11 files changed, 683 insertions, 7 deletions

diff --git a/arch/s390/include/asm/hw_irq.h b/arch/s390/include/asm/hw_irq.h
new file mode 100644
index 000000000000..7e3d2586c1ff
--- /dev/null
+++ b/arch/s390/include/asm/hw_irq.h
@@ -0,0 +1,22 @@
+#ifndef _HW_IRQ_H
+#define _HW_IRQ_H
+
+#include <linux/msi.h>
+#include <linux/pci.h>
+
+static inline struct msi_desc *irq_get_msi_desc(unsigned int irq)
+{
+        return __irq_get_msi_desc(irq);
+}
+
+/* Must be called with msi map lock held */
+static inline int irq_set_msi_desc(unsigned int irq, struct msi_desc *msi)
+{
+        if (!msi)
+                return -EINVAL;
+
+        msi->irq = irq;
+        return 0;
+}
+
+#endif
diff --git a/arch/s390/include/asm/irq.h b/arch/s390/include/asm/irq.h
index 6703dd986fd4..e6972f85d2b0 100644
--- a/arch/s390/include/asm/irq.h
+++ b/arch/s390/include/asm/irq.h
@@ -33,6 +33,8 @@ enum interruption_class {
         IOINT_APB,
         IOINT_ADM,
         IOINT_CSC,
+        IOINT_PCI,
+        IOINT_MSI,
         NMI_NMI,
         NR_IRQS,
 };
@@ -51,4 +53,14 @@ void service_subclass_irq_unregister(void);
 void measurement_alert_subclass_register(void);
 void measurement_alert_subclass_unregister(void);
 
+#ifdef CONFIG_LOCKDEP
+#  define disable_irq_nosync_lockdep(irq)       disable_irq_nosync(irq)
+#  define disable_irq_nosync_lockdep_irqsave(irq, flags) \
+                                                disable_irq_nosync(irq)
+#  define disable_irq_lockdep(irq)              disable_irq(irq)
+#  define enable_irq_lockdep(irq)               enable_irq(irq)
+#  define enable_irq_lockdep_irqrestore(irq, flags) \
+                                                enable_irq(irq)
+#endif
+
 #endif /* _ASM_IRQ_H */
diff --git a/arch/s390/include/asm/isc.h b/arch/s390/include/asm/isc.h
index 5ae606456b0a..68d7d68300f2 100644
--- a/arch/s390/include/asm/isc.h
+++ b/arch/s390/include/asm/isc.h
@@ -18,6 +18,7 @@
 #define CHSC_SCH_ISC 7                  /* CHSC subchannels */
 /* Adapter interrupts. */
 #define QDIO_AIRQ_ISC IO_SCH_ISC        /* I/O subchannel in qdio mode */
+#define PCI_ISC 2                       /* PCI I/O subchannels */
 #define AP_ISC 6                        /* adjunct processor (crypto) devices */
 
 /* Functions for registration of I/O interruption subclasses */
diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
index 6f98a54950ea..2a6084fa4b1a 100644
--- a/arch/s390/include/asm/pci.h
+++ b/arch/s390/include/asm/pci.h
@@ -20,6 +20,10 @@ void pci_iounmap(struct pci_dev *, void __iomem *);
 int pci_domain_nr(struct pci_bus *);
 int pci_proc_domain(struct pci_bus *);
 
+/* MSI arch hooks */
+#define arch_setup_msi_irqs     arch_setup_msi_irqs
+#define arch_teardown_msi_irqs  arch_teardown_msi_irqs
+
 #define ZPCI_BUS_NR                     0       /* default bus number */
 #define ZPCI_DEVFN                      0       /* default device number */
 
@@ -29,6 +33,15 @@ int pci_proc_domain(struct pci_bus *);
 #define ZPCI_FC_BLOCKED                 0x20
 #define ZPCI_FC_DMA_ENABLED             0x10
 
+struct msi_map {
+        unsigned long irq;
+        struct msi_desc *msi;
+        struct hlist_node msi_chain;
+};
+
+#define ZPCI_NR_MSI_VECS        64
+#define ZPCI_MSI_MASK           (ZPCI_NR_MSI_VECS - 1)
+
 enum zpci_state {
         ZPCI_FN_STATE_RESERVED,
         ZPCI_FN_STATE_STANDBY,
@@ -56,6 +69,12 @@ struct zpci_dev {
         u8              pfgid;          /* function group ID */
         u16             domain;
 
