cregit-Linux how code gets into the kernel

Release 4.7 drivers/infiniband/hw/qib/qib_wc_x86_64.c

/*
 * 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; }

Contributors

PersonTokensPropCommitsCommitProp
ralph campbellralph campbell33395.69%116.67%
mike marciniszynmike marciniszyn82.30%466.67%
luis r. rodriguezluis r. rodriguez72.01%116.67%
Total348100.00%6100.00%

/** * 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); }

Contributors

PersonTokensPropCommitsCommitProp
ralph campbellralph campbell1694.12%150.00%
luis r. rodriguezluis r. rodriguez15.88%150.00%
Total17100.00%2100.00%

/** * 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; }

Contributors

PersonTokensPropCommitsCommitProp
ralph campbellralph campbell14100.00%1100.00%
Total14100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
ralph campbellralph campbell37995.71%116.67%
mike marciniszynmike marciniszyn92.27%466.67%
luis r. rodriguezluis r. rodriguez82.02%116.67%
Total396100.00%6100.00%
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