Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Naveen Naidu <naveennaidu479@gmail.com>
To:     bhelgaas@google.com
Cc:     Naveen Naidu <naveennaidu479@gmail.com>,
        linux-kernel-mentees@lists.linuxfoundation.org,
        linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
        Robert Richter <rric@kernel.org>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Rob Herring <robh@kernel.org>,
        =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= <kw@linux.com>,
        linux-arm-kernel@lists.infradead.org
Subject: [PATCH 03/22] PCI: thunder: Use SET_PCI_ERROR_RESPONSE() when device not found
Date:   Mon, 11 Oct 2021 23:15:10 +0530
Message-Id: <c5f9e140106cd6a38026300a4e5e5e6ad9257fb3.1633972263.git.naveennaidu479@gmail.com>
In-Reply-To: <cover.1633972263.git.naveennaidu479@gmail.com>
References: <cover.1633972263.git.naveennaidu479@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

An MMIO read from a PCI device that doesn't exist or doesn't respond
causes a PCI error.  There's no real data to return to satisfy the
CPU read, so most hardware fabricates ~0 data.

Use SET_PCI_ERROR_RESPONSE() to set the error response, when a faulty
read occurs.

This helps unify PCI error response checking and make error check
consistent and easier to find.

Signed-off-by: Naveen Naidu <naveennaidu479@gmail.com>
---
 drivers/pci/controller/pci-thunder-ecam.c | 20 ++++++++++----------
 drivers/pci/controller/pci-thunder-pem.c  |  2 +-
 2 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/pci/controller/pci-thunder-ecam.c b/drivers/pci/controller/pci-thunder-ecam.c
index ffd84656544f..4c57ad2aa9aa 100644
--- a/drivers/pci/controller/pci-thunder-ecam.c
+++ b/drivers/pci/controller/pci-thunder-ecam.c
@@ -42,7 +42,7 @@ static int handle_ea_bar(u32 e0, int bar, struct pci_bus *bus,
 	if (where_a == 0x4) {
 		addr = bus->ops->map_bus(bus, devfn, bar); /* BAR 0 */
 		if (!addr) {
-			*val = ~0;
+			SET_PCI_ERROR_RESPONSE(val);
 			return PCIBIOS_DEVICE_NOT_FOUND;
 		}
 		v = readl(addr);
@@ -57,7 +57,7 @@ static int handle_ea_bar(u32 e0, int bar, struct pci_bus *bus,
 
 		addr = bus->ops->map_bus(bus, devfn, bar); /* BAR 0 */
 		if (!addr) {
-			*val = ~0;
+			SET_PCI_ERROR_RESPONSE(val);
 			return PCIBIOS_DEVICE_NOT_FOUND;
 		}
 		barl_orig = readl(addr + 0);
@@ -73,7 +73,7 @@ static int handle_ea_bar(u32 e0, int bar, struct pci_bus *bus,
 	if (where_a == 0xc) {
 		addr = bus->ops->map_bus(bus, devfn, bar + 4); /* BAR 1 */
 		if (!addr) {
-			*val = ~0;
+			SET_PCI_ERROR_RESPONSE(val);
 			return PCIBIOS_DEVICE_NOT_FOUND;
 		}
 		v = readl(addr); /* EA entry-3. Base-H */
@@ -105,7 +105,7 @@ static int thunder_ecam_p2_config_read(struct pci_bus *bus, unsigned int devfn,
 
 	addr = bus->ops->map_bus(bus, devfn, where_a);
 	if (!addr) {
-		*val = ~0;
+		SET_PCI_ERROR_RESPONSE(val);
 		return PCIBIOS_DEVICE_NOT_FOUND;
 	}
 
@@ -136,7 +136,7 @@ static int thunder_ecam_config_read(struct pci_bus *bus, unsigned int devfn,
 
 	addr = bus->ops->map_bus(bus, devfn, 0xc);
 	if (!addr) {
-		*val = ~0;
+		SET_PCI_ERROR_RESPONSE(val);
 		return PCIBIOS_DEVICE_NOT_FOUND;
 	}
 
@@ -147,7 +147,7 @@ static int thunder_ecam_config_read(struct pci_bus *bus, unsigned int devfn,
 
 	addr = bus->ops->map_bus(bus, devfn, 8);
 	if (!addr) {
-		*val = ~0;
+		SET_PCI_ERROR_RESPONSE(val);
 		return PCIBIOS_DEVICE_NOT_FOUND;
 	}
 
@@ -177,7 +177,7 @@ static int thunder_ecam_config_read(struct pci_bus *bus, unsigned int devfn,
 
 	addr = bus->ops->map_bus(bus, devfn, 0);
 	if (!addr) {
-		*val = ~0;
+		SET_PCI_ERROR_RESPONSE(val);
 		return PCIBIOS_DEVICE_NOT_FOUND;
 	}
 
@@ -197,7 +197,7 @@ static int thunder_ecam_config_read(struct pci_bus *bus, unsigned int devfn,
 
 		addr = bus->ops->map_bus(bus, devfn, 0x70);
 		if (!addr) {
-			*val = ~0;
+			SET_PCI_ERROR_RESPONSE(val);
 			return PCIBIOS_DEVICE_NOT_FOUND;
 		}
 		/* E_CAP */
@@ -212,7 +212,7 @@ static int thunder_ecam_config_read(struct pci_bus *bus, unsigned int devfn,
 		if (where_a == 0xb0) {
 			addr = bus->ops->map_bus(bus, devfn, where_a);
 			if (!addr) {
-				*val = ~0;
+				SET_PCI_ERROR_RESPONSE(val);
 				return PCIBIOS_DEVICE_NOT_FOUND;
 			}
 			v = readl(addr);
@@ -269,7 +269,7 @@ static int thunder_ecam_config_read(struct pci_bus *bus, unsigned int devfn,
 		if (where_a == 0x70) {
 			addr = bus->ops->map_bus(bus, devfn, where_a);
 			if (!addr) {
-				*val = ~0;
+				SET_PCI_ERROR_RESPONSE(val);
 				return PCIBIOS_DEVICE_NOT_FOUND;
 			}
 			v = readl(addr);
diff --git a/drivers/pci/controller/pci-thunder-pem.c b/drivers/pci/controller/pci-thunder-pem.c
index 0660b9da204f..a463a1b61f23 100644
--- a/drivers/pci/controller/pci-thunder-pem.c
+++ b/drivers/pci/controller/pci-thunder-pem.c
@@ -42,7 +42,7 @@ static int thunder_pem_bridge_read(struct pci_bus *bus, unsigned int devfn,
 	struct thunder_pem_pci *pem_pci = (struct thunder_pem_pci *)cfg->priv;
 
 	if (devfn != 0 || where >= 2048) {
-		*val = ~0;
+		SET_PCI_ERROR_RESPONSE(val);
 		return PCIBIOS_DEVICE_NOT_FOUND;
 	}
 
-- 
2.25.1