net: fill in MODULE_DESCRIPTION()s for Broadcom bgmac

W=1 builds now warn if module is built without a MODULE_DESCRIPTION().
Add descriptions to the Broadcom iProc GBit driver.

Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://lore.kernel.org/r/20240123190332.677489-3-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: ethernet: broadcom: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new() which already returns void. Eventually after all drivers
are converted, .remove_new() is renamed to .remove().

Trivially convert these drivers from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: broadcom: bcm4908_enet: report queued and transmitted bytes

This allows BQL to operate avoiding buffer bloat and reducing latency.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Link: https://lore.kernel.org/r/20221031104856.32388-1-zajec5@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: broadcom: bcm4908_enet: use build_skb()

RX code can be more efficient with the build_skb(). Allocating actual
SKB around eth packet buffer - right before passing it up - results in
a better cache usage.

Without RPS (echo 0 > rps_cpus) BCM4908 NAT masq performance "jumps"
between two speeds: ~900 Mbps and 940 Mbps (it's a 4 CPUs SoC). This
change bumps the lower speed from 905 Mb/s to 918 Mb/s (tested using
single stream iperf 2.0.5 traffic).

There are more optimizations to consider. One obvious to try is GRO
however as BCM4908 doesn't do hw csum is may actually lower performance.
Sometimes. Some early testing:

┌─────────────────────────────────┬─────────────────────┬────────────────────┐
│ │ netif_receive_skb() │ napi_gro_receive() │
├─────────────────────────────────┼─────────────────────┼────────────────────┤
│ netdev_alloc_skb() │ 905 Mb/s │ 892 Mb/s │
│ napi_alloc_frag() + build_skb() │ 918 Mb/s │ 917 Mb/s │
└─────────────────────────────────┴─────────────────────┴────────────────────┘

Another ideas:
1. napi_build_skb()
2. skb_copy_from_linear_data() for small packets

Those need proper testing first though. That can be done later.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Link: https://lore.kernel.org/r/20221025132245.22871-1-zajec5@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

net: broadcom: bcm4908_enet: update TX stats after actual transmission

Queueing packets doesn't guarantee their transmission. Update TX stats
after hardware confirms consuming submitted data.

This also fixes a possible race and NULL dereference.
bcm4908_enet_start_xmit() could try to access skb after freeing it in
the bcm4908_enet_poll_tx().

Reported-by: Florian Fainelli <f.fainelli@gmail.com>
Fixes: 4feffeadbcb2e ("net: broadcom: bcm4908enet: add BCM4908 controller driver")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20221027112430.8696-1-zajec5@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: drop the weight argument from netif_napi_add

We tell driver developers to always pass NAPI_POLL_WEIGHT
as the weight to netif_napi_add(). This may be confusing
to newcomers, drop the weight argument, those who really
need to tweak the weight can use netif_napi_add_weight().

Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> # for CAN
Link: https://lore.kernel.org/r/20220927132753.750069-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: broadcom: bcm4908_enet: handle -EPROBE_DEFER when getting MAC

Reading MAC from OF may return -EPROBE_DEFER if underlaying NVMEM device
isn't ready yet. In such case pass that error code up and "wait" to be
probed later.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Link: https://lore.kernel.org/r/20220915133013.2243-1-zajec5@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: broadcom: Fix return type for implementation of

Since Linux now supports CFI, it will be a good idea to fix mismatched
return type for implementation of hooks. Otherwise this might get
cought out by CFI and cause a panic.

bcm4908_enet_start_xmit() would return either NETDEV_TX_BUSY or
NETDEV_TX_OK, so change the return type to netdev_tx_t directly.

Signed-off-by: GUO Zihua <guozihua@huawei.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20220902075407.52358-1-guozihua@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: switch to netif_napi_add_tx()

Switch net callers to the new API not requiring
the NAPI_POLL_WEIGHT argument.

Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Acked-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Acked-by: Alexandra Winter <wintera@linux.ibm.com>
Link: https://lore.kernel.org/r/20220504163725.550782-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: broadcom: bcm4908enet: remove redundant variable bytes

The variable bytes is being used to summate slot lengths,
however the value is never used afterwards. The summation
is redundant so remove variable bytes.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20211222003937.727325-1-colin.i.king@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: bcm4908: Handle dma_set_coherent_mask error codes

The return value of dma_set_coherent_mask() is not always 0.
To catch the exception in case that dma is not support the mask.

Fixes: 9d61d138ab30 ("net: broadcom: rename BCM4908 driver & update DT binding")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: broadcom: bcm4908_enet: use kcalloc() instead of kzalloc()

Use 2-factor multiplication argument form kcalloc() instead
of kzalloc().

Link: https://github.com/KSPP/linux/issues/162
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20211006180843.GA913399@embeddedor
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

ethernet: use of_get_ethdev_address()

Use the new of_get_ethdev_address() helper for the cases
where dev->dev_addr is passed in directly as the destination.

@@
expression dev, np;
@@
- of_get_mac_address(np, dev->dev_addr)
+ of_get_ethdev_address(np, dev)

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: broadcom: bcm4908_enet: reset DMA rings sw indexes properly

Resetting software indexes in bcm4908_dma_alloc_buf_descs() is not
enough as it's called during device probe only. Driver resets DMA on
every .ndo_open callback and it's required to reset indexes then.

This fixes inconsistent rings state and stalled traffic after interface
down & up sequence.

Fixes: 4feffeadbcb2 ("net: broadcom: bcm4908enet: add BCM4908 controller driver")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

of: net: pass the dst buffer to of_get_mac_address()

of_get_mac_address() returns a "const void*" pointer to a MAC address.
Lately, support to fetch the MAC address by an NVMEM provider was added.
But this will only work with platform devices. It will not work with
PCI devices (e.g. of an integrated root complex) and esp. not with DSA
ports.

