tests: Add a test for privileged instruction interrupts

This adds a test that tries to execute various privileged instructions
with MSR[PR] = 1.  This also incidentally tests some of the MSR bit
manipulations.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

tests/privileged/Makefile

@@ -0,0 +1,3 @@
+TEST=privileged
+
+include ../Makefile.test

tests/privileged/head.S

@@ -0,0 +1,91 @@
+/* Copyright 2013-2014 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * 	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define STACK_TOP 0x8000
+
+/* Load an immediate 64-bit value into a register */
+#define LOAD_IMM64(r, e)			\
+	lis     r,(e)@highest;			\
+	ori     r,r,(e)@higher;			\
+	rldicr  r,r, 32, 31;			\
+	oris    r,r, (e)@h;			\
+	ori     r,r, (e)@l;
+
+	.section ".head","ax"
+
+	/*
+	 * Microwatt currently enters in LE mode at 0x0, so we don't need to
+	 * do any endian fix ups
+	 */
+	. = 0
+.global _start
+_start:
+	b	boot_entry
+
+.global boot_entry
+boot_entry:
+	/* setup stack */
+	LOAD_IMM64(%r1, STACK_TOP - 0x100)
+	LOAD_IMM64(%r12, main)
+	mtctr	%r12
+	bctrl
+	attn // terminate on exit
+	b .
+
+	/* Call a function with a specified MSR value */
+	.global	call_with_msr
+call_with_msr:
+	mtsrr0	%r4
+	mr	%r12,%r4
+	mtsrr1	%r5
+	rfid
+
+#define EXCEPTION(nr)		\
+	.= nr			;\
+	li	%r3,nr		;\
+	blr
+
+	EXCEPTION(0x300)
+	EXCEPTION(0x380)
+	EXCEPTION(0x400)
+	EXCEPTION(0x480)
+	EXCEPTION(0x500)
+	EXCEPTION(0x600)
+	EXCEPTION(0x700)
+	EXCEPTION(0x800)
+	EXCEPTION(0x900)
+	EXCEPTION(0x980)
+	EXCEPTION(0xa00)
+	EXCEPTION(0xb00)
+
+	/*
+	 * System call - used to exit from tests where MSR[PR]
+	 * may have been set.
+	 */
+	. = 0xc00
+	blr
+
+	EXCEPTION(0xd00)
+	EXCEPTION(0xe00)
+	EXCEPTION(0xe20)
+	EXCEPTION(0xe40)
+	EXCEPTION(0xe60)
+	EXCEPTION(0xe80)
+	EXCEPTION(0xf00)
+	EXCEPTION(0xf20)
+	EXCEPTION(0xf40)
+	EXCEPTION(0xf60)
+	EXCEPTION(0xf80)

tests/privileged/powerpc.lds

@@ -0,0 +1,13 @@
+SECTIONS
+{
+	_start = .;
+	. = 0;
+	.head : {
+		KEEP(*(.head))
+ 	}
+	. = 0x2000;
+	.text : { *(.text) }
+	. = 0x4000;
+	.data : { *(.data) }
+	.bss : { *(.bss) }
+}

tests/privileged/privileged.c

@@ -0,0 +1,152 @@
+#include <stddef.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+#include "console.h"
+
+#define MSR_EE	0x8000
+#define MSR_PR	0x4000
+#define MSR_IR	0x0020
+#define MSR_DR	0x0010
+
+extern int call_with_msr(unsigned long arg, int (*fn)(unsigned long), unsigned long msr);
+
+#define SRR0	26
+#define SRR1	27
+
+static inline unsigned long mfspr(int sprnum)
+{
+	long val;
+
+	__asm__ volatile("mfspr %0,%1" : "=r" (val) : "i" (sprnum));
+	return val;
+}
+
+static inline void mtspr(int sprnum, unsigned long val)
+{
+	__asm__ volatile("mtspr %0,%1" : : "i" (sprnum), "r" (val));
+}
+
+void print_string(const char *str)
+{
+	for (; *str; ++str)
+		putchar(*str);
+}
+
+void print_hex(unsigned long val, int ndigits)
+{
+	int i, x;
+
+	for (i = (ndigits - 1) * 4; i >= 0; i -= 4) {
+		x = (val >> i) & 0xf;
+		if (x >= 10)
+			putchar(x + 'a' - 10);
+		else
+			putchar(x + '0');
+	}
+}
+
+// i < 100
+void print_test_number(int i)
+{
+	print_string("test ");
+	putchar(48 + i/10);
+	putchar(48 + i%10);
+	putchar(':');
+}
+
+int priv_fn_1(unsigned long x)
+{
+	__asm__ volatile("attn");
+	__asm__ volatile("li 3,0; sc");
+	return 0;
+}
+
+int priv_fn_2(unsigned long x)
+{
+	__asm__ volatile("mfmsr 3");
+	__asm__ volatile("sc");
+	return 0;
+}
+
+int priv_fn_3(unsigned long x)
+{
+	__asm__ volatile("mtmsrd 3");
+	__asm__ volatile("li 3,0; sc");
+	return 0;
+}
+
+int priv_fn_4(unsigned long x)
+{
+	__asm__ volatile("rfid");
+	__asm__ volatile("li 3,0; sc");
+	return 0;
+}
+
+int priv_fn_5(unsigned long x)
+{
+	__asm__ volatile("mfsrr0 3");
+	__asm__ volatile("sc");
+	return 0;
+}
+
+int priv_fn_6(unsigned long x)
+{
+	__asm__ volatile("mtsrr0 3");
+	__asm__ volatile("sc");
+	return 0;
+}
+
+int priv_test(int (*fn)(unsigned long))
+{
+	unsigned long msr;
+	int vec;
+
+	__asm__ volatile ("mtdec %0" : : "r" (0x7fffffff));
+	__asm__ volatile ("mfmsr %0" : "=r" (msr));
+	/* this should fail */
+	vec = call_with_msr(0, fn, msr | MSR_PR);
+	if (vec != 0x700)
+		return vec | 1;
+	/* SRR1 should be set correctly */
+	msr |= MSR_PR | MSR_EE | MSR_IR | MSR_DR;
+	if (mfspr(SRR1) != (msr | 0x40000))
+		return 2;
+	return 0;
+}
+
+int fail = 0;
+
+void do_test(int num, int (*fn)(unsigned long))
+{
+	int ret;
+
+	print_test_number(num);
+	ret = priv_test(fn);
+	if (ret == 0) {
+		print_string("PASS\r\n");
+	} else {
+		fail = 1;
+		print_string("FAIL ");
+		print_hex(ret, 4);
+		print_string(" SRR0=");
+		print_hex(mfspr(SRR0), 16);
+		print_string(" SRR1=");
+		print_hex(mfspr(SRR1), 16);
+		print_string("\r\n");
+	}
+}
+
+int main(void)
+{
+	potato_uart_init();
+
+	do_test(1, priv_fn_1);
+	do_test(2, priv_fn_2);
+	do_test(3, priv_fn_3);
+	do_test(4, priv_fn_4);
+	do_test(5, priv_fn_5);
+	do_test(6, priv_fn_6);
+
+	return fail;
+}

tests/test_privileged.console_out

@@ -0,0 +1,6 @@
+test 01:PASS
+test 02:PASS
+test 03:PASS
+test 04:PASS
+test 05:PASS
+test 06:PASS

tests/update_console_tests

@@ -3,7 +3,7 @@
 # Script to update console related tests from source
 #
 
-for i in sc illegal decrementer ; do
+for i in sc illegal decrementer privileged ; do
     cd $i
     make
     cd -