irq_domain: Replace irq_alloc_host() with revmap-specific initializers

Each revmap type has different arguments for setting up the revmap.
This patch splits up the generator functions so that each revmap type
can do its own setup and the user doesn't need to keep track of how
each revmap type handles the arguments.

This patch also adds a host_data argument to the generators.  There are
cases where the host_data pointer will be needed before the function returns.
ie. the legacy map calls the .map callback for each irq before returning.

v2: - Add void *host_data argument to irq_domain_add_*() functions
    - fixed failure to compile
    - Moved IRQ_DOMAIN_MAP_* defines into irqdomain.c

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Milton Miller <miltonm@bga.com>
Tested-by: Olof Johansson <olof@lixom.net>

35 files changed, 198 insertions, 185 deletions

diff --git a/arch/powerpc/platforms/512x/mpc5121_ads_cpld.c b/arch/powerpc/platforms/512x/mpc5121_ads_cpld.c
index fefa7977fa9..291d61c9471 100644
--- a/arch/powerpc/platforms/512x/mpc5121_ads_cpld.c
+++ b/arch/powerpc/platforms/512x/mpc5121_ads_cpld.c
@@ -190,8 +190,7 @@ mpc5121_ads_cpld_pic_init(void)
 
 	cpld_pic_node = of_node_get(np);
 
-	cpld_pic_host =
-	    irq_alloc_host(np, IRQ_DOMAIN_MAP_LINEAR, 16, &cpld_pic_host_ops, 16);
+	cpld_pic_host = irq_domain_add_linear(np, 16, &cpld_pic_host_ops, NULL);
 	if (!cpld_pic_host) {
 		printk(KERN_ERR "CPLD PIC: failed to allocate irq host!\n");
 		goto end;
diff --git a/arch/powerpc/platforms/52xx/media5200.c b/arch/powerpc/platforms/52xx/media5200.c
index a746415c424..5db5cfb6a4f 100644
--- a/arch/powerpc/platforms/52xx/media5200.c
+++ b/arch/powerpc/platforms/52xx/media5200.c
@@ -173,15 +173,12 @@ static void __init media5200_init_irq(void)
 
 	spin_lock_init(&media5200_irq.lock);
 
-	media5200_irq.irqhost = irq_alloc_host(fpga_np, IRQ_DOMAIN_MAP_LINEAR,
-					       MEDIA5200_NUM_IRQS,
-					       &media5200_irq_ops, -1);
+	media5200_irq.irqhost = irq_domain_add_linear(fpga_np,
+			MEDIA5200_NUM_IRQS, &media5200_irq_ops, &media5200_irq);
 	if (!media5200_irq.irqhost)
 		goto out;
 	pr_debug("%s: allocated irqhost\n", __func__);
 
-	media5200_irq.irqhost->host_data = &media5200_irq;
-
 	irq_set_handler_data(cascade_virq, &media5200_irq);
 	irq_set_chained_handler(cascade_virq, media5200_irq_cascade);
 
diff --git a/arch/powerpc/platforms/52xx/mpc52xx_gpt.c b/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
index e90af8fd841..b53275d1272 100644
--- a/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
+++ b/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
@@ -252,14 +252,12 @@ mpc52xx_gpt_irq_setup(struct mpc52xx_gpt_priv *gpt, struct device_node *node)
 	if (!cascade_virq)
 		return;
 
-	gpt->irqhost = irq_alloc_host(node, IRQ_DOMAIN_MAP_LINEAR, 1,
-				      &mpc52xx_gpt_irq_ops, -1);
+	gpt->irqhost = irq_domain_add_linear(node, 1, &mpc52xx_gpt_irq_ops, gpt);
 	if (!gpt->irqhost) {
-		dev_err(gpt->dev, "irq_alloc_host() failed\n");
+		dev_err(gpt->dev, "irq_domain_add_linear() failed\n");
 		return;
 	}
 
-	gpt->irqhost->host_data = gpt;
 	irq_set_handler_data(cascade_virq, gpt);
 	irq_set_chained_handler(cascade_virq, mpc52xx_gpt_irq_cascade);
 
diff --git a/arch/powerpc/platforms/52xx/mpc52xx_pic.c b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
index 8c997f1a912..41fa67126c4 100644
--- a/arch/powerpc/platforms/52xx/mpc52xx_pic.c
+++ b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
@@ -444,9 +444,9 @@ void __init mpc52xx_init_irq(void)
 	 * As last step, add an irq host to translate the real
 	 * hw irq information provided by the ofw to linux virq
 	 */
-	mpc52xx_irqhost = irq_alloc_host(picnode, IRQ_DOMAIN_MAP_LINEAR,
+	mpc52xx_irqhost = irq_domain_add_linear(picnode,
 	                                 MPC52xx_IRQ_HIGHTESTHWIRQ,
-	                                 &mpc52xx_irqhost_ops, -1);
+	                                 &mpc52xx_irqhost_ops, NULL);
 
