PCI/AER: Use for_each_set_bit() to simplify code

task #29600094

commit 6a8c97345a15f9c60ff6c6ac1629a3e9ec140320 upstream.
Backport summary: for 4.19 kernel ICX PCIe Gen4 support.

Simplify error counting code by using for_each_set_bit() library function.

Link: https://lore.kernel.org/r/20190827151823.75312-1-andriy.shevchenko@linux.intel.comSigned-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NKuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
(cherry picked from commit 6a8c97345a15f9c60ff6c6ac1629a3e9ec140320)
Signed-off-by: NEthan Zhao <haifeng.zhao@intel.com>
Signed-off-by: NArtie Ding <artie.ding@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>

drivers/pci/pcie/aer.c

@@ -15,6 +15,7 @@
 #define pr_fmt(fmt) "AER: " fmt
 #define dev_fmt pr_fmt
 
+#include <linux/bitops.h>
 #include <linux/cper.h>
 #include <linux/pci.h>
 #include <linux/pci-acpi.h>
@@ -716,7 +717,8 @@ const struct attribute_group aer_stats_attr_group = {
 static void pci_dev_aer_stats_incr(struct pci_dev *pdev,
 				   struct aer_err_info *info)
 {
-	int status, i, max = -1;
+	unsigned long status = info->status & ~info->mask;
+	int i, max = -1;
 	u64 *counter = NULL;
 	struct aer_stats *aer_stats = pdev->aer_stats;
 
@@ -741,9 +743,7 @@ static void pci_dev_aer_stats_incr(struct pci_dev *pdev,
 		break;
 	}
 
-	status = (info->status & ~info->mask);
-	for (i = 0; i < max; i++)
-		if (status & (1 << i))
+	for_each_set_bit(i, &status, max)
 		counter[i]++;
 }
 
@@ -776,14 +776,11 @@ static void __print_tlp_header(struct pci_dev *dev,
 static void __aer_print_error(struct pci_dev *dev,
 			      struct aer_err_info *info)
 {
-	int i, status;
+	unsigned long status = info->status & ~info->mask;
 	const char *errmsg = NULL;
-	status = (info->status & ~info->mask);
-
-	for (i = 0; i < 32; i++) {
-		if (!(status & (1 << i)))
-			continue;
+	int i;
 
+	for_each_set_bit(i, &status, 32) {
 		if (info->severity == AER_CORRECTABLE)
 			errmsg = i < ARRAY_SIZE(aer_correctable_error_string) ?
 				aer_correctable_error_string[i] : NULL;