diff options
Diffstat (limited to 'arch/mips/sni/io.c')
| -rw-r--r-- | arch/mips/sni/io.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/arch/mips/sni/io.c b/arch/mips/sni/io.c new file mode 100644 index 000000000..f62fdc2d7 --- /dev/null +++ b/arch/mips/sni/io.c @@ -0,0 +1,172 @@ +/* + * 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. + * + * Low level I/O functions for SNI. + */ +#include <linux/string.h> +#include <asm/mipsconfig.h> +#include <asm/addrspace.h> +#include <asm/system.h> +#include <asm/spinlock.h> +#include <asm/sni.h> + +unsigned char sni_map_isa_cache; + +#define unused __attribute__((unused)) + +/* + * The PCIMT_CSMAPISA is shared by all processors; we need locking. + * + * XXX It's legal to use all the I/O memory access functions in interrupt + * code, so we need to use the _irq locking stuff which may result in + * significant IRQ latencies. + */ +static spinlock_t csmapisa_lock unused = SPIN_LOCK_UNLOCKED; + +/* + * Urgs... We only can see a 16mb window of the 4gb EISA address space + * at PCIMT_EISA_BASE. Maladia segmentitis ... + * + * XXX Check out if accessing PCIMT_CSMAPISA really is slow. + * For now assume so. + */ +static inline void update_isa_cache(unsigned long address) +{ + unsigned char upper; + + upper = address >> 24; + if (sni_map_isa_cache != upper) { + sni_map_isa_cache = upper; + *(volatile unsigned char *)PCIMT_CSMAPISA = ~upper; + } +} + +static unsigned char sni_readb(unsigned long addr) +{ + unsigned char res; + + spin_lock_irq(&csmapisa_lock); + update_isa_cache(addr); + addr &= 0xffffff; + res = *(volatile unsigned char *) (PCIMT_EISA_BASE + addr); + spin_unlock_irq(&csmapisa_lock); + + return res; +} + +static unsigned short sni_readw(unsigned long addr) +{ + unsigned short res; + + spin_lock_irq(&csmapisa_lock); + update_isa_cache(addr); + addr &= 0xffffff; + res = *(volatile unsigned char *) (PCIMT_EISA_BASE + addr); + spin_unlock_irq(&csmapisa_lock); + + return res; +} + +static unsigned int sni_readl(unsigned long addr) +{ + unsigned int res; + + spin_lock_irq(&csmapisa_lock); + update_isa_cache(addr); + addr &= 0xffffff; + res = *(volatile unsigned char *) (PCIMT_EISA_BASE + addr); + spin_unlock_irq(&csmapisa_lock); + + return res; +} + +static void sni_writeb(unsigned char val, unsigned long addr) +{ + spin_lock_irq(&csmapisa_lock); + update_isa_cache(addr); + addr &= 0xffffff; + *(volatile unsigned char *) (PCIMT_EISA_BASE + addr) = val; + spin_unlock_irq(&csmapisa_lock); +} + +static void sni_writew(unsigned short val, unsigned long addr) +{ + spin_lock_irq(&csmapisa_lock); + update_isa_cache(addr); + addr &= 0xffffff; + *(volatile unsigned char *) (PCIMT_EISA_BASE + addr) = val; + spin_unlock_irq(&csmapisa_lock); +} + +static void sni_writel(unsigned int val, unsigned long addr) +{ + spin_lock_irq(&csmapisa_lock); + update_isa_cache(addr); + addr &= 0xffffff; + *(volatile unsigned char *) (PCIMT_EISA_BASE + addr) = val; + spin_unlock_irq(&csmapisa_lock); +} + +static void sni_memset_io(unsigned long addr, int val, unsigned long len) +{ + unsigned long waddr; + + waddr = PCIMT_EISA_BASE | (addr & 0xffffff); + spin_lock_irq(&csmapisa_lock); + while(len) { + unsigned long fraglen; + + fraglen = (~addr + 1) & 0xffffff; + fraglen = (fraglen < len) ? fraglen : len; + update_isa_cache(addr); + memset((char *)waddr, val, fraglen); + addr += fraglen; + waddr = waddr + fraglen - 0x1000000; + len -= fraglen; + } + spin_unlock_irq(&csmapisa_lock); +} + +static void sni_memcpy_fromio(unsigned long to, unsigned long from, unsigned long len) +{ + unsigned long waddr; + + waddr = PCIMT_EISA_BASE | (from & 0xffffff); + spin_lock_irq(&csmapisa_lock); + while(len) { + unsigned long fraglen; + + fraglen = (~from + 1) & 0xffffff; + fraglen = (fraglen < len) ? fraglen : len; + update_isa_cache(from); + memcpy((void *)to, (void *)waddr, fraglen); + to += fraglen; + from += fraglen; + waddr = waddr + fraglen - 0x1000000; + len -= fraglen; + } + spin_unlock_irq(&csmapisa_lock); +} + +static void sni_memcpy_toio(unsigned long to, unsigned long from, unsigned long len) +{ + unsigned long waddr; + + waddr = PCIMT_EISA_BASE | (to & 0xffffff); + spin_lock_irq(&csmapisa_lock); + while(len) { + unsigned long fraglen; + + fraglen = (~to + 1) & 0xffffff; + fraglen = (fraglen < len) ? fraglen : len; + update_isa_cache(to); + memcpy((char *)to + PCIMT_EISA_BASE, (void *)from, fraglen); + to += fraglen; + from += fraglen; + waddr = waddr + fraglen - 0x1000000; + len -= fraglen; + } + spin_unlock_irq(&csmapisa_lock); +} |