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authorIngo Molnar <mingo@kernel.org>2013-01-24 15:47:48 +0400
committerIngo Molnar <mingo@kernel.org>2013-01-24 15:47:48 +0400
commitbefddb21c845f8fb49e637997891ef97c6a869dc (patch)
tree0e7629123184f2dd50291ad6d477b894175f0f26 /arch/s390/pci/pci_msi.c
parente716efde75267eab919cdb2bef5b2cb77f305326 (diff)
parent7d1f9aeff1ee4a20b1aeb377dd0f579fe9647619 (diff)
downloadlinux-befddb21c845f8fb49e637997891ef97c6a869dc.tar.xz
Merge tag 'v3.8-rc4' into irq/core
Merge Linux 3.8-rc4 before pulling in new commits - we were on an old v3.7 base. Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/s390/pci/pci_msi.c')
-rw-r--r--arch/s390/pci/pci_msi.c141
1 files changed, 141 insertions, 0 deletions
diff --git a/arch/s390/pci/pci_msi.c b/arch/s390/pci/pci_msi.c
new file mode 100644
index 000000000000..90fd3482b9e2
--- /dev/null
+++ b/arch/s390/pci/pci_msi.c
@@ -0,0 +1,141 @@
+/*
+ * 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 hlist_node *entry;
+ struct msi_map *map;
+
+ hlist_for_each_entry_rcu(map, entry,
+ &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);
+}