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. <[email protected]>
---
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 [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
