff_t *irq_vector = IRQ_VECTOR ( irq );
|
||||
|
||||
if ( irq > IRQ_MAX ) {
|
||||
DBG ( "Invalid IRQ number %d\n" );
|
||||
return 0;
|
||||
}
|
||||
if ( ( irq_vector->segment != handler->segment ) ||
|
||||
( irq_vector->offset != handler->offset ) ) {
|
||||
DBG ( "Cannot remove handler for IRQ %d\n" );
|
||||
return 0;
|
||||
}
|
||||
|
||||
DBG ( "Removing handler for IRQ %d\n", irq );
|
||||
disable_irq ( irq );
|
||||
irq_vector->segment = previous_handler->segment;
|
||||
irq_vector->offset = previous_handler->offset;
|
||||
if ( *previously_enabled ) enable_irq ( irq );
|
||||
return 1;
|
||||
}
|
||||
|
||||
/* Install the trivial IRQ handler. This routine installs the
|
||||
* handler, tests it and enables the IRQ.
|
||||
*/
|
||||
|
||||
int install_trivial_irq_handler ( irq_t irq ) {
|
||||
segoff_t trivial_irq_handler_segoff = SEGOFF(trivial_irq_handler);
|
||||
|
||||
if ( trivial_irq_installed_on != IRQ_NONE ) {
|
||||
DBG ( "Can install trivial IRQ handler only once\n" );
|
||||
return 0;
|
||||
}
|
||||
if ( SEGMENT(trivial_irq_handler) > 0xffff ) {
|
||||
DBG ( "Trivial IRQ handler not in base memory\n" );
|
||||
return 0;
|
||||
}
|
||||
|
||||
DBG ( "Installing trivial IRQ handler on IRQ %d\n", irq );
|
||||
if ( ! install_irq_handler ( irq, &trivial_irq_handler_segoff,
|
||||
trivial_irq_chain,
|
||||
trivial_irq_chain_to ) )
|
||||
return 0;
|
||||
trivial_irq_installed_on = irq;
|
||||
|
||||
DBG ( "Testing trivial IRQ handler\n" );
|
||||
disable_irq ( irq );
|
||||
*trivial_irq_trigger_count = 0;
|
||||
trivial_irq_previous_trigger_count = 0;
|
||||
fake_irq ( irq );
|
||||
if ( ! trivial_irq_triggered ( irq ) ) {
|
||||
DBG ( "Installation of trivial IRQ handler failed\n" );
|
||||
remove_trivial_irq_handler ( irq );
|
||||
return 0;
|
||||
}
|
||||
/* Send EOI just in case there was a leftover interrupt */
|
||||
send_specific_eoi ( irq );
|
||||
DBG ( "Trivial IRQ handler installed successfully\n" );
|
||||
enable_irq ( irq );
|
||||
return 1;
|
||||
}
|
||||
|
||||
/* Remove the trivial IRQ handler.
|
||||
*/
|
||||
|
||||
int remove_trivial_irq_handler ( irq_t irq ) {
|
||||
segoff_t trivial_irq_handler_segoff = SEGOFF(trivial_irq_handler);
|
||||
|
||||
if ( trivial_irq_installed_on == IRQ_NONE ) return 1;
|
||||
if ( irq != trivial_irq_installed_on ) {
|
||||
DBG ( "Cannot uninstall trivial IRQ handler from IRQ %d; "
|
||||
"is installed on IRQ %d\n", irq,
|
||||
trivial_irq_installed_on );
|
||||
return 0;
|
||||
}
|
||||
|
||||
if ( ! remove_irq_handler ( irq, &trivial_irq_handler_segoff,
|
||||
trivial_irq_chain,
|
||||
trivial_irq_chain_to ) )
|
||||
return 0;
|
||||
|
||||
if ( trivial_irq_triggered ( trivial_irq_installed_on ) ) {
|
||||
DBG ( "Sending EOI for unwanted trivial IRQ\n" );
|
||||
send_specific_eoi ( trivial_irq_installed_on );
|
||||
}
|
||||
|
||||
trivial_irq_installed_on = IRQ_NONE;
|
||||
return 1;
|
||||
}
|
||||
|
||||
/* Safe method to detect whether or not trivial IRQ has been
|
||||
* triggered. Using this call avoids potential race conditions. This
|
||||
* call will return success only once per trigger.
