Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / crypto / xor.c

diff --git a/kernel/crypto/xor.c b/kernel/crypto/xor.c
new file mode 100644 (file)
index 0000000..35d6b3a
--- /dev/null
+++ b/kernel/crypto/xor.c
@@ -0,0 +1,169 @@
+/*
+ * xor.c : Multiple Devices driver for Linux
+ *
+ * Copyright (C) 1996, 1997, 1998, 1999, 2000,
+ * Ingo Molnar, Matti Aarnio, Jakub Jelinek, Richard Henderson.
+ *
+ * Dispatch optimized RAID-5 checksumming functions.
+ *
+ * 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, or (at your option)
+ * any later version.
+ *
+ * You should have received a copy of the GNU General Public License
+ * (for example /usr/src/linux/COPYING); if not, write to the Free
+ * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#define BH_TRACE 0
+#include <linux/module.h>
+#include <linux/gfp.h>
+#include <linux/raid/xor.h>
+#include <linux/jiffies.h>
+#include <linux/preempt.h>
+#include <asm/xor.h>
+
+/* The xor routines to use.  */
+static struct xor_block_template *active_template;
+
+void
+xor_blocks(unsigned int src_count, unsigned int bytes, void *dest, void **srcs)
+{
+       unsigned long *p1, *p2, *p3, *p4;
+
+       p1 = (unsigned long *) srcs[0];
+       if (src_count == 1) {
+               active_template->do_2(bytes, dest, p1);
+               return;
+       }
+
+       p2 = (unsigned long *) srcs[1];
+       if (src_count == 2) {
+               active_template->do_3(bytes, dest, p1, p2);
+               return;
+       }
+
+       p3 = (unsigned long *) srcs[2];
+       if (src_count == 3) {
+               active_template->do_4(bytes, dest, p1, p2, p3);
+               return;
+       }
+
+       p4 = (unsigned long *) srcs[3];
+       active_template->do_5(bytes, dest, p1, p2, p3, p4);
+}
+EXPORT_SYMBOL(xor_blocks);
+
+/* Set of all registered templates.  */
+static struct xor_block_template *__initdata template_list;
+
+#define BENCH_SIZE (PAGE_SIZE)
+
+static void __init
+do_xor_speed(struct xor_block_template *tmpl, void *b1, void *b2)
+{
+       int speed;
+       unsigned long now, j;
+       int i, count, max;
+
+       tmpl->next = template_list;
+       template_list = tmpl;
+
+       preempt_disable();
+
+       /*
+        * Count the number of XORs done during a whole jiffy, and use
+        * this to calculate the speed of checksumming.  We use a 2-page
+        * allocation to have guaranteed color L1-cache layout.
+        */
+       max = 0;
+       for (i = 0; i < 5; i++) {
+               j = jiffies;
+               count = 0;
+               while ((now = jiffies) == j)
+                       cpu_relax();
+               while (time_before(jiffies, now + 1)) {
+                       mb(); /* prevent loop optimzation */
+                       tmpl->do_2(BENCH_SIZE, b1, b2);
+                       mb();
+                       count++;
+                       mb();
+               }
+               if (count > max)
+                       max = count;
+       }
+
+       preempt_enable();
+
+       speed = max * (HZ * BENCH_SIZE / 1024);
+       tmpl->speed = speed;
+
+       printk(KERN_INFO "   %-10s: %5d.%03d MB/sec\n", tmpl->name,
+              speed / 1000, speed % 1000);
+}
+
+static int __init
+calibrate_xor_blocks(void)
+{
+       void *b1, *b2;
+       struct xor_block_template *f, *fastest;
+
+       /*
+        * Note: Since the memory is not actually used for _anything_ but to
+        * test the XOR speed, we don't really want kmemcheck to warn about
+        * reading uninitialized bytes here.
+        */
+       b1 = (void *) __get_free_pages(GFP_KERNEL | __GFP_NOTRACK, 2);
+       if (!b1) {
+               printk(KERN_WARNING "xor: Yikes!  No memory available.\n");
+               return -ENOMEM;
+       }
+       b2 = b1 + 2*PAGE_SIZE + BENCH_SIZE;
+
+       /*
+        * If this arch/cpu has a short-circuited selection, don't loop through
+        * all the possible functions, just test the best one
+        */
+
+       fastest = NULL;
+
+#ifdef XOR_SELECT_TEMPLATE
+               fastest = XOR_SELECT_TEMPLATE(fastest);
+#endif
+
+#define xor_speed(templ)       do_xor_speed((templ), b1, b2)
+
+       if (fastest) {
+               printk(KERN_INFO "xor: automatically using best "
+                                "checksumming function:\n");
+               xor_speed(fastest);
+               goto out;
+       } else {
+               printk(KERN_INFO "xor: measuring software checksum speed\n");
+               XOR_TRY_TEMPLATES;
+               fastest = template_list;
+               for (f = fastest; f; f = f->next)
+                       if (f->speed > fastest->speed)
+                               fastest = f;
+       }
+
+       printk(KERN_INFO "xor: using function: %s (%d.%03d MB/sec)\n",
+              fastest->name, fastest->speed / 1000, fastest->speed % 1000);
+
+#undef xor_speed
+
+ out:
+       free_pages((unsigned long)b1, 2);
+
+       active_template = fastest;
+       return 0;
+}
+
+static __exit void xor_exit(void) { }
+
+MODULE_LICENSE("GPL");
+
+/* when built-in xor.o must initialize before drivers/md/md.o */
+core_initcall(calibrate_xor_blocks);
+module_exit(xor_exit);