Commit d1f9b39d authored by Ilpo Järvinen's avatar Ilpo Järvinen Committed by Bjorn Helgaas
Browse files

PCI: Use FIELD_GET() to extract Link Width 

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: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
[bhelgaas: drop duplicate include of <linux/bitfield.h>]
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 408599ec

drivers/pci/pci-sysfs.c

+2 −3
Original line number Diff line number Diff line
@@ -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);

drivers/pci/pci.c

+2 −3
Original line number Diff line number Diff line
@@ -6257,8 +6257,7 @@ 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);
@@ -6330,7 +6329,7 @@ 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;

}