// SPDX-License-Identifier: GPL-2.0
/*
 * arch/parisc/lib/io.c
 *
 * Copyright (c) Matthew Wilcox 2001 for Hewlett-Packard
 * Copyright (c) Randolph Chung 2001 <tausq@debian.org>
 *
 * IO accessing functions which shouldn't be inlined because they're too big
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <asm/io.h>

/* Copies a block of memory to a device in an efficient manner.
 * Assumes the device can cope with 32-bit transfers.  If it can't,
 * don't use this function.
 */
void memcpy_toio(volatile void __iomem *dst, const void *src, int count)
{
        if (((unsigned long)dst & 3) != ((unsigned long)src & 3))
                goto bytecopy;
        while ((unsigned long)dst & 3) {
                writeb(*(char *)src, dst++);
                src++;
                count--;
        }
        while (count > 3) {
                __raw_writel(*(u32 *)src, dst);
                src += 4;
                dst += 4;
                count -= 4;
        }
 bytecopy:
        while (count--) {
                writeb(*(char *)src, dst++);
                src++;
        }
}

/*
** Copies a block of memory from a device in an efficient manner.
** Assumes the device can cope with 32-bit transfers.  If it can't,
** don't use this function.
**
** CR16 counts on C3000 reading 256 bytes from Symbios 896 RAM:
**      27341/64    = 427 cyc per int
**      61311/128   = 478 cyc per short
**      122637/256  = 479 cyc per byte
** Ergo bus latencies dominant (not transfer size).
**      Minimize total number of transfers at cost of CPU cycles.
**      TODO: only look at src alignment and adjust the stores to dest.
*/
void memcpy_fromio(void *dst, const volatile void __iomem *src, int count)
{
        /* first compare alignment of src/dst */ 
        if ( (((unsigned long)dst ^ (unsigned long)src) & 1) || (count < 2) )
                goto bytecopy;

        if ( (((unsigned long)dst ^ (unsigned long)src) & 2) || (count < 4) )
                goto shortcopy;

        /* Then check for misaligned start address */
        if ((unsigned long)src & 1) {
                *(u8 *)dst = readb(src);
                src++;
                dst++;
                count--;
                if (count < 2) goto bytecopy;
        }

        if ((unsigned long)src & 2) {
                *(u16 *)dst = __raw_readw(src);
                src += 2;
                dst += 2;
                count -= 2;
        }

        while (count > 3) {
                *(u32 *)dst = __raw_readl(src);
                dst += 4;
                src += 4;
                count -= 4;
        }

 shortcopy:
        while (count > 1) {
                *(u16 *)dst = __raw_readw(src);
                src += 2;
                dst += 2;
                count -= 2;
        }

 bytecopy:
        while (count--) {
                *(char *)dst = readb(src);
                src++;
                dst++;
        }
}

/* Sets a block of memory on a device to a given value.
 * Assumes the device can cope with 32-bit transfers.  If it can't,
 * don't use this function.
 */
void memset_io(volatile void __iomem *addr, unsigned char val, int count)
{
        u32 val32 = (val << 24) | (val << 16) | (val << 8) | val;
        while ((unsigned long)addr & 3) {
                writeb(val, addr++);
                count--;
        }
        while (count > 3) {
                __raw_writel(val32, addr);
                addr += 4;
                count -= 4;
        }
        while (count--) {
                writeb(val, addr++);
        }
}

/*
 * Read COUNT 8-bit bytes from port PORT into memory starting at
 * SRC.
 */
void insb (unsigned long port, void *dst, unsigned long count)
{
        unsigned char *p;

        p = (unsigned char *)dst;

        while (((unsigned long)p) & 0x3) {
                if (!count)
                        return;
                count--;
                *p = inb(port);
                p++;
        }

        while (count >= 4) {
                unsigned int w;
                count -= 4;
                w = inb(port) << 24;
                w |= inb(port) << 16;
                w |= inb(port) << 8;
                w |= inb(port);
                *(unsigned int *) p = w;
                p += 4;
        }

        while (count) {
                --count;
                *p = inb(port);
                p++;
        }
}


