floppy.h

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/*
 * Architecture specific parts of the Floppy driver
 *
 * 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.
 *
 * Copyright (C) 1995
 */
#ifndef _ASM_X86_FLOPPY_H
#define _ASM_X86_FLOPPY_H

#include <linux/vmalloc.h>

/*
 * The DMA channel used by the floppy controller cannot access data at
 * addresses >= 16MB
 *
 * Went back to the 1MB limit, as some people had problems with the floppy
 * driver otherwise. It doesn't matter much for performance anyway, as most
 * floppy accesses go through the track buffer.
 */
#define _CROSS_64KB(a, s, vdma)                     \
    (!(vdma) &&                         \
     ((unsigned long)(a)/K_64 != ((unsigned long)(a) + (s) - 1) / K_64))

#define CROSS_64KB(a, s) _CROSS_64KB(a, s, use_virtual_dma & 1)


#define SW fd_routine[use_virtual_dma & 1]
#define CSW fd_routine[can_use_virtual_dma & 1]


#define fd_inb(port)        inb_p(port)
#define fd_outb(value, port)    outb_p(value, port)

#define fd_request_dma()    CSW._request_dma(FLOPPY_DMA, "floppy")
#define fd_free_dma()       CSW._free_dma(FLOPPY_DMA)
#define fd_enable_irq()     enable_irq(FLOPPY_IRQ)
#define fd_disable_irq()    disable_irq(FLOPPY_IRQ)
#define fd_free_irq()       free_irq(FLOPPY_IRQ, NULL)
#define fd_get_dma_residue()    SW._get_dma_residue(FLOPPY_DMA)
#define fd_dma_mem_alloc(size)  SW._dma_mem_alloc(size)
#define fd_dma_setup(addr, size, mode, io) SW._dma_setup(addr, size, mode, io)

#define FLOPPY_CAN_FALLBACK_ON_NODMA

static int virtual_dma_count;
static int virtual_dma_residue;
static char *virtual_dma_addr;
static int virtual_dma_mode;
static int doing_pdma;

static irqreturn_t floppy_hardint(int irq, void *dev_id)
{
    unsigned char st;

#undef TRACE_FLPY_INT

#ifdef TRACE_FLPY_INT
    static int calls;
    static int bytes;
    static int dma_wait;
#endif
    if (!doing_pdma)
        return floppy_interrupt(irq, dev_id);

#ifdef TRACE_FLPY_INT
    if (!calls)
        bytes = virtual_dma_count;
#endif

    {
        int lcount;
        char *lptr;

        st = 1;
        for (lcount = virtual_dma_count, lptr = virtual_dma_addr;
             lcount; lcount--, lptr++) {
            st = inb(virtual_dma_port + 4) & 0xa0;
            if (st != 0xa0)
                break;
            if (virtual_dma_mode)
                outb_p(*lptr, virtual_dma_port + 5);
            else
                *lptr = inb_p(virtual_dma_port + 5);
        }
        virtual_dma_count = lcount;
        virtual_dma_addr = lptr;
        st = inb(virtual_dma_port + 4);
    }

#ifdef TRACE_FLPY_INT
    calls++;
#endif
    if (st == 0x20)
        return IRQ_HANDLED;
    if (!(st & 0x20)) {
        virtual_dma_residue += virtual_dma_count;
        virtual_dma_count = 0;
#ifdef TRACE_FLPY_INT
        printk(KERN_DEBUG "count=%x, residue=%x calls=%d bytes=%d dma_wait=%d\n",
               virtual_dma_count, virtual_dma_residue, calls, bytes,
               dma_wait);
        calls = 0;
        dma_wait = 0;
#endif
        doing_pdma = 0;
        floppy_interrupt(irq, dev_id);
        return IRQ_HANDLED;
    }
#ifdef TRACE_FLPY_INT
    if (!virtual_dma_count)
        dma_wait++;
#endif
    return IRQ_HANDLED;
}

static void fd_disable_dma(void)
{
    if (!(can_use_virtual_dma & 1))
        disable_dma(FLOPPY_DMA);
    doing_pdma = 0;
    virtual_dma_residue += virtual_dma_count;
    virtual_dma_count = 0;
}

static int vdma_request_dma(unsigned int dmanr, const char *device_id)
{
    return 0;
}

static void vdma_nop(unsigned int dummy)
{
}


static int vdma_get_dma_residue(unsigned int dummy)
{
    return virtual_dma_count + virtual_dma_residue;
}


static int fd_request_irq(void)
{
    if (can_use_virtual_dma)
        return request_irq(FLOPPY_IRQ, floppy_hardint,
                   IRQF_DISABLED, "floppy", NULL);
    else
        return request_irq(FLOPPY_IRQ, floppy_interrupt,
                   IRQF_DISABLED, "floppy", NULL);
}

static unsigned long dma_mem_alloc(unsigned long size)
{
    return __get_dma_pages(GFP_KERNEL|__GFP_NORETRY, get_order(size));
}


static unsigned long vdma_mem_alloc(unsigned long size)
{
    return (unsigned long)vmalloc(size);