+        /* IRQ stuff */
+        u64             msi_addr;       /* MSI address */
+        struct zdev_irq_map *irq_map;
+        struct msi_map *msi_map[ZPCI_NR_MSI_VECS];
+        unsigned int    aisb;           /* number of the summary bit */
+
         struct zpci_bar_struct bars[PCI_BAR_COUNT];
 
         enum pci_bus_speed max_bus_speed;
@@ -83,6 +102,14 @@ int clp_add_pci_device(u32, u32, int);
 int clp_enable_fh(struct zpci_dev *, u8);
 int clp_disable_fh(struct zpci_dev *);
 
+/* MSI */
+struct msi_desc *__irq_get_msi_desc(unsigned int);
+int zpci_msi_set_mask_bits(struct msi_desc *, u32, u32);
+int zpci_setup_msi_irq(struct zpci_dev *, struct msi_desc *, unsigned int, int);
+void zpci_teardown_msi_irq(struct zpci_dev *, struct msi_desc *);
+int zpci_msihash_init(void);
+void zpci_msihash_exit(void);
+
 /* Helpers */
 struct zpci_dev *get_zdev(struct pci_dev *);
 struct zpci_dev *get_zdev_by_fid(u32);
diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
index 6cdc55b26d68..bf24293970ce 100644
--- a/arch/s390/kernel/irq.c
+++ b/arch/s390/kernel/irq.c
@@ -58,6 +58,8 @@ static const struct irq_class intrclass_names[] = {
         [IOINT_APB]  = {.name = "APB", .desc = "[I/O] AP Bus"},
         [IOINT_ADM]  = {.name = "ADM", .desc = "[I/O] EADM Subchannel"},
         [IOINT_CSC]  = {.name = "CSC", .desc = "[I/O] CHSC Subchannel"},
+        [IOINT_PCI]  = {.name = "PCI", .desc = "[I/O] PCI Interrupt" },
+        [IOINT_MSI] =  {.name = "MSI", .desc = "[I/O] MSI Interrupt" },
         [NMI_NMI]    = {.name = "NMI", .desc = "[NMI] Machine Check"},
 };
 
diff --git a/arch/s390/pci/Makefile b/arch/s390/pci/Makefile
index 1afd68c4c984..628be7bc006c 100644
--- a/arch/s390/pci/Makefile
+++ b/arch/s390/pci/Makefile
@@ -2,4 +2,4 @@
 # Makefile for the s390 PCI subsystem.
 #
 
-obj-$(CONFIG_PCI)       += pci.o pci_clp.o
+obj-$(CONFIG_PCI)       += pci.o pci_clp.o pci_msi.o
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index 70f6c56c8d0f..d11dc8a25f34 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -23,17 +23,25 @@
 #include <linux/err.h>
 #include <linux/export.h>
 #include <linux/delay.h>
+#include <linux/irq.h>
+#include <linux/kernel_stat.h>
 #include <linux/seq_file.h>
 #include <linux/pci.h>
 #include <linux/msi.h>
 
+#include <asm/isc.h>
+#include <asm/airq.h>
 #include <asm/facility.h>
 #include <asm/pci_insn.h>
 #include <asm/pci_clp.h>
 
 #define DEBUG                           /* enable pr_debug */
 
+#define SIC_IRQ_MODE_ALL                0
+#define SIC_IRQ_MODE_SINGLE             1
+
 #define ZPCI_NR_DMA_SPACES              1
+#define ZPCI_MSI_VEC_BITS               6
 #define ZPCI_NR_DEVICES                 CONFIG_PCI_NR_FUNCTIONS
 
 /* list of all detected zpci devices */
@@ -43,12 +51,63 @@ DEFINE_MUTEX(zpci_list_lock);
 static DECLARE_BITMAP(zpci_domain, ZPCI_NR_DEVICES);
 static DEFINE_SPINLOCK(zpci_domain_lock);
 