|
||||
*/
|
||||
|
||||
int trivial_irq_triggered ( irq_t irq ) {
|
||||
uint16_t trivial_irq_this_trigger_count = *trivial_irq_trigger_count;
|
||||
int triggered = ( trivial_irq_this_trigger_count -
|
||||
trivial_irq_previous_trigger_count );
|
||||
|
||||
/* irq is not used at present, but we have it in the API for
|
||||
* future-proofing; in case we want the facility to have
|
||||
* multiple trivial IRQ handlers installed simultaneously.
|
||||
*
|
||||
* Avoid compiler warning about unused variable.
|
||||
*/
|
||||
if ( irq == IRQ_NONE ) {};
|
||||
|
||||
trivial_irq_previous_trigger_count = trivial_irq_this_trigger_count;
|
||||
return triggered ? 1 : 0;
|
||||
}
|
||||
|
||||
/* Copy trivial IRQ handler to a new location. Typically used to copy
|
||||
* the handler into base memory; when relocation is being used we need
|
||||
* to do this before installing the handler.
|
||||
/** @file
|
||||
*
|
||||
* Minimal support for the 8259 Programmable Interrupt Controller
|
||||
*
|
||||
* Call with target=NULL in order to restore the handler to its
|
||||
* original location.
|
||||
*/
|
||||
|
||||
int copy_trivial_irq_handler ( void *target, size_t target_size ) {
|
||||
irq_t currently_installed_on = trivial_irq_installed_on;
|
||||
uint32_t offset = ( target == NULL ? 0 :
|
||||
target - (void*)_trivial_irq_handler );
|
||||
|
||||
if (( target != NULL ) && ( target_size < TRIVIAL_IRQ_HANDLER_SIZE )) {
|
||||
DBG ( "Insufficient space to copy trivial IRQ handler\n" );
|
||||
return 0;
|
||||
}
|
||||
|
||||
if ( currently_installed_on != IRQ_NONE ) {
|
||||
DBG ("WARNING: relocating trivial IRQ handler while in use\n");
|
||||
if ( ! remove_trivial_irq_handler ( currently_installed_on ) )
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* Do the actual copy */
|
||||
if ( target != NULL ) {
|
||||
DBG ( "Copying trivial IRQ handler to %hx:%hx\n",
|
||||
SEGMENT(target), OFFSET(target) );
|
||||
memcpy ( target, _trivial_irq_handler,
|
||||
TRIVIAL_IRQ_HANDLER_SIZE );
|
||||
} else {
|
||||
DBG ( "Restoring trivial IRQ handler to original location\n" );
|
||||
}
|
||||
/* Update all the pointers to structures within the handler */
|
||||
trivial_irq_handler = ( void (*)P((void)) )
|
||||
( (void*)_trivial_irq_handler + offset );
|
||||
trivial_irq_trigger_count = (uint16_t*)
|
||||
( (void*)&_trivial_irq_trigger_count + offset );
|
||||
trivial_irq_chain_to = (segoff_t*)
|
||||
( (void*)&_trivial_irq_chain_to + offset );
|
||||
trivial_irq_chain = (uint8_t*)
|
||||
( (void*)&_trivial_irq_chain + offset );
|
||||
|
||||
if ( currently_installed_on != IRQ_NONE ) {
|
||||
if ( ! install_trivial_irq_handler ( currently_installed_on ) )
|
||||
return 0;
|
||||
}
|
||||
return 1;
|
||||
}
|
||||
|
||||
/* Send non-specific EOI(s). This seems to be inherently unsafe.
