The scatter-gather feature will allow to enable the Generic Segmentation Offload.
Generic Segmentation Offload can be enabled/disabled using ethtool -K DEVNAME gso on|off.

e.g:
ethtool -K eth0 gso off

When enabled, the driver may be provided with socket buffers splitted into many fragments.
These fragments need to be queued into the TX ring in reverse order, starting from to the
last one down to the first one, to avoid a race condition with the MAC.
Especially the 'TX_USED' bit in word 1 of the transmit buffer descriptor of the
first fragment should be cleared at the very final step of the queueing algorithm.
This will tell the hardware that fragments are ready to be sent.

Also since the MAC only update the status word of the first buffer descriptor of the
ethernet frame, the queueing algorithm can no longer expect a 'TX_USED' bit to be set by
the MAC into the buffer descriptor following the one for last fragment of the skb.
This is why the driver sets the 'TX_USED' bit before queueing any fragment, so the end of
queue position is well defined for the MAC.
Signed-off-by: NCyrille Pitchen <cyrille.pitchen@atmel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This addition will also allow to configure DMA burst length.
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NCyrille Pitchen <cyrille.pitchen@atmel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Under "heavy" RX load, the driver cannot handle the descriptors fast
enough. In detail, when a descriptor is consumed, its used flag is
cleared and once the RX budget is consumed all descriptors with a
cleared used flag are prepared to receive more data. Under load though,
the HW may constantly receive more data and use those descriptors with a
cleared used flag before they are actually prepared for next usage.

The head and tail pointers into the RX-ring should always be valid and
we can omit clearing and checking of the used flag.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Coverage data suggests that the unlikely case of receiving data while
the receive handler is running may not be that unlikely.
Coverage data after running iperf for a while:
    91320:  891:	work_done = bp->macbgem_ops.mog_rx(bp, budget);
    91320:  892:	if (work_done < budget) {
     2362:  893:		napi_complete(napi);
        -:  894:
        -:  895:		/* Packets received while interrupts were disabled */
     4724:  896:		status = macb_readl(bp, RSR);
     2362:  897:		if (unlikely(status)) {
      762:  898:			if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE)
      762:  899:				macb_writel(bp, ISR, MACB_BIT(RCOMP));
        -:  900:			napi_reschedule(napi);
        -:  901:		} else {
     1600:  902:			macb_writel(bp, IER, MACB_RX_INT_FLAGS);
        -:  903:		}
        -:  904:	}
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When data is received during the driver processing received data the
NAPI is re-scheduled. In that case the RX interrupt should not be
re-enabled.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A few interrupt flags were not cleared in the ISR, resulting in a sytem
trapped in the ISR in cases one of those interrupts occurred. Clear all
flags to avoid such situations.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Just as commit "net: macb: DMA-unmap full rx-buffer"
(48330e08), pass the size that
was used for mapping the memory also to the unmap routine to
avoid warnings from the DMA_API.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

macb_mdio_reset() does nothing useful and is optional for the MDIO bus
code, so let's just remove it.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replace kfree_skb with dev_kfree_skb_any in macb_start_xmit that can
be called in hard irq and other contexts.

macb_start_xmit only frees skbs when dropping them so
dev_kfree_skb_any is used.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