+struct callback {
+        irq_handler_t   handler;
+        void            *data;
+};
+
+struct zdev_irq_map {
+        unsigned long   aibv;           /* AI bit vector */
+        int             msi_vecs;       /* consecutive MSI-vectors used */
+        int             __unused;
+        struct callback cb[ZPCI_NR_MSI_VECS]; /* callback handler array */
+        spinlock_t      lock;           /* protect callbacks against de-reg */
+};
+
+struct intr_bucket {
+        /* amap of adapters, one bit per dev, corresponds to one irq nr */
+        unsigned long   *alloc;
+        /* AI summary bit, global page for all devices */
+        unsigned long   *aisb;
+        /* pointer to aibv and callback data in zdev */
+        struct zdev_irq_map *imap[ZPCI_NR_DEVICES];
+        /* protects the whole bucket struct */
+        spinlock_t      lock;
+};
+
+static struct intr_bucket *bucket;
+
+/* Adapter local summary indicator */
+static u8 *zpci_irq_si;
+
+static atomic_t irq_retries = ATOMIC_INIT(0);
+
 /* I/O Map */
 static DEFINE_SPINLOCK(zpci_iomap_lock);
 static DECLARE_BITMAP(zpci_iomap, ZPCI_IOMAP_MAX_ENTRIES);
 struct zpci_iomap_entry *zpci_iomap_start;
 EXPORT_SYMBOL_GPL(zpci_iomap_start);
 
+/* highest irq summary bit */
+static int __read_mostly aisb_max;
+
+static struct kmem_cache *zdev_irq_cache;
+
+static inline int irq_to_msi_nr(unsigned int irq)
+{
+        return irq & ZPCI_MSI_MASK;
+}
+
+static inline int irq_to_dev_nr(unsigned int irq)
+{
+        return irq >> ZPCI_MSI_VEC_BITS;
+}
+
+static inline struct zdev_irq_map *get_imap(unsigned int irq)
+{
+        return bucket->imap[irq_to_dev_nr(irq)];
+}
+
 struct zpci_dev *get_zdev(struct pci_dev *pdev)
 {
         return (struct zpci_dev *) pdev->sysdata;
@@ -120,6 +179,67 @@ static int zpci_store_fib(struct zpci_dev *zdev, u8 *fc)
         return (cc) ? -EIO : 0;
 }
 
+/* Modify PCI: Register adapter interruptions */
+static int zpci_register_airq(struct zpci_dev *zdev, unsigned int aisb,
+                              u64 aibv)
+{
+        u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_REG_INT);
+        struct zpci_fib *fib;
+        int rc;
+
+        fib = (void *) get_zeroed_page(GFP_KERNEL);
+        if (!fib)
+                return -ENOMEM;
+
+        fib->isc = PCI_ISC;
+        fib->noi = zdev->irq_map->msi_vecs;
+        fib->sum = 1;           /* enable summary notifications */
+        fib->aibv = aibv;
+        fib->aibvo = 0;         /* every function has its own page */
+        fib->aisb = (u64) bucket->aisb + aisb / 8;
+        fib->aisbo = aisb & ZPCI_MSI_MASK;
+
+        rc = mpcifc_instr(req, fib);
+        pr_debug("%s mpcifc returned noi: %d\n", __func__, fib->noi);
+
+        free_page((unsigned long) fib);
+        return rc;
+}
+
+struct mod_pci_args {
+        u64 base;
+        u64 limit;
+        u64 iota;
+};
+
+static int mod_pci(struct zpci_dev *zdev, int fn, u8 dmaas, struct mod_pci_args *args)
+{
+        u64 req = ZPCI_CREATE_REQ(zdev->fh, dmaas, fn);
+        struct zpci_fib *fib;
+        int rc;
+
+        /* The FIB must be available even if it's not used */
+        fib = (void *) get_zeroed_page(GFP_KERNEL);
+        if (!fib)
+                return -ENOMEM;
+
+        fib->pba = args->base;
+        fib->pal = args->limit;
+        fib->iota = args->iota;
+
+        rc = mpcifc_instr(req, fib);
+        free_page((unsigned long) fib);
+        return rc;
+}
+
+/* Modify PCI: Unregister adapter interruptions */
+static int zpci_unregister_airq(struct zpci_dev *zdev)
+{
+        struct mod_pci_args args = { 0, 0, 0 };
+
+        return mod_pci(zdev, ZPCI_MOD_FC_DEREG_INT, 0, &args);
+}
+
 #define ZPCI_PCIAS_CFGSPC       15
 
 static int zpci_cfg_load(struct zpci_dev *zdev, int offset, u32 *val, u8 len)
@@ -150,6 +270,55 @@ static int zpci_cfg_store(struct zpci_dev *zdev, int offset, u32 val, u8 len)
         return rc;
 }
 
