2 * Copyright IBM Corp. 2012
5 * Jan Glauber <jang@linux.vnet.ibm.com>
8 #define COMPONENT "zPCI"
9 #define pr_fmt(fmt) COMPONENT ": " fmt
11 #include <linux/kernel.h>
12 #include <linux/err.h>
13 #include <linux/rculist.h>
14 #include <linux/hash.h>
15 #include <linux/pci.h>
16 #include <linux/msi.h>
17 #include <asm/hw_irq.h>
19 /* mapping of irq numbers to msi_desc */
20 static struct hlist_head *msi_hash;
21 static unsigned int msihash_shift = 6;
22 #define msi_hashfn(nr) hash_long(nr, msihash_shift)
24 static DEFINE_SPINLOCK(msi_map_lock);
26 struct msi_desc *__irq_get_msi_desc(unsigned int irq)
28 struct hlist_node *entry;
31 hlist_for_each_entry_rcu(map, entry,
32 &msi_hash[msi_hashfn(irq)], msi_chain)
38 int zpci_msi_set_mask_bits(struct msi_desc *msi, u32 mask, u32 flag)
40 if (msi->msi_attrib.is_msix) {
41 int offset = msi->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE +
42 PCI_MSIX_ENTRY_VECTOR_CTRL;
43 msi->masked = readl(msi->mask_base + offset);
44 writel(flag, msi->mask_base + offset);
46 if (msi->msi_attrib.maskbit) {
50 pos = (long) msi->mask_base;
51 pci_read_config_dword(msi->dev, pos, &mask_bits);
53 mask_bits |= flag & mask;
54 pci_write_config_dword(msi->dev, pos, mask_bits);
60 msi->msi_attrib.maskbit = !!flag;
64 int zpci_setup_msi_irq(struct zpci_dev *zdev, struct msi_desc *msi,
65 unsigned int nr, int offset)
71 map = kmalloc(sizeof(*map), GFP_KERNEL);
77 zdev->msi_map[nr & ZPCI_MSI_MASK] = map;
79 pr_debug("%s hashing irq: %u to bucket nr: %llu\n",
80 __func__, nr, msi_hashfn(nr));
81 hlist_add_head_rcu(&map->msi_chain, &msi_hash[msi_hashfn(nr)]);
83 spin_lock(&msi_map_lock);
84 rc = irq_set_msi_desc(nr, msi);
86 spin_unlock(&msi_map_lock);
87 hlist_del_rcu(&map->msi_chain);
89 zdev->msi_map[nr & ZPCI_MSI_MASK] = NULL;
92 spin_unlock(&msi_map_lock);
94 msg.data = nr - offset;
95 msg.address_lo = zdev->msi_addr & 0xffffffff;
96 msg.address_hi = zdev->msi_addr >> 32;
97 write_msi_msg(nr, &msg);
101 void zpci_teardown_msi_irq(struct zpci_dev *zdev, struct msi_desc *msi)
103 int irq = msi->irq & ZPCI_MSI_MASK;
106 msi->msg.address_lo = 0;
107 msi->msg.address_hi = 0;
110 zpci_msi_set_mask_bits(msi, 1, 1);
112 spin_lock(&msi_map_lock);
113 map = zdev->msi_map[irq];
114 hlist_del_rcu(&map->msi_chain);
116 zdev->msi_map[irq] = NULL;
117 spin_unlock(&msi_map_lock);
121 * The msi hash table has 256 entries which is good for 4..20
122 * devices (a typical device allocates 10 + CPUs MSI's). Maybe make
123 * the hash table size adjustable later.
125 int __init zpci_msihash_init(void)
129 msi_hash = kmalloc(256 * sizeof(*msi_hash), GFP_KERNEL);
133 for (i = 0; i < (1U << msihash_shift); i++)
134 INIT_HLIST_HEAD(&msi_hash[i]);
138 void __init zpci_msihash_exit(void)