}

#define nodma_mem_alloc(size) vdma_mem_alloc(size)

static void _fd_dma_mem_free(unsigned long addr, unsigned long size)
{
    if ((unsigned long)addr >= (unsigned long)high_memory)
        vfree((void *)addr);
    else
        free_pages(addr, get_order(size));
}

#define fd_dma_mem_free(addr, size)  _fd_dma_mem_free(addr, size)

static void _fd_chose_dma_mode(char *addr, unsigned long size)
{
    if (can_use_virtual_dma == 2) {
        if ((unsigned long)addr >= (unsigned long)high_memory ||
            isa_virt_to_bus(addr) >= 0x1000000 ||
            _CROSS_64KB(addr, size, 0))
            use_virtual_dma = 1;
        else
            use_virtual_dma = 0;
    } else {
        use_virtual_dma = can_use_virtual_dma & 1;
    }
}

#define fd_chose_dma_mode(addr, size) _fd_chose_dma_mode(addr, size)


static int vdma_dma_setup(char *addr, unsigned long size, int mode, int io)
{
    doing_pdma = 1;
    virtual_dma_port = io;
    virtual_dma_mode = (mode == DMA_MODE_WRITE);
    virtual_dma_addr = addr;
    virtual_dma_count = size;
    virtual_dma_residue = 0;
    return 0;
}

static int hard_dma_setup(char *addr, unsigned long size, int mode, int io)
{
#ifdef FLOPPY_SANITY_CHECK
    if (CROSS_64KB(addr, size)) {
        printk("DMA crossing 64-K boundary %p-%p\n", addr, addr+size);
        return -1;
    }
#endif
    /* actual, physical DMA */
    doing_pdma = 0;
    clear_dma_ff(FLOPPY_DMA);
    set_dma_mode(FLOPPY_DMA, mode);
    set_dma_addr(FLOPPY_DMA, isa_virt_to_bus(addr));
    set_dma_count(FLOPPY_DMA, size);
    enable_dma(FLOPPY_DMA);
    return 0;
}

static struct fd_routine_l {
    int (*_request_dma)(unsigned int dmanr, const char *device_id);
    void (*_free_dma)(unsigned int dmanr);
    int (*_get_dma_residue)(unsigned int dummy);
    unsigned long (*_dma_mem_alloc)(unsigned long size);
    int (*_dma_setup)(char *addr, unsigned long size, int mode, int io);
} fd_routine[] = {
    {
        request_dma,
        free_dma,
        get_dma_residue,
        dma_mem_alloc,
        hard_dma_setup
    },
    {
        vdma_request_dma,
        vdma_nop,
        vdma_get_dma_residue,
        vdma_mem_alloc,
        vdma_dma_setup
    }
};


static int FDC1 = 0x3f0;
static int FDC2 = -1;

/*
 * Floppy types are stored in the rtc's CMOS RAM and so rtc_lock
 * is needed to prevent corrupted CMOS RAM in case "insmod floppy"
 * coincides with another rtc CMOS user.        Paul G.
 */
#define FLOPPY0_TYPE                    \
({                          \
    unsigned long flags;                \
    unsigned char val;              \
    spin_lock_irqsave(&rtc_lock, flags);        \
    val = (CMOS_READ(0x10) >> 4) & 15;      \
    spin_unlock_irqrestore(&rtc_lock, flags);   \
    val;                        \
})

#define FLOPPY1_TYPE                    \
({                          \
    unsigned long flags;                \
    unsigned char val;              \
    spin_lock_irqsave(&rtc_lock, flags);        \
    val = CMOS_READ(0x10) & 15;         \
    spin_unlock_irqrestore(&rtc_lock, flags);   \
    val;                        \
})

#define N_FDC 2
#define N_DRIVE 8

#define EXTRA_FLOPPY_PARAMS

#endif /* _ASM_X86_FLOPPY_H */