+void synchronize_irq(unsigned int irq)
+{
+        /*
+         * Not needed, the handler is protected by a lock and IRQs that occur
+         * after the handler is deleted are just NOPs.
+         */
+}
+EXPORT_SYMBOL_GPL(synchronize_irq);
+
+void enable_irq(unsigned int irq)
+{
+        struct msi_desc *msi = irq_get_msi_desc(irq);
+
+        zpci_msi_set_mask_bits(msi, 1, 0);
+}
+EXPORT_SYMBOL_GPL(enable_irq);
+
+void disable_irq(unsigned int irq)
+{
+        struct msi_desc *msi = irq_get_msi_desc(irq);
+
+        zpci_msi_set_mask_bits(msi, 1, 1);
+}
+EXPORT_SYMBOL_GPL(disable_irq);
+
+void disable_irq_nosync(unsigned int irq)
+{
+        disable_irq(irq);
+}
+EXPORT_SYMBOL_GPL(disable_irq_nosync);
+
+unsigned long probe_irq_on(void)
+{
+        return 0;
+}
+EXPORT_SYMBOL_GPL(probe_irq_on);
+
+int probe_irq_off(unsigned long val)
+{
+        return 0;
+}
+EXPORT_SYMBOL_GPL(probe_irq_off);
+
+unsigned int probe_irq_mask(unsigned long val)
+{
+        return val;
+}
+EXPORT_SYMBOL_GPL(probe_irq_mask);
+
 void __devinit pcibios_fixup_bus(struct pci_bus *bus)
 {
 }
@@ -219,6 +388,155 @@ static struct pci_ops pci_root_ops = {
         .write = pci_write,
 };
 