 	if (!mpc52xx_irqhost)
 		panic(__FILE__ ": Cannot allocate the IRQ host\n");
diff --git a/arch/powerpc/platforms/82xx/pq2ads-pci-pic.c b/arch/powerpc/platforms/82xx/pq2ads-pci-pic.c
index bdba174e7b3..4ef9d6918e2 100644
--- a/arch/powerpc/platforms/82xx/pq2ads-pci-pic.c
+++ b/arch/powerpc/platforms/82xx/pq2ads-pci-pic.c
@@ -156,17 +156,13 @@ int __init pq2ads_pci_init_irq(void)
 	out_be32(&priv->regs->mask, ~0);
 	mb();
 
-	host = irq_alloc_host(np, IRQ_DOMAIN_MAP_LINEAR, NUM_IRQS,
-	                      &pci_pic_host_ops, NUM_IRQS);
+	host = irq_domain_add_linear(np, NUM_IRQS, &pci_pic_host_ops, priv);
 	if (!host) {
 		ret = -ENOMEM;
 		goto out_unmap_regs;
 	}
 
-	host->host_data = priv;
-
 	priv->host = host;
-	host->host_data = priv;
 	irq_set_handler_data(irq, priv);
 	irq_set_chained_handler(irq, pq2ads_pci_irq_demux);
 
diff --git a/arch/powerpc/platforms/85xx/socrates_fpga_pic.c b/arch/powerpc/platforms/85xx/socrates_fpga_pic.c
index e3ef7c9ed7b..1092c121adf 100644
--- a/arch/powerpc/platforms/85xx/socrates_fpga_pic.c
+++ b/arch/powerpc/platforms/85xx/socrates_fpga_pic.c
@@ -280,9 +280,8 @@ void socrates_fpga_pic_init(struct device_node *pic)
 	int i;
 
 	/* Setup an irq_domain structure */
-	socrates_fpga_pic_irq_host = irq_alloc_host(pic, IRQ_DOMAIN_MAP_LINEAR,
-			SOCRATES_FPGA_NUM_IRQS,	&socrates_fpga_pic_host_ops,
-			SOCRATES_FPGA_NUM_IRQS);
+	socrates_fpga_pic_irq_host = irq_domain_add_linear(pic,
+		    SOCRATES_FPGA_NUM_IRQS, &socrates_fpga_pic_host_ops, NULL);
 	if (socrates_fpga_pic_irq_host == NULL) {
 		pr_err("FPGA PIC: Unable to allocate host\n");
 		return;
diff --git a/arch/powerpc/platforms/86xx/gef_pic.c b/arch/powerpc/platforms/86xx/gef_pic.c
index 0cf8af230bc..126a94b530e 100644
--- a/arch/powerpc/platforms/86xx/gef_pic.c
+++ b/arch/powerpc/platforms/86xx/gef_pic.c
@@ -212,9 +212,8 @@ void __init gef_pic_init(struct device_node *np)
 	}
 
 	/* Setup an irq_domain structure */
-	gef_pic_irq_host = irq_alloc_host(np, IRQ_DOMAIN_MAP_LINEAR,
-					  GEF_PIC_NUM_IRQS,
-					  &gef_pic_host_ops, NO_IRQ);
+	gef_pic_irq_host = irq_domain_add_linear(np, GEF_PIC_NUM_IRQS,
+					  &gef_pic_host_ops, NULL);
 	if (gef_pic_irq_host == NULL)
 		return;
 
diff --git a/arch/powerpc/platforms/cell/axon_msi.c b/arch/powerpc/platforms/cell/axon_msi.c
index 1bfd18a48a7..cf9fd3c8a9b 100644
--- a/arch/powerpc/platforms/cell/axon_msi.c
+++ b/arch/powerpc/platforms/cell/axon_msi.c
@@ -392,16 +392,13 @@ static int axon_msi_probe(struct platform_device *device)
 	}
 	memset(msic->fifo_virt, 0xff, MSIC_FIFO_SIZE_BYTES);
 
-	msic->irq_domain = irq_alloc_host(dn, IRQ_DOMAIN_MAP_NOMAP,
-					NR_IRQS, &msic_host_ops, 0);
+	msic->irq_domain = irq_domain_add_nomap(dn, &msic_host_ops, msic);
 	if (!msic->irq_domain) {
 		printk(KERN_ERR "axon_msi: couldn't allocate irq_domain for %s\n",
 		       dn->full_name);
 		goto out_free_fifo;
 	}
 
