path: root/arch/sparc/kernel/entry.S

/* arch/sparc/kernel/entry.S:  Sparc trap low-level entry points.
 *
 * Copyright (C) 1995, 2007 David S. Miller (davem@davemloft.net)
 * Copyright (C) 1996 Eddie C. Dost   (ecd@skynet.be)
 * Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
 * Copyright (C) 1996-1999 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
 * Copyright (C) 1997 Anton Blanchard (anton@progsoc.uts.edu.au)
 */

#include <linux/linkage.h>
#include <linux/errno.h>

#include <asm/head.h>
#include <asm/asi.h>
#include <asm/smp.h>
#include <asm/contregs.h>
#include <asm/ptrace.h>
#include <asm/asm-offsets.h>
#include <asm/psr.h>
#include <asm/vaddrs.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/winmacro.h>
#include <asm/signal.h>
#include <asm/obio.h>
#include <asm/mxcc.h>
#include <asm/thread_info.h>
#include <asm/param.h>
#include <asm/unistd.h>

#include <asm/asmmacro.h>

#define curptr      g6

/* These are just handy. */
#define _SV	save	%sp, -STACKFRAME_SZ, %sp
#define _RS     restore 

#define FLUSH_ALL_KERNEL_WINDOWS \
	_SV; _SV; _SV; _SV; _SV; _SV; _SV; \
	_RS; _RS; _RS; _RS; _RS; _RS; _RS;

	.text

#ifdef CONFIG_KGDB
	.align	4
	.globl		arch_kgdb_breakpoint
	.type		arch_kgdb_breakpoint,#function
arch_kgdb_breakpoint:
	ta		0x7d
	retl
	 nop
	.size		arch_kgdb_breakpoint,.-arch_kgdb_breakpoint
#endif

#if defined(CONFIG_BLK_DEV_FD) || defined(CONFIG_BLK_DEV_FD_MODULE)
	.align	4
	.globl	floppy_hardint
floppy_hardint:
	/*
	 * This code cannot touch registers %l0 %l1 and %l2
	 * because SAVE_ALL depends on their values. It depends
	 * on %l3 also, but we regenerate it before a call.
	 * Other registers are:
	 * %l3 -- base address of fdc registers
	 * %l4 -- pdma_vaddr
	 * %l5 -- scratch for ld/st address
	 * %l6 -- pdma_size
	 * %l7 -- scratch [floppy byte, ld/st address, aux. data]
	 */

	/* Do we have work to do? */
	sethi	%hi(doing_pdma), %l7
	ld	[%l7 + %lo(doing_pdma)], %l7
	cmp	%l7, 0
	be	floppy_dosoftint
	 nop

	/* Load fdc register base */
	sethi	%hi(fdc_status), %l3
	ld	[%l3 + %lo(fdc_status)], %l3

	/* Setup register addresses */
	sethi	%hi(pdma_vaddr), %l5	! transfer buffer
	ld	[%l5 + %lo(pdma_vaddr)], %l4
	sethi	%hi(pdma_size), %l5	! bytes to go
	ld	[%l5 + %lo(pdma_size)], %l6
next_byte:
  	ldub	[%l3], %l7

	andcc	%l7, 0x80, %g0		! Does fifo still have data
	bz	floppy_fifo_emptied	! fifo has been emptied...
	 andcc	%l7, 0x20, %g0		! in non-dma mode still?
	bz	floppy_overrun		! nope, overrun
	 andcc	%l7, 0x40, %g0		! 0=write 1=read
	bz	floppy_write
	 sub	%l6, 0x1, %l6

	/* Ok, actually read this byte */
	ldub	[%l3 + 1], %l7
	orcc	%g0, %l6, %g0
	stb	%l7, [%l4]
	bne	next_byte
	 add	%l4, 0x1, %l4

	b	floppy_tdone
	 nop

floppy_write:
	/* Ok, actually write this byte */
	ldub	[%l4], %l7
	orcc	%g0, %l6, %g0
	stb	%l7, [%l3 + 1]
	bne	next_byte
	 add	%l4, 0x1, %l4

	/* fall through... */
floppy_tdone:
	sethi	%hi(pdma_vaddr), %l5
	st	%l4, [%l5 + %lo(pdma_vaddr)]
	sethi	%hi(pdma_size), %l5
	st	%l6, [%l5 + %lo(pdma_size)]
	/* Flip terminal count pin */
	set	auxio_register, %l7
	ld	[%l7], %l7

	ldub	[%l7], %l5

	or	%l5, 0xc2, %l5
	stb	%l5, [%l7]
	andn    %l5, 0x02, %l5

2:
	/* Kill some time so the bits set */
	WRITE_PAUSE
	WRITE_PAUSE

	stb     %l5, [%l7]

	/* Prevent recursion */
	sethi	%hi(doing_pdma), %l7
	b	floppy_dosoftint
	 st	%g0, [%l7 + %lo(doing_pdma)]

	/* We emptied the FIFO, but we haven't read everything
	 * as of yet.  Store the current transfer address and
	 * bytes left to read so we can continue when the next
	 * fast IRQ comes in.
	 */
floppy_fifo_emptied:
	sethi	%hi(pdma_vaddr), %l5
	st	%l4, [%l5 + %lo(pdma_vaddr)]
	sethi	%hi(pdma_size), %l7
	st	%l6, [%l7 + %lo(pdma_size)]

	/* Restore condition codes */
	wr	%l0, 0x0, %psr
	WRITE_PAUSE

	jmp	%l1
	rett	%l2

floppy_overrun:
	sethi	%hi(pdma_vaddr), %l5
	st	%l4, [%l5 + %lo(pdma_vaddr)]
	sethi	%hi(pdma_size), %l5
	st	%l6, [%l5 + %lo(pdma_size)]
	/* Prevent recursion */
	sethi	%hi(doing_pdma), %l7
	st	%g0, [%l7 + %lo(doing_pdma)]

	/* fall through... */
floppy_dosoftint:
	rd	%wim, %l3
	SAVE_ALL

	/* Set all IRQs off. */
	or	%l0, PSR_PIL, %l4
	wr	%l4, 0x0, %psr
	WRITE_PAUSE
	wr	%l4, PSR_ET, %psr
	WRITE_PAUSE

	mov	11, %o0			! floppy irq level (unused anyway)