diff options
Diffstat (limited to 'drivers/infiniband/hw/ipath/ipath_wc_x86_64.c')
| -rw-r--r-- | drivers/infiniband/hw/ipath/ipath_wc_x86_64.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/ipath/ipath_wc_x86_64.c b/drivers/infiniband/hw/ipath/ipath_wc_x86_64.c new file mode 100644 index 000000000000..adc5322f15c1 --- /dev/null +++ b/drivers/infiniband/hw/ipath/ipath_wc_x86_64.c @@ -0,0 +1,157 @@ +/* + * 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 "ipath_kernel.h" + +/** + * ipath_enable_wc - enable write combining for MMIO writes to the device + * @dd: infinipath device + * + * This routine is x86_64-specific; it twiddles the CPU's MTRRs to enable + * write combining. + */ +int ipath_enable_wc(struct ipath_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. + */ + pioaddr = addr + dd->ipath_piobufbase; + piolen = (dd->ipath_piobcnt2k + + dd->ipath_piobcnt4k) * + ALIGN(dd->ipath_piobcnt2k + + dd->ipath_piobcnt4k, dd->ipath_palign); + + 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; + ipath_dbg("pioaddr %llx not on right boundary for size " + "%llx, fixing\n", + (unsigned long long) pioaddr, + (unsigned long long) piolen); + atmp = pioaddr & ~(piolen - 1); + if (atmp < addr || (atmp + piolen) > (addr + len)) { + ipath_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 { + ipath_dbg("changing WC base from %llx to %llx, " + "len from %llx to %llx\n", + (unsigned long long) pioaddr, + (unsigned long long) atmp, + (unsigned long long) piolen, + (unsigned long long) piolen << 1); + pioaddr = atmp; + piolen <<= 1; + } + } + + if (!ret) { + int cookie; + ipath_cdbg(VERBOSE, "Setting mtrr for chip to WC " + "(addr %llx, len=0x%llx)\n", + (unsigned long long) pioaddr, + (unsigned long long) piolen); + cookie = mtrr_add(pioaddr, piolen, MTRR_TYPE_WRCOMB, 0); + if (cookie < 0) { + { + dev_info(&dd->pcidev->dev, + "mtrr_add() WC for PIO bufs " + "failed (%d)\n", + cookie); + ret = -EINVAL; + } + } else { + ipath_cdbg(VERBOSE, "Set mtrr for chip to WC, " + "cookie is %d\n", cookie); + dd->ipath_wc_cookie = cookie; + } + } + + return ret; +} + +/** + * ipath_disable_wc - disable write combining for MMIO writes to the device + * @dd: infinipath device + */ +void ipath_disable_wc(struct ipath_devdata *dd) +{ + if (dd->ipath_wc_cookie) { + ipath_cdbg(VERBOSE, "undoing WCCOMB on pio buffers\n"); + mtrr_del(dd->ipath_wc_cookie, 0, 0); + dd->ipath_wc_cookie = 0; + } +} + +/** + * ipath_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 ipath_unordered_wc(void) +{ + return boot_cpu_data.x86_vendor != X86_VENDOR_AMD; +} |