Support for MIPSsim, the cycle accurate MIPS simulator.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/Kconfig

@@ -448,6 +448,17 @@ config MOMENCO_OCELOT_3
 	  The Ocelot-3 is based off Discovery III System Controller and
 	  PMC-Sierra Rm79000 core.
 
+config MIPS_SIM
+	bool 'Support for MIPS simulator (MIPSsim)'
+	select DMA_NONCOHERENT
+	select IRQ_CPU
+	select SYS_SUPPORTS_32BIT_KERNEL
+	select SYS_SUPPORTS_BIG_ENDIAN
+	select SYS_SUPPORTS_LITTLE_ENDIAN
+	help
+	  This option enables support for MIPS Technologies MIPSsim software
+	  emulator.
+
 config MOMENCO_JAGUAR_ATX
 	bool "Support for Momentum Jaguar board"
 	select BOOT_ELF32

arch/mips/Makefile

@@ -436,6 +436,13 @@ load-$(CONFIG_MIPS_MALTA)	+= 0xffffffff80100000
 core-$(CONFIG_MIPS_SEAD)	+= arch/mips/mips-boards/sead/
 load-$(CONFIG_MIPS_SEAD)	+= 0xffffffff80100000
 
+#
+# MIPS SIM
+#
+core-$(CONFIG_MIPS_SIM)		+= arch/mips/mips-boards/sim/
+cflags-$(CONFIG_MIPS_SIM)	+= -Iinclude/asm-mips/mach-sim
+load-$(CONFIG_MIPS_SIM)		+= 0x80100000
+
 #
 # Momentum Ocelot board
 #

arch/mips/kernel/head.S

@@ -116,7 +116,7 @@
 EXPORT(stext)					# used for profiling
 EXPORT(_stext)
 
-#ifdef CONFIG_QEMU
+#if defined(CONFIG_QEMU) || defined(CONFIG_MIPS_SIM)
 	/*
 	 * Give us a fighting chance of running if execution beings at the
 	 * kernel load address.  This is needed because this platform does

arch/mips/mips-boards/sim/Makefile

+#
+# Copyright (C) 2005 MIPS Technologies, Inc.  All rights reserved.
+#
+# This program is free software; you can distribute it and/or modify it
+# under the terms of the GNU General Public License (Version 2) as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+# for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
+#
+
+obj-y := sim_setup.o sim_mem.o sim_time.o sim_printf.o sim_int.o sim_irq.o \
+	sim_cmdline.o
+obj-$(CONFIG_SMP) += sim_smp.o

arch/mips/mips-boards/sim/cmdline.c

+/*
+ * Carsten Langgaard, carstenl@mips.com
+ * Copyright (C) 1999,2000 MIPS Technologies, Inc.  All rights reserved.
+ *
+ * This program is free software; you can distribute it and/or modify it
+ * under the terms of the GNU General Public License (Version 2) as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ * Kernel command line creation using the prom monitor (YAMON) argc/argv.
+ */
+#include <linux/init.h>
+#include <linux/string.h>
+
+#include <asm/bootinfo.h>
+
+extern int prom_argc;
+extern int *_prom_argv;
+
+/*
+ * YAMON (32-bit PROM) pass arguments and environment as 32-bit pointer.
+ * This macro take care of sign extension.
+ */
+#define prom_argv(index) ((char *)(((int *)(int)_prom_argv)[(index)]))
+
+char arcs_cmdline[CL_SIZE];
+
+char * __init prom_getcmdline(void)
+{
+	return &(arcs_cmdline[0]);
+}
+
+
+void  __init prom_init_cmdline(void)
+{
+	char *cp;
+	int actr;
+
+	actr = 1; /* Always ignore argv[0] */
+
+	cp = &(arcs_cmdline[0]);
+	while(actr < prom_argc) {
+	        strcpy(cp, prom_argv(actr));
+		cp += strlen(prom_argv(actr));
+		*cp++ = ' ';
+		actr++;
+	}
+	if (cp != &(arcs_cmdline[0])) /* get rid of trailing space */
+		--cp;
+	*cp = '\0';
+}

