xref: /linux/arch/powerpc/platforms/powernv/pci-cxl.c (revision 24bce201d79807b668bf9d9e0aca801c5c0d5f78)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright 2014-2016 IBM Corp.
4  */
5 
6 #include <linux/module.h>
7 #include <misc/cxl-base.h>
8 #include <asm/pnv-pci.h>
9 #include <asm/opal.h>
10 
11 #include "pci.h"
12 
13 int pnv_phb_to_cxl_mode(struct pci_dev *dev, uint64_t mode)
14 {
15 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
16 	struct pnv_phb *phb = hose->private_data;
17 	struct pnv_ioda_pe *pe;
18 	int rc;
19 
20 	pe = pnv_ioda_get_pe(dev);
21 	if (!pe)
22 		return -ENODEV;
23 
24 	pe_info(pe, "Switching PHB to CXL\n");
25 
26 	rc = opal_pci_set_phb_cxl_mode(phb->opal_id, mode, pe->pe_number);
27 	if (rc == OPAL_UNSUPPORTED)
28 		dev_err(&dev->dev, "Required cxl mode not supported by firmware - update skiboot\n");
29 	else if (rc)
30 		dev_err(&dev->dev, "opal_pci_set_phb_cxl_mode failed: %i\n", rc);
31 
32 	return rc;
33 }
34 EXPORT_SYMBOL(pnv_phb_to_cxl_mode);
35 
36 /* Find PHB for cxl dev and allocate MSI hwirqs?
37  * Returns the absolute hardware IRQ number
38  */
39 int pnv_cxl_alloc_hwirqs(struct pci_dev *dev, int num)
40 {
41 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
42 	struct pnv_phb *phb = hose->private_data;
43 	int hwirq = msi_bitmap_alloc_hwirqs(&phb->msi_bmp, num);
44 
45 	if (hwirq < 0) {
46 		dev_warn(&dev->dev, "Failed to find a free MSI\n");
47 		return -ENOSPC;
48 	}
49 
50 	return phb->msi_base + hwirq;
51 }
52 EXPORT_SYMBOL(pnv_cxl_alloc_hwirqs);
53 
54 void pnv_cxl_release_hwirqs(struct pci_dev *dev, int hwirq, int num)
55 {
56 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
57 	struct pnv_phb *phb = hose->private_data;
58 
59 	msi_bitmap_free_hwirqs(&phb->msi_bmp, hwirq - phb->msi_base, num);
60 }
61 EXPORT_SYMBOL(pnv_cxl_release_hwirqs);
62 
63 void pnv_cxl_release_hwirq_ranges(struct cxl_irq_ranges *irqs,
64 				  struct pci_dev *dev)
65 {
66 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
67 	struct pnv_phb *phb = hose->private_data;
68 	int i, hwirq;
69 
70 	for (i = 1; i < CXL_IRQ_RANGES; i++) {
71 		if (!irqs->range[i])
72 			continue;
73 		pr_devel("cxl release irq range 0x%x: offset: 0x%lx  limit: %ld\n",
74 			 i, irqs->offset[i],
75 			 irqs->range[i]);
76 		hwirq = irqs->offset[i] - phb->msi_base;
77 		msi_bitmap_free_hwirqs(&phb->msi_bmp, hwirq,
78 				       irqs->range[i]);
79 	}
80 }
81 EXPORT_SYMBOL(pnv_cxl_release_hwirq_ranges);
82 
83 int pnv_cxl_alloc_hwirq_ranges(struct cxl_irq_ranges *irqs,
84 			       struct pci_dev *dev, int num)
85 {
86 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
87 	struct pnv_phb *phb = hose->private_data;
88 	int i, hwirq, try;
89 
90 	memset(irqs, 0, sizeof(struct cxl_irq_ranges));
91 
92 	/* 0 is reserved for the multiplexed PSL DSI interrupt */
93 	for (i = 1; i < CXL_IRQ_RANGES && num; i++) {
94 		try = num;
95 		while (try) {
96 			hwirq = msi_bitmap_alloc_hwirqs(&phb->msi_bmp, try);
97 			if (hwirq >= 0)
98 				break;
99 			try /= 2;
100 		}
101 		if (!try)
102 			goto fail;
103 
104 		irqs->offset[i] = phb->msi_base + hwirq;
105 		irqs->range[i] = try;
106 		pr_devel("cxl alloc irq range 0x%x: offset: 0x%lx  limit: %li\n",
107 			 i, irqs->offset[i], irqs->range[i]);
108 		num -= try;
109 	}
110 	if (num)
111 		goto fail;
112 
113 	return 0;
114 fail:
115 	pnv_cxl_release_hwirq_ranges(irqs, dev);
116 	return -ENOSPC;
117 }
118 EXPORT_SYMBOL(pnv_cxl_alloc_hwirq_ranges);
119 
120 int pnv_cxl_get_irq_count(struct pci_dev *dev)
121 {
122 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
123 	struct pnv_phb *phb = hose->private_data;
124 
125 	return phb->msi_bmp.irq_count;
126 }
127 EXPORT_SYMBOL(pnv_cxl_get_irq_count);
128 
129 int pnv_cxl_ioda_msi_setup(struct pci_dev *dev, unsigned int hwirq,
130 			   unsigned int virq)
131 {
132 	struct pci_controller *hose = pci_bus_to_host(dev->bus);
133 	struct pnv_phb *phb = hose->private_data;
134 	unsigned int xive_num = hwirq - phb->msi_base;
135 	struct pnv_ioda_pe *pe;
136 	int rc;
137 
138 	if (!(pe = pnv_ioda_get_pe(dev)))
139 		return -ENODEV;
140 
141 	/* Assign XIVE to PE */
142 	rc = opal_pci_set_xive_pe(phb->opal_id, pe->pe_number, xive_num);
143 	if (rc) {
144 		pe_warn(pe, "%s: OPAL error %d setting msi_base 0x%x "
145 			"hwirq 0x%x XIVE 0x%x PE\n",
146 			pci_name(dev), rc, phb->msi_base, hwirq, xive_num);
147 		return -EIO;
148 	}
149 	pnv_set_msi_irq_chip(phb, virq);
150 
151 	return 0;
152 }
153 EXPORT_SYMBOL(pnv_cxl_ioda_msi_setup);
154