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From:   Kishon Vijay Abraham I <kishon@ti.com>
To:     Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Arnd Bergmann <arnd@arndb.de>, Jon Mason <jdmason@kudzu.us>,
        Dave Jiang <dave.jiang@intel.com>,
        Allen Hubbe <allenbh@gmail.com>,
        Tom Joseph <tjoseph@cadence.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Rob Herring <robh+dt@kernel.org>
CC:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jonathan Corbet <corbet@lwn.net>, <linux-pci@vger.kernel.org>,
        <linux-doc@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <devicetree@vger.kernel.org>, <linux-ntb@googlegroups.com>,
        Kishon Vijay Abraham I <kishon@ti.com>
Subject: [PATCH 08/19] PCI: endpoint: Make *_free_bar() to return error codes on failure
Date:   Thu, 14 May 2020 20:29:16 +0530
Message-ID: <20200514145927.17555-9-kishon@ti.com>
In-Reply-To: <20200514145927.17555-1-kishon@ti.com>
References: <20200514145927.17555-1-kishon@ti.com>
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Sender: linux-kernel-owner@vger.kernel.org
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Modify pci_epc_get_next_free_bar() and pci_epc_get_first_free_bar() to
return error values if there are no free BARs available.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 drivers/pci/endpoint/functions/pci-epf-test.c |  2 ++
 drivers/pci/endpoint/pci-epc-core.c           | 12 ++++++------
 include/linux/pci-epc.h                       |  8 ++++----
 include/linux/pci-epf.h                       |  1 +
 4 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index 60330f3e3751..ba43e1e05958 100644
--- a/drivers/pci/endpoint/functions/pci-epf-test.c
+++ b/drivers/pci/endpoint/functions/pci-epf-test.c
@@ -831,6 +831,8 @@ static int pci_epf_test_bind(struct pci_epf *epf)
 		linkup_notifier = epc_features->linkup_notifier;
 		core_init_notifier = epc_features->core_init_notifier;
 		test_reg_bar = pci_epc_get_first_free_bar(epc_features);
+		if (test_reg_bar < 0)
+			return -EINVAL;
 		pci_epf_configure_bar(epf, epc_features);
 	}
 
diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 85e542aae617..df8789fee01e 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -150,8 +150,8 @@ EXPORT_SYMBOL_GPL(of_pci_epc_get_by_name);
  * Invoke to get the first unreserved BAR that can be used by the endpoint
  * function. For any incorrect value in reserved_bar return '0'.
  */
-unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features
-					*epc_features)
+enum pci_barno
+pci_epc_get_first_free_bar(const struct pci_epc_features *epc_features)
 {
 	return pci_epc_get_next_free_bar(epc_features, BAR_0);
 }
@@ -165,13 +165,13 @@ EXPORT_SYMBOL_GPL(pci_epc_get_first_free_bar);
  * Invoke to get the next unreserved BAR starting from @bar that can be used
  * for endpoint function. For any incorrect value in reserved_bar return '0'.
  */
-unsigned int pci_epc_get_next_free_bar(const struct pci_epc_features
-				       *epc_features, enum pci_barno bar)
+enum pci_barno pci_epc_get_next_free_bar(const struct pci_epc_features
+					 *epc_features, enum pci_barno bar)
 {
 	unsigned long free_bar;
 
 	if (!epc_features)
-		return 0;
+		return BAR_0;
 
 	/* If 'bar - 1' is a 64-bit BAR, move to the next BAR */
 	if ((epc_features->bar_fixed_64bit << 1) & 1 << bar)
@@ -186,7 +186,7 @@ unsigned int pci_epc_get_next_free_bar(const struct pci_epc_features
 
 	free_bar = find_next_zero_bit(&free_bar, 6, bar);
 	if (free_bar > 5)
-		return 0;
+		return NO_BAR;
 
 	return free_bar;
 }
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 68f7c0d81442..463586889453 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -201,10 +201,10 @@ int pci_epc_start(struct pci_epc *epc);
 void pci_epc_stop(struct pci_epc *epc);
 const struct pci_epc_features *pci_epc_get_features(struct pci_epc *epc,
 						    u8 func_no);
-unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features
-					*epc_features);
-unsigned int pci_epc_get_next_free_bar(const struct pci_epc_features
-				       *epc_features, enum pci_barno bar);
+enum pci_barno
+pci_epc_get_first_free_bar(const struct pci_epc_features *epc_features);
+enum pci_barno pci_epc_get_next_free_bar(const struct pci_epc_features
+					 *epc_features, enum pci_barno bar);
 struct pci_epc *pci_epc_get(const char *epc_name);
 void pci_epc_put(struct pci_epc *epc);
 
diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
index 8fb77ab1968f..e51f3070bcc4 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h
@@ -22,6 +22,7 @@ enum pci_notify_event {
 };
 
 enum pci_barno {
+	NO_BAR = -1,
 	BAR_0,
 	BAR_1,
 	BAR_2,
-- 
2.17.1