arch/mips/mips-boards/sim/sim_IRQ.c

+/*
+ * Carsten Langgaard, carstenl@mips.com
+ * Copyright (C) 1999, 2000 MIPS Technologies, Inc.  All rights reserved.
+ *
+ *  This program is free software; you can distribute it and/or modify it
+ *  under the terms of the GNU General Public License (Version 2) as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ *  for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ * Interrupt exception dispatch code.
+ */
+#include <linux/config.h>
+
+#include <asm/asm.h>
+#include <asm/mipsregs.h>
+#include <asm/regdef.h>
+#include <asm/stackframe.h>
+
+/* A lot of complication here is taken away because:
+ *
+ * 1) We handle one interrupt and return, sitting in a loop and moving across
+ *    all the pending IRQ bits in the cause register is _NOT_ the answer, the
+ *    common case is one pending IRQ so optimize in that direction.
+ *
+ * 2) We need not check against bits in the status register IRQ mask, that
+ *    would make this routine slow as hell.
+ *
+ * 3) Linux only thinks in terms of all IRQs on or all IRQs off, nothing in
+ *    between like BSD spl() brain-damage.
+ *
+ * Furthermore, the IRQs on the MIPS board look basically (barring software
+ * IRQs which we don't use at all and all external interrupt sources are
+ * combined together on hardware interrupt 0 (MIPS IRQ 2)) like:
+ *
+ *	MIPS IRQ	Source
+ *      --------        ------
+ *             0	Software (ignored)
+ *             1        Software (ignored)
+ *             2        Combined hardware interrupt (hw0)
+ *             3        Hardware (ignored)
+ *             4        Hardware (ignored)
+ *             5        Hardware (ignored)
+ *             6        Hardware (ignored)
+ *             7        R4k timer (what we use)
+ *
+ * Note: On the SEAD board thing are a little bit different.
+ *       Here IRQ 2 (hw0) is wired to the UART0 and IRQ 3 (hw1) is wired
+ *       wired to UART1.
+ *
+ * We handle the IRQ according to _our_ priority which is:
+ *
+ * Highest ----     R4k Timer
+ * Lowest  ----     Combined hardware interrupt
+ *
+ * then we just return, if multiple IRQs are pending then we will just take
+ * another exception, big deal.
+ */
+
+	.text
+	.set	noreorder
+	.set	noat
+	.align	5
+	NESTED(mipsIRQ, PT_SIZE, sp)
+	SAVE_ALL
+	CLI
+	.set	at
+
+	mfc0	s0, CP0_CAUSE		# get irq bits
+	mfc0	s1, CP0_STATUS		# get irq mask
+	and	s0, s1
+
+	/* First we check for r4k counter/timer IRQ. */
+	andi	a0, s0, CAUSEF_IP7
+	beq	a0, zero, 1f
+	 andi	a0, s0, CAUSEF_IP2	# delay slot, check hw0 interrupt
+
+	/* Wheee, a timer interrupt. */
+	move	a0, sp
+	jal	mips_timer_interrupt
+	 nop
+
+	j	ret_from_irq
+	 nop
+
+1:
+#if defined(CONFIG_MIPS_SEAD)
+	beq	a0, zero, 1f
+	 andi	a0, s0, CAUSEF_IP3	# delay slot, check hw1 interrupt
+#else
+	beq	a0, zero, 1f		# delay slot, check hw3 interrupt
+ 	 andi	a0, s0, CAUSEF_IP5
+#endif
+
+	/* Wheee, combined hardware level zero interrupt. */
+#if defined(CONFIG_MIPS_ATLAS)
+	jal	atlas_hw0_irqdispatch
+#elif defined(CONFIG_MIPS_MALTA)
+	jal	malta_hw0_irqdispatch
+#elif defined(CONFIG_MIPS_SEAD)
+	jal	sead_hw0_irqdispatch
+#else
+#error "MIPS board not supported\n"
+#endif
+	 move	a0, sp			# delay slot
+
+	j	ret_from_irq
+	 nop				# delay slot
+
+1:
+#if defined(CONFIG_MIPS_SEAD)
+	beq	a0, zero, 1f
+	 andi	a0, s0, CAUSEF_IP5	# delay slot, check hw3 interrupt
+	jal	sead_hw1_irqdispatch
+	 move	a0, sp			# delay slot
+	j	ret_from_irq
+	 nop				# delay slot
+1:
+#endif
+#if defined(CONFIG_MIPS_MALTA)
+	beq	a0, zero, 1f            # check hw3 (coreHI) interrupt
+	 nop
+	jal	corehi_irqdispatch
+	 move	a0, sp
+	j	ret_from_irq
+	 nop
+1:
+#endif
+	/*
+	 * Here by mistake?  This is possible, what can happen is that by the
+	 * time we take the exception the IRQ pin goes low, so just leave if
+	 * this is the case.
+	 */
+	move	a1,s0
+	PRINT("Got interrupt: c0_cause = %08x\n")
+	mfc0	a1, CP0_EPC
+	PRINT("c0_epc = %08x\n")
+
+	j	ret_from_irq
+	 nop
+	END(mipsIRQ)

