From 1a84b99ccbb954ce201024691babfe4d7d9f506f Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Sat, 14 Dec 2013 13:06:07 -0700 Subject: [PATCH] PCI: pciehp: Remove error checks when accessing PCIe Capability There's not much point in checking the return value from every config space access because the only likely errors are design-time things like unaligned accesses or invalid register numbers. The checking clutters the code significantly, so this patch removes it. No functional change. Reference: http://lkml.kernel.org/r/CA+55aFzP4xEbcNmZ+MS0SQ3LrULzSq+dBiT_X9U-bPpR-Ukgrw@mail.gmail.com Signed-off-by: Bjorn Helgaas --- drivers/pci/hotplug/pciehp_hpc.c | 177 +++++++------------------------ 1 file changed, 41 insertions(+), 136 deletions(-) diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 53bb5501d199..6afdd2358227 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -112,10 +112,10 @@ static int pcie_poll_cmd(struct controller *ctrl) { struct pci_dev *pdev = ctrl_dev(ctrl); u16 slot_status; - int err, timeout = 1000; + int timeout = 1000; - err = pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); - if (!err && (slot_status & PCI_EXP_SLTSTA_CC)) { + pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); + if (slot_status & PCI_EXP_SLTSTA_CC) { pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, PCI_EXP_SLTSTA_CC); return 1; @@ -123,9 +123,8 @@ static int pcie_poll_cmd(struct controller *ctrl) while (timeout > 0) { msleep(10); timeout -= 10; - err = pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, - &slot_status); - if (!err && (slot_status & PCI_EXP_SLTSTA_CC)) { + pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); + if (slot_status & PCI_EXP_SLTSTA_CC) { pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, PCI_EXP_SLTSTA_CC); return 1; @@ -157,19 +156,12 @@ static void pcie_wait_cmd(struct controller *ctrl, int poll) static int pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask) { struct pci_dev *pdev = ctrl_dev(ctrl); - int retval = 0; u16 slot_status; u16 slot_ctrl; mutex_lock(&ctrl->ctrl_lock); - retval = pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); - if (retval) { - ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS register\n", - __func__); - goto out; - } - + pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); if (slot_status & PCI_EXP_SLTSTA_CC) { if (!ctrl->no_cmd_complete) { /* @@ -193,24 +185,17 @@ static int pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask) } } - retval = pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl); - if (retval) { - ctrl_err(ctrl, "%s: Cannot read SLOTCTRL register\n", __func__); - goto out; - } - + pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl); slot_ctrl &= ~mask; slot_ctrl |= (cmd & mask); ctrl->cmd_busy = 1; smp_mb(); - retval = pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, slot_ctrl); - if (retval) - ctrl_err(ctrl, "Cannot write to SLOTCTRL register\n"); + pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, slot_ctrl); /* * Wait for command completion. */ - if (!retval && !ctrl->no_cmd_complete) { + if (!ctrl->no_cmd_complete) { int poll = 0; /* * if hotplug interrupt is not enabled or command @@ -222,20 +207,17 @@ static int pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask) poll = 1; pcie_wait_cmd(ctrl, poll); } - out: mutex_unlock(&ctrl->ctrl_lock); - return retval; + return 0; } static bool check_link_active(struct controller *ctrl) { struct pci_dev *pdev = ctrl_dev(ctrl); - bool ret = false; u16 lnk_status; + bool ret; - if (pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status)) - return ret; - + pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status); ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA); if (ret) @@ -299,9 +281,8 @@ static bool pci_bus_check_dev(struct pci_bus *bus, int devfn) int pciehp_check_link_status(struct controller *ctrl) { struct pci_dev *pdev = ctrl_dev(ctrl); + bool found; u16 lnk_status; - int retval = 0; - bool found = false; /* * Data Link Layer Link Active Reporting must be capable for @@ -318,53 +299,37 @@ int pciehp_check_link_status(struct controller *ctrl) found = pci_bus_check_dev(ctrl->pcie->port->subordinate, PCI_DEVFN(0, 0)); - retval = pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status); - if (retval) { - ctrl_err(ctrl, "Cannot read LNKSTATUS register\n"); - return retval; - } - + pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status); ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status); if ((lnk_status & PCI_EXP_LNKSTA_LT) || !(lnk_status & PCI_EXP_LNKSTA_NLW)) { ctrl_err(ctrl, "Link Training Error occurs \n"); - retval = -1; - return retval; + return -1; } pcie_update_link_speed(ctrl->pcie->port->subordinate, lnk_status); - if (!found && !retval) - retval = -1; + if (!found) + return -1; - return retval; + return 0; } static int __pciehp_link_set(struct controller *ctrl, bool enable) { struct pci_dev *pdev = ctrl_dev(ctrl); u16 lnk_ctrl; - int retval = 0; - retval = pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, &lnk_ctrl); - if (retval) { - ctrl_err(ctrl, "Cannot read LNKCTRL register\n"); - return retval; - } + pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, &lnk_ctrl); if (enable) lnk_ctrl &= ~PCI_EXP_LNKCTL_LD; else lnk_ctrl |= PCI_EXP_LNKCTL_LD; - retval = pcie_capability_write_word(pdev, PCI_EXP_LNKCTL, lnk_ctrl); - if (retval) { - ctrl_err(ctrl, "Cannot write LNKCTRL register\n"); - return retval; - } + pcie_capability_write_word(pdev, PCI_EXP_LNKCTL, lnk_ctrl); ctrl_dbg(ctrl, "%s: lnk_ctrl = %x\n", __func__, lnk_ctrl); - - return retval; + return 0; } static int pciehp_link_enable(struct controller *ctrl) @@ -383,14 +348,8 @@ int pciehp_get_attention_status(struct slot *slot, u8 *status) struct pci_dev *pdev = ctrl_dev(ctrl); u16 slot_ctrl; u8 atten_led_state; - int retval = 0; - - retval = pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl); - if (retval) { - ctrl_err(ctrl, "%s: Cannot read SLOTCTRL register\n", __func__); - return retval; - } + pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl); ctrl_dbg(ctrl, "%s: SLOTCTRL %x, value read %x\n", __func__, pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl); @@ -423,13 +382,8 @@ int pciehp_get_power_status(struct slot *slot, u8 *status) struct pci_dev *pdev = ctrl_dev(ctrl); u16 slot_ctrl; u8 pwr_state; - int retval = 0; - retval = pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl); - if (retval) { - ctrl_err(ctrl, "%s: Cannot read SLOTCTRL register\n", __func__); - return retval; - } + pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl); ctrl_dbg(ctrl, "%s: SLOTCTRL %x value read %x\n", __func__, pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl); @@ -447,55 +401,35 @@ int pciehp_get_power_status(struct slot *slot, u8 *status) break; } - return retval; + return 0; } int pciehp_get_latch_status(struct slot *slot, u8 *status) { - struct controller *ctrl = slot->ctrl; - struct pci_dev *pdev = ctrl_dev(ctrl); + struct pci_dev *pdev = ctrl_dev(slot->ctrl); u16 slot_status; - int retval; - retval = pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); - if (retval) { - ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS register\n", - __func__); - return retval; - } + pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); *status = !!(slot_status & PCI_EXP_SLTSTA_MRLSS); return 0; } int pciehp_get_adapter_status(struct slot *slot, u8 *status) { - struct controller *ctrl = slot->ctrl; - struct pci_dev *pdev = ctrl_dev(ctrl); + struct pci_dev *pdev = ctrl_dev(slot->ctrl); u16 slot_status; - int retval; - retval = pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); - if (retval) { - ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS register\n", - __func__); - return retval; - } + pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); *status = !!(slot_status & PCI_EXP_SLTSTA_PDS); return 0; } int pciehp_query_power_fault(struct slot *slot) { - struct controller *ctrl = slot->ctrl; - struct pci_dev *pdev = ctrl_dev(ctrl); + struct pci_dev *pdev = ctrl_dev(slot->ctrl); u16 slot_status; - int retval; - retval = pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); - if (retval) { - ctrl_err(ctrl, "Cannot check for power fault\n"); - return retval; - } + pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); return !!(slot_status & PCI_EXP_SLTSTA_PFD); } @@ -570,25 +504,13 @@ int pciehp_power_on_slot(struct slot * slot) u16 slot_cmd; u16 cmd_mask; u16 slot_status; - int retval = 0; + int retval; /* Clear sticky power-fault bit from previous power failures */ - retval = pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); - if (retval) { - ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS register\n", - __func__); - return retval; - } + pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status); slot_status &= PCI_EXP_SLTSTA_PFD; - if (slot_status) { - retval = pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, slot_status); - if (retval) { - ctrl_err(ctrl, - "%s: Cannot write to SLOTSTATUS register\n", - __func__); - return retval; - } - } + if (slot_status) + pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, slot_status); ctrl->power_fault_detected = 0; slot_cmd = POWER_ON; @@ -649,12 +571,7 @@ static irqreturn_t pcie_isr(int irq, void *dev_id) */ intr_loc = 0; do { - if (pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, - &detected)) { - ctrl_err(ctrl, "%s: Cannot read SLOTSTATUS\n", - __func__); - return IRQ_NONE; - } + pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &detected); detected &= (PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD | PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC | @@ -663,13 +580,9 @@ static irqreturn_t pcie_isr(int irq, void *dev_id) intr_loc |= detected; if (!intr_loc) return IRQ_NONE; - if (detected && - pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, - intr_loc)) { - ctrl_err(ctrl, "%s: Cannot write to SLOTSTATUS\n", - __func__); - return IRQ_NONE; - } + if (detected) + pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, + intr_loc); } while (detected); ctrl_dbg(ctrl, "%s: intr_loc %x\n", __func__, intr_loc); @@ -894,11 +807,7 @@ struct controller *pcie_init(struct pcie_device *dev) goto abort; } ctrl->pcie = dev; - if (pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap)) { - ctrl_err(ctrl, "Cannot read SLOTCAP register\n"); - goto abort_ctrl; - } - + pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap); ctrl->slot_cap = slot_cap; mutex_init(&ctrl->ctrl_lock); init_waitqueue_head(&ctrl->queue); @@ -914,18 +823,14 @@ struct controller *pcie_init(struct pcie_device *dev) ctrl->no_cmd_complete = 1; /* Check if Data Link Layer Link Active Reporting is implemented */ - if (pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, &link_cap)) { - ctrl_err(ctrl, "%s: Cannot read LNKCAP register\n", __func__); - goto abort_ctrl; - } + pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, &link_cap); if (link_cap & PCI_EXP_LNKCAP_DLLLARC) { ctrl_dbg(ctrl, "Link Active Reporting supported\n"); ctrl->link_active_reporting = 1; } /* Clear all remaining event bits in Slot Status register */ - if (pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, 0x1f)) - goto abort_ctrl; + pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, 0x1f); /* Disable software notification */ pcie_disable_notification(ctrl); -- 2.39.5