[PATCH 3.7.0 5/9] i82975x_edac: optimise mode detection

[Arvind R]

Subject: [PATCH 3.7.0 5/9] i82975x_edac: optimise mode detection

Minor optimisation of dual channel symmetric operation. Return
value changed to bool.
Signed-off-by: Arvind R. <arvino55@xxxxxxxxx>
---
 i82975x_edac.c |   45 ++++++++++++++++++++----------------------
 1 file changed, 22 insertions(+), 23 deletions(-)

--- a/drivers/edac/i82975x_edac.c	2012-12-15 22:14:18.000000000 +0530
+++ b/drivers/edac/i82975x_edac.c	2012-12-15 22:17:12.000000000 +0530
@@ -31,6 +31,7 @@

 #define I82975X_NR_DIMMS		8
 #define I82975X_NR_CSROWS(nr_chans)	(I82975X_NR_DIMMS / (nr_chans))
+#define	I82975X_NR_CSROWS_PER_CHANNEL	4

 /* Intel 82975X register addresses - device 0 function 0 - DRAM Controller */
 #define I82975X_EAP		0x58	/* Dram Error Address Pointer (32b)
@@ -337,29 +338,6 @@ static void i82975x_check(struct mem_ctl
 	i82975x_process_error_info(mci, &info, 1);
 }

-/* Return 1 if dual channel mode is active.  Else return 0. */
-static int dual_channel_active(void __iomem *mch_window)
-{
-	/*
-	 * We treat interleaved-symmetric configuration as dual-channel - EAP's
-	 * bit-0 giving the channel of the error location.
-	 *
-	 * All other configurations are treated as single channel - the EAP's
-	 * bit-0 will resolve ok in symmetric area of mixed
-	 * (symmetric/asymmetric) configurations
-	 */
-	u8	drb[4][2];
-	int	row;
-	int    dualch;
-
-	for (dualch = 1, row = 0; dualch && (row < 4); row++) {
-		drb[row][0] = readb(mch_window + I82975X_DRB + row);
-		drb[row][1] = readb(mch_window + I82975X_DRB + row + 0x80);
-		dualch = dualch && (drb[row][0] == drb[row][1]);
-	}
-	return dualch;
-}
-
 static void i82975x_init_csrows(struct mem_ctl_info *mci,
 		struct pci_dev *pdev, void __iomem *mch_window)
 {
@@ -527,6 +505,27 @@ static void i82975x_print_dram_timings(v
 }
 #endif

+/* Return 1 if dual channel mode is active.  Else return 0. */
+static bool dual_channel_active(void __iomem *mch_window)
+{
+	/*
+	 * We treat interleaved-symmetric configuration as dual-channel.
+	 * All other configurations are virtual single channel mode.
+	 * bit-0 of EAP always provides the real channel in error.
+	 */
+	u8	drb[2];
+	int	row;
+	bool    dualch;
+
+	for (dualch = 1, row = 0; dualch &&
+			(row < I82975X_NR_CSROWS_PER_CHANNEL); row++) {
+		drb[0] = readb(mch_window + I82975X_DRB + row);
+		drb[1] = readb(mch_window + I82975X_DRB + row + 0x80);
+		dualch &= (drb[0] == drb[1]);
+	}
+	return dualch;
+}
+
 static int i82975x_probe1(struct pci_dev *pdev, int dev_idx)
 {
 	int rc = -ENODEV;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/