arch/mips/mips-boards/sim/sim_cmdline.c

+/*
+ * Copyright (C) 2005 MIPS Technologies, Inc.  All rights reserved.
+ *
+ *  This program is free software; you can distribute it and/or modify it
+ *  under the terms of the GNU General Public License (Version 2) as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ *  for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ */
+#include <linux/init.h>
+#include <linux/string.h>
+#include <asm/bootinfo.h>
+
+extern char arcs_cmdline[];
+
+char * __init prom_getcmdline(void)
+{
+	return arcs_cmdline;
+}
+
+
+void  __init prom_init_cmdline(void)
+{
+    /* nothing to do */
+}

arch/mips/mips-boards/sim/sim_int.c

+/*
+ * Copyright (C) 1999, 2005 MIPS Technologies, Inc.  All rights reserved.
+ *
+ *  This program is free software; you can distribute it and/or modify it
+ *  under the terms of the GNU General Public License (Version 2) as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ *  for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ */
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+#include <asm/mips-boards/simint.h>
+
+
+extern void mips_cpu_irq_init(int);
+
+extern asmlinkage void simIRQ(void);
+
+asmlinkage void sim_hw0_irqdispatch(struct pt_regs *regs)
+{
+	do_IRQ(2, regs);
+}
+
+void __init arch_init_irq(void)
+{
+	/* Now safe to set the exception vector. */
+	set_except_vector(0, simIRQ);
+
+	mips_cpu_irq_init(MIPSCPU_INT_BASE);
+}

arch/mips/mips-boards/sim/sim_irq.S

+/*
+ * Copyright (C) 1999, 2005 MIPS Technologies, Inc.  All rights reserved.
+ *
+ *  This program is free software; you can distribute it and/or modify it
+ *  under the terms of the GNU General Public License (Version 2) as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ *  for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ * Interrupt exception dispatch code.
+ *
+ */
+#include <linux/config.h>
+
+#include <asm/asm.h>
+#include <asm/mipsregs.h>
+#include <asm/regdef.h>
+#include <asm/stackframe.h>
+
+#include <asm/mips-boards/simint.h>
+
+
+	.text
+	.set	noreorder
+	.set	noat
+	.align	5
+	NESTED(simIRQ, PT_SIZE, sp)
+	SAVE_ALL
+	CLI
+	.set	at
+
+	mfc0	s0, CP0_CAUSE		# get irq bits
+	mfc0	s1, CP0_STATUS		# get irq mask
+	andi	s0, ST0_IM		# CAUSE.CE may be non-zero!
+	and	s0, s1
+
+#if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
+ 	.set	mips32
+	clz	a0, s0
+	.set	mips0
+	negu	a0
+	addu	a0, 31-CAUSEB_IP
+	bltz	a0, spurious
+#else
+	beqz	s0, spurious
+	 li	a0, 7
+
+	and	t0, s0, 0xf000
+	sltiu	t0, t0, 1
+	sll	t0, 2
+	subu	a0, t0
+	sll	s0, t0
+
+	and	t0, s0, 0xc000
+	sltiu	t0, t0, 1
+	sll	t0, 1
+	subu	a0, t0
+	sll	s0, t0
+
+	and	t0, s0, 0x8000
+	sltiu	t0, t0, 1
+	# sll	t0, 0
+	subu	a0, t0
+	# sll	s0, t0
+#endif
+
+#ifdef CASCADE_IRQ
+	 li	a1, CASCADE_IRQ
+	bne	a0, a1, 1f
+	 addu	a0, MIPSCPU_INT_BASE
+
+	jal	CASCADE_DISPATCH
+	 move	 a0, sp
+
+	j	ret_from_irq
+	 nop
+1:
+#else
+	 addu	a0, MIPSCPU_INT_BASE
+#endif
+
+	jal	do_IRQ
+	 move	a1, sp
+
+	j	ret_from_irq
+	 nop
+
+
+spurious:
+	j	spurious_interrupt
+	 nop
+	END(simIRQ)

