linux-kernel - [PATCH AUTOSEL 6.5 21/34] PCI: Do error check on own line to split long "if" conditions

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Date:   Tue,  7 Nov 2023 10:48:01 -0500
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
        Bjorn Helgaas <bhelgaas@...gle.com>,
        Sasha Levin <sashal@...nel.org>, linux-pci@...r.kernel.org
Subject: [PATCH AUTOSEL 6.5 21/34] PCI: Do error check on own line to split long "if" conditions

From: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>

[ Upstream commit d15f18053e5cc5576af9e7eef0b2a91169b6326d ]

Placing PCI error code check inside "if" condition usually results in need
to split lines. Combined with additional conditions the "if" condition
becomes messy.

Convert to the usual error handling pattern with an additional variable to
improve code readability. In addition, reverse the logic in
pci_find_vsec_capability() to get rid of &&.

No functional changes intended.

Link: https://lore.kernel.org/r/20230911125354.25501-5-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
[bhelgaas: PCI_POSSIBLE_ERROR()]
Signed-off-by: Bjorn Helgaas <bhelgaas@...gle.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/pci/pci.c    | 9 ++++++---
 drivers/pci/probe.c  | 6 +++---
 drivers/pci/quirks.c | 6 +++---
 3 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 702fe577089b4..3cd907eb67b74 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -732,15 +732,18 @@ u16 pci_find_vsec_capability(struct pci_dev *dev, u16 vendor, int cap)
 {
 	u16 vsec = 0;
 	u32 header;
+	int ret;
 
 	if (vendor != dev->vendor)
 		return 0;
 
 	while ((vsec = pci_find_next_ext_capability(dev, vsec,
 						     PCI_EXT_CAP_ID_VNDR))) {
-		if (pci_read_config_dword(dev, vsec + PCI_VNDR_HEADER,
-					  &header) == PCIBIOS_SUCCESSFUL &&
-		    PCI_VNDR_HEADER_ID(header) == cap)
+		ret = pci_read_config_dword(dev, vsec + PCI_VNDR_HEADER, &header);
+		if (ret != PCIBIOS_SUCCESSFUL)
+			continue;
+
+		if (PCI_VNDR_HEADER_ID(header) == cap)
 			return vsec;
 	}
 
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 24a83cf5ace8c..cd08d39fdb1ff 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1653,15 +1653,15 @@ static void pci_set_removable(struct pci_dev *dev)
 static bool pci_ext_cfg_is_aliased(struct pci_dev *dev)
 {
 #ifdef CONFIG_PCI_QUIRKS
-	int pos;
+	int pos, ret;
 	u32 header, tmp;
 
 	pci_read_config_dword(dev, PCI_VENDOR_ID, &header);
 
 	for (pos = PCI_CFG_SPACE_SIZE;
 	     pos < PCI_CFG_SPACE_EXP_SIZE; pos += PCI_CFG_SPACE_SIZE) {
-		if (pci_read_config_dword(dev, pos, &tmp) != PCIBIOS_SUCCESSFUL
-		    || header != tmp)
+		ret = pci_read_config_dword(dev, pos, &tmp);
+		if ((ret != PCIBIOS_SUCCESSFUL) || (header != tmp))
 			return false;
 	}
 
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 321156ca273d5..91c34b05374ce 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -5381,7 +5381,7 @@ int pci_dev_specific_disable_acs_redir(struct pci_dev *dev)
  */
 static void quirk_intel_qat_vf_cap(struct pci_dev *pdev)
 {
-	int pos, i = 0;
+	int pos, i = 0, ret;
 	u8 next_cap;
 	u16 reg16, *cap;
 	struct pci_cap_saved_state *state;
@@ -5427,8 +5427,8 @@ static void quirk_intel_qat_vf_cap(struct pci_dev *pdev)
 		pdev->pcie_mpss = reg16 & PCI_EXP_DEVCAP_PAYLOAD;
 
 		pdev->cfg_size = PCI_CFG_SPACE_EXP_SIZE;
-		if (pci_read_config_dword(pdev, PCI_CFG_SPACE_SIZE, &status) !=
-		    PCIBIOS_SUCCESSFUL || (status == 0xffffffff))
+		ret = pci_read_config_dword(pdev, PCI_CFG_SPACE_SIZE, &status);
+		if ((ret != PCIBIOS_SUCCESSFUL) || (PCI_POSSIBLE_ERROR(status)))
 			pdev->cfg_size = PCI_CFG_SPACE_SIZE;
 
 		if (pci_find_saved_cap(pdev, PCI_CAP_ID_EXP))
-- 
2.42.0