path: root/net/sched
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authorHarini Katakam <harini.katakam@xilinx.com>2018-07-06 12:18:58 +0530
committerDavid S. Miller <davem@davemloft.net>2018-07-07 20:54:25 +0900
commit404cd086f29e867fc99f1174e8f3246a4ea14b7b (patch)
tree628216d7ad81abce9949d91f036135669367074b /net/sched
parentnet: macb: Free RX ring for all queues (diff)
net: macb: Allocate valid memory for TX and RX BD prefetch
GEM version in ZynqMP and most versions greater than r1p07 supports TX and RX BD prefetch. The number of BDs that can be prefetched is a HW configurable parameter. For ZynqMP, this parameter is 4. When GEM DMA is accessing the last BD in the ring, even before the BD is processed and the WRAP bit is noticed, it will have prefetched BDs outside the BD ring. These will not be processed but it is necessary to have accessible memory after the last BD. Especially in cases where SMMU is used, memory locations immediately after the last BD may not have translation tables triggering HRESP errors. Hence always allocate extra BDs to accommodate for prefetch. The value of tx/rx bd prefetch for any given SoC version is: 2 ^ (corresponding field in design config 10 register). (value of this field >= 1) Added a capability flag so that older IP versions that do not have DCFG10 or this prefetch capability are not affected. Signed-off-by: Harini Katakam <harini.katakam@xilinx.com> Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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