1 /*
2 * This program is free software; you can redistribute it and/or modify it
3 * under the terms and conditions of the GNU General Public License,
4 * version 2, as published by the Free Software Foundation.
5 *
6 * This program is distributed in the hope it will be useful, but WITHOUT
7 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
8 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
9 * more details.
10 *
11 * You should have received a copy of the GNU General Public License along with
12 * this program; If not, see <http://www.gnu.org/licenses/>.
13 */
14
15 #include <xen/param.h>
16 #include <xen/sched.h>
17 #include <xen/pci.h>
18 #include <xen/pci_regs.h>
19 #include "../ats.h"
20
21 bool_t __read_mostly ats_enabled = 0;
22 boolean_param("ats", ats_enabled);
23
enable_ats_device(struct pci_dev * pdev,struct list_head * ats_list)24 int enable_ats_device(struct pci_dev *pdev, struct list_head *ats_list)
25 {
26 u32 value;
27 u16 seg = pdev->seg;
28 u8 bus = pdev->bus, devfn = pdev->devfn;
29 int pos;
30
31 pos = pci_find_ext_capability(seg, bus, devfn, PCI_EXT_CAP_ID_ATS);
32 BUG_ON(!pos);
33
34 if ( iommu_verbose )
35 dprintk(XENLOG_INFO, "%04x:%02x:%02x.%u: ATS capability found\n",
36 seg, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
37
38 value = pci_conf_read16(pdev->sbdf, pos + ATS_REG_CTL);
39 if ( value & ATS_ENABLE )
40 {
41 struct pci_dev *other;
42
43 list_for_each_entry ( other, ats_list, ats.list )
44 if ( other == pdev )
45 {
46 pos = 0;
47 break;
48 }
49 }
50
51 if ( !(value & ATS_ENABLE) )
52 {
53 value |= ATS_ENABLE;
54 pci_conf_write16(pdev->sbdf, pos + ATS_REG_CTL, value);
55 }
56
57 if ( pos )
58 {
59 pdev->ats.cap_pos = pos;
60 value = pci_conf_read16(pdev->sbdf, pos + ATS_REG_CAP);
61 pdev->ats.queue_depth = value & ATS_QUEUE_DEPTH_MASK ?:
62 ATS_QUEUE_DEPTH_MASK + 1;
63 list_add(&pdev->ats.list, ats_list);
64 }
65
66 if ( iommu_verbose )
67 dprintk(XENLOG_INFO, "%04x:%02x:%02x.%u: ATS %s enabled\n",
68 seg, bus, PCI_SLOT(devfn), PCI_FUNC(devfn),
69 pos ? "is" : "was");
70
71 return pos;
72 }
73
disable_ats_device(struct pci_dev * pdev)74 void disable_ats_device(struct pci_dev *pdev)
75 {
76 u32 value;
77 u16 seg = pdev->seg;
78 u8 bus = pdev->bus, devfn = pdev->devfn;
79
80 BUG_ON(!pdev->ats.cap_pos);
81
82 value = pci_conf_read16(pdev->sbdf, pdev->ats.cap_pos + ATS_REG_CTL);
83 value &= ~ATS_ENABLE;
84 pci_conf_write16(pdev->sbdf, pdev->ats.cap_pos + ATS_REG_CTL, value);
85
86 list_del(&pdev->ats.list);
87
88 if ( iommu_verbose )
89 dprintk(XENLOG_INFO, "%04x:%02x:%02x.%u: ATS is disabled\n",
90 seg, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
91 }
92