I/OAT: Add DCA services (2ed6dc34) · Commits · 戴 / test

drivers/dca/Kconfig

+1 −5

Original line number	Diff line number	Diff line
		@@ -3,9 +3,5 @@
		#

		config DCA
		tristate "DCA support for clients and providers"
		default m
		help
		This is a server to help modules that want to use Direct Cache
		Access to find DCA providers that will supply correct CPU tags.
		tristate

drivers/dma/Kconfig

+35 −25

Original line number	Diff line number	Diff line
		@@ -2,42 +2,52 @@
		# DMA engine configuration
		#

		menu "DMA Engine support"
		depends on HAS_DMA
		menuconfig DMADEVICES
		bool "DMA Offload Engine support"
		depends on (PCI && X86) \|\| ARCH_IOP32X \|\| ARCH_IOP33X \|\| ARCH_IOP13XX
		help
		Intel(R) offload engines enable offloading memory copies in the
		network stack and RAID operations in the MD driver.

		if DMADEVICES

		comment "DMA Devices"

		config INTEL_IOATDMA
		tristate "Intel I/OAT DMA support"
		depends on PCI && X86
		select DMA_ENGINE
		select DCA
		help
		Enable support for the Intel(R) I/OAT DMA engine present
		in recent Intel Xeon chipsets.

		Say Y here if you have such a chipset.

		If unsure, say N.

		config INTEL_IOP_ADMA
		tristate "Intel IOP ADMA support"
		depends on ARCH_IOP32X \|\| ARCH_IOP33X \|\| ARCH_IOP13XX
		select ASYNC_CORE
		select DMA_ENGINE
		help
		Enable support for the Intel(R) IOP Series RAID engines.

		config DMA_ENGINE
		bool "Support for DMA engines"
		---help---
		DMA engines offload bulk memory operations from the CPU to dedicated
		hardware, allowing the operations to happen asynchronously.
		bool

		comment "DMA Clients"
		depends on DMA_ENGINE

		config NET_DMA
		bool "Network: TCP receive copy offload"
		depends on DMA_ENGINE && NET
		default y
		---help---
		help
		This enables the use of DMA engines in the network stack to
		offload receive copy-to-user operations, freeing CPU cycles.
		Since this is the main user of the DMA engine, it should be enabled;
		say Y here.

		comment "DMA Devices"

		config INTEL_IOATDMA
		tristate "Intel I/OAT DMA support"
		depends on DMA_ENGINE && PCI
		default m
		---help---
		Enable support for the Intel(R) I/OAT DMA engine.

		config INTEL_IOP_ADMA
		tristate "Intel IOP ADMA support"
		depends on DMA_ENGINE && (ARCH_IOP32X \|\| ARCH_IOP33X \|\| ARCH_IOP13XX)
		select ASYNC_CORE
		default m
		---help---
		Enable support for the Intel(R) IOP Series RAID engines.

		endmenu
		endif

drivers/dma/Makefile

+1 −1

Original line number	Diff line number	Diff line
		obj-$(CONFIG_DMA_ENGINE) += dmaengine.o
		obj-$(CONFIG_NET_DMA) += iovlock.o
		obj-$(CONFIG_INTEL_IOATDMA) += ioatdma.o
		ioatdma-objs := ioat.o ioat_dma.o
		ioatdma-objs := ioat.o ioat_dma.o ioat_dca.o
		obj-$(CONFIG_INTEL_IOP_ADMA) += iop-adma.o

drivers/dma/ioat.c

+16 −1

Original line number	Diff line number	Diff line
		/*
		* Intel I/OAT DMA Linux driver
		* Copyright(c) 2004 - 2007 Intel Corporation.
		* Copyright(c) 2007 Intel Corporation.
		*
		* This program is free software; you can redistribute it and/or modify it
		* under the terms and conditions of the GNU General Public License,
		@@ -29,6 +29,7 @@
		#include <linux/module.h>
		#include <linux/pci.h>
		#include <linux/interrupt.h>
		#include <linux/dca.h>
		#include "ioatdma.h"
		#include "ioatdma_registers.h"
		#include "ioatdma_hw.h"
		@@ -49,6 +50,7 @@ struct ioat_device {
		struct pci_dev *pdev;
		void __iomem *iobase;
		struct ioatdma_device *dma;
		struct dca_provider *dca;
		};

		static int __devinit ioat_probe(struct pci_dev *pdev,
		@@ -57,6 +59,10 @@ static int __devinit ioat_probe(struct pci_dev *pdev,
		static void __devexit ioat_remove(struct pci_dev *pdev);
		#endif

		static int ioat_dca_enabled = 1;
		module_param(ioat_dca_enabled, int, 0644);
		MODULE_PARM_DESC(ioat_dca_enabled, "control support of dca service (default: 1)");

		static int ioat_setup_functionality(struct pci_dev pdev, void __iomem iobase)
		{
		struct ioat_device *device = pci_get_drvdata(pdev);
		@@ -67,6 +73,8 @@ static int ioat_setup_functionality(struct pci_dev pdev, void __iomem iobase)
		switch (version) {
		case IOAT_VER_1_2:
		device->dma = ioat_dma_probe(pdev, iobase);
		if (ioat_dca_enabled)
		device->dca = ioat_dca_init(pdev, iobase);
		break;
		default:
		err = -ENODEV;
		@@ -83,6 +91,13 @@ static void ioat_shutdown_functionality(struct pci_dev *pdev)
		ioat_dma_remove(device->dma);
		device->dma = NULL;
		}

		if (device->dca) {
		unregister_dca_provider(device->dca);
		free_dca_provider(device->dca);
		device->dca = NULL;
		}

