Searched hist:b5dceda1f7ef66cba6f8d766502f242a27f96e6d (Results 1 – 2 of 2) sorted by relevance
/linux/lib/raid6/ |
H A D | mktables.c | diff b5dceda1f7ef66cba6f8d766502f242a27f96e6d Mon May 15 07:04:52 CEST 2017 Anup Patel <anup.patel@broadcom.com> lib/raid6: Add log-of-2 table for RAID6 HW requiring disk position
The raid6_gfexp table represents {2}^n values for 0 <= n < 256. The Linux async_tx framework pass values from raid6_gfexp as coefficients for each source to prep_dma_pq() callback of DMA channel with PQ capability. This creates problem for RAID6 offload engines (such as Broadcom SBA) which take disk position (i.e. log of {2}) instead of multiplicative cofficients from raid6_gfexp table.
This patch adds raid6_gflog table having log-of-2 value for any given x such that 0 <= x < 256. For any given disk coefficient x, the corresponding disk position is given by raid6_gflog[x]. The RAID6 offload engine driver can use this newly added raid6_gflog table to get disk position from multiplicative coefficient.
Signed-off-by: Anup Patel <anup.patel@broadcom.com> Reviewed-by: Scott Branden <scott.branden@broadcom.com> Reviewed-by: Ray Jui <ray.jui@broadcom.com> Acked-by: Shaohua Li <shli@fb.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
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/linux/include/linux/raid/ |
H A D | pq.h | diff b5dceda1f7ef66cba6f8d766502f242a27f96e6d Mon May 15 07:04:52 CEST 2017 Anup Patel <anup.patel@broadcom.com> lib/raid6: Add log-of-2 table for RAID6 HW requiring disk position
The raid6_gfexp table represents {2}^n values for 0 <= n < 256. The Linux async_tx framework pass values from raid6_gfexp as coefficients for each source to prep_dma_pq() callback of DMA channel with PQ capability. This creates problem for RAID6 offload engines (such as Broadcom SBA) which take disk position (i.e. log of {2}) instead of multiplicative cofficients from raid6_gfexp table.
This patch adds raid6_gflog table having log-of-2 value for any given x such that 0 <= x < 256. For any given disk coefficient x, the corresponding disk position is given by raid6_gflog[x]. The RAID6 offload engine driver can use this newly added raid6_gflog table to get disk position from multiplicative coefficient.
Signed-off-by: Anup Patel <anup.patel@broadcom.com> Reviewed-by: Scott Branden <scott.branden@broadcom.com> Reviewed-by: Ray Jui <ray.jui@broadcom.com> Acked-by: Shaohua Li <shli@fb.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
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