linux.git/drivers/net/ethernet/intel, branch v4.16

e1000e: Fix link check race condition

2018-03-12T19:05:39+00:00

Alex reported the following race condition:

/* link goes up... interrupt... schedule watchdog */
\ e1000_watchdog_task
	\ e1000e_has_link
		\ hw->mac.ops.check_for_link() === e1000e_check_for_copper_link
			\ e1000e_phy_has_link_generic(..., &link)
				link = true

					 /* link goes down... interrupt */
					 \ e1000_msix_other
						 hw->mac.get_link_status = true

			/* link is up */
			mac->get_link_status = false

		link_active = true
		/* link_active is true, wrongly, and stays so because
		 * get_link_status is false */

Avoid this problem by making sure that we don't set get_link_status = false
after having checked the link.

It seems this problem has been present since the introduction of e1000e.

Link: https://lkml.org/lkml/2018/1/29/338
Reported-by: Alexander Duyck 
Signed-off-by: Benjamin Poirier 
Acked-by: Alexander Duyck 
Tested-by: Aaron Brown 
Signed-off-by: Jeff Kirsher

Revert "e1000e: Separate signaling for link check/link up"

2018-03-12T18:34:05+00:00

This reverts commit 19110cfbb34d4af0cdfe14cd243f3b09dc95b013.
This reverts commit 4110e02eb45ea447ec6f5459c9934de0a273fb91.
This reverts commit d3604515c9eda464a92e8e67aae82dfe07fe3c98.

Commit 19110cfbb34d ("e1000e: Separate signaling for link check/link up")
changed what happens to the link status when there is an error which
happens after "get_link_status = false" in the copper check_for_link
callbacks. Previously, such an error would be ignored and the link
considered up. After that commit, any error implies that the link is down.

Revert commit 19110cfbb34d ("e1000e: Separate signaling for link check/link
up") and its followups. After reverting, the race condition described in
the log of commit 19110cfbb34d is reintroduced. It may still be triggered
by LSC events but this should keep the link down in case the link is
electrically unstable, as discussed. The race may no longer be
triggered by RXO events because commit 4aea7a5c5e94 ("e1000e: Avoid
receiver overrun interrupt bursts") restored reading icr in the Other
handler.

Link: https://lkml.org/lkml/2018/3/1/789
Signed-off-by: Benjamin Poirier 
Acked-by: Alexander Duyck 
Tested-by: Aaron Brown 
Signed-off-by: Jeff Kirsher

e1000e: allocate ring descriptors with dma_zalloc_coherent

2018-03-05T21:34:59+00:00

Descriptor rings were not initialized at zero when allocated
When area contained garbage data, it caused skb_over_panic in
e1000_clean_rx_irq (if data had E1000_RXD_STAT_DD bit set)

This patch makes use of dma_zalloc_coherent to make sure the
ring is memset at 0 to prevent the area from containing garbage.

Following is the signature of the panic:
IODDR0@0.0: skbuff: skb_over_panic: text:80407b20 len:64010 put:64010 head:ab46d800 data:ab46d842 tail:0xab47d24c end:0xab46df40 dev:eth0
IODDR0@0.0: BUG: failure at net/core/skbuff.c:105/skb_panic()!
IODDR0@0.0: Kernel panic - not syncing: BUG!
IODDR0@0.0:
IODDR0@0.0: Process swapper/0 (pid: 0, threadinfo=81728000, task=8173cc00 ,cpu: 0)
IODDR0@0.0: SP = <815a1c0c>
IODDR0@0.0: Stack:      00000001
IODDR0@0.0: b2d89800 815e33ac
IODDR0@0.0: ea73c040 00000001
IODDR0@0.0: 60040003 0000fa0a
IODDR0@0.0: 00000002
IODDR0@0.0:
IODDR0@0.0: 804540c0 815a1c70
IODDR0@0.0: b2744000 602ac070
IODDR0@0.0: 815a1c44 b2d89800
IODDR0@0.0: 8173cc00 815a1c08
IODDR0@0.0:
IODDR0@0.0:     00000006
IODDR0@0.0: 815a1b50 00000000
IODDR0@0.0: 80079434 00000001
IODDR0@0.0: ab46df40 b2744000
IODDR0@0.0: b2d89800
IODDR0@0.0:
IODDR0@0.0: 0000fa0a 8045745c
IODDR0@0.0: 815a1c88 0000fa0a
IODDR0@0.0: 80407b20 b2789f80
IODDR0@0.0: 00000005 80407b20
IODDR0@0.0:
IODDR0@0.0:
IODDR0@0.0: Call Trace:
IODDR0@0.0: [<804540bc>] skb_panic+0xa4/0xa8
IODDR0@0.0: [<80079430>] console_unlock+0x2f8/0x6d0
IODDR0@0.0: [<80457458>] skb_put+0xa0/0xc0
IODDR0@0.0: [<80407b1c>] e1000_clean_rx_irq+0x2dc/0x3e8
IODDR0@0.0: [<80407b1c>] e1000_clean_rx_irq+0x2dc/0x3e8
IODDR0@0.0: [<804079c8>] e1000_clean_rx_irq+0x188/0x3e8
IODDR0@0.0: [<80407b1c>] e1000_clean_rx_irq+0x2dc/0x3e8
IODDR0@0.0: [<80468b48>] __dev_kfree_skb_any+0x88/0xa8
IODDR0@0.0: [<804101ac>] e1000e_poll+0x94/0x288
IODDR0@0.0: [<8046e9d4>] net_rx_action+0x19c/0x4e8
IODDR0@0.0:   ...
IODDR0@0.0: Maximum depth to print reached. Use kstack= To specify a custom value (where 0 means to display the full backtrace)
IODDR0@0.0: ---[ end Kernel panic - not syncing: BUG!

Signed-off-by: Pierre-Yves Kerbrat 
Signed-off-by: Marius Gligor 
Tested-by: Aaron Brown 
Reviewed-by: Alexander Duyck 
Signed-off-by: Jeff Kirsher

e1000e: Fix check_for_link return value with autoneg off

2018-03-05T18:15:51+00:00

When autoneg is off, the .check_for_link callback functions clear the
get_link_status flag and systematically return a "pseudo-error". This means
that the link is not detected as up until the next execution of the
e1000_watchdog_task() 2 seconds later.

Fixes: 19110cfbb34d ("e1000e: Separate signaling for link check/link up")
Signed-off-by: Benjamin Poirier 
Acked-by: Sasha Neftin 
Tested-by: Aaron Brown 
Signed-off-by: Jeff Kirsher

e1000e: Avoid missed interrupts following ICR read

2018-03-05T18:08:20+00:00

The 82574 specification update errata 12 states that interrupts may be
missed if ICR is read while INT_ASSERTED is not set. Avoid that problem by
setting all bits related to events that can trigger the Other interrupt in
IMS.

The Other interrupt is raised for such events regardless of whether or not
they are set in IMS. However, only when they are set is the INT_ASSERTED
bit also set in ICR.

By doing this, we ensure that INT_ASSERTED is always set when we read ICR
in e1000_msix_other() and steer clear of the errata. This also ensures that
ICR will automatically be cleared on read, therefore we no longer need to
clear bits explicitly.

Signed-off-by: Benjamin Poirier 
Acked-by: Alexander Duyck 
Tested-by: Aaron Brown 
Signed-off-by: Jeff Kirsher

e1000e: Fix queue interrupt re-raising in Other interrupt

2018-03-05T18:06:39+00:00

Restores the ICS write for Rx/Tx queue interrupts which was present before
commit 16ecba59bc33 ("e1000e: Do not read ICR in Other interrupt", v4.5-rc1)
but was not restored in commit 4aea7a5c5e94
("e1000e: Avoid receiver overrun interrupt bursts", v4.15-rc1).

This re-raises the queue interrupts in case the txq or rxq bits were set in
ICR and the Other interrupt handler read and cleared ICR before the queue
interrupt was raised.

Fixes: 4aea7a5c5e94 ("e1000e: Avoid receiver overrun interrupt bursts")
Signed-off-by: Benjamin Poirier 
Acked-by: Alexander Duyck 
Tested-by: Aaron Brown 
Signed-off-by: Jeff Kirsher

Partial revert "e1000e: Avoid receiver overrun interrupt bursts"

2018-03-05T18:03:52+00:00

This partially reverts commit 4aea7a5c5e940c1723add439f4088844cd26196d.

We keep the fix for the first part of the problem (1) described in the log
of that commit, that is to read ICR in the other interrupt handler. We
remove the fix for the second part of the problem (2), Other interrupt
throttling.

Bursts of "Other" interrupts may once again occur during rxo (receive
overflow) traffic conditions. This is deemed acceptable in the interest of
avoiding unforeseen fallout from changes that are not strictly necessary.
As discussed, the e1000e driver should be in "maintenance mode".

Link: https://www.spinics.net/lists/netdev/msg480675.html
Signed-off-by: Benjamin Poirier 
Acked-by: Alexander Duyck 
Tested-by: Aaron Brown 
Signed-off-by: Jeff Kirsher

e1000e: Remove Other from EIAC

2018-03-05T17:30:14+00:00

It was reported that emulated e1000e devices in vmware esxi 6.5 Build
7526125 do not link up after commit 4aea7a5c5e94 ("e1000e: Avoid receiver
overrun interrupt bursts", v4.15-rc1). Some tracing shows that after
e1000e_trigger_lsc() is called, ICR reads out as 0x0 in e1000_msix_other()
on emulated e1000e devices. In comparison, on real e1000e 82574 hardware,
icr=0x80000004 (_INT_ASSERTED | _LSC) in the same situation.

Some experimentation showed that this flaw in vmware e1000e emulation can
be worked around by not setting Other in EIAC. This is how it was before
16ecba59bc33 ("e1000e: Do not read ICR in Other interrupt", v4.5-rc1).

Fixes: 4aea7a5c5e94 ("e1000e: Avoid receiver overrun interrupt bursts")
Signed-off-by: Benjamin Poirier 
Tested-by: Aaron Brown 
Signed-off-by: Jeff Kirsher

ixgbe: fix crash in build_skb Rx code path

2018-02-26T18:44:24+00:00

Add check for build_skb enabled ring in ixgbe_dma_sync_frag().
In that case &skb_shinfo(skb)->frags[0] may not always be set which
can lead to a crash. Instead we derive the page offset from skb->data.

Fixes: 42073d91a214
("ixgbe: Have the CPU take ownership of the buffers sooner")
CC: stable 
Reported-by: Ambarish Soman 
Suggested-by: Alexander Duyck 
Signed-off-by: Emil Tantilov 
Tested-by: Andrew Bowers 
Signed-off-by: Jeff Kirsher 
Signed-off-by: David S. Miller

i40e: Fix the number of queues available to be mapped for use

2018-02-08T02:53:32+00:00

Fix the number of queues per enabled TC and report available queues
to the kernel without having to limit them to the max RSS limit so
they are available to be mapped for XPS. This allows a queue per
processing thread available for handling traffic for the given
traffic class.

Signed-off-by: Amritha Nambiar 
Tested-by: Andrew Bowers 
Signed-off-by: Jeff Kirsher 
Signed-off-by: David S. Miller