PCI: Use FIELD_GET() to extract Link Width

[ Upstream commit d1f9b39 ] Use FIELD_GET() to extract PCIe Negotiated and Maximum Link Width fields instead of custom masking and shifting. Link: https://lore.kernel.org/r/20230919125648.1920-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> [bhelgaas: drop duplicate include of <linux/bitfield.h>] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
xanmod · Nov 28, 2023 · 5bb6d73 · 5bb6d73
1 parent f6fe726
commit 5bb6d73
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Showing 2 changed files with 4 additions and 6 deletions.
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
@@ -12,7 +12,7 @@
  * Modeled after usb's driverfs.c
  */
 
-
+#include <linux/bitfield.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/pci.h>
@@ -230,8 +230,7 @@ static ssize_t current_link_width_show(struct device *dev,
 	if (err)
 		return -EINVAL;
 
-	return sysfs_emit(buf, "%u\n",
-		(linkstat & PCI_EXP_LNKSTA_NLW) >> PCI_EXP_LNKSTA_NLW_SHIFT);
+	return sysfs_emit(buf, "%u\n", FIELD_GET(PCI_EXP_LNKSTA_NLW, linkstat));
 }
 static DEVICE_ATTR_RO(current_link_width);
 

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
@@ -6255,8 +6255,7 @@ u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev,
 		pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta);
 
 		next_speed = pcie_link_speed[lnksta & PCI_EXP_LNKSTA_CLS];
-		next_width = (lnksta & PCI_EXP_LNKSTA_NLW) >>
-			PCI_EXP_LNKSTA_NLW_SHIFT;
+		next_width = FIELD_GET(PCI_EXP_LNKSTA_NLW, lnksta);
 
 		next_bw = next_width * PCIE_SPEED2MBS_ENC(next_speed);
 
@@ -6328,7 +6327,7 @@ enum pcie_link_width pcie_get_width_cap(struct pci_dev *dev)
 
 	pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap);
 	if (lnkcap)
-		return (lnkcap & PCI_EXP_LNKCAP_MLW) >> 4;
+		return FIELD_GET(PCI_EXP_LNKCAP_MLW, lnkcap);
 
 	return PCIE_LNK_WIDTH_UNKNOWN;
 }