From 3923fc5f4a489ab2b9e2f4ffe34c0c6ccabdb9e6 Mon Sep 17 00:00:00 2001
From: Vladimir Sokolovsky <vlad@mellanox.com>
Date: Wed, 5 Nov 2014 14:50:03 +0200
Subject: [PATCH] Added pcie_get_mps/pcie_set_mps

Signed-off-by: Vladimir Sokolovsky <vlad@mellanox.com>
---
 compat/Makefile             |  1 +
 compat/compat-3.13.c        | 42 +++++++++++++++++++++++++++++++++++++
 include/linux/compat-3.13.h |  6 ++++++
 3 files changed, 49 insertions(+)
 create mode 100644 compat/compat-3.13.c

diff --git a/compat/Makefile b/compat/Makefile
index f025580..b58baac 100644
--- a/compat/Makefile
+++ b/compat/Makefile
@@ -52,6 +52,7 @@ compat-$(CONFIG_COMPAT_KERNEL_3_7) += compat-3.7.o
 compat-$(CONFIG_COMPAT_KERNEL_3_9) += compat-3.9.o
 compat-$(CONFIG_COMPAT_KERNEL_3_11) += compat-3.11.o
 compat-$(CONFIG_COMPAT_KERNEL_3_12) += compat-3.12.o
+compat-$(CONFIG_COMPAT_KERNEL_3_13) += compat-3.13.o
 compat-$(CONFIG_COMPAT_KERNEL_3_16) += compat-3.16.o
 compat-$(CONFIG_COMPAT_KERNEL_3_18) += compat-3.18.o
 
diff --git a/compat/compat-3.13.c b/compat/compat-3.13.c
new file mode 100644
index 0000000..c65634c
--- /dev/null
+++ b/compat/compat-3.13.c
@@ -0,0 +1,42 @@
+#include <linux/pci.h>
+
+/**
+ * pcie_get_mps - get PCI Express maximum payload size
+ * @dev: PCI device to query
+ *
+ * Returns maximum payload size in bytes
+ */
+int pcie_get_mps(struct pci_dev *dev)
+{
+	u16 ctl;
+
+	pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl);
+
+	return 128 << ((ctl & PCI_EXP_DEVCTL_PAYLOAD) >> 5);
+}
+EXPORT_SYMBOL(pcie_get_mps);
+
+/**
+ * pcie_set_mps - set PCI Express maximum payload size
+ * @dev: PCI device to query
+ * @mps: maximum payload size in bytes
+ *    valid values are 128, 256, 512, 1024, 2048, 4096
+ *
+ * If possible sets maximum payload size
+ */
+int pcie_set_mps(struct pci_dev *dev, int mps)
+{
+	u16 v;
+
+	if (mps < 128 || mps > 4096 || !is_power_of_2(mps))
+		return -EINVAL;
+
+	v = ffs(mps) - 8;
+	if (v > dev->pcie_mpss)
+		return -EINVAL;
+	v <<= 5;
+
+	return pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
+						  PCI_EXP_DEVCTL_PAYLOAD, v);
+}
+EXPORT_SYMBOL(pcie_set_mps);
diff --git a/include/linux/compat-3.13.h b/include/linux/compat-3.13.h
index 619b8f9..9d40500 100644
--- a/include/linux/compat-3.13.h
+++ b/include/linux/compat-3.13.h
@@ -16,6 +16,12 @@ static inline void reinit_completion(struct completion *x)
 
 #endif
 
+#define pcie_get_mps LINUX_BACKPORT(pcie_get_mps)
+int pcie_get_mps(struct pci_dev *dev);
+
+#define pcie_set_mps LINUX_BACKPORT(pcie_set_mps)
+int pcie_set_mps(struct pci_dev *dev, int mps);
+
 #endif /* (LINUX_VERSION_CODE < KERNEL_VERSION(3,13,0)) */
 
 #endif /* LINUX_3_13_COMPAT_H */
-- 
2.41.0