+/* store the last handled bit to implement fair scheduling of devices */
+static DEFINE_PER_CPU(unsigned long, next_sbit);
+
+static void zpci_irq_handler(void *dont, void *need)
+{
+        unsigned long sbit, mbit, last = 0, start = __get_cpu_var(next_sbit);
+        int rescan = 0, max = aisb_max;
+        struct zdev_irq_map *imap;
+
+        kstat_cpu(smp_processor_id()).irqs[IOINT_PCI]++;
+        sbit = start;
+
+scan:
+        /* find summary_bit */
+        for_each_set_bit_left_cont(sbit, bucket->aisb, max) {
+                clear_bit(63 - (sbit & 63), bucket->aisb + (sbit >> 6));
+                last = sbit;
+
+                /* find vector bit */
+                imap = bucket->imap[sbit];
+                for_each_set_bit_left(mbit, &imap->aibv, imap->msi_vecs) {
+                        kstat_cpu(smp_processor_id()).irqs[IOINT_MSI]++;
+                        clear_bit(63 - mbit, &imap->aibv);
+
+                        spin_lock(&imap->lock);
+                        if (imap->cb[mbit].handler)
+                                imap->cb[mbit].handler(mbit,
+                                        imap->cb[mbit].data);
+                        spin_unlock(&imap->lock);
+                }
+        }
+
+        if (rescan)
+                goto out;
+
+        /* scan the skipped bits */
+        if (start > 0) {
+                sbit = 0;
+                max = start;
+                start = 0;
+                goto scan;
+        }
+
+        /* enable interrupts again */
+        sic_instr(SIC_IRQ_MODE_SINGLE, NULL, PCI_ISC);
+
+        /* check again to not lose initiative */
+        rmb();
+        max = aisb_max;
+        sbit = find_first_bit_left(bucket->aisb, max);
+        if (sbit != max) {
+                atomic_inc(&irq_retries);
+                rescan++;
+                goto scan;
+        }
+out:
+        /* store next device bit to scan */
+        __get_cpu_var(next_sbit) = (++last >= aisb_max) ? 0 : last;
+}
+
+/* msi_vecs - number of requested interrupts, 0 place function to error state */
+static int zpci_setup_msi(struct pci_dev *pdev, int msi_vecs)
+{
+        struct zpci_dev *zdev = get_zdev(pdev);
+        unsigned int aisb, msi_nr;
+        struct msi_desc *msi;
+        int rc;
+
+        /* store the number of used MSI vectors */
+        zdev->irq_map->msi_vecs = min(msi_vecs, ZPCI_NR_MSI_VECS);
+
+        spin_lock(&bucket->lock);
+        aisb = find_first_zero_bit(bucket->alloc, PAGE_SIZE);
+        /* alloc map exhausted? */
+        if (aisb == PAGE_SIZE) {
+                spin_unlock(&bucket->lock);
+                return -EIO;
+        }
+        set_bit(aisb, bucket->alloc);
+        spin_unlock(&bucket->lock);
+
+        zdev->aisb = aisb;
+        if (aisb + 1 > aisb_max)
+                aisb_max = aisb + 1;
+
+        /* wire up IRQ shortcut pointer */
+        bucket->imap[zdev->aisb] = zdev->irq_map;
+        pr_debug("%s: imap[%u] linked to %p\n", __func__, zdev->aisb, zdev->irq_map);
+
+        /* TODO: irq number 0 wont be found if we return less than requested MSIs.
+         * ignore it for now and fix in common code.
+         */
+        msi_nr = aisb << ZPCI_MSI_VEC_BITS;
+
+        list_for_each_entry(msi, &pdev->msi_list, list) {
+                rc = zpci_setup_msi_irq(zdev, msi, msi_nr,
+                                          aisb << ZPCI_MSI_VEC_BITS);
+                if (rc)
+                        return rc;
+                msi_nr++;
+        }
+
+        rc = zpci_register_airq(zdev, aisb, (u64) &zdev->irq_map->aibv);
+        if (rc) {
+                clear_bit(aisb, bucket->alloc);
+                dev_err(&pdev->dev, "register MSI failed with: %d\n", rc);
+                return rc;
+        }
+        return (zdev->irq_map->msi_vecs == msi_vecs) ?
+                0 : zdev->irq_map->msi_vecs;
+}
+
+static void zpci_teardown_msi(struct pci_dev *pdev)
+{
+        struct zpci_dev *zdev = get_zdev(pdev);
+        struct msi_desc *msi;
+        int aisb, rc;
+
+        rc = zpci_unregister_airq(zdev);
+        if (rc) {
+                dev_err(&pdev->dev, "deregister MSI failed with: %d\n", rc);
+                return;
+        }
+
+        msi = list_first_entry(&pdev->msi_list, struct msi_desc, list);
+        aisb = irq_to_dev_nr(msi->irq);
+
+        list_for_each_entry(msi, &pdev->msi_list, list)
+                zpci_teardown_msi_irq(zdev, msi);
+
+        clear_bit(aisb, bucket->alloc);
+        if (aisb + 1 == aisb_max)
+                aisb_max--;
+}
+
+int arch_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
+{
+        pr_debug("%s: requesting %d MSI-X interrupts...", __func__, nvec);
+        if (type != PCI_CAP_ID_MSIX && type != PCI_CAP_ID_MSI)
+                return -EINVAL;
+        return zpci_setup_msi(pdev, nvec);
+}
+
+void arch_teardown_msi_irqs(struct pci_dev *pdev)
+{
+        pr_info("%s: on pdev: %p\n", __func__, pdev);
+        zpci_teardown_msi(pdev);
+}
+
 static void zpci_map_resources(struct zpci_dev *zdev)
 {
         struct pci_dev *pdev = zdev->pdev;
@@ -257,11 +575,23 @@ struct zpci_dev *zpci_alloc_device(void)
         zdev = kzalloc(sizeof(*zdev), GFP_KERNEL);
         if (!zdev)
                 return ERR_PTR(-ENOMEM);
+
+        /* Alloc aibv & callback space */
+        zdev->irq_map = kmem_cache_alloc(zdev_irq_cache, GFP_KERNEL);
+        if (!zdev->irq_map)
+                goto error;
+        memset(zdev->irq_map, 0, sizeof(*zdev->irq_map));
+        WARN_ON((u64) zdev->irq_map & 0xff);
         return zdev;
+
+error:
+        kfree(zdev);
+        return ERR_PTR(-ENOMEM);
 }
 
 void zpci_free_device(struct zpci_dev *zdev)
 {
+        kmem_cache_free(zdev_irq_cache, zdev->irq_map);
         kfree(zdev);
 }
 
@@ -320,6 +650,118 @@ void pcibios_disable_device(struct pci_dev *pdev)
         pdev->sysdata = NULL;
 }
 
