PCI: Align checking of syscall user config accessors

stable inclusion
from stable-5.10.20
commit 4ce87382d87c9bcbb677f6f7967be3ec917a735b
bugzilla: 50608

--------------------------------

[ Upstream commit ef9e4005 ]

After 34e32072 ("PCI: handle positive error codes"),
pci_user_read_config_*() and pci_user_write_config_*() return 0 or negative
errno values, not PCIBIOS_* values like PCIBIOS_SUCCESSFUL or
PCIBIOS_BAD_REGISTER_NUMBER.

Remove comparisons with PCIBIOS_SUCCESSFUL and check only for non-zero.  It
happens that PCIBIOS_SUCCESSFUL is zero, so this is not a functional
change, but it aligns this code with the user accessors.

[bhelgaas: commit log]
Fixes: 34e32072 ("PCI: handle positive error codes")
Link: https://lore.kernel.org/r/f1220314-e518-1e18-bf94-8e6f8c703758@gmail.comSigned-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/pci/syscall.c

@@ -20,7 +20,7 @@ SYSCALL_DEFINE5(pciconfig_read, unsigned long, bus, unsigned long, dfn,
 	u16 word;
 	u32 dword;
 	long err;
-	long cfg_ret;
+	int cfg_ret;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
@@ -46,7 +46,7 @@ SYSCALL_DEFINE5(pciconfig_read, unsigned long, bus, unsigned long, dfn,
 	}
 
 	err = -EIO;
-	if (cfg_ret != PCIBIOS_SUCCESSFUL)
+	if (cfg_ret)
 		goto error;
 
 	switch (len) {
@@ -105,7 +105,7 @@ SYSCALL_DEFINE5(pciconfig_write, unsigned long, bus, unsigned long, dfn,
 		if (err)
 			break;
 		err = pci_user_write_config_byte(dev, off, byte);
-		if (err != PCIBIOS_SUCCESSFUL)
+		if (err)
 			err = -EIO;
 		break;
 
@@ -114,7 +114,7 @@ SYSCALL_DEFINE5(pciconfig_write, unsigned long, bus, unsigned long, dfn,
 		if (err)
 			break;
 		err = pci_user_write_config_word(dev, off, word);
-		if (err != PCIBIOS_SUCCESSFUL)
+		if (err)
 			err = -EIO;
 		break;
 
@@ -123,7 +123,7 @@ SYSCALL_DEFINE5(pciconfig_write, unsigned long, bus, unsigned long, dfn,
 		if (err)
 			break;
 		err = pci_user_write_config_dword(dev, off, dword);
-		if (err != PCIBIOS_SUCCESSFUL)
+		if (err)
 			err = -EIO;
 		break;