bc0a733fac
x86: define outb_pic and inb_pic to stop using outb_p and inb_p The delay between io port accesses to the PIC is now defined using outb_pic and inb_pic. This fix provides the next step, using udelay(2) to define the *PIC specific* timing requirements, rather than on bus-oriented timing, which is not well calibrated. Again, the primary reason for fixing this is to use proper delay strategy, and in particular to fix crashes that can result from using port 80 writes on machines that have resources on port 80, such as the ENE chips used by Quanta in latops it designs and sells to, e.g. HP. Signed-off-by: David P. Reed <dpreed@reed.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
58 lines
1.5 KiB
C
58 lines
1.5 KiB
C
#ifndef __ASM_I8259_H__
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#define __ASM_I8259_H__
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#include <linux/delay.h>
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extern unsigned int cached_irq_mask;
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#define __byte(x,y) (((unsigned char *) &(y))[x])
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#define cached_master_mask (__byte(0, cached_irq_mask))
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#define cached_slave_mask (__byte(1, cached_irq_mask))
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/* i8259A PIC registers */
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#define PIC_MASTER_CMD 0x20
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#define PIC_MASTER_IMR 0x21
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#define PIC_MASTER_ISR PIC_MASTER_CMD
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#define PIC_MASTER_POLL PIC_MASTER_ISR
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#define PIC_MASTER_OCW3 PIC_MASTER_ISR
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#define PIC_SLAVE_CMD 0xa0
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#define PIC_SLAVE_IMR 0xa1
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/* i8259A PIC related value */
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#define PIC_CASCADE_IR 2
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#define MASTER_ICW4_DEFAULT 0x01
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#define SLAVE_ICW4_DEFAULT 0x01
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#define PIC_ICW4_AEOI 2
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extern spinlock_t i8259A_lock;
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extern void init_8259A(int auto_eoi);
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extern void enable_8259A_irq(unsigned int irq);
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extern void disable_8259A_irq(unsigned int irq);
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extern unsigned int startup_8259A_irq(unsigned int irq);
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/* the PIC may need a careful delay on some platforms, hence specific calls */
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static inline unsigned char inb_pic(unsigned int port)
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{
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unsigned char value = inb(port);
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/*
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* delay for some accesses to PIC on motherboard or in chipset
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* must be at least one microsecond, so be safe here:
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*/
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udelay(2);
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return value;
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}
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static inline void outb_pic(unsigned char value, unsigned int port)
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{
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outb(value, port);
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/*
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* delay for some accesses to PIC on motherboard or in chipset
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* must be at least one microsecond, so be safe here:
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*/
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udelay(2);
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}
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#endif /* __ASM_I8259_H__ */
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