|
||||
/**
|
||||
* Send non-specific EOI(s)
|
||||
*
|
||||
* @v irq IRQ number
|
||||
*
|
||||
* This seems to be inherently unsafe.
|
||||
*/
|
||||
|
||||
void send_nonspecific_eoi ( irq_t irq ) {
|
||||
static inline void send_nonspecific_eoi ( unsigned int irq ) {
|
||||
DBG ( "Sending non-specific EOI for IRQ %d\n", irq );
|
||||
if ( irq >= IRQ_PIC_CUTOFF ) {
|
||||
outb ( ICR_EOI_NON_SPECIFIC, PIC2_ICR );
|
||||
|
|
@ -265,61 +39,25 @@ void send_nonspecific_eoi ( irq_t irq ) {
|
|||
outb ( ICR_EOI_NON_SPECIFIC, PIC1_ICR );
|
||||
}
|
||||
|
||||
/* Send specific EOI(s).
|
||||
/**
|
||||
* Send specific EOI(s)
|
||||
*
|
||||
* @v irq IRQ number
|
||||
*/
|
||||
|
||||
void send_specific_eoi ( irq_t irq ) {
|
||||
static inline void send_specific_eoi ( unsigned int irq ) {
|
||||
DBG ( "Sending specific EOI for IRQ %d\n", irq );
|
||||
outb ( ICR_EOI_SPECIFIC | ICR_VALUE(irq), ICR_REG(irq) );
|
||||
outb ( ( ICR_EOI_SPECIFIC | ICR_VALUE ( irq ) ), ICR_REG ( irq ) );
|
||||
if ( irq >= IRQ_PIC_CUTOFF ) {
|
||||
outb ( ICR_EOI_SPECIFIC | ICR_VALUE(CHAINED_IRQ),
|
||||
ICR_REG(CHAINED_IRQ) );
|
||||
outb ( ( ICR_EOI_SPECIFIC | ICR_VALUE ( CHAINED_IRQ ) ),
|
||||
ICR_REG ( CHAINED_IRQ ) );
|
||||
}
|
||||
}
|
||||
|
||||
/* Fake an IRQ
|
||||
/**
|
||||
* Send End-Of-Interrupt to the PIC
|
||||
*
|
||||
* @v irq IRQ number
|
||||
*/
|
||||
|
||||
void fake_irq ( irq_t irq ) {
|
||||
struct {
|
||||
uint16_t int_number;
|
||||
} PACKED in_stack;
|
||||
|
||||
/* Convert IRQ to INT number:
|
||||
*
|
||||
* subb $0x08,%cl Invert bit 3, set bits 4-7 iff irq < 8
|
||||
* xorb $0x70,%cl Invert bits 4-6
|
||||
* andb $0x7f,%cl Clear bit 7
|
||||
*
|
||||
* No, it's not the most intuitive method, but I was proud to
|
||||
* get it down to three lines of assembler when this routine
|
||||
* was originally implemented in pcbios.S.
|
||||
*/
|
||||
in_stack.int_number = ( ( irq - 8 ) ^ 0x70 ) & 0x7f;
|
||||
|
||||
RM_FRAGMENT(rm_fake_irq,
|
||||
"popw %ax\n\t" /* %ax = INT number */
|
||||
"call 1f\n1:\tpop %bx\n\t"
|
||||
"movb %al, %cs:(2f-1b+1)(%bx)\n\t" /* Overwrite INT number..*/
|
||||
"\n2:\tint $0x00\n\t" /* ..in this instruction */
|
||||
);
|
||||
|
||||
real_call ( rm_fake_irq, &in_stack, NULL );
|
||||
void send_eoi ( unsigned int irq ) {
|
||||
send_specific_eoi ( irq );
|
||||
}
|
||||
|
||||
/* Dump current 8259 status: enabled IRQs and handler addresses.