		}

		static struct pci_driver ioat_pci_drv = {

drivers/dma/ioat_dca.c

0 → 100644

+263 −0

Original line number	Diff line number	Diff line
		/*
		* Intel I/OAT DMA Linux driver
		* Copyright(c) 2007 Intel Corporation.
		*
		* This program is free software; you can redistribute it and/or modify it
		* under the terms and conditions of the GNU General Public License,
		* version 2, as published by the Free Software Foundation.
		*
		* This program is distributed in the hope that it will be useful, but WITHOUT
		* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
		* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
		* more details.
		*
		* You should have received a copy of the GNU General Public License along with
		* this program; if not, write to the Free Software Foundation, Inc.,
		* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
		*
		* The full GNU General Public License is included in this distribution in
		* the file called "COPYING".
		*
		*/

		#include <linux/kernel.h>
		#include <linux/pci.h>
		#include <linux/smp.h>
		#include <linux/interrupt.h>
		#include <linux/dca.h>

		/* either a kernel change is needed, or we need something like this in kernel */
		#ifndef CONFIG_SMP
		#include <asm/smp.h>
		#undef cpu_physical_id
		#define cpu_physical_id(cpu) (cpuid_ebx(1) >> 24)
		#endif

		#include "ioatdma.h"
		#include "ioatdma_registers.h"

		/*
		* Bit 16 of a tag map entry is the "valid" bit, if it is set then bits 0:15
		* contain the bit number of the APIC ID to map into the DCA tag. If the valid
		* bit is not set, then the value must be 0 or 1 and defines the bit in the tag.
		*/
		#define DCA_TAG_MAP_VALID 0x80

		/*
		* "Legacy" DCA systems do not implement the DCA register set in the
		* I/OAT device. Software needs direct support for their tag mappings.
		*/

		#define APICID_BIT(x) (DCA_TAG_MAP_VALID \| (x))
		#define IOAT_TAG_MAP_LEN 8

		static u8 ioat_tag_map_BNB[IOAT_TAG_MAP_LEN] = {
		1, APICID_BIT(1), APICID_BIT(2), APICID_BIT(2), };
		static u8 ioat_tag_map_SCNB[IOAT_TAG_MAP_LEN] = {
		1, APICID_BIT(1), APICID_BIT(2), APICID_BIT(2), };
		static u8 ioat_tag_map_CNB[IOAT_TAG_MAP_LEN] = {
		1, APICID_BIT(1), APICID_BIT(3), APICID_BIT(4), APICID_BIT(2), };
		static u8 ioat_tag_map_UNISYS[IOAT_TAG_MAP_LEN] = { 0 };

		/* pack PCI B/D/F into a u16 */
		static inline u16 dcaid_from_pcidev(struct pci_dev *pci)
		{
		return (pci->bus->number << 8) \| pci->devfn;
		}

		static int dca_enabled_in_bios(void)
		{
		/* CPUID level 9 returns DCA configuration */
		/* Bit 0 indicates DCA enabled by the BIOS */
		unsigned long cpuid_level_9;
		int res;

		cpuid_level_9 = cpuid_eax(9);
		res = test_bit(0, &cpuid_level_9);
		if (!res)
		printk(KERN_ERR "ioat dma: DCA is disabled in BIOS\n");

		return res;
		}

		static int system_has_dca_enabled(void)
		{
		if (boot_cpu_has(X86_FEATURE_DCA))
		return dca_enabled_in_bios();

		printk(KERN_ERR "ioat dma: boot cpu doesn't have X86_FEATURE_DCA\n");
		return 0;
		}

		struct ioat_dca_slot {
		struct pci_dev pdev; / requester device */
		u16 rid; /* requester id, as used by IOAT */
		};

		#define IOAT_DCA_MAX_REQ 6

		struct ioat_dca_priv {
		void __iomem *iobase;
		void *dca_base;
		int max_requesters;
		int requester_count;
		u8 tag_map[IOAT_TAG_MAP_LEN];
		struct ioat_dca_slot req_slots[0];
		};