-	msic->irq_domain->host_data = msic;
-
 	irq_set_handler_data(virq, msic);
 	irq_set_chained_handler(virq, axon_msi_cascade);
 	pr_devel("axon_msi: irq 0x%x setup for axon_msi\n", virq);
diff --git a/arch/powerpc/platforms/cell/beat_interrupt.c b/arch/powerpc/platforms/cell/beat_interrupt.c
index 21b64cfef5e..bbdf57440cd 100644
--- a/arch/powerpc/platforms/cell/beat_interrupt.c
+++ b/arch/powerpc/platforms/cell/beat_interrupt.c
@@ -239,9 +239,7 @@ void __init beatic_init_IRQ(void)
 	ppc_md.get_irq = beatic_get_irq;
 
 	/* Allocate an irq host */
-	beatic_host = irq_alloc_host(NULL, IRQ_DOMAIN_MAP_NOMAP, 0,
-				     &beatic_pic_host_ops,
-					 0);
+	beatic_host = irq_domain_add_nomap(NULL, &beatic_pic_host_ops, NULL);
 	BUG_ON(beatic_host == NULL);
 	irq_set_default_host(beatic_host);
 }
diff --git a/arch/powerpc/platforms/cell/interrupt.c b/arch/powerpc/platforms/cell/interrupt.c
index 6888475e7c6..c844797a689 100644
--- a/arch/powerpc/platforms/cell/interrupt.c
+++ b/arch/powerpc/platforms/cell/interrupt.c
@@ -378,8 +378,8 @@ static int __init setup_iic(void)
 void __init iic_init_IRQ(void)
 {
 	/* Setup an irq host data structure */
-	iic_host = irq_alloc_host(NULL, IRQ_DOMAIN_MAP_LINEAR, IIC_SOURCE_COUNT,
-				  &iic_host_ops, IIC_IRQ_INVALID);
+	iic_host = irq_domain_add_linear(NULL, IIC_SOURCE_COUNT, &iic_host_ops,
+					 NULL);
 	BUG_ON(iic_host == NULL);
 	irq_set_default_host(iic_host);
 
diff --git a/arch/powerpc/platforms/cell/spider-pic.c b/arch/powerpc/platforms/cell/spider-pic.c
index 1f935a772ef..6521d202284 100644
--- a/arch/powerpc/platforms/cell/spider-pic.c
+++ b/arch/powerpc/platforms/cell/spider-pic.c
@@ -299,12 +299,10 @@ static void __init spider_init_one(struct device_node *of_node, int chip,
 		panic("spider_pic: can't map registers !");
 
 	/* Allocate a host */
-	pic->host = irq_alloc_host(of_node, IRQ_DOMAIN_MAP_LINEAR,
-				   SPIDER_SRC_COUNT, &spider_host_ops,
-				   SPIDER_IRQ_INVALID);
+	pic->host = irq_domain_add_linear(of_node, SPIDER_SRC_COUNT,
+					  &spider_host_ops, pic);
 	if (pic->host == NULL)
 		panic("spider_pic: can't allocate irq host !");
-	pic->host->host_data = pic;
 
 	/* Go through all sources and disable them */
 	for (i = 0; i < SPIDER_SRC_COUNT; i++) {
diff --git a/arch/powerpc/platforms/embedded6xx/flipper-pic.c b/arch/powerpc/platforms/embedded6xx/flipper-pic.c
index f862361730f..434597166ca 100644
--- a/arch/powerpc/platforms/embedded6xx/flipper-pic.c
+++ b/arch/powerpc/platforms/embedded6xx/flipper-pic.c
@@ -159,15 +159,13 @@ struct irq_domain * __init flipper_pic_init(struct device_node *np)
 
 	__flipper_quiesce(io_base);
 
-	irq_domain = irq_alloc_host(np, IRQ_DOMAIN_MAP_LINEAR, FLIPPER_NR_IRQS,
-				  &flipper_irq_domain_ops, -1);
+	irq_domain = irq_domain_add_linear(np, FLIPPER_NR_IRQS,
+				  &flipper_irq_domain_ops, io_base);
 	if (!irq_domain) {
 		pr_err("failed to allocate irq_domain\n");
 		return NULL;
 	}
 
-	irq_domain->host_data = io_base;
-
 out:
 	return irq_domain;
 }
diff --git a/arch/powerpc/platforms/embedded6xx/hlwd-pic.c b/arch/powerpc/platforms/embedded6xx/hlwd-pic.c
index 2d4a5d48fbb..499d410b95f 100644
--- a/arch/powerpc/platforms/embedded6xx/hlwd-pic.c
+++ b/arch/powerpc/platforms/embedded6xx/hlwd-pic.c
@@ -177,13 +177,12 @@ struct irq_domain *hlwd_pic_init(struct device_node *np)
 
 	__hlwd_quiesce(io_base);
 
-	irq_domain = irq_alloc_host(np, IRQ_DOMAIN_MAP_LINEAR, HLWD_NR_IRQS,
-				  &hlwd_irq_domain_ops, -1);
+	irq_domain = irq_domain_add_linear(np, HLWD_NR_IRQS,
+					   &hlwd_irq_domain_ops, io_base);
 	if (!irq_domain) {
 		pr_err("failed to allocate irