Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/arch/mips/kernel/cpu-bugs64.c b/arch/mips/kernel/cpu-bugs64.c
new file mode 100644
index 0000000..11ebe5d
--- /dev/null
+++ b/arch/mips/kernel/cpu-bugs64.c
@@ -0,0 +1,321 @@
+/*
+ * Copyright (C) 2003, 2004 Maciej W. Rozycki
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include <linux/config.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/ptrace.h>
+#include <linux/stddef.h>
+
+#include <asm/bugs.h>
+#include <asm/compiler.h>
+#include <asm/cpu.h>
+#include <asm/fpu.h>
+#include <asm/mipsregs.h>
+#include <asm/system.h>
+
+static inline void align_mod(const int align, const int mod)
+{
+ asm volatile(
+ ".set push\n\t"
+ ".set noreorder\n\t"
+ ".balign %0\n\t"
+ ".rept %1\n\t"
+ "nop\n\t"
+ ".endr\n\t"
+ ".set pop"
+ :
+ : "n" (align), "n" (mod));
+}
+
+static inline void mult_sh_align_mod(long *v1, long *v2, long *w,
+ const int align, const int mod)
+{
+ unsigned long flags;
+ int m1, m2;
+ long p, s, lv1, lv2, lw;
+
+ /*
+ * We want the multiply and the shift to be isolated from the
+ * rest of the code to disable gcc optimizations. Hence the
+ * asm statements that execute nothing, but make gcc not know
+ * what the values of m1, m2 and s are and what lv2 and p are
+ * used for.
+ */
+
+ local_irq_save(flags);
+ /*
+ * The following code leads to a wrong result of the first
+ * dsll32 when executed on R4000 rev. 2.2 or 3.0 (PRId
+ * 00000422 or 00000430, respectively).
+ *
+ * See "MIPS R4000PC/SC Errata, Processor Revision 2.2 and
+ * 3.0" by MIPS Technologies, Inc., errata #16 and #28 for
+ * details. I got no permission to duplicate them here,
+ * sigh... --macro
+ */
+ asm volatile(
+ ""
+ : "=r" (m1), "=r" (m2), "=r" (s)
+ : "0" (5), "1" (8), "2" (5));
+ align_mod(align, mod);
+ /*
+ * The trailing nop is needed to fullfill the two-instruction
+ * requirement between reading hi/lo and staring a mult/div.
+ * Leaving it out may cause gas insert a nop itself breaking
+ * the desired alignment of the next chunk.
+ */
+ asm volatile(
+ ".set push\n\t"
+ ".set noat\n\t"
+ ".set noreorder\n\t"
+ ".set nomacro\n\t"
+ "mult %2, %3\n\t"
+ "dsll32 %0, %4, %5\n\t"
+ "mflo $0\n\t"
+ "dsll32 %1, %4, %5\n\t"
+ "nop\n\t"
+ ".set pop"
+ : "=&r" (lv1), "=r" (lw)
+ : "r" (m1), "r" (m2), "r" (s), "I" (0)
+ : "hi", "lo", GCC_REG_ACCUM);
+ /* We have to use single integers for m1 and m2 and a double
+ * one for p to be sure the mulsidi3 gcc's RTL multiplication
+ * instruction has the workaround applied. Older versions of
+ * gcc have correct umulsi3 and mulsi3, but other
+ * multiplication variants lack the workaround.
+ */
+ asm volatile(
+ ""
+ : "=r" (m1), "=r" (m2), "=r" (s)
+ : "0" (m1), "1" (m2), "2" (s));
+ align_mod(align, mod);
+ p = m1 * m2;
+ lv2 = s << 32;
+ asm volatile(
+ ""
+ : "=r" (lv2)
+ : "0" (lv2), "r" (p));
+ local_irq_restore(flags);
+
+ *v1 = lv1;
+ *v2 = lv2;
+ *w = lw;
+}
+
+static inline void check_mult_sh(void)
+{
+ long v1[8], v2[8], w[8];
+ int bug, fix, i;
+
+ printk("Checking for the multiply/shift bug... ");
+
+ /*
+ * Testing discovered false negatives for certain code offsets
+ * into cache lines. Hence we test all possible offsets for
+ * the worst assumption of an R4000 I-cache line width of 32
+ * bytes.
+ *
+ * We can't use a loop as alignment directives need to be
+ * immediates.
+ */
+ mult_sh_align_mod(&v1[0], &v2[0], &w[0], 32, 0);
+ mult_sh_align_mod(&v1[1], &v2[1], &w[1], 32, 1);
+ mult_sh_align_mod(&v1[2], &v2[2], &w[2], 32, 2);
+ mult_sh_align_mod(&v1[3], &v2[3], &w[3], 32, 3);
+ mult_sh_align_mod(&v1[4], &v2[4], &w[4], 32, 4);
+ mult_sh_align_mod(&v1[5], &v2[5], &w[5], 32, 5);
+ mult_sh_align_mod(&v1[6], &v2[6], &w[6], 32, 6);
+ mult_sh_align_mod(&v1[7], &v2[7], &w[7], 32, 7);
+
+ bug = 0;
+ for (i = 0; i < 8; i++)
+ if (v1[i] != w[i])
+ bug = 1;
+
+ if (bug == 0) {
+ printk("no.\n");
+ return;
+ }
+
+ printk("yes, workaround... ");
+
+ fix = 1;
+ for (i = 0; i < 8; i++)
+ if (v2[i] != w[i])
+ fix = 0;
+
+ if (fix == 1) {
+ printk("yes.\n");
+ return;
+ }
+
+ printk("no.\n");
+ panic("Reliable operation impossible!\n"
+#ifndef CONFIG_CPU_R4000
+ "Configure for R4000 to enable the workaround."
+#else
+ "Please report to <linux-mips@linux-mips.org>."
+#endif
+ );
+}
+
+static volatile int daddi_ov __initdata = 0;
+
+asmlinkage void __init do_daddi_ov(struct pt_regs *regs)
+{
+ daddi_ov = 1;
+ regs->cp0_epc += 4;
+}
+
+static inline void check_daddi(void)
+{
+ extern asmlinkage void handle_daddi_ov(void);
+ unsigned long flags;
+ void *handler;
+ long v, tmp;
+
+ printk("Checking for the daddi bug... ");
+
+ local_irq_save(flags);
+ handler = set_except_vector(12, handle_daddi_ov);
+ /*
+ * The following code fails to trigger an overflow exception
+ * when executed on R4000 rev. 2.2 or 3.0 (PRId 00000422 or
+ * 00000430, respectively).
+ *
+ * See "MIPS R4000PC/SC Errata, Processor Revision 2.2 and
+ * 3.0" by MIPS Technologies, Inc., erratum #23 for details.
+ * I got no permission to duplicate it here, sigh... --macro
+ */
+ asm volatile(
+ ".set push\n\t"
+ ".set noat\n\t"
+ ".set noreorder\n\t"
+ ".set nomacro\n\t"
+ "addiu %1, $0, %2\n\t"
+ "dsrl %1, %1, 1\n\t"
+#ifdef HAVE_AS_SET_DADDI
+ ".set daddi\n\t"
+#endif
+ "daddi %0, %1, %3\n\t"
+ ".set pop"
+ : "=r" (v), "=&r" (tmp)
+ : "I" (0xffffffffffffdb9a), "I" (0x1234));
+ set_except_vector(12, handler);
+ local_irq_restore(flags);
+
+ if (daddi_ov) {
+ printk("no.\n");
+ return;
+ }
+
+ printk("yes, workaround... ");
+
+ local_irq_save(flags);
+ handler = set_except_vector(12, handle_daddi_ov);
+ asm volatile(
+ "addiu %1, $0, %2\n\t"
+ "dsrl %1, %1, 1\n\t"
+ "daddi %0, %1, %3"
+ : "=r" (v), "=&r" (tmp)
+ : "I" (0xffffffffffffdb9a), "I" (0x1234));
+ set_except_vector(12, handler);
+ local_irq_restore(flags);
+
+ if (daddi_ov) {
+ printk("yes.\n");
+ return;
+ }
+
+ printk("no.\n");
+ panic("Reliable operation impossible!\n"
+#if !defined(CONFIG_CPU_R4000) && !defined(CONFIG_CPU_R4400)
+ "Configure for R4000 or R4400 to enable the workaround."
+#else
+ "Please report to <linux-mips@linux-mips.org>."
+#endif
+ );
+}
+
+static inline void check_daddiu(void)
+{
+ long v, w, tmp;
+
+ printk("Checking for the daddiu bug... ");
+
+ /*
+ * The following code leads to a wrong result of daddiu when
+ * executed on R4400 rev. 1.0 (PRId 00000440).
+ *
+ * See "MIPS R4400PC/SC Errata, Processor Revision 1.0" by
+ * MIPS Technologies, Inc., erratum #7 for details.
+ *
+ * According to "MIPS R4000PC/SC Errata, Processor Revision
+ * 2.2 and 3.0" by MIPS Technologies, Inc., erratum #41 this
+ * problem affects R4000 rev. 2.2 and 3.0 (PRId 00000422 and
+ * 00000430, respectively), too. Testing failed to trigger it
+ * so far.
+ *
+ * I got no permission to duplicate the errata here, sigh...
+ * --macro
+ */
+ asm volatile(
+ ".set push\n\t"
+ ".set noat\n\t"
+ ".set noreorder\n\t"
+ ".set nomacro\n\t"
+ "addiu %2, $0, %3\n\t"
+ "dsrl %2, %2, 1\n\t"
+#ifdef HAVE_AS_SET_DADDI
+ ".set daddi\n\t"
+#endif
+ "daddiu %0, %2, %4\n\t"
+ "addiu %1, $0, %4\n\t"
+ "daddu %1, %2\n\t"
+ ".set pop"
+ : "=&r" (v), "=&r" (w), "=&r" (tmp)
+ : "I" (0xffffffffffffdb9a), "I" (0x1234));
+
+ if (v == w) {
+ printk("no.\n");
+ return;
+ }
+
+ printk("yes, workaround... ");
+
+ asm volatile(
+ "addiu %2, $0, %3\n\t"
+ "dsrl %2, %2, 1\n\t"
+ "daddiu %0, %2, %4\n\t"
+ "addiu %1, $0, %4\n\t"
+ "daddu %1, %2"
+ : "=&r" (v), "=&r" (w), "=&r" (tmp)
+ : "I" (0xffffffffffffdb9a), "I" (0x1234));
+
+ if (v == w) {
+ printk("yes.\n");
+ return;
+ }
+
+ printk("no.\n");
+ panic("Reliable operation impossible!\n"
+#if !defined(CONFIG_CPU_R4000) && !defined(CONFIG_CPU_R4400)
+ "Configure for R4000 or R4400 to enable the workaround."
+#else
+ "Please report to <linux-mips@linux-mips.org>."
+#endif
+ );
+}
+
+void __init check_bugs64(void)
+{
+ check_mult_sh();
+ check_daddi();
+ check_daddiu();
+}