+int zpci_request_irq(unsigned int irq, irq_handler_t handler, void *data)
+{
+        int msi_nr = irq_to_msi_nr(irq);
+        struct zdev_irq_map *imap;
+        struct msi_desc *msi;
+
+        msi = irq_get_msi_desc(irq);
+        if (!msi)
+                return -EIO;
+
+        imap = get_imap(irq);
+        spin_lock_init(&imap->lock);
+
+        pr_debug("%s: register handler for IRQ:MSI %d:%d\n", __func__, irq >> 6, msi_nr);
+        imap->cb[msi_nr].handler = handler;
+        imap->cb[msi_nr].data = data;
+
+        /*
+         * The generic MSI code returns with the interrupt disabled on the
+         * card, using the MSI mask bits. Firmware doesn't appear to unmask
+         * at that level, so we do it here by hand.
+         */
+        zpci_msi_set_mask_bits(msi, 1, 0);
+        return 0;
+}
+
+void zpci_free_irq(unsigned int irq)
+{
+        struct zdev_irq_map *imap = get_imap(irq);
+        int msi_nr = irq_to_msi_nr(irq);
+        unsigned long flags;
+
+        pr_debug("%s: for irq: %d\n", __func__, irq);
+
+        spin_lock_irqsave(&imap->lock, flags);
+        imap->cb[msi_nr].handler = NULL;
+        imap->cb[msi_nr].data = NULL;
+        spin_unlock_irqrestore(&imap->lock, flags);
+}
+
+int request_irq(unsigned int irq, irq_handler_t handler,
+                unsigned long irqflags, const char *devname, void *dev_id)
+{
+        pr_debug("%s: irq: %d  handler: %p  flags: %lx  dev: %s\n",
+                __func__, irq, handler, irqflags, devname);
+
+        return zpci_request_irq(irq, handler, dev_id);
+}
+EXPORT_SYMBOL_GPL(request_irq);
+
+void free_irq(unsigned int irq, void *dev_id)
+{
+        zpci_free_irq(irq);
+}
+EXPORT_SYMBOL_GPL(free_irq);
+
+static int __init zpci_irq_init(void)
+{
+        int cpu, rc;
+
+        bucket = kzalloc(sizeof(*bucket), GFP_KERNEL);
+        if (!bucket)
+                return -ENOMEM;
+
+        bucket->aisb = (unsigned long *) get_zeroed_page(GFP_KERNEL);
+        if (!bucket->aisb) {
+                rc = -ENOMEM;
+                goto out_aisb;
+        }
+
+        bucket->alloc = (unsigned long *) get_zeroed_page(GFP_KERNEL);
+        if (!bucket->alloc) {
+                rc = -ENOMEM;
+                goto out_alloc;
+        }
+
+        isc_register(PCI_ISC);
+        zpci_irq_si = s390_register_adapter_interrupt(&zpci_irq_handler, NULL, PCI_ISC);
+        if (IS_ERR(zpci_irq_si)) {
+                rc = PTR_ERR(zpci_irq_si);
+                zpci_irq_si = NULL;
+                goto out_ai;
+        }
+
+        for_each_online_cpu(cpu)
+                per_cpu(next_sbit, cpu) = 0;
+
+        spin_lock_init(&bucket->lock);
+        /* set summary to 1 to be called every time for the ISC */
+        *zpci_irq_si = 1;
+        sic_instr(SIC_IRQ_MODE_SINGLE, NULL, PCI_ISC);
+        return 0;
+
+out_ai:
+        isc_unregister(PCI_ISC);
+        free_page((unsigned long) bucket->alloc);
+out_alloc:
+        free_page((unsigned long) bucket->aisb);
+out_aisb:
+        kfree(bucket);
+        return rc;
+}
+
+static void zpci_irq_exit(void)
+{
+        free_page((unsigned long) bucket->alloc);
+        free_page((unsigned long) bucket->aisb);
+        s390_unregister_adapter_interrupt(zpci_irq_si, PCI_ISC);
+        isc_unregister(PCI_ISC);
+        kfree(bucket);
+}
+
 static struct resource *zpci_alloc_bus_resource(unsigned long start, unsigned long size,
                                                 unsigned long flags, int domain)
 {
@@ -523,13 +965,20 @@ static inline int barsize(u8 size)
 
 static int zpci_mem_init(void)
 {
+        zdev_irq_cache = kmem_cache_create("PCI_IRQ_cache", sizeof(struct zdev_irq_map),
+                                L1_CACHE_BYTES, SLAB_HWCACHE_ALIGN, NULL);
+        if (!zdev_irq_cache)
+                goto error_zdev;
+
         /* TODO: use realloc */
         zpci_iomap_start = kzalloc(ZPCI_IOMAP_MAX_ENTRIES * sizeof(*zpci_iomap_start),
                                    GFP_KERNEL);
         if (!zpci_iomap_start)
-                goto error_zdev;
+                goto error_iomap;
         return 0;
 
