xref: /linux/arch/powerpc/platforms/powernv/pci-cxl.c (revision e9f0878c4b2004ac19581274c1ae4c61ae3ca70e)
1 /*
2  * Copyright 2014-2016 IBM Corp.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version
7  * 2 of the License, or (at your option) any later version.
8  */
9 
10 #include <linux/module.h>
11 #include <asm/pnv-pci.h>
12 #include <asm/opal.h>
13 
14 #include "pci.h"
15 
16 int pnv_phb_to_cxl_mode(struct pci_dev *dev, uint64_t mode)
17 {
18 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
19 	struct pnv_phb *phb = hose->private_data;
20 	struct pnv_ioda_pe *pe;
21 	int rc;
22 
23 	pe = pnv_ioda_get_pe(dev);
24 	if (!pe)
25 		return -ENODEV;
26 
27 	pe_info(pe, "Switching PHB to CXL\n");
28 
29 	rc = opal_pci_set_phb_cxl_mode(phb->opal_id, mode, pe->pe_number);
30 	if (rc == OPAL_UNSUPPORTED)
31 		dev_err(&dev->dev, "Required cxl mode not supported by firmware - update skiboot\n");
32 	else if (rc)
33 		dev_err(&dev->dev, "opal_pci_set_phb_cxl_mode failed: %i\n", rc);
34 
35 	return rc;
36 }
37 EXPORT_SYMBOL(pnv_phb_to_cxl_mode);
38 
39 /* Find PHB for cxl dev and allocate MSI hwirqs?
40  * Returns the absolute hardware IRQ number
41  */
42 int pnv_cxl_alloc_hwirqs(struct pci_dev *dev, int num)
43 {
44 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
45 	struct pnv_phb *phb = hose->private_data;
46 	int hwirq = msi_bitmap_alloc_hwirqs(&phb->msi_bmp, num);
47 
48 	if (hwirq < 0) {
49 		dev_warn(&dev->dev, "Failed to find a free MSI\n");
50 		return -ENOSPC;
51 	}
52 
53 	return phb->msi_base + hwirq;
54 }
55 EXPORT_SYMBOL(pnv_cxl_alloc_hwirqs);
56 
57 void pnv_cxl_release_hwirqs(struct pci_dev *dev, int hwirq, int num)
58 {
59 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
60 	struct pnv_phb *phb = hose->private_data;
61 
62 	msi_bitmap_free_hwirqs(&phb->msi_bmp, hwirq - phb->msi_base, num);
63 }
64 EXPORT_SYMBOL(pnv_cxl_release_hwirqs);
65 
66 void pnv_cxl_release_hwirq_ranges(struct cxl_irq_ranges *irqs,
67 				  struct pci_dev *dev)
68 {
69 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
70 	struct pnv_phb *phb = hose->private_data;
71 	int i, hwirq;
72 
73 	for (i = 1; i < CXL_IRQ_RANGES; i++) {
74 		if (!irqs->range[i])
75 			continue;
76 		pr_devel("cxl release irq range 0x%x: offset: 0x%lx  limit: %ld\n",
77 			 i, irqs->offset[i],
78 			 irqs->range[i]);
79 		hwirq = irqs->offset[i] - phb->msi_base;
80 		msi_bitmap_free_hwirqs(&phb->msi_bmp, hwirq,
81 				       irqs->range[i]);
82 	}
83 }
84 EXPORT_SYMBOL(pnv_cxl_release_hwirq_ranges);
85 
86 int pnv_cxl_alloc_hwirq_ranges(struct cxl_irq_ranges *irqs,
87 			       struct pci_dev *dev, int num)
88 {
89 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
90 	struct pnv_phb *phb = hose->private_data;
91 	int i, hwirq, try;
92 
93 	memset(irqs, 0, sizeof(struct cxl_irq_ranges));
94 
95 	/* 0 is reserved for the multiplexed PSL DSI interrupt */
96 	for (i = 1; i < CXL_IRQ_RANGES && num; i++) {
97 		try = num;
98 		while (try) {
99 			hwirq = msi_bitmap_alloc_hwirqs(&phb->msi_bmp, try);
100 			if (hwirq >= 0)
101 				break;
102 			try /= 2;
103 		}
104 		if (!try)
105 			goto fail;
106 
107 		irqs->offset[i] = phb->msi_base + hwirq;
108 		irqs->range[i] = try;
109 		pr_devel("cxl alloc irq range 0x%x: offset: 0x%lx  limit: %li\n",
110 			 i, irqs->offset[i], irqs->range[i]);
111 		num -= try;
112 	}
113 	if (num)
114 		goto fail;
115 
116 	return 0;
117 fail:
118 	pnv_cxl_release_hwirq_ranges(irqs, dev);
119 	return -ENOSPC;
120 }
121 EXPORT_SYMBOL(pnv_cxl_alloc_hwirq_ranges);
122 
123 int pnv_cxl_get_irq_count(struct pci_dev *dev)
124 {
125 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
126 	struct pnv_phb *phb = hose->private_data;
127 
128 	return phb->msi_bmp.irq_count;
129 }
130 EXPORT_SYMBOL(pnv_cxl_get_irq_count);
131 
132 int pnv_cxl_ioda_msi_setup(struct pci_dev *dev, unsigned int hwirq,
133 			   unsigned int virq)
134 {
135 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
136 	struct pnv_phb *phb = hose->private_data;
137 	unsigned int xive_num = hwirq - phb->msi_base;
138 	struct pnv_ioda_pe *pe;
139 	int rc;
140 
141 	if (!(pe = pnv_ioda_get_pe(dev)))
142 		return -ENODEV;
143 
144 	/* Assign XIVE to PE */
145 	rc = opal_pci_set_xive_pe(phb->opal_id, pe->pe_number, xive_num);
146 	if (rc) {
147 		pe_warn(pe, "%s: OPAL error %d setting msi_base 0x%x "
148 			"hwirq 0x%x XIVE 0x%x PE\n",
149 			pci_name(dev), rc, phb->msi_base, hwirq, xive_num);
150 		return -EIO;
151 	}
152 	pnv_set_msi_irq_chip(phb, virq);
153 
154 	return 0;
155 }
156 EXPORT_SYMBOL(pnv_cxl_ioda_msi_setup);
157 
158 #if IS_MODULE(CONFIG_CXL)
159 static inline int get_cxl_module(void)
160 {
161 	struct module *cxl_module;
162 
163 	mutex_lock(&module_mutex);
164 
165 	cxl_module = find_module("cxl");
166 	if (cxl_module)
167 		__module_get(cxl_module);
168 
169 	mutex_unlock(&module_mutex);
170 
171 	if (!cxl_module)
172 		return -ENODEV;
173 
174 	return 0;
175 }
176 #else
177 static inline int get_cxl_module(void) { return 0; }
178 #endif
179