[linux-block.git] / drivers / dma / ioat_dca.c

/*
 * 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;
}
Commit	Line	Data
2ed6dc34 SN	1	/*
	2	* Intel I/OAT DMA Linux driver
	3	* Copyright(c) 2007 Intel Corporation.
	4	*
	5	* This program is free software; you can redistribute it and/or modify it
	6	* under the terms and conditions of the GNU General Public License,
	7	* version 2, as published by the Free Software Foundation.
	8	*
	9	* This program is distributed in the hope that it will be useful, but WITHOUT
	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	12	* more details.
	13	*
	14	* You should have received a copy of the GNU General Public License along with
	15	* this program; if not, write to the Free Software Foundation, Inc.,
	16	* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
	17	*
	18	* The full GNU General Public License is included in this distribution in
	19	* the file called "COPYING".
	20	*
	21	*/
	22
	23	#include <linux/kernel.h>
	24	#include <linux/pci.h>
	25	#include <linux/smp.h>
	26	#include <linux/interrupt.h>
	27	#include <linux/dca.h>
	28
	29	/* either a kernel change is needed, or we need something like this in kernel */
	30	#ifndef CONFIG_SMP
	31	#include <asm/smp.h>
	32	#undef cpu_physical_id
	33	#define cpu_physical_id(cpu) (cpuid_ebx(1) >> 24)
	34	#endif
	35
	36	#include "ioatdma.h"
	37	#include "ioatdma_registers.h"
	38
	39	/*
	40	* Bit 16 of a tag map entry is the "valid" bit, if it is set then bits 0:15
	41	* contain the bit number of the APIC ID to map into the DCA tag. If the valid
	42	* bit is not set, then the value must be 0 or 1 and defines the bit in the tag.
	43	*/
	44	#define DCA_TAG_MAP_VALID 0x80
	45
	46	/*
	47	* "Legacy" DCA systems do not implement the DCA register set in the
	48	* I/OAT device. Software needs direct support for their tag mappings.
	49	*/
	50
	51	#define APICID_BIT(x) (DCA_TAG_MAP_VALID \| (x))
	52	#define IOAT_TAG_MAP_LEN 8
	53
	54	static u8 ioat_tag_map_BNB[IOAT_TAG_MAP_LEN] = {
	55	1, APICID_BIT(1), APICID_BIT(2), APICID_BIT(2), };
	56	static u8 ioat_tag_map_SCNB[IOAT_TAG_MAP_LEN] = {
	57	1, APICID_BIT(1), APICID_BIT(2), APICID_BIT(2), };
	58	static u8 ioat_tag_map_CNB[IOAT_TAG_MAP_LEN] = {
	59	1, APICID_BIT(1), APICID_BIT(3), APICID_BIT(4), APICID_BIT(2), };
	60	static u8 ioat_tag_map_UNISYS[IOAT_TAG_MAP_LEN] = { 0 };
	61
	62	/* pack PCI B/D/F into a u16 */
	63	static inline u16 dcaid_from_pcidev(struct pci_dev *pci)
	64	{
65	return (pci->bus->number << 8) \| pci->devfn;
66	}
67
68	static int dca_enabled_in_bios(void)
69	{
70	/* CPUID level 9 returns DCA configuration */
71	/* Bit 0 indicates DCA enabled by the BIOS */
72	unsigned long cpuid_level_9;
73	int res;
74
75	cpuid_level_9 = cpuid_eax(9);
76	res = test_bit(0, &cpuid_level_9);
77	if (!res)
78	printk(KERN_ERR "ioat dma: DCA is disabled in BIOS\n");
79
80	return res;
81	}
82
83	static int system_has_dca_enabled(void)
84	{
85	if (boot_cpu_has(X86_FEATURE_DCA))
86	return dca_enabled_in_bios();
87
88	printk(KERN_ERR "ioat dma: boot cpu doesn't have X86_FEATURE_DCA\n");
89	return 0;
90	}
91
92	struct ioat_dca_slot {
93	struct pci_dev pdev; / requester device */
94	u16 rid; /* requester id, as used by IOAT */
95	};
96
97	#define IOAT_DCA_MAX_REQ 6
98
99	struct ioat_dca_priv {
100	void __iomem *iobase;
101	void *dca_base;
102	int max_requesters;
103	int requester_count;
104	u8 tag_map[IOAT_TAG_MAP_LEN];
105	struct ioat_dca_slot req_slots[0];
106	};
107
108	/* 5000 series chipset DCA Port Requester ID Table Entry Format
109	* [15:8] PCI-Express Bus Number
110	* [7:3] PCI-Express Device Number
111	* [2:0] PCI-Express Function Number
112	*
113	* 5000 series chipset DCA control register format
114	* [7:1] Reserved (0)
115	* [0] Ignore Function Number
116	*/
117