There is an of_* variant of the nvmem binding which works without
devices. The returned data of a nvmem_cell_read() has to be freed after
use. On the other hand the return of_get_mac_address() points to some
static data without a lifetime. The trick for now, was to allocate a
device resource managed buffer which is then returned. This will only
work if we have an actual device.

Change it, so that the caller of of_get_mac_address() has to supply a
buffer where the MAC address is written to. Unfortunately, this will
touch all drivers which use the of_get_mac_address().

Usually the code looks like:

const char *addr;
addr = of_get_mac_address(np);
if (!IS_ERR(addr))
ether_addr_copy(ndev->dev_addr, addr);

This can then be simply rewritten as:

of_get_mac_address(np, ndev->dev_addr);

Sometimes is_valid_ether_addr() is used to test the MAC address.
of_get_mac_address() already makes sure, it just returns a valid MAC
address. Thus we can just test its return code. But we have to be
careful if there are still other sources for the MAC address before the
of_get_mac_address(). In this case we have to keep the
is_valid_ether_addr() call.

The following coccinelle patch was used to convert common cases to the
new style. Afterwards, I've manually gone over the drivers and fixed the
return code variable: either used a new one or if one was already
available use that. Mansour Moufid, thanks for that coccinelle patch!

<spml>
@a@
identifier x;
expression y, z;
@@
- x = of_get_mac_address(y);
+ x = of_get_mac_address(y, z);
<...
- ether_addr_copy(z, x);
...>

@@
identifier a.x;
@@
- if (<+... x ...+>) {}

@@
identifier a.x;
@@
if (<+... x ...+>) {
...
}
- else {}

@@
identifier a.x;
expression e;
@@
- if (<+... x ...+>@e)
- {}
- else
+ if (!(e))
{...}

@@
expression x, y, z;
@@
- x = of_get_mac_address(y, z);
+ of_get_mac_address(y, z);
... when != x
</spml>

All drivers, except drivers/net/ethernet/aeroflex/greth.c, were
compile-time tested.

Suggested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: broadcom: bcm4908_enet: support TX interrupt

It appears that each DMA channel has its own interrupt and both rings
can be configured (the same way) to handle interrupts.

1. Make ring interrupts code generic (make it operate on given ring)
2. Move napi to ring (so each has its own)
3. Make IRQ handler generic (match ring against received IRQ number)
4. Add (optional) support for TX interrupt

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: broadcom: bcm4908_enet: read MAC from OF

BCM4908 devices have MAC address accessible using NVMEM so it's needed
to use OF helper for reading it.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: broadcom: bcm4908enet: Fix a double free in bcm4908_enet_dma_alloc

In bcm4908_enet_dma_alloc, if callee bcm4908_dma_alloc_buf_descs() failed,
it will free the ring->cpu_addr by dma_free_coherent() and return error.
Then bcm4908_enet_dma_free() will be called, and free the same cpu_addr
by dma_free_coherent() again.

My patch set ring->cpu_addr to NULL after it is freed in
bcm4908_dma_alloc_buf_descs() to avoid the double free.

Fixes: 4feffeadbcb2e ("net: broadcom: bcm4908enet: add BCM4908 controller driver")
Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: broadcom: bcm4908_enet: enable RX after processing packets

When receiving a lot of packets hardware may run out of free
descriptiors and stop RX ring. Enable it every time after handling
received packets.

Fixes: 4feffeadbcb2 ("net: broadcom: bcm4908enet: add BCM4908 controller driver")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20210226132038.29849-1-zajec5@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: broadcom: bcm4908_enet: fix NAPI poll returned value

Missing increment was resulting in poll function always returning 0
instead of amount of processed packets.

Fixes: 4feffeadbcb2 ("net: broadcom: bcm4908enet: add BCM4908 controller driver")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20210224151842.2419-2-zajec5@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: broadcom: bcm4908_enet: fix RX path possible mem leak

After filling RX ring slot with new skb it's required to free old skb.
Immediately on error or later in the net subsystem.

Fixes: 4feffeadbcb2 ("net: broadcom: bcm4908enet: add BCM4908 controller driver")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20210224151842.2419-1-zajec5@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: broadcom: bcm4908_enet: set MTU on open & on request

Hardware comes up with default max frame size set to 1518. When using it
with switch it results in actual Ethernet MTU 1492:
1518 - 14 (Ethernet header) - 4 (Broadcom's tag) - 4 (802.1q) - 4 (FCS)

Above means hardware in its default state can't handle standard Ethernet
traffic (MTU 1500).

Define maximum possible Ethernet overhead and always set MAC max frame
length accordingly. This change fixes handling Ethernet frames of length
1506 - 1514.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: broadcom: bcm4908_enet: fix endianness in xmit code

Use le32_to_cpu() for reading __le32 struct field filled by hw.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: broadcom: bcm4908_enet: fix received skb length

Use ETH_FCS_LEN instead of magic value and drop incorrect + 2

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: broadcom: bcm4908_enet: fix minor typos

1. Fix "ensable" typo noticed by Andrew
2. Fix chipset name in the struct net_device_ops variable

Suggested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: broadcom: bcm4908_enet: drop "inline" from C functions

It seems preferred to let compiler optimize code if applicable.
While at it drop unused enet_umac_maskset().

Suggested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: broadcom: bcm4908_enet: drop unneeded memset()

dma_alloc_coherent takes care of zeroing allocated memory

Suggested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: broadcom: rename BCM4908 driver & update DT binding

compatible string was updated to match normal naming convention so
update driver as well

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>