When allocating RX buffers a fixed size is used, while freeing is based
on actually received bytes, resulting in the following kernel warning
when CONFIG_DMA_API_DEBUG is enabled:
 WARNING: CPU: 0 PID: 0 at lib/dma-debug.c:1051 check_unmap+0x258/0x894()
 macb e000b000.ethernet: DMA-API: device driver frees DMA memory with different size [device address=0x000000002d170040] [map size=1536 bytes] [unmap size=60 bytes]
 Modules linked in:
 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.0-rc3-xilinx-00220-g49f84081ce4f #65
 [<c001516c>] (unwind_backtrace) from [<c0011df8>] (show_stack+0x10/0x14)
 [<c0011df8>] (show_stack) from [<c03c775c>] (dump_stack+0x7c/0xc8)
 [<c03c775c>] (dump_stack) from [<c00245cc>] (warn_slowpath_common+0x60/0x84)
 [<c00245cc>] (warn_slowpath_common) from [<c0024670>] (warn_slowpath_fmt+0x2c/0x3c)
 [<c0024670>] (warn_slowpath_fmt) from [<c0227d44>] (check_unmap+0x258/0x894)
 [<c0227d44>] (check_unmap) from [<c0228588>] (debug_dma_unmap_page+0x64/0x70)
 [<c0228588>] (debug_dma_unmap_page) from [<c02ab78c>] (gem_rx+0x118/0x170)
 [<c02ab78c>] (gem_rx) from [<c02ac4d4>] (macb_poll+0x24/0x94)
 [<c02ac4d4>] (macb_poll) from [<c031222c>] (net_rx_action+0x6c/0x188)
 [<c031222c>] (net_rx_action) from [<c0028a28>] (__do_softirq+0x108/0x280)
 [<c0028a28>] (__do_softirq) from [<c0028e8c>] (irq_exit+0x84/0xf8)
 [<c0028e8c>] (irq_exit) from [<c000f360>] (handle_IRQ+0x68/0x8c)
 [<c000f360>] (handle_IRQ) from [<c0008528>] (gic_handle_irq+0x3c/0x60)
 [<c0008528>] (gic_handle_irq) from [<c0012904>] (__irq_svc+0x44/0x78)
 Exception stack(0xc056df20 to 0xc056df68)
 df20: 00000001 c0577430 00000000 c0577430 04ce8e0d 00000002 edfce238 00000000
 df40: 04e20f78 00000002 c05981f4 00000000 00000008 c056df68 c0064008 c02d7658
 df60: 20000013 ffffffff
 [<c0012904>] (__irq_svc) from [<c02d7658>] (cpuidle_enter_state+0x54/0xf8)
 [<c02d7658>] (cpuidle_enter_state) from [<c02d77dc>] (cpuidle_idle_call+0xe0/0x138)
 [<c02d77dc>] (cpuidle_idle_call) from [<c000f660>] (arch_cpu_idle+0x8/0x3c)
 [<c000f660>] (arch_cpu_idle) from [<c006bec4>] (cpu_startup_entry+0xbc/0x124)
 [<c006bec4>] (cpu_startup_entry) from [<c053daec>] (start_kernel+0x350/0x3b0)
 ---[ end trace d5fdc38641bd3a11 ]---
 Mapped at:
  [<c0227184>] debug_dma_map_page+0x48/0x11c
  [<c02ab32c>] gem_rx_refill+0x154/0x1f8
  [<c02ac7b4>] macb_open+0x270/0x3e0
  [<c03152e0>] __dev_open+0x7c/0xfc
  [<c031554c>] __dev_change_flags+0x8c/0x140

Fixing this by passing the same size which is passed during mapping the
memory to the unmap function as well.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: NBen Hutchings <ben@decadent.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With CONFIG_DMA_API_DEBUG enabled the following warning is printed:
 WARNING: CPU: 0 PID: 619 at lib/dma-debug.c:1101 check_unmap+0x758/0x894()
 macb e000b000.ethernet: DMA-API: device driver failed to check map error[device address=0x000000002d171c02] [size=322 bytes] [mapped as single]
 Modules linked in:
 CPU: 0 PID: 619 Comm: udhcpc Not tainted 3.14.0-rc3-xilinx-00219-gd158fc7f #63
 [<c001516c>] (unwind_backtrace) from [<c0011df8>] (show_stack+0x10/0x14)
 [<c0011df8>] (show_stack) from [<c03c7714>] (dump_stack+0x7c/0xc8)
 [<c03c7714>] (dump_stack) from [<c00245cc>] (warn_slowpath_common+0x60/0x84)
 [<c00245cc>] (warn_slowpath_common) from [<c0024670>] (warn_slowpath_fmt+0x2c/0x3c)
 [<c0024670>] (warn_slowpath_fmt) from [<c0228244>] (check_unmap+0x758/0x894)
 [<c0228244>] (check_unmap) from [<c0228588>] (debug_dma_unmap_page+0x64/0x70)
 [<c0228588>] (debug_dma_unmap_page) from [<c02aba64>] (macb_interrupt+0x1f8/0x2dc)
 [<c02aba64>] (macb_interrupt) from [<c006c6e4>] (handle_irq_event_percpu+0x2c/0x178)
 [<c006c6e4>] (handle_irq_event_percpu) from [<c006c86c>] (handle_irq_event+0x3c/0x5c)
 [<c006c86c>] (handle_irq_event) from [<c006f548>] (handle_fasteoi_irq+0xb8/0x100)
 [<c006f548>] (handle_fasteoi_irq) from [<c006c148>] (generic_handle_irq+0x20/0x30)
 [<c006c148>] (generic_handle_irq) from [<c000f35c>] (handle_IRQ+0x64/0x8c)
 [<c000f35c>] (handle_IRQ) from [<c0008528>] (gic_handle_irq+0x3c/0x60)
 [<c0008528>] (gic_handle_irq) from [<c0012904>] (__irq_svc+0x44/0x78)
 Exception stack(0xed197f60 to 0xed197fa8)
 7f60: 00000134 60000013 bd94362e bd94362e be96b37c 00000014 fffffd72 00000122
 7f80: c000ebe4 ed196000 00000000 00000011 c032c0d8 ed197fa8 c0064008 c000ea20
 7fa0: 60000013 ffffffff
 [<c0012904>] (__irq_svc) from [<c000ea20>] (ret_fast_syscall+0x0/0x48)
 ---[ end trace 478f921d0d542d1e ]---
 Mapped at:
  [<c0227184>] debug_dma_map_page+0x48/0x11c
  [<c02aaca0>] macb_start_xmit+0x184/0x2a8
  [<c03143c0>] dev_hard_start_xmit+0x334/0x470
  [<c032c09c>] sch_direct_xmit+0x78/0x2f8
  [<c0314814>] __dev_queue_xmit+0x318/0x708