118	static int ioat_dca_add_requester(struct dca_provider dca, struct device dev)
119	{
120	struct ioat_dca_priv *ioatdca = dca_priv(dca);
121	struct pci_dev *pdev;
122	int i;
123	u16 id;
124
125	/* This implementation only supports PCI-Express */
126	if (dev->bus != &pci_bus_type)
127	return -ENODEV;
128	pdev = to_pci_dev(dev);
129	id = dcaid_from_pcidev(pdev);
130
131	if (ioatdca->requester_count == ioatdca->max_requesters)
132	return -ENODEV;
133
134	for (i = 0; i < ioatdca->max_requesters; i++) {
135	if (ioatdca->req_slots[i].pdev == NULL) {
136	/* found an empty slot */
137	ioatdca->requester_count++;
138	ioatdca->req_slots[i].pdev = pdev;
139	ioatdca->req_slots[i].rid = id;
140	writew(id, ioatdca->dca_base + (i * 4));
141	/* make sure the ignore function bit is off */
142	writeb(0, ioatdca->dca_base + (i * 4) + 2);
143	return i;
144	}
145	}
146	/* Error, ioatdma->requester_count is out of whack */
147	return -EFAULT;
148	}
149
150	static int ioat_dca_remove_requester(struct dca_provider *dca,
151	struct device *dev)
152	{
153	struct ioat_dca_priv *ioatdca = dca_priv(dca);
154	struct pci_dev *pdev;
155	int i;
156
157	/* This implementation only supports PCI-Express */
158	if (dev->bus != &pci_bus_type)
159	return -ENODEV;
160	pdev = to_pci_dev(dev);
161
162	for (i = 0; i < ioatdca->max_requesters; i++) {
163	if (ioatdca->req_slots[i].pdev == pdev) {
164	writew(0, ioatdca->dca_base + (i * 4));
165	ioatdca->req_slots[i].pdev = NULL;
166	ioatdca->req_slots[i].rid = 0;
167	ioatdca->requester_count--;
168	return i;
169	}
170	}
171	return -ENODEV;
172	}
173
174	static u8 ioat_dca_get_tag(struct dca_provider *dca, int cpu)
175	{
176	struct ioat_dca_priv *ioatdca = dca_priv(dca);
177	int i, apic_id, bit, value;
178	u8 entry, tag;
179
180	tag = 0;
181	apic_id = cpu_physical_id(cpu);
182
183	for (i = 0; i < IOAT_TAG_MAP_LEN; i++) {
184	entry = ioatdca->tag_map[i];
185	if (entry & DCA_TAG_MAP_VALID) {
186	bit = entry & ~DCA_TAG_MAP_VALID;
187	value = (apic_id & (1 << bit)) ? 1 : 0;
188	} else {
189	value = entry ? 1 : 0;
190	}
191	tag \|= (value << i);
192	}
193	return tag;
194	}
195
196	static struct dca_ops ioat_dca_ops = {
197	.add_requester = ioat_dca_add_requester,
198	.remove_requester = ioat_dca_remove_requester,
199	.get_tag = ioat_dca_get_tag,
200	};
201
202
203	struct dca_provider ioat_dca_init(struct pci_dev pdev, void __iomem *iobase)
204	{
205	struct dca_provider *dca;
206	struct ioat_dca_priv *ioatdca;
207	u8 *tag_map = NULL;
208	int i;
209	int err;
210
211	if (!system_has_dca_enabled())
212	return NULL;
213
214	/* I/OAT v1 systems must have a known tag_map to support DCA */
215	switch (pdev->vendor) {
216	case PCI_VENDOR_ID_INTEL:
217	switch (pdev->device) {
218	case PCI_DEVICE_ID_INTEL_IOAT:
219	tag_map = ioat_tag_map_BNB;
220	break;
221	case PCI_DEVICE_ID_INTEL_IOAT_CNB:
222	tag_map = ioat_tag_map_CNB;
223	break;
224	case PCI_DEVICE_ID_INTEL_IOAT_SCNB:
225	tag_map = ioat_tag_map_SCNB;
226	break;
227	}
228	break;
229	case PCI_VENDOR_ID_UNISYS:
230	switch (pdev->device) {
231	case PCI_DEVICE_ID_UNISYS_DMA_DIRECTOR:
232	tag_map = ioat_tag_map_UNISYS;
233	break;
234	}
235	break;
236	}
237	if (tag_map == NULL)
238	return NULL;
239
240	dca = alloc_dca_provider(&ioat_dca_ops,
241	sizeof(*ioatdca) +
242	(sizeof(struct ioat_dca_slot) * IOAT_DCA_MAX_REQ));
243	if (!dca)
244	return NULL;
245
246	ioatdca = dca_priv(dca);
247	ioatdca->max_requesters = IOAT_DCA_MAX_REQ;
248
249	ioatdca->dca_base = iobase + 0x54;
250
251	/* copy over the APIC ID to DCA tag mapping */
252	for (i = 0; i < IOAT_TAG_MAP_LEN; i++)
253	ioatdca->tag_map[i] = tag_map[i];
254
255	err = register_dca_provider(dca, &pdev->dev);
256	if (err) {
257	free_dca_provider(dca);
258	return NULL;
259	}
260
261	return dca;
262	}
263