[SCSI] bfa: Use pcie_set()/get_readrq() to simplify code

Use pcie_get_readrq()/pcie_set_readrq() to simplify code.

Jon Mason proposed a similar patch a couple years ago (see below).

[bhelgaas: validate pcie_max_read_reqsz, add pointer to Jon's patch]
Reference: http://lkml.kernel.org/r/1309191190-14670-1-git-send-email-jdmason@kudzu.us
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Anil Gurumurthy <agurumur@brocade.com>
Cc: Vijaya Mohan Guvva <vmohan@brocade.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>

1 files changed, 12 insertions, 41 deletions

diff --git a/drivers/scsi/bfa/bfad.c b/drivers/scsi/bfa/bfad.c
index f8ca7becacca..7591fa4e28bb 100644
--- a/drivers/scsi/bfa/bfad.c
+++ b/drivers/scsi/bfa/bfad.c
@@ -766,49 +766,20 @@ bfad_pci_init(struct pci_dev *pdev, struct bfad_s *bfad)
         bfad->pcidev = pdev;
 
         /* Adjust PCIe Maximum Read Request Size */
-        if (pcie_max_read_reqsz > 0) {
-                int pcie_cap_reg;
-                u16 pcie_dev_ctl;
-                u16 mask = 0xffff;
-
-                switch (pcie_max_read_reqsz) {
-                case 128:
-                        mask = 0x0;
-                        break;
-                case 256:
-                        mask = 0x1000;
-                        break;
-                case 512:
-                        mask = 0x2000;
-                        break;
-                case 1024:
-                        mask = 0x3000;
-                        break;
-                case 2048:
-                        mask = 0x4000;
-                        break;
-                case 4096:
-                        mask = 0x5000;
-                        break;
-                default:
-                        break;
-                }
-
-                pcie_cap_reg = pci_find_capability(pdev, PCI_CAP_ID_EXP);
-                if (mask != 0xffff && pcie_cap_reg) {
-                        pcie_cap_reg += 0x08;
-                        pci_read_config_word(pdev, pcie_cap_reg, &pcie_dev_ctl);
-                        if ((pcie_dev_ctl & 0x7000) != mask) {
-                                printk(KERN_WARNING "BFA[%s]: "
+        if (pci_is_pcie(pdev) && pcie_max_read_reqsz) {
+                if (pcie_max_read_reqsz >= 128 &&
+                    pcie_max_read_reqsz <= 4096 &&
+                    is_power_of_2(pcie_max_read_reqsz)) {
+                        int max_rq = pcie_get_readrq(pdev);
+                        printk(KERN_WARNING "BFA[%s]: "
                                 "pcie_max_read_request_size is %d, "
-                                "reset to %d\n", bfad->pci_name,
-                                (1 << ((pcie_dev_ctl & 0x7000) >> 12)) << 7,
+                                "reset to %d\n", bfad->pci_name, max_rq,
                                 pcie_max_read_reqsz);
-
-                                pcie_dev_ctl &= ~0x7000;
-                                pci_write_config_word(pdev, pcie_cap_reg,
-                                                pcie_dev_ctl | mask);
-                        }
+                        pcie_set_readrq(pdev, pcie_max_read_reqsz);
+                } else {
+                        printk(KERN_WARNING "BFA[%s]: invalid "
+                               "pcie_max_read_request_size %d ignored\n",
+                               bfad->pci_name, pcie_max_read_reqsz);
                 }
         }