/*
 * Read COUNT 16-bit words from port PORT into memory starting at
 * SRC.  SRC must be at least short aligned.  This is used by the
 * IDE driver to read disk sectors.  Performance is important, but
 * the interfaces seems to be slow: just using the inlined version
 * of the inw() breaks things.
 */
void insw (unsigned long port, void *dst, unsigned long count)
{
        unsigned int l = 0, l2;
        unsigned char *p;

        p = (unsigned char *)dst;
        
        if (!count)
                return;
        
        switch (((unsigned long)p) & 0x3)
        {
         case 0x00:                     /* Buffer 32-bit aligned */
                while (count>=2) {
                        
                        count -= 2;
                        l = cpu_to_le16(inw(port)) << 16;
                        l |= cpu_to_le16(inw(port));
                        *(unsigned int *)p = l;
                        p += 4;
                }
                if (count) {
                        *(unsigned short *)p = cpu_to_le16(inw(port));
                }
                break;
        
         case 0x02:                     /* Buffer 16-bit aligned */
                *(unsigned short *)p = cpu_to_le16(inw(port));
                p += 2;
                count--;
                while (count>=2) {
                        
                        count -= 2;
                        l = cpu_to_le16(inw(port)) << 16;
                        l |= cpu_to_le16(inw(port));
                        *(unsigned int *)p = l;
                        p += 4;
                }
                if (count) {
                        *(unsigned short *)p = cpu_to_le16(inw(port));
                }
                break;
                
         case 0x01:                     /* Buffer 8-bit aligned */
         case 0x03:
                /* I don't bother with 32bit transfers
                 * in this case, 16bit will have to do -- DE */
                --count;
                
                l = cpu_to_le16(inw(port));
                *p = l >> 8;
                p++;
                while (count--)
                {
                        l2 = cpu_to_le16(inw(port));
                        *(unsigned short *)p = (l & 0xff) << 8 | (l2 >> 8);
                        p += 2;
                        l = l2;
                }
                *p = l & 0xff;
                break;
        }
}



/*
 * Read COUNT 32-bit words from port PORT into memory starting at
 * SRC. Now works with any alignment in SRC. Performance is important,
 * but the interfaces seems to be slow: just using the inlined version
 * of the inl() breaks things.
 */
void insl (unsigned long port, void *dst, unsigned long count)
{
        unsigned int l = 0, l2;
        unsigned char *p;

        p = (unsigned char *)dst;
        
        if (!count)
                return;
        
        switch (((unsigned long) dst) & 0x3)
        {
         case 0x00:                     /* Buffer 32-bit aligned */
                while (count--)
                {
                        *(unsigned int *)p = cpu_to_le32(inl(port));
                        p += 4;
                }
                break;
        
         case 0x02:                     /* Buffer 16-bit aligned */
                --count;
                
                l = cpu_to_le32(inl(port));
                *(unsigned short *)p = l >> 16;
                p += 2;
                
                while (count--)
                {
                        l2 = cpu_to_le32(inl(port));
                        *(unsigned int *)p = (l & 0xffff) << 16 | (l2 >> 16);
                        p += 4;
                        l = l2;
                }
                *(unsigned short *)p = l & 0xffff;
                break;
         case 0x01:                     /* Buffer 8-bit aligned */
                --count;
                
                l = cpu_to_le32(inl(port));
                *(unsigned char *)p = l >> 24;
                p++;
                *(unsigned short *)p = (l >> 8) & 0xffff;
                p += 2;
                while (count--)
                {
                        l2 = cpu_to_le32(inl(port));
                        *(unsigned int *)p = (l & 0xff) << 24 | (l2 >> 8);
                        p += 4;
                        l = l2;
                }
                *p = l & 0xff;
                break;
         case 0x03:                     /* Buffer 8-bit aligned */
                --count;
                
                l = cpu_to_le32(inl(port));
                *p = l >> 24;
                p++;
                while (count--)
                {
                        l2 = cpu_to_le32(inl(port));
                        *(unsigned int *)p = (l & 0xffffff) << 8 | l2 >> 24;
                        p += 4;
                        l = l2;
                }
                *(unsigned short *)p = (l >> 8) & 0xffff;
                p += 2;
                *p = l & 0xff;
                break;
        }
}


/*
 * Like insb but in the opposite direction.
 * Don't worry as much about doing aligned memory transfers:
 * doing byte reads the "slow" way isn't nearly as slow as
 * doing byte writes the slow way (no r-m-w cycle).
 */
void outsb(unsigned long port, const void * src, unsigned long count)
{
        const unsigned char *p;

        p = (const unsigned char *)src;
        while (count) {
                count--;
                outb(*p, port);
                p++;
        }
}

