Patch "PCI: Use FIELD_GET() to extract Link Width" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    PCI: Use FIELD_GET() to extract Link Width

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     pci-use-field_get-to-extract-link-width.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 07f95ec83ce0aa16626793cd8dfd3113acee964c
Author: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Date:   Tue Sep 19 15:56:46 2023 +0300

    PCI: Use FIELD_GET() to extract Link Width
    
    [ Upstream commit d1f9b39da4a5347150246871325190018cda8cb3 ]
    
    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@xxxxxxxxxxxxxxx
    Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
    [bhelgaas: drop duplicate include of <linux/bitfield.h>]
    Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
    Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index f2909ae93f2f8..c271720c7f86f 100644
--- 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>
@@ -208,8 +208,7 @@ 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
index 244c1c2e08767..371ba983b4084 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -6071,8 +6071,7 @@ 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);
 
@@ -6144,7 +6143,7 @@ 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;
 }