diff options
Diffstat (limited to 'drivers/infiniband/hw/qib/qib_wc_x86_64.c')
| -rw-r--r-- | drivers/infiniband/hw/qib/qib_wc_x86_64.c | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/qib/qib_wc_x86_64.c b/drivers/infiniband/hw/qib/qib_wc_x86_64.c new file mode 100644 index 000000000..edd0ddbd4 --- /dev/null +++ b/drivers/infiniband/hw/qib/qib_wc_x86_64.c @@ -0,0 +1,150 @@ +/* + * Copyright (c) 2012 Intel Corporation. All rights reserved. + * Copyright (c) 2006 - 2012 QLogic Corporation. All rights reserved. + * Copyright (c) 2003, 2004, 2005, 2006 PathScale, Inc. All rights reserved. + * + * This software is available to you under a choice of one of two + * licenses. You may choose to be licensed under the terms of the GNU + * General Public License (GPL) Version 2, available from the file + * COPYING in the main directory of this source tree, or the + * OpenIB.org BSD license below: + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * - Redistributions of source code must retain the above + * copyright notice, this list of conditions and the following + * disclaimer. + * + * - Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials + * provided with the distribution. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +/* + * This file is conditionally built on x86_64 only. Otherwise weak symbol + * versions of the functions exported from here are used. + */ + +#include <linux/pci.h> +#include <asm/mtrr.h> +#include <asm/processor.h> + +#include "qib.h" + +/** + * qib_enable_wc - enable write combining for MMIO writes to the device + * @dd: qlogic_ib device + * + * This routine is x86_64-specific; it twiddles the CPU's MTRRs to enable + * write combining. + */ +int qib_enable_wc(struct qib_devdata *dd) +{ + int ret = 0; + u64 pioaddr, piolen; + unsigned bits; + const unsigned long addr = pci_resource_start(dd->pcidev, 0); + const size_t len = pci_resource_len(dd->pcidev, 0); + + /* + * Set the PIO buffers to be WCCOMB, so we get HT bursts to the + * chip. Linux (possibly the hardware) requires it to be on a power + * of 2 address matching the length (which has to be a power of 2). + * For rev1, that means the base address, for rev2, it will be just + * the PIO buffers themselves. + * For chips with two sets of buffers, the calculations are + * somewhat more complicated; we need to sum, and the piobufbase + * register has both offsets, 2K in low 32 bits, 4K in high 32 bits. + * The buffers are still packed, so a single range covers both. + */ + if (dd->piobcnt2k && dd->piobcnt4k) { + /* 2 sizes for chip */ + unsigned long pio2kbase, pio4kbase; + + pio2kbase = dd->piobufbase & 0xffffffffUL; + pio4kbase = (dd->piobufbase >> 32) & 0xffffffffUL; + if (pio2kbase < pio4kbase) { + /* all current chips */ + pioaddr = addr + pio2kbase; + piolen = pio4kbase - pio2kbase + + dd->piobcnt4k * dd->align4k; + } else { + pioaddr = addr + pio4kbase; + piolen = pio2kbase - pio4kbase + + dd->piobcnt2k * dd->palign; + } + } else { /* single buffer size (2K, currently) */ + pioaddr = addr + dd->piobufbase; + piolen = dd->piobcnt2k * dd->palign + + dd->piobcnt4k * dd->align4k; + } + + for (bits = 0; !(piolen & (1ULL << bits)); bits++) + ; /* do nothing */ + + if (piolen != (1ULL << bits)) { + piolen >>= bits; + while (piolen >>= 1) + bits++; + piolen = 1ULL << (bits + 1); + } + if (pioaddr & (piolen - 1)) { + u64 atmp = pioaddr & ~(piolen - 1); + + if (atmp < addr || (atmp + piolen) > (addr + len)) { + qib_dev_err(dd, + "No way to align address/size (%llx/%llx), no WC mtrr\n", + (unsigned long long) atmp, + (unsigned long long) piolen << 1); + ret = -ENODEV; + } else { + pioaddr = atmp; + piolen <<= 1; + } + } + + if (!ret) { + dd->wc_cookie = arch_phys_wc_add(pioaddr, piolen); + if (dd->wc_cookie < 0) + /* use error from routine */ + ret = dd->wc_cookie; + } + + return ret; +} + +/** + * qib_disable_wc - disable write combining for MMIO writes to the device + * @dd: qlogic_ib device + */ +void qib_disable_wc(struct qib_devdata *dd) +{ + arch_phys_wc_del(dd->wc_cookie); +} + +/** + * qib_unordered_wc - indicate whether write combining is ordered + * + * Because our performance depends on our ability to do write combining mmio + * writes in the most efficient way, we need to know if we are on an Intel + * or AMD x86_64 processor. AMD x86_64 processors flush WC buffers out in + * the order completed, and so no special flushing is required to get + * correct ordering. Intel processors, however, will flush write buffers + * out in "random" orders, and so explicit ordering is needed at times. + */ +int qib_unordered_wc(void) +{ + return boot_cpu_data.x86_vendor != X86_VENDOR_AMD; +} |