Received-SPF: pass (google.com: domain of linux-kernel+bounces-190619-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= <ilpo.jarvinen@linux.intel.com>
To: Juergen Gross <jgross@suse.com>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
	Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	x86@kernel.org,
	"H. Peter Anvin" <hpa@zytor.com>,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
	Ian Campbell <ian.campbell@citrix.com>,
	xen-devel@lists.xenproject.org,
	linux-pci@vger.kernel.org,
	linux-kernel@vger.kernel.org
Cc: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= <ilpo.jarvinen@linux.intel.com>,
	stable@vger.kernel.org
Subject: [PATCH 3/4] x86/pci/xen: Fix PCIBIOS_* return code handling
Date: Mon, 27 May 2024 15:55:37 +0300
Message-Id: <20240527125538.13620-3-ilpo.jarvinen@linux.intel.com>
In-Reply-To: <20240527125538.13620-1-ilpo.jarvinen@linux.intel.com>
References: <20240527125538.13620-1-ilpo.jarvinen@linux.intel.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

xen_pcifront_enable_irq() uses pci_read_config_byte() that returns
PCIBIOS_* codes. The error handling, however, assumes the codes are
normal errnos because it checks for < 0.

xen_pcifront_enable_irq() also returns the PCIBIOS_* code back to the
caller but the function is used as the (*pcibios_enable_irq) function
which should return normal errnos.

Convert the error check to plain non-zero check which works for
PCIBIOS_* return codes and convert the PCIBIOS_* return code using
pcibios_err_to_errno() into normal errno before returning it.

Fixes: 3f2a230caf21 ("xen: handled remapped IRQs when enabling a pcifront PCI device.")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Cc: stable@vger.kernel.org
---
 arch/x86/pci/xen.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index 652cd53e77f6..0f2fe524f60d 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -38,10 +38,10 @@ static int xen_pcifront_enable_irq(struct pci_dev *dev)
 	u8 gsi;
 
 	rc = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi);
-	if (rc < 0) {
+	if (rc) {
 		dev_warn(&dev->dev, "Xen PCI: failed to read interrupt line: %d\n",
 			 rc);
-		return rc;
+		return pcibios_err_to_errno(rc);
 	}
 	/* In PV DomU the Xen PCI backend puts the PIRQ in the interrupt line.*/
 	pirq = gsi;
-- 
2.39.2