due to missing checks of the dma mapping. Add the appropriate checks to fix
this.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: NBen Hutchings <ben@decadent.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When adjusting the link speed, the target frequency is determined by a
'swith (LINK_SPEED)' statement, that assigns the target rate only for
valid and expected LINK_SPEED values. This incomplete switch statement
leads to the following build warning:
     drivers/net/ethernet/cadence/macb.c: In function 'macb_handle_link_change':
  >> drivers/net/ethernet/cadence/macb.c:241:14: warning: 'rate' may be used uninitialized in this function [-Wmaybe-uninitialized]
        netdev_warn(dev, "unable to generate target frequency: %ld Hz\n",
                   ^
     drivers/net/ethernet/cadence/macb.c:215:13: note: 'rate' was declared here
       long ferr, rate, rate_rounded;

Fixing this by bailing out of that function in the switch's default case
before the rate variable is used.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Adjust the ethernet clock according to the negotiated link speed.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use the device managed interface to request the IRQ, simplifying error
paths.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use the device managed version of ioremap to remap IO memory,
simplifying error paths.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Migrate to using the device managed interface for clocks and clean up
the associated error paths.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Migrate the suspend/resume functions to use the dev_pm_ops PM interface.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly. This is a cosmetic change
to make the code simpler and enhance the readability.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replace misleading -1 (-EPERM) by a more appropriate return code (-ENXIO)
in macb_mii_probe function.
Save macb_mii_probe return before branching to err_out_unregister to avoid
erronous 0 return.
Signed-off-by: NBoris BREZILLON <b.brezillon@overkiz.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The macb driver only handle PHY description through platform_data
(macb_platform_data).
Thus, when using dt you cannot define phy properties like phy address or
phy irq pin.

This patch makes use of the of_mdiobus_register to add support for
phy device definition using dt.
A fallback to the autoscan procedure is added in case there is no phy
devices defined in dt.
Signed-off-by: NBoris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJongsung Kim <neidhard.kim@lge.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

GEM is able to adapt its DMA buffer size, so change
the RX path to take advantage of this possibility and
remove all kind of memcpy in this path.
This modification introduces function pointers for managing
differences between MACB and GEM adapter type.
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Macb Ethernet controller requires a RX buffer of 128 bytes. It is
highly sub-optimal for Gigabit-capable GEM that is able to use
a bigger DMA buffer. Change this constant and associated macros
with data stored in the private structure.
RX DMA buffer size has to be multiple of 64 bytes as indicated in
DMA Configuration Register specification.
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver core clears the driver data to NULL after device_release
or on probe failure, since commit 0998d063
(device-core: Ensure drvdata = NULL when no driver is bound).
Thus, it is not needed to manually clear the device driver data to NULL.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NRob Herring <rob.herring@calxeda.com>
Acked-by: NRoland Stigge <stigge@antcom.de>
Acked-by: NMugunthan V N <mugunthanvnm@ti.com>
Reviewed-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Tested-by: NRoland Stigge <stigge@antcom.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 749a2b66 (net/macb: clear tx/rx completion flags in ISR)
introduces clear-on-write on ISR register. This behavior is not always
implemented when using Cadence MACB/GEM and is breaking other platforms.
We are using the Design Configuration Register 1 information and a capability
property to actually activate this clear-on-write behavior on ISR.
Reported-by: NHein Tibosch <hein_tibosch@yahoo.es>
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Tested-by: NHein Tibosch <hein_tibosch@yahoo.es>
Acked-by: NJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix to return a negative error code from the error handling
case instead of 0, as returned elsewhere in this function.