|
||||
*/
|
||||
|
||||
#ifdef DEBUG_IRQ
|
||||
void dump_irq_status ( void ) {
|
||||
int irq = 0;
|
||||
|
||||
for ( irq = 0; irq < 16; irq++ ) {
|
||||
if ( irq_enabled ( irq ) ) {
|
||||
printf ( "IRQ%d enabled, ISR at %hx:%hx\n", irq,
|
||||
IRQ_VECTOR(irq)->segment,
|
||||
IRQ_VECTOR(irq)->offset );
|
||||
}
|
||||
}
|
||||
}
|
||||
#endif
|
||||
|
|
|
|||
|
|
@ -10,38 +10,38 @@
|
|||
/* For segoff_t */
|
||||
#include "realmode.h"
|
||||
|
||||
#define IRQ_PIC_CUTOFF (8)
|
||||
#define IRQ_PIC_CUTOFF 8
|
||||
|
||||
/* 8259 register locations */
|
||||
#define PIC1_ICW1 (0x20)
|
||||
#define PIC1_OCW2 (0x20)
|
||||
#define PIC1_OCW3 (0x20)
|
||||
#define PIC1_ICR (0x20)
|
||||
#define PIC1_IRR (0x20)
|
||||
#define PIC1_ISR (0x20)
|
||||
#define PIC1_ICW2 (0x21)
|
||||
#define PIC1_ICW3 (0x21)
|
||||
#define PIC1_ICW4 (0x21)
|
||||
#define PIC1_IMR (0x21)
|
||||
#define PIC2_ICW1 (0xa0)
|
||||
#define PIC2_OCW2 (0xa0)
|
||||
#define PIC2_OCW3 (0xa0)
|
||||
#define PIC2_ICR (0xa0)
|
||||
#define PIC2_IRR (0xa0)
|
||||
#define PIC2_ISR (0xa0)
|
||||
#define PIC2_ICW2 (0xa1)
|
||||
#define PIC2_ICW3 (0xa1)
|
||||
#define PIC2_ICW4 (0xa1)
|
||||
#define PIC2_IMR (0xa1)
|
||||
#define PIC1_ICW1 0x20
|
||||
#define PIC1_OCW2 0x20
|
||||
#define PIC1_OCW3 0x20
|
||||
#define PIC1_ICR 0x20
|
||||
#define PIC1_IRR 0x20
|
||||
#define PIC1_ISR 0x20
|
||||
#define PIC1_ICW2 0x21
|
||||
#define PIC1_ICW3 0x21
|
||||
#define PIC1_ICW4 0x21
|
||||
#define PIC1_IMR 0x21
|
||||
#define PIC2_ICW1 0xa0
|
||||
#define PIC2_OCW2 0xa0
|
||||
#define PIC2_OCW3 0xa0
|
||||
#define PIC2_ICR 0xa0
|
||||
#define PIC2_IRR 0xa0
|
||||
#define PIC2_ISR 0xa0
|
||||
#define PIC2_ICW2 0xa1
|
||||
#define PIC2_ICW3 0xa1
|
||||
#define PIC2_ICW4 0xa1
|
||||
#define PIC2_IMR 0xa1
|
||||
|
||||
/* Register command values */
|
||||
#define OCW3_ID (0x08)
|
||||
#define OCW3_READ_IRR (0x03)
|
||||
#define OCW3_READ_ISR (0x02)
|
||||
#define ICR_EOI_NON_SPECIFIC (0x20)
|
||||
#define ICR_EOI_NOP (0x40)
|
||||
#define ICR_EOI_SPECIFIC (0x60)
|
||||
#define ICR_EOI_SET_PRIORITY (0xc0)
|
||||
#define OCW3_ID 0x08
|
||||
#define OCW3_READ_IRR 0x03
|
||||
#define OCW3_READ_ISR 0x02
|
||||
#define ICR_EOI_NON_SPECIFIC 0x20
|
||||
#define ICR_EOI_NOP 0x40
|
||||
#define ICR_EOI_SPECIFIC 0x60
|
||||
#define ICR_EOI_SET_PRIORITY 0xc0
|
||||
|
||||
