s390: convert interrupt handling to use generic hardirq

With the introduction of PCI it became apparent that s390 should
convert to generic hardirqs as too many drivers do not have the
correct dependency for GENERIC_HARDIRQS. On the architecture
level s390 does not have irq lines. It has external interrupts,
I/O interrupts and adapter interrupts. This patch hard-codes all
external interrupts as irq #1, all I/O interrupts as irq #2 and
all adapter interrupts as irq #3. The additional information from
the lowcore associated with the interrupt is stored in the
pt_regs of the interrupt frame, where the interrupt handler can
pick it up. For PCI/MSI interrupts the adapter interrupt handler
scans the relevant bit fields and calls generic_handle_irq with
the virtual irq number for the MSI interrupt.

Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 0 insertions, 134 deletions

diff --git a/arch/s390/pci/pci_msi.c b/arch/s390/pci/pci_msi.c
deleted file mode 100644
index d4b480a18b0f..000000000000
--- a/arch/s390/pci/pci_msi.c
+++ /dev/null
@@ -1,134 +0,0 @@
-/*
- * 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 const unsigned int msi_hash_bits = 8;
-#define MSI_HASH_BUCKETS (1U << msi_hash_bits)
-#define msi_hashfn(nr)	hash_long(nr, msi_hash_bits)
-
-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 = zdev->msi_map + (nr & ZPCI_MSI_VEC_MASK);
-	map->irq = nr;
-	map->msi = msi;
-	INIT_HLIST_NODE(&map->msi_chain);
-
-	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);
-		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 nr = msi->irq & ZPCI_MSI_VEC_MASK;
-	struct msi_map *map;
-
-	zpci_msi_set_mask_bits(msi, 1, 1);
-	msi->msg.address_lo = 0;
-	msi->msg.address_hi = 0;
-	msi->msg.data = 0;
-	msi->irq = 0;
-
-	spin_lock(&msi_map_lock);
-	map = zdev->msi_map + nr;
-	hlist_del_rcu(&map->msi_chain);
-	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(MSI_HASH_BUCKETS * sizeof(*msi_hash), GFP_KERNEL);
-	if (!msi_hash)
-		return -ENOMEM;
-
-	for (i = 0; i < MSI_HASH_BUCKETS; i++)
-		INIT_HLIST_HEAD(&msi_hash[i]);
-	return 0;
-}
-
-void __init zpci_msihash_exit(void)
-{
-	kfree(msi_hash);
-}