arch/mips/mips-boards/sim/sim_mem.c

+/*
+ * Copyright (C) 2005 MIPS Technologies, Inc.  All rights reserved.
+ *
+ *  This program is free software; you can distribute it and/or modify it
+ *  under the terms of the GNU General Public License (Version 2) as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ *  for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ */
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/bootmem.h>
+
+#include <asm/bootinfo.h>
+#include <asm/page.h>
+
+#include <asm/mips-boards/prom.h>
+
+/*#define DEBUG*/
+
+enum simmem_memtypes {
+	simmem_reserved = 0,
+	simmem_free,
+};
+struct prom_pmemblock mdesc[PROM_MAX_PMEMBLOCKS];
+
+#ifdef DEBUG
+static char *mtypes[3] = {
+	"SIM reserved memory",
+	"SIM free memory",
+};
+#endif
+
+/* References to section boundaries */
+extern char _end;
+
+#define PFN_ALIGN(x)    (((unsigned long)(x) + (PAGE_SIZE - 1)) & PAGE_MASK)
+
+
+struct prom_pmemblock * __init prom_getmdesc(void)
+{
+	unsigned int memsize;
+
+	memsize = 0x02000000;
+	prom_printf("Setting default memory size 0x%08x\n", memsize);
+
+	memset(mdesc, 0, sizeof(mdesc));
+
+	mdesc[0].type = simmem_reserved;
+	mdesc[0].base = 0x00000000;
+	mdesc[0].size = 0x00001000;
+
+	mdesc[1].type = simmem_free;
+	mdesc[1].base = 0x00001000;
+	mdesc[1].size = 0x000ff000;
+
+	mdesc[2].type = simmem_reserved;
+	mdesc[2].base = 0x00100000;
+	mdesc[2].size = CPHYSADDR(PFN_ALIGN(&_end)) - mdesc[2].base;
+
+	mdesc[3].type = simmem_free;
+	mdesc[3].base = CPHYSADDR(PFN_ALIGN(&_end));
+	mdesc[3].size = memsize - mdesc[3].base;
+
+	return &mdesc[0];
+}
+
+static int __init prom_memtype_classify (unsigned int type)
+{
+	switch (type) {
+	case simmem_free:
+		return BOOT_MEM_RAM;
+	case simmem_reserved:
+	default:
+		return BOOT_MEM_RESERVED;
+	}
+}
+
+void __init prom_meminit(void)
+{
+	struct prom_pmemblock *p;
+
+	p = prom_getmdesc();
+
+	while (p->size) {
+		long type;
+		unsigned long base, size;
+
+		type = prom_memtype_classify (p->type);
+		base = p->base;
+		size = p->size;
+
+		add_memory_region(base, size, type);
+                p++;
+	}
+}
+
+unsigned long __init prom_free_prom_memory(void)
+{
+	int i;
+	unsigned long freed = 0;
+	unsigned long addr;
+
+	for (i = 0; i < boot_mem_map.nr_map; i++) {
+		if (boot_mem_map.map[i].type != BOOT_MEM_ROM_DATA)
+			continue;
+
+		addr = boot_mem_map.map[i].addr;
+		while (addr < boot_mem_map.map[i].addr
+			      + boot_mem_map.map[i].size) {
+			ClearPageReserved(virt_to_page(__va(addr)));
+			set_page_count(virt_to_page(__va(addr)), 1);
+			free_page((unsigned long)__va(addr));
+			addr += PAGE_SIZE;
+			freed += PAGE_SIZE;
+		}
+	}
+	printk("Freeing prom memory: %ldkb freed\n", freed >> 10);
+
+	return freed;
+}

arch/mips/mips-boards/sim/sim_printf.c

+/*
+ * Carsten Langgaard, carstenl@mips.com
+ * Copyright (C) 1999,2000 MIPS Technologies, Inc.  All rights reserved.
+ *
+ *  This program is free software; you can distribute it and/or modify it
+ *  under the terms of the GNU General Public License (Version 2) as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ *  for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ * Putting things on the screen/serial line using YAMONs facilities.
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/serial_reg.h>
+#include <linux/spinlock.h>
+#include <asm/io.h>
+#include <asm/system.h>
+
+static inline unsigned int serial_in(int offset)
+{
+	return inb(0x3f8 + offset);
+}
+
+static inline void serial_out(int offset, int value)
+{
+	outb(value, 0x3f8 + offset);
+}
+
+int putPromChar(char c)
+{
+	while ((serial_in(UART_LSR) & UART_LSR_THRE) == 0)
+		;
+