/* Macros to enable/disable IRQs */
|
||||
#define IMR_REG(x) ( (x) < IRQ_PIC_CUTOFF ? PIC1_IMR : PIC2_IMR )
|
||||
|
|
@ -51,46 +51,19 @@
|
|||
#define disable_irq(x) outb ( inb( IMR_REG(x) ) | IMR_BIT(x), IMR_REG(x) )
|
||||
|
||||
/* Macros for acknowledging IRQs */
|
||||
#define ICR_REG(x) ( (x) < IRQ_PIC_CUTOFF ? PIC1_ICR : PIC2_ICR )
|
||||
#define ICR_VALUE(x) ( (x) % IRQ_PIC_CUTOFF )
|
||||
#define ICR_REG( irq ) ( (irq) < IRQ_PIC_CUTOFF ? PIC1_ICR : PIC2_ICR )
|
||||
#define ICR_VALUE( irq ) ( (irq) % IRQ_PIC_CUTOFF )
|
||||
#define CHAINED_IRQ 2
|
||||
|
||||
/* Utility macros to convert IRQ numbers to INT numbers and INT vectors */
|
||||
#define IRQ_INT(x) ( (x)<IRQ_PIC_CUTOFF ? (x)+0x08 : (x)-IRQ_PIC_CUTOFF+0x70 )
|
||||
#define INT_VECTOR(x) ( (segoff_t*) phys_to_virt( 4 * (x) ) )
|
||||
#define IRQ_VECTOR(x) ( INT_VECTOR ( IRQ_INT(x) ) )
|
||||
#define IRQ_INT( irq ) ( ( ( (irq) - IRQ_PIC_CUTOFF ) ^ 0x70 ) & 0x7f )
|
||||
|
||||
/* Other constants */
|
||||
typedef uint8_t irq_t;
|
||||
#define IRQ_MAX (15)
|
||||
#define IRQ_NONE (0xff)
|
||||
#define IRQ_MAX 15
|
||||
#define IRQ_NONE -1U
|
||||
|
||||
/* Function prototypes
|
||||
*/
|
||||
int install_irq_handler ( irq_t irq, segoff_t *handler,
|
||||
uint8_t *previously_enabled,
|
||||
segoff_t *previous_handler );
|
||||
int remove_irq_handler ( irq_t irq, segoff_t *handler,
|
||||
uint8_t *previously_enabled,
|
||||
segoff_t *previous_handler );
|
||||
int install_trivial_irq_handler ( irq_t irq );
|
||||
int remove_trivial_irq_handler ( irq_t irq );
|
||||
int trivial_irq_triggered ( irq_t irq );
|
||||
int copy_trivial_irq_handler ( void *target, size_t target_size );
|
||||
void send_non_specific_eoi ( irq_t irq );
|
||||
void send_specific_eoi ( irq_t irq );
|
||||
void fake_irq ( irq_t irq );
|
||||
#ifdef DEBUG_IRQ
|
||||
void dump_irq_status ( void );
|
||||
#else
|
||||
#define dump_irq_status()
|
||||
#endif
|
||||
|
||||
/* Other code (e.g. undi.c) needs to know the size of the trivial IRQ
|
||||
* handler code, so we put prototypes and the size macro here.
|
||||
*/
|
||||
extern void _trivial_irq_handler ( void );
|
||||
extern char _trivial_irq_handler_size[];
|
||||
#define TRIVIAL_IRQ_HANDLER_SIZE FRAGMENT_SIZE(_trivial_irq_handler)
|
||||
void send_eoi ( unsigned int irq );
|
||||
|
||||
#endif /* PIC8259_H */
|
||||
|
|
|
|||
Reference in New Issue