		/* 5000 series chipset DCA Port Requester ID Table Entry Format
		* [15:8] PCI-Express Bus Number
		* [7:3] PCI-Express Device Number
		* [2:0] PCI-Express Function Number
		*
		* 5000 series chipset DCA control register format
		* [7:1] Reserved (0)
		* [0] Ignore Function Number
		*/

		static int ioat_dca_add_requester(struct dca_provider dca, struct device dev)
		{
		struct ioat_dca_priv *ioatdca = dca_priv(dca);
		struct pci_dev *pdev;
		int i;
		u16 id;

		/* This implementation only supports PCI-Express */
		if (dev->bus != &pci_bus_type)
		return -ENODEV;
		pdev = to_pci_dev(dev);
		id = dcaid_from_pcidev(pdev);

		if (ioatdca->requester_count == ioatdca->max_requesters)
		return -ENODEV;

		for (i = 0; i < ioatdca->max_requesters; i++) {
		if (ioatdca->req_slots[i].pdev == NULL) {
		/* found an empty slot */
		ioatdca->requester_count++;
		ioatdca->req_slots[i].pdev = pdev;
		ioatdca->req_slots[i].rid = id;
		writew(id, ioatdca->dca_base + (i * 4));
		/* make sure the ignore function bit is off */
		writeb(0, ioatdca->dca_base + (i * 4) + 2);
		return i;
		}
		}
		/* Error, ioatdma->requester_count is out of whack */
		return -EFAULT;
		}

		static int ioat_dca_remove_requester(struct dca_provider *dca,
		struct device *dev)
		{
		struct ioat_dca_priv *ioatdca = dca_priv(dca);
		struct pci_dev *pdev;
		int i;

		/* This implementation only supports PCI-Express */
		if (dev->bus != &pci_bus_type)
		return -ENODEV;
		pdev = to_pci_dev(dev);

		for (i = 0; i < ioatdca->max_requesters; i++) {
		if (ioatdca->req_slots[i].pdev == pdev) {
		writew(0, ioatdca->dca_base + (i * 4));
		ioatdca->req_slots[i].pdev = NULL;
		ioatdca->req_slots[i].rid = 0;
		ioatdca->requester_count--;
		return i;
		}
		}
		return -ENODEV;
		}

		static u8 ioat_dca_get_tag(struct dca_provider *dca, int cpu)
		{
		struct ioat_dca_priv *ioatdca = dca_priv(dca);
		int i, apic_id, bit, value;
		u8 entry, tag;

		tag = 0;
		apic_id = cpu_physical_id(cpu);

		for (i = 0; i < IOAT_TAG_MAP_LEN; i++) {
		entry = ioatdca->tag_map[i];
		if (entry & DCA_TAG_MAP_VALID) {
		bit = entry & ~DCA_TAG_MAP_VALID;
		value = (apic_id & (1 << bit)) ? 1 : 0;
		} else {
		value = entry ? 1 : 0;
		}
		tag \|= (value << i);
		}
		return tag;
		}

		static struct dca_ops ioat_dca_ops = {
		.add_requester = ioat_dca_add_requester,
		.remove_requester = ioat_dca_remove_requester,
		.get_tag = ioat_dca_get_tag,
		};


		struct dca_provider ioat_dca_init(struct pci_dev pdev, void __iomem *iobase)
		{
		struct dca_provider *dca;
		struct ioat_dca_priv *ioatdca;
		u8 *tag_map = NULL;
		int i;
		int err;

		if (!system_has_dca_enabled())
		return NULL;

		/* I/OAT v1 systems must have a known tag_map to support DCA */
		switch (pdev->vendor) {
		case PCI_VENDOR_ID_INTEL:
		switch (pdev->device) {
		case PCI_DEVICE_ID_INTEL_IOAT:
		tag_map = ioat_tag_map_BNB;
		break;
		case PCI_DEVICE_ID_INTEL_IOAT_CNB:
		tag_map = ioat_tag_map_CNB;
		break;
		case PCI_DEVICE_ID_INTEL_IOAT_SCNB:
		tag_map = ioat_tag_map_SCNB;
		break;
		}
		break;
		case PCI_VENDOR_ID_UNISYS:
		switch (pdev->device) {
		case PCI_DEVICE_ID_UNISYS_DMA_DIRECTOR:
		tag_map = ioat_tag_map_UNISYS;
		break;
		}
		break;
		}
		if (tag_map == NULL)
		return NULL;

		dca = alloc_dca_provider(&ioat_dca_ops,
		sizeof(*ioatdca) +
		(sizeof(struct ioat_dca_slot) * IOAT_DCA_MAX_REQ));
		if (!dca)
		return NULL;

		ioatdca = dca_priv(dca);
		ioatdca->max_requesters = IOAT_DCA_MAX_REQ;

		ioatdca->dca_base = iobase + 0x54;

		/* copy over the APIC ID to DCA tag mapping */
		for (i = 0; i < IOAT_TAG_MAP_LEN; i++)
		ioatdca->tag_map[i] = tag_map[i];

		err = register_dca_provider(dca, &pdev->dev);
		if (err) {
		free_dca_provider(dca);
		return NULL;
		}

		return dca;
		}

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