When lan966x_fdma_reload() fails to allocate new RX buffers, the restore
path restarts DMA using old descriptors whose pages were already freed
via lan966x_fdma_rx_free_pages(). Since page_pool_put_full_page() can
release pages back to the buddy allocator, the hardware may DMA into
memory now owned by other kernel subsystems.

Additionally, on the restore path, the newly created page pool (if
allocation partially succeeded) is overwritten without being destroyed,
leaking it.

Fix both issues by deferring the release of old pages until after the
new allocation succeeds. Save the old page array before the allocation
so old pages can be freed on the success path. On the failure path, the
old descriptors, pages and page pool are all still valid, making the
restore safe. Also ensure the restore path re-enables NAPI and wakes
the netdev, matching the success path.

Fixes: 89ba464fcf54 ("net: lan966x: refactor buffer reload function")
Cc: stable@vger.kernel.org
Signed-off-by: David Carlier <devnexen@gmail.com>
Link: https://patch.msgid.link/20260405055241.35767-4-devnexen@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

lan966x_fdma_rx_alloc() creates a page pool but does not destroy it if
the subsequent fdma_alloc_coherent() call fails, leaking the pool.

Similarly, lan966x_fdma_init() frees the coherent DMA memory when
lan966x_fdma_tx_alloc() fails but does not destroy the page pool that
was successfully created by lan966x_fdma_rx_alloc(), leaking it.

Add the missing page_pool_destroy() calls in both error paths.

Fixes: 11871aba1974 ("net: lan96x: Use page_pool API")
Cc: stable@vger.kernel.org
Signed-off-by: David Carlier <devnexen@gmail.com>
Link: https://patch.msgid.link/20260405055241.35767-3-devnexen@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

page_pool_create() can return an ERR_PTR on failure. The return value
is used unconditionally in the loop that follows, passing the error
pointer through xdp_rxq_info_reg_mem_model() into page_pool_use_xdp_mem(),
which dereferences it, causing a kernel oops.

Add an IS_ERR check after page_pool_create() to return early on failure.

Fixes: 11871aba1974 ("net: lan96x: Use page_pool API")
Cc: stable@vger.kernel.org
Signed-off-by: David Carlier <devnexen@gmail.com>
Link: https://patch.msgid.link/20260405055241.35767-2-devnexen@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

This converts some of the visually simpler cases that have been split
over multiple lines.  I only did the ones that are easy to verify the
resulting diff by having just that final GFP_KERNEL argument on the next
line.

Somebody should probably do a proper coccinelle script for this, but for
me the trivial script actually resulted in an assertion failure in the
middle of the script.  I probably had made it a bit _too_ trivial.

So after fighting that far a while I decided to just do some of the
syntactically simpler cases with variations of the previous 'sed'
scripts.

The more syntactically complex multi-line cases would mostly really want
whitespace cleanup anyway.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This was done entirely with mindless brute force, using

    git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook <kees@kernel.org>

To initialize the taprio block in lan966x, it is required to configure
the register REVISIT_DLY. The purpose of this register is to set the
delay before revisit the next gate and the value of this register depends
on the system clock. The problem is that the we calculated wrong the value
of the system clock period in picoseconds. The actual system clock is
~165.617754MHZ and this correspond to a period of 6038 pico seconds and
not 15125 as currently set.

Fixes: e462b2717380b4 ("net: lan966x: Add offload support for taprio")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20251121061411.810571-1-horatiu.vultur@microchip.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

The following warning was seen when we try to connect using ssh to the device.

BUG: sleeping function called from invalid context at kernel/locking/mutex.c:575
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 104, name: dropbear
preempt_count: 1, expected: 0
INFO: lockdep is turned off.
CPU: 0 UID: 0 PID: 104 Comm: dropbear Tainted: G        W           6.18.0-rc2-00399-g6f1ab1b109b9-dirty #530 NONE
Tainted: [W]=WARN
Hardware name: Generic DT based system
Call trace:
 unwind_backtrace from show_stack+0x10/0x14
 show_stack from dump_stack_lvl+0x7c/0xac
 dump_stack_lvl from __might_resched+0x16c/0x2b0
 __might_resched from __mutex_lock+0x64/0xd34
 __mutex_lock from mutex_lock_nested+0x1c/0x24
 mutex_lock_nested from lan966x_stats_get+0x5c/0x558
 lan966x_stats_get from dev_get_stats+0x40/0x43c
 dev_get_stats from dev_seq_printf_stats+0x3c/0x184
 dev_seq_printf_stats from dev_seq_show+0x10/0x30
 dev_seq_show from seq_read_iter+0x350/0x4ec
 seq_read_iter from seq_read+0xfc/0x194
 seq_read from proc_reg_read+0xac/0x100
 proc_reg_read from vfs_read+0xb0/0x2b0
 vfs_read from ksys_read+0x6c/0xec
 ksys_read from ret_fast_syscall+0x0/0x1c
Exception stack(0xf0b11fa8 to 0xf0b11ff0)
1fa0:                   00000001 00001000 00000008 be9048d8 00001000 00000001
1fc0: 00000001 00001000 00000008 00000003 be905920 0000001e 00000000 00000001
1fe0: 0005404c be9048c0 00018684 b6ec2cd8

It seems that we are using a mutex in a atomic context which is wrong.
Change the mutex with a spinlock.

Fixes: 12c2d0a5b8e2 ("net: lan966x: add ethtool configuration and statistics")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/20251105074955.1766792-1-horatiu.vultur@microchip.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

When running these commands on DUT (and similar at the other end)
ip link set dev eth0 up
ip link add link eth0 name eth0.10 type vlan id 10
ip addr add 10.0.0.1/24 dev eth0.10
ip link set dev eth0.10 up
ping 10.0.0.2

The ping will fail.

The reason why is failing is because, the network interfaces for lan966x
have a flag saying that the HW can insert the vlan tags into the
frames(NETIF_F_HW_VLAN_CTAG_TX). Meaning that the frames that are
transmitted don't have the vlan tag inside the skb data, but they have
it inside the skb. We already get that vlan tag and put it in the IFH
but the problem is that we don't configure the HW to rewrite the frame
when the interface is in host mode.
The fix consists in actually configuring the HW to insert the vlan tag
if it is different than 0.

Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Fixes: 6d2c186afa5d ("net: lan966x: Add vlan support.")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Link: https://patch.msgid.link/20250528093619.3738998-1-horatiu.vultur@microchip.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Merge in late fixes to prepare for the 6.16 net-next PR.

No conflicts nor adjacent changes.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>