Original-idea-by: <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With of_get_mac_address() and of_get_phy_mode() now defined as dummy
functions if OF_NET is not configured, it is no longer necessary to
provide OF dependent functions as front-end. Also, the two functions
depend on OF_NET, not on OF, so the conditional code was not correct
anyway.

Drop the front-end functions and call of_get_mac_address() and
of_get_phy_mode() directly instead.
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use clk_prepare_enable/clk_disable_unprepare to be safe on SMP systems.
Signed-off-by: NSteffen Trumtrar <s.trumtrar@pengutronix.de>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Fabio Estevam <festevam@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The core has a bit for swapping packet data endianism.
Reset default from Cadence is off. Xilinx however, who uses this core on the
Zynq SoCs, opted for on.
Force it to off. This shouldn't change the behaviour for current users of the
macb, but enables usage on Zynq devices.
Signed-off-by: NSteffen Trumtrar <s.trumtrar@pengutronix.de>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

At least in the cadence IP core on the Xilinx Zynq SoC the TCOMP/RCOMP flags
are not auto-cleaned. As these flags are evaluated, they need to be cleaned.
Signed-off-by: NSteffen Trumtrar <s.trumtrar@pengutronix.de>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch uses module_platform_driver_probe() macro which makes
the code smaller and simpler.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When interrupts are disabled, an RX condition can occur but
it is not reported when enabling interrupts again. We need to check
RSR and use napi_reschedule() if condition is met.
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The flags argument of the phy_{attach,connect,connect_direct} functions
is then used to assign a struct phy_device dev_flags with its value.
All callers but the tg3 driver pass the flag 0, which results in the
underlying PHY drivers in drivers/net/phy/ not being able to actually
use any of the flags they would set in dev_flags. This patch gets rid of
the flags argument, and passes phydev->dev_flags to the internal PHY
library call phy_attach_direct() such that drivers which actually modify
a phy device dev_flags get the value preserved for use by the underlying
phy driver.
Acked-by: NKosta Zertsekel <konszert@marvell.com>
Signed-off-by: NFlorian Fainelli <florian@openwrt.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

CONFIG_HOTPLUG is going away as an option.  As result the __dev*
markings will be going away.

Remove use of __devinit, __devexit_p, __devinitdata, __devinitconst,
and __devexit.
Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add information to the DMA Configuration Register to
maximize system performance:
- rx/tx packet buffer full memory size
- allow possibility to use INCR16 if supported
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Joachim Eastwood <manabian@gmail.com
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If ndo_validate_addr is set to the generic eth_validate_addr
function there is no point in calling is_valid_ether_addr
from driver ndo_open if ndo_open is not used elsewhere in
the driver.

With this change is_valid_ether_addr will be called from the
generic eth_validate_addr function. So there should be no change
in the actual behavior.
Signed-off-by: NJoachim Eastwood <manabian@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move to circular buffers management macro and correct an error
with circular buffer initial condition.

Without this patch, the macb_tx_ring_avail() function was
not reporting the proper ring availability at startup:
macb macb: eth0: BUG! Tx Ring full when queue awake!
macb macb: eth0: tx_head = 0, tx_tail = 0
And hanginig forever...

I remove the macb_tx_ring_avail() function and use the
proven macros from circ_buf.h. CIRC_CNT() is used in the
"consumer" part of the driver: macb_tx_interrupt() to match
advice from Documentation/circular-buffers.txt.
Reported-by: NJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Tested-by: NJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Only the first register set is used for matching but
we support getting the initial hw addr from any of
the registers.

To prevent stale entries and false matches clear unused
register sets. This most important for the at91_ether
driver where u-boot always uses the 2nd register set.
Signed-off-by: NJoachim Eastwood <manabian@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJoachim Eastwood <manabian@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJoachim Eastwood <manabian@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>