diff options
Diffstat (limited to 'drivers/net/ethernet/chelsio/cxgb4/t4_hw.c')
| -rw-r--r-- | drivers/net/ethernet/chelsio/cxgb4/t4_hw.c | 75 |
1 files changed, 56 insertions, 19 deletions
diff --git a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c index 87000cd39737..0de8eb72325c 100644 --- a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c +++ b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c @@ -6369,7 +6369,6 @@ int t4_fixup_host_params(struct adapter *adap, unsigned int page_size, unsigned int stat_len = cache_line_size > 64 ? 128 : 64; unsigned int fl_align = cache_line_size < 32 ? 32 : cache_line_size; unsigned int fl_align_log = fls(fl_align) - 1; - unsigned int ingpad; t4_write_reg(adap, SGE_HOST_PAGE_SIZE_A, HOSTPAGESIZEPF0_V(sge_hps) | @@ -6389,6 +6388,10 @@ int t4_fixup_host_params(struct adapter *adap, unsigned int page_size, INGPADBOUNDARY_SHIFT_X) | EGRSTATUSPAGESIZE_V(stat_len != 64)); } else { + unsigned int pack_align; + unsigned int ingpad, ingpack; + unsigned int pcie_cap; + /* T5 introduced the separation of the Free List Padding and * Packing Boundaries. Thus, we can select a smaller Padding * Boundary to avoid uselessly chewing up PCIe Link and Memory @@ -6401,27 +6404,62 @@ int t4_fixup_host_params(struct adapter *adap, unsigned int page_size, * Size (the minimum unit of transfer to/from Memory). If we * have a Padding Boundary which is smaller than the Memory * Line Size, that'll involve a Read-Modify-Write cycle on the - * Memory Controller which is never good. For T5 the smallest - * Padding Boundary which we can select is 32 bytes which is - * larger than any known Memory Controller Line Size so we'll - * use that. - * - * T5 has a different interpretation of the "0" value for the - * Packing Boundary. This corresponds to 16 bytes instead of - * the expected 32 bytes. We never have a Packing Boundary - * less than 32 bytes so we can't use that special value but - * on the other hand, if we wanted 32 bytes, the best we can - * really do is 64 bytes. - */ - if (fl_align <= 32) { + * Memory Controller which is never good. + */ + + /* We want the Packing Boundary to be based on the Cache Line + * Size in order to help avoid False Sharing performance + * issues between CPUs, etc. We also want the Packing + * Boundary to incorporate the PCI-E Maximum Payload Size. We + * get best performance when the Packing Boundary is a + * multiple of the Maximum Payload Size. + */ + pack_align = fl_align; + pcie_cap = pci_find_capability(adap->pdev, PCI_CAP_ID_EXP); + if (pcie_cap) { + unsigned int mps, mps_log; + u16 devctl; + + /* The PCIe Device Control Maximum Payload Size field + * [bits 7:5] encodes sizes as powers of 2 starting at + * 128 bytes. + */ + pci_read_config_word(adap->pdev, + pcie_cap + PCI_EXP_DEVCTL, + &devctl); + mps_log = ((devctl & PCI_EXP_DEVCTL_PAYLOAD) >> 5) + 7; + mps = 1 << mps_log; + if (mps > pack_align) + pack_align = mps; + } + + /* N.B. T5/T6 have a crazy special interpretation of the "0" + * value for the Packing Boundary. This corresponds to 16 + * bytes instead of the expected 32 bytes. So if we want 32 + * bytes, the best we can really do is 64 bytes ... + */ + if (pack_align <= 16) { + ingpack = INGPACKBOUNDARY_16B_X; + fl_align = 16; + } else if (pack_align == 32) { + ingpack = INGPACKBOUNDARY_64B_X; fl_align = 64; - fl_align_log = 6; + } else { + unsigned int pack_align_log = fls(pack_align) - 1; + + ingpack = pack_align_log - INGPACKBOUNDARY_SHIFT_X; + fl_align = pack_align; } + /* Use the smallest Ingress Padding which isn't smaller than + * the Memory Controller Read/Write Size. We'll take that as + * being 8 bytes since we don't know of any system with a + * wider Memory Controller Bus Width. + */ if (is_t5(adap->params.chip)) - ingpad = INGPCIEBOUNDARY_32B_X; + ingpad = INGPADBOUNDARY_32B_X; else - ingpad = T6_INGPADBOUNDARY_32B_X; + ingpad = T6_INGPADBOUNDARY_8B_X; t4_set_reg_field(adap, SGE_CONTROL_A, INGPADBOUNDARY_V(INGPADBOUNDARY_M) | @@ -6430,8 +6468,7 @@ int t4_fixup_host_params(struct adapter *adap, unsigned int page_size, EGRSTATUSPAGESIZE_V(stat_len != 64)); t4_set_reg_field(adap, SGE_CONTROL2_A, INGPACKBOUNDARY_V(INGPACKBOUNDARY_M), - INGPACKBOUNDARY_V(fl_align_log - - INGPACKBOUNDARY_SHIFT_X)); + INGPACKBOUNDARY_V(ingpack)); } /* * Adjust various SGE Free List Host Buffer Sizes. |