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/*
* Copyright IBM Corp. 2012
*
* Author(s):
* Jan Glauber <jang@linux.vnet.ibm.com>
*/
#define COMPONENT "zPCI"
#define pr_fmt(fmt) COMPONENT ": " fmt
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/rculist.h>
#include <linux/hash.h>
#include <linux/pci.h>
#include <linux/msi.h>
#include <asm/hw_irq.h>
/* mapping of irq numbers to msi_desc */
static struct hlist_head *msi_hash;
static unsigned int msihash_shift = 6;
#define msi_hashfn(nr) hash_long(nr, msihash_shift)
static DEFINE_SPINLOCK(msi_map_lock);
struct msi_desc *__irq_get_msi_desc(unsigned int irq)
{
struct msi_map *map;
hlist_for_each_entry_rcu(map,
&msi_hash[msi_hashfn(irq)], msi_chain)
if (map->irq == irq)
return map->msi;
return NULL;
}
int zpci_msi_set_mask_bits(struct msi_desc *msi, u32 mask, u32 flag)
{
if (msi->msi_attrib.is_msix) {
int offset = msi->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE +
PCI_MSIX_ENTRY_VECTOR_CTRL;
msi->masked = readl(msi->mask_base + offset);
writel(flag, msi->mask_base + offset);
} else {
if (msi->msi_attrib.maskbit) {
int pos;
u32 mask_bits;
pos = (long) msi->mask_base;
pci_read_config_dword(msi->dev, pos, &mask_bits);
mask_bits &= ~(mask);
mask_bits |= flag & mask;
pci_write_config_dword(msi->dev, pos, mask_bits);
} else {
return 0;
}
}
msi->msi_attrib.maskbit = !!flag;
return 1;
}
int zpci_setup_msi_irq(struct zpci_dev *zdev, struct msi_desc *msi,
unsigned int nr, int offset)
{
struct msi_map *map;
struct msi_msg msg;
int rc;
map = kmalloc(sizeof(*map), GFP_KERNEL);
if (map == NULL)
return -ENOMEM;
map->irq = nr;
map->msi = msi;
zdev->msi_map[nr & ZPCI_MSI_MASK] = map;
pr_debug("%s hashing irq: %u to bucket nr: %llu\n",
__func__, nr, msi_hashfn(nr));
hlist_add_head_rcu(&map->msi_chain, &msi_hash[msi_hashfn(nr)]);
spin_lock(&msi_map_lock);
rc = irq_set_msi_desc(nr, msi);
if (rc) {
spin_unlock(&msi_map_lock);
hlist_del_rcu(&map->msi_chain);
kfree(map);
zdev->msi_map[nr & ZPCI_MSI_MASK] = NULL;
return rc;
}
spin_unlock(&msi_map_lock);
msg.data = nr - offset;
msg.address_lo = zdev->msi_addr & 0xffffffff;
msg.address_hi = zdev->msi_addr >> 32;
write_msi_msg(nr, &msg);
return 0;
}
void zpci_teardown_msi_irq(struct zpci_dev *zdev, struct msi_desc *msi)
{
int irq = msi->irq & ZPCI_MSI_MASK;
struct msi_map *map;
msi->msg.address_lo = 0;
msi->msg.address_hi = 0;
msi->msg.data = 0;
msi->irq = 0;
zpci_msi_set_mask_bits(msi, 1, 1);
spin_lock(&msi_map_lock);
map = zdev->msi_map[irq];
hlist_del_rcu(&map->msi_chain);
kfree(map);
zdev->msi_map[irq] = NULL;
spin_unlock(&msi_map_lock);
}
/*
* The msi hash table has 256 entries which is good for 4..20
* devices (a typical device allocates 10 + CPUs MSI's). Maybe make
* the hash table size adjustable later.
*/
int __init zpci_msihash_init(void)
{
unsigned int i;
msi_hash = kmalloc(256 * sizeof(*msi_hash), GFP_KERNEL);
if (!msi_hash)
return -ENOMEM;
for (i = 0; i < (1U << msihash_shift); i++)
INIT_HLIST_HEAD(&msi_hash[i]);
return 0;
}
void __init zpci_msihash_exit(void)
{
kfree(msi_hash);
}
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