calibration: lift jhash from 3.8

jhash changed from 2.6.24.7-rt27, so we have to lift it from a later kernel

calibration: lift jhash from 3.8
jhash changed from 2.6.24.7-rt27, so we have to lift it from a later kernel
92b41d36 · Juan David González Cobas · 0c955a31 · 92b41d36
Commit 92b41d36 authored May 17, 2013 by Juan David González Cobas
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calibration.c kernel/calibration.c +78 -1

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--- a/kernel/calibration.c
+++ b/kernel/calibration.c
@@ -13,7 +13,6 @@
 #include <linux/moduleparam.h>
 #include <linux/time.h>
 #include <linux/firmware.h>
-#include <linux/jhash.h>
 #include "fine-delay.h"
 #include "../sdb-lib/libsdbfs.h"

@@ -28,6 +27,82 @@ module_param(calibration_default, int, 0444);
 module_param(calibration_save, int, 0444);
 module_param(calibration_check, int, 0444);

+/* jhash() differs in 2.6.24 and the calibration hashes
+ * were computed with a later version. Hence, we lift
+ * this code from 3.8
+ */
+struct __una_u32 { u32 x; } __packed;
+static inline u32 __get_unaligned_cpu32(const void *p)
+{
+        const struct __una_u32 *ptr = (const struct __una_u32 *)p;
+        return ptr->x;
+}
+
+#define JHASH_INITVAL           0xdeadbeef
+/* __jhash_mix -- mix 3 32-bit values reversibly. */
+#define __jhash_mix(a, b, c)                    \
+{                                               \
+        a -= c;  a ^= rol32(c, 4);  c += b;     \
+        b -= a;  b ^= rol32(a, 6);  a += c;     \
+        c -= b;  c ^= rol32(b, 8);  b += a;     \
+        a -= c;  a ^= rol32(c, 16); c += b;     \
+        b -= a;  b ^= rol32(a, 19); a += c;     \
+        c -= b;  c ^= rol32(b, 4);  b += a;     \
+}
+
+/* __jhash_final - final mixing of 3 32-bit values (a,b,c) into c */
+#define __jhash_final(a, b, c)                  \
+{                                               \
+        c ^= b; c -= rol32(b, 14);              \
+        a ^= c; a -= rol32(c, 11);              \
+        b ^= a; b -= rol32(a, 25);              \
+        c ^= b; c -= rol32(b, 16);              \
+        a ^= c; a -= rol32(c, 4);               \
+        b ^= a; b -= rol32(a, 14);              \
+        c ^= b; c -= rol32(b, 24);              \
+}
+
+
+static inline u32 jhash(const void *key, u32 length, u32 initval)
+{
+        u32 a, b, c;
+        const u8 *k = key;
+
+        /* Set up the internal state */
+        a = b = c = JHASH_INITVAL + length + initval;
+
+        /* All but the last block: affect some 32 bits of (a,b,c) */
+        while (length > 12) {
+                a += __get_unaligned_cpu32(k);
+                b += __get_unaligned_cpu32(k + 4);
+                c += __get_unaligned_cpu32(k + 8);
+                __jhash_mix(a, b, c);
+                length -= 12;
+                k += 12;
+        }
+        /* Last block: affect all 32 bits of (c) */
+        /* All the case statements fall through */
+        switch (length) {
+        case 12: c += (u32)k[11]<<24;
+        case 11: c += (u32)k[10]<<16;
+        case 10: c += (u32)k[9]<<8;
+        case 9:  c += k[8];
+        case 8:  b += (u32)k[7]<<24;
+        case 7:  b += (u32)k[6]<<16;
+        case 6:  b += (u32)k[5]<<8;
+        case 5:  b += k[4];
+        case 4:  a += (u32)k[3]<<24;
+        case 3:  a += (u32)k[2]<<16;
+        case 2:  a += (u32)k[1]<<8;
+        case 1:  a += k[0];
+                 __jhash_final(a, b, c);
+        case 0: /* Nothing left to add */
+                break;
+        }
+
+        return c;
+}
+
 /* Stupid dumping tool */
 static void dumpstruct(char *name, void *ptr, int size)
 {
@@ -169,6 +244,8 @@ int fd_handle_eeprom_calibration(struct fd_dev *fd)
 				 (long)calib->zero_offset[i]);
 		dev_info(d, "calib: tdc_offset %i\n", calib->tdc_zero_offset);
 		dev_info(d, "calib: vcxo %i\n", calib->vcxo_default_tune);
+		dev_info(d, "calib hash: %08x\n", hash);
+		dev_info(d, "calib hash original: %08x\n", horig);
 	}

 	if (hash != horig) {