/*
 * Like insw but in the opposite direction.  This is used by the IDE
 * driver to write disk sectors.  Performance is important, but the
 * interfaces seems to be slow: just using the inlined version of the
 * outw() breaks things.
 */
void outsw (unsigned long port, const void *src, unsigned long count)
{
        unsigned int l = 0, l2;
        const unsigned char *p;

        p = (const unsigned char *)src;
        
        if (!count)
                return;
        
        switch (((unsigned long)p) & 0x3)
        {
         case 0x00:                     /* Buffer 32-bit aligned */
                while (count>=2) {
                        count -= 2;
                        l = *(unsigned int *)p;
                        p += 4;
                        outw(le16_to_cpu(l >> 16), port);
                        outw(le16_to_cpu(l & 0xffff), port);
                }
                if (count) {
                        outw(le16_to_cpu(*(unsigned short*)p), port);
                }
                break;
        
         case 0x02:                     /* Buffer 16-bit aligned */
                
                outw(le16_to_cpu(*(unsigned short*)p), port);
                p += 2;
                count--;
                
                while (count>=2) {
                        count -= 2;
                        l = *(unsigned int *)p;
                        p += 4;
                        outw(le16_to_cpu(l >> 16), port);
                        outw(le16_to_cpu(l & 0xffff), port);
                }
                if (count) {
                        outw(le16_to_cpu(*(unsigned short *)p), port);
                }
                break;
                
         case 0x01:                     /* Buffer 8-bit aligned */      
                /* I don't bother with 32bit transfers
                 * in this case, 16bit will have to do -- DE */
                
                l  = *p << 8;
                p++;
                count--;
                while (count)
                {
                        count--;
                        l2 = *(unsigned short *)p;
                        p += 2;
                        outw(le16_to_cpu(l | l2 >> 8), port);
                        l = l2 << 8;
                }
                l2 = *(unsigned char *)p;
                outw (le16_to_cpu(l | l2>>8), port);
                break;
        
        }
}


/*
 * Like insl but in the opposite direction.  This is used by the IDE
 * driver to write disk sectors.  Works with any alignment in SRC.
 *  Performance is important, but the interfaces seems to be slow:
 * just using the inlined version of the outl() breaks things.
 */
void outsl (unsigned long port, const void *src, unsigned long count)
{
        unsigned int l = 0, l2;
        const unsigned char *p;

        p = (const unsigned char *)src;
        
        if (!count)
                return;
        
        switch (((unsigned long)p) & 0x3)
        {
         case 0x00:                     /* Buffer 32-bit aligned */
                while (count--)
                {
                        outl(le32_to_cpu(*(unsigned int *)p), port);
                        p += 4;
                }
                break;
        
         case 0x02:                     /* Buffer 16-bit aligned */
                --count;
                
                l = *(unsigned short *)p;
                p += 2;
                
                while (count--)
                {
                        l2 = *(unsigned int *)p;
                        p += 4;
                        outl (le32_to_cpu(l << 16 | l2 >> 16), port);
                        l = l2;
                }
                l2 = *(unsigned short *)p;
                outl (le32_to_cpu(l << 16 | l2), port);
                break;
         case 0x01:                     /* Buffer 8-bit aligned */
                --count;

                l = *p << 24;
                p++;
                l |= *(unsigned short *)p << 8;
                p += 2;

                while (count--)
                {
                        l2 = *(unsigned int *)p;
                        p += 4;
                        outl (le32_to_cpu(l | l2 >> 24), port);
                        l = l2 << 8;
                }
                l2 = *p;
                outl (le32_to_cpu(l | l2), port);
                break;
         case 0x03:                     /* Buffer 8-bit aligned */
                --count;
                
                l = *p << 24;
                p++;

                while (count--)
                {
                        l2 = *(unsigned int *)p;
                        p += 4;
                        outl (le32_to_cpu(l | l2 >> 8), port);
                        l = l2 << 24;
                }
                l2 = *(unsigned short *)p << 16;
                p += 2;
                l2 |= *p;
                outl (le32_to_cpu(l | l2), port);
                break;
        }
}

EXPORT_SYMBOL(insb);
EXPORT_SYMBOL(insw);
EXPORT_SYMBOL(insl);
EXPORT_SYMBOL(outsb);
EXPORT_SYMBOL(outsw);
EXPORT_SYMBOL(outsl);