PCI/MSI: Use FIELD_GET/PREP()

Instead of custom masking and shifting, use FIELD_GET/PREP() with
register fields.

Link: https://lore.kernel.org/r/20231018113254.17616-8-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c
index ef1d8857a51ba691701e049efb9c05d668e9dc27..682fa877478fe9df875c465d2b7d1a92f414aa5a 100644 (file)
--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -6,6 +6,7 @@
  * Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
  * Copyright (C) 2016 Christoph Hellwig.
  */
+#include <linux/bitfield.h>
 #include <linux/err.h>
 #include <linux/export.h>
 #include <linux/irq.h>
@@ -188,7 +189,7 @@ static inline void pci_write_msg_msi(struct pci_dev *dev, struct msi_desc *desc,
 
        pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl);
        msgctl &= ~PCI_MSI_FLAGS_QSIZE;
-       msgctl |= desc->pci.msi_attrib.multiple << 4;
+       msgctl |= FIELD_PREP(PCI_MSI_FLAGS_QSIZE, desc->pci.msi_attrib.multiple);
        pci_write_config_word(dev, pos + PCI_MSI_FLAGS, msgctl);
 
        pci_write_config_dword(dev, pos + PCI_MSI_ADDRESS_LO, msg->address_lo);
@@ -299,7 +300,7 @@ static int msi_setup_msi_desc(struct pci_dev *dev, int nvec,
        desc.pci.msi_attrib.is_64       = !!(control & PCI_MSI_FLAGS_64BIT);
        desc.pci.msi_attrib.can_mask    = !!(control & PCI_MSI_FLAGS_MASKBIT);
        desc.pci.msi_attrib.default_irq = dev->irq;
-       desc.pci.msi_attrib.multi_cap   = (control & PCI_MSI_FLAGS_QMASK) >> 1;
+       desc.pci.msi_attrib.multi_cap   = FIELD_GET(PCI_MSI_FLAGS_QMASK, control);
        desc.pci.msi_attrib.multiple    = ilog2(__roundup_pow_of_two(nvec));
        desc.affinity                   = masks;
 
@@ -478,7 +479,7 @@ int pci_msi_vec_count(struct pci_dev *dev)
                return -EINVAL;
 
        pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &msgctl);
-       ret = 1 << ((msgctl & PCI_MSI_FLAGS_QMASK) >> 1);
+       ret = 1 << FIELD_GET(PCI_MSI_FLAGS_QMASK, msgctl);
 
        return ret;
 }
@@ -511,7 +512,8 @@ void __pci_restore_msi_state(struct pci_dev *dev)
        pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
        pci_msi_update_mask(entry, 0, 0);
        control &= ~PCI_MSI_FLAGS_QSIZE;
-       control |= (entry->pci.msi_attrib.multiple << 4) | PCI_MSI_FLAGS_ENABLE;
+       control |= PCI_MSI_FLAGS_ENABLE |
+                  FIELD_PREP(PCI_MSI_FLAGS_QSIZE, entry->pci.msi_attrib.multiple);
        pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control);
 }