+error_iomap:
+        kmem_cache_destroy(zdev_irq_cache);
 error_zdev:
         return -ENOMEM;
 }
@@ -537,6 +986,7 @@ error_zdev:
 static void zpci_mem_exit(void)
 {
         kfree(zpci_iomap_start);
+        kmem_cache_destroy(zdev_irq_cache);
 }
 
 unsigned int pci_probe = 1;
@@ -570,6 +1020,14 @@ static int __init pci_base_init(void)
         if (rc)
                 goto out_mem;
 
+        rc = zpci_msihash_init();
+        if (rc)
+                goto out_hash;
+
+        rc = zpci_irq_init();
+        if (rc)
+                goto out_irq;
+
         rc = clp_find_pci_devices();
         if (rc)
                 goto out_find;
@@ -578,6 +1036,10 @@ static int __init pci_base_init(void)
         return 0;
 
 out_find:
+        zpci_irq_exit();
+out_irq:
+        zpci_msihash_exit();
+out_hash:
         zpci_mem_exit();
 out_mem:
         return rc;
diff --git a/arch/s390/pci/pci_clp.c b/arch/s390/pci/pci_clp.c
index 291da1a96560..72694fb6d525 100644
--- a/arch/s390/pci/pci_clp.c
+++ b/arch/s390/pci/pci_clp.c
@@ -48,6 +48,9 @@ static void clp_free_block(void *ptr)
 static void clp_store_query_pci_fngrp(struct zpci_dev *zdev,
                                       struct clp_rsp_query_pci_grp *response)
 {
+        zdev->msi_addr = response->msia;
+
+        pr_debug("Supported number of MSI vectors: %u\n", response->noi);
         switch (response->version) {
         case 1:
                 zdev->max_bus_speed = PCIE_SPEED_5_0GT;
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);
+}
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index a825d78fd0aa..5099636a6e5f 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -207,6 +207,8 @@ static void msix_mask_irq(struct msi_desc *desc, u32 flag)
         desc->masked = __msix_mask_irq(desc, flag);
 }
 
+#ifdef CONFIG_GENERIC_HARDIRQS
+
 static void msi_set_mask_bit(struct irq_data *data, u32 flag)
 {
         struct msi_desc *desc = irq_data_get_msi(data);
@@ -230,6 +232,8 @@ void unmask_msi_irq(struct irq_data *data)
         msi_set_mask_bit(data, 0);
 }
 
+#endif /* CONFIG_GENERIC_HARDIRQS */
+
 void __read_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
 {
         BUG_ON(entry->dev->current_state != PCI_D0);
@@ -337,8 +341,10 @@ static void free_msi_irqs(struct pci_dev *dev)
                 if (!entry->irq)
                         continue;
                 nvec = 1 << entry->msi_attrib.multiple;
+#ifdef CONFIG_GENERIC_HARDIRQS
                 for (i = 0; i < nvec; i++)
                         BUG_ON(irq_has_action(entry->irq + i));
+#endif
         }
 
         arch_teardown_msi_irqs(dev);
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 216b0ba109d7..e21ed837c673 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -10,9 +10,6 @@
  */
 
 #include <linux/smp.h>
-
-#ifndef CONFIG_S390
-
 #include <linux/linkage.h>
 #include <linux/cache.h>
 #include <linux/spinlock.h>
@@ -737,8 +734,11 @@ static inline void irq_gc_lock(struct irq_chip_generic *gc) { }
 static inline void irq_gc_unlock(struct irq_chip_generic *gc) { }
 #endif
 
-#endif /* CONFIG_GENERIC_HARDIRQS */
+#else /* !CONFIG_GENERIC_HARDIRQS */
 
-#endif /* !CONFIG_S390 */
+extern struct msi_desc *irq_get_msi_desc(unsigned int irq);
+extern int irq_set_msi_desc(unsigned int irq, struct msi_desc *entry);
+
+#endif /* CONFIG_GENERIC_HARDIRQS */
 
 #endif /* _LINUX_IRQ_H */