1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 * Copyright 2017 IBM Corp.
4 */
5
6 #ifndef _MISC_CXLLIB_H
7 #define _MISC_CXLLIB_H
8
9 #include <linux/pci.h>
10 #include <asm/reg.h>
11
12 /*
13 * cxl driver exports a in-kernel 'library' API which can be called by
14 * other drivers to help interacting with an IBM XSL.
15 */
16
17 /*
18 * tells whether capi is supported on the PCIe slot where the
19 * device is seated
20 *
21 * Input:
22 * dev: device whose slot needs to be checked
23 * flags: 0 for the time being
24 */
25 bool cxllib_slot_is_supported(struct pci_dev *dev, unsigned long flags);
26
27
28 /*
29 * Returns the configuration parameters to be used by the XSL or device
30 *
31 * Input:
32 * dev: device, used to find PHB
33 * Output:
34 * struct cxllib_xsl_config:
35 * version
36 * capi BAR address, i.e. 0x2000000000000-0x2FFFFFFFFFFFF
37 * capi BAR size
38 * data send control (XSL_DSNCTL)
39 * dummy read address (XSL_DRA)
40 */
41 #define CXL_XSL_CONFIG_VERSION1 1
42 struct cxllib_xsl_config {
43 u32 version; /* format version for register encoding */
44 u32 log_bar_size;/* log size of the capi_window */
45 u64 bar_addr; /* address of the start of capi window */
46 u64 dsnctl; /* matches definition of XSL_DSNCTL */
47 u64 dra; /* real address that can be used for dummy read */
48 };
49
50 int cxllib_get_xsl_config(struct pci_dev *dev, struct cxllib_xsl_config *cfg);
51
52
53 /*
54 * Activate capi for the pci host bridge associated with the device.
55 * Can be extended to deactivate once we know how to do it.
56 * Device must be ready to accept messages from the CAPP unit and
57 * respond accordingly (TLB invalidates, ...)
58 *
59 * PHB is switched to capi mode through calls to skiboot.
60 * CAPP snooping is activated
61 *
62 * Input:
63 * dev: device whose PHB should switch mode
64 * mode: mode to switch to i.e. CAPI or PCI
65 * flags: options related to the mode
66 */
67 enum cxllib_mode {
68 CXL_MODE_CXL,
69 CXL_MODE_PCI,
70 };
71
72 #define CXL_MODE_NO_DMA 0
73 #define CXL_MODE_DMA_TVT0 1
74 #define CXL_MODE_DMA_TVT1 2
75
76 int cxllib_switch_phb_mode(struct pci_dev *dev, enum cxllib_mode mode,
77 unsigned long flags);
78
79
80 /*
81 * Set the device for capi DMA.
82 * Define its dma_ops and dma offset so that allocations will be using TVT#1
83 *
84 * Input:
85 * dev: device to set
86 * flags: options. CXL_MODE_DMA_TVT1 should be used
87 */
88 int cxllib_set_device_dma(struct pci_dev *dev, unsigned long flags);
89
90
91 /*
92 * Get the Process Element structure for the given thread
93 *
94 * Input:
95 * task: task_struct for the context of the translation
96 * translation_mode: whether addresses should be translated
97 * Output:
98 * attr: attributes to fill up the Process Element structure from CAIA
99 */
100 struct cxllib_pe_attributes {
101 u64 sr;
102 u32 lpid;
103 u32 tid;
104 u32 pid;
105 };
106 #define CXL_TRANSLATED_MODE 0
107 #define CXL_REAL_MODE 1
108
109 int cxllib_get_PE_attributes(struct task_struct *task,
110 unsigned long translation_mode, struct cxllib_pe_attributes *attr);
111
112
113 /*
114 * Handle memory fault.
115 * Fault in all the pages of the specified buffer for the permissions
116 * provided in ‘flags’
117 *
118 * Shouldn't be called from interrupt context
119 *
120 * Input:
121 * mm: struct mm for the thread faulting the pages
122 * addr: base address of the buffer to page in
123 * size: size of the buffer to page in
124 * flags: permission requested (DSISR_ISSTORE...)
125 */
126 int cxllib_handle_fault(struct mm_struct *mm, u64 addr, u64 size, u64 flags);
127
128
129 #endif /* _MISC_CXLLIB_H */