4.4-stable patches

added patches:
	net-systemport-add-global-locking-for-descriptor-lifecycle.patch

diff --git a/queue-4.4/net-systemport-add-global-locking-for-descriptor-lifecycle.patch b/queue-4.4/net-systemport-add-global-locking-for-descriptor-lifecycle.patch
new file mode 100644 (file)
index 0000000..d09a3fd
--- /dev/null
+++ b/queue-4.4/net-systemport-add-global-locking-for-descriptor-lifecycle.patch
@@ -0,0 +1,77 @@
+From 8b8e6e782456f1ce02a7ae914bbd5b1053f0b034 Mon Sep 17 00:00:00 2001
+From: Florian Fainelli <f.fainelli@gmail.com>
+Date: Wed, 15 Dec 2021 12:24:49 -0800
+Subject: net: systemport: Add global locking for descriptor lifecycle
+
+From: Florian Fainelli <f.fainelli@gmail.com>
+
+commit 8b8e6e782456f1ce02a7ae914bbd5b1053f0b034 upstream.
+
+The descriptor list is a shared resource across all of the transmit queues, and
+the locking mechanism used today only protects concurrency across a given
+transmit queue between the transmit and reclaiming. This creates an opportunity
+for the SYSTEMPORT hardware to work on corrupted descriptors if we have
+multiple producers at once which is the case when using multiple transmit
+queues.
+
+This was particularly noticeable when using multiple flows/transmit queues and
+it showed up in interesting ways in that UDP packets would get a correct UDP
+header checksum being calculated over an incorrect packet length. Similarly TCP
+packets would get an equally correct checksum computed by the hardware over an
+incorrect packet length.
+
+The SYSTEMPORT hardware maintains an internal descriptor list that it re-arranges
+when the driver produces a new descriptor anytime it writes to the
+WRITE_PORT_{HI,LO} registers, there is however some delay in the hardware to
+re-organize its descriptors and it is possible that concurrent TX queues
+eventually break this internal allocation scheme to the point where the
+length/status part of the descriptor gets used for an incorrect data buffer.
+
+The fix is to impose a global serialization for all TX queues in the short
+section where we are writing to the WRITE_PORT_{HI,LO} registers which solves
+the corruption even with multiple concurrent TX queues being used.
+
+Fixes: 80105befdb4b ("net: systemport: add Broadcom SYSTEMPORT Ethernet MAC driver")
+Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
+Link: https://lore.kernel.org/r/20211215202450.4086240-1-f.fainelli@gmail.com
+Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/net/ethernet/broadcom/bcmsysport.c |    5 +++++
+ drivers/net/ethernet/broadcom/bcmsysport.h |    1 +
+ 2 files changed, 6 insertions(+)
+
+--- a/drivers/net/ethernet/broadcom/bcmsysport.c
++++ b/drivers/net/ethernet/broadcom/bcmsysport.c
+@@ -90,9 +90,13 @@ static inline void tdma_port_write_desc_
+                                            struct dma_desc *desc,
+                                            unsigned int port)
+ {
++      unsigned long desc_flags;
++
+       /* Ports are latched, so write upper address first */
++      spin_lock_irqsave(&priv->desc_lock, desc_flags);
+       tdma_writel(priv, desc->addr_status_len, TDMA_WRITE_PORT_HI(port));
+       tdma_writel(priv, desc->addr_lo, TDMA_WRITE_PORT_LO(port));
++      spin_unlock_irqrestore(&priv->desc_lock, desc_flags);
+ }
+ 
+ /* Ethtool operations */
+@@ -1608,6 +1612,7 @@ static int bcm_sysport_open(struct net_d
+       }
+ 
+       /* Initialize both hardware and software ring */
++      spin_lock_init(&priv->desc_lock);
+       for (i = 0; i < dev->num_tx_queues; i++) {
+               ret = bcm_sysport_init_tx_ring(priv, i);
+               if (ret) {
+--- a/drivers/net/ethernet/broadcom/bcmsysport.h
++++ b/drivers/net/ethernet/broadcom/bcmsysport.h
+@@ -660,6 +660,7 @@ struct bcm_sysport_priv {
+       int                     wol_irq;
+ 
+       /* Transmit rings */
++      spinlock_t              desc_lock;
+       struct bcm_sysport_tx_ring tx_rings[TDMA_NUM_RINGS];
+ 
+       /* Receive queue */

diff --git a/queue-4.4/series b/queue-4.4/series
index 938e0b306859f2bc57a8d91601138aff05bba2e7..ffea8fe1ef732ed17d1ef3dd2b2a5fe87422fa73 100644 (file)
--- a/queue-4.4/series
+++ b/queue-4.4/series
@@ -13,3 +13,4 @@ usb-gadget-brequesttype-is-a-bitfield-not-a-enum.patch
 pci-msi-clear-pci_msix_flags_maskall-on-error.patch
 usb-serial-option-add-telit-fn990-compositions.patch
 timekeeping-really-make-sure-wall_to_monotonic-isn-t-positive.patch
+net-systemport-add-global-locking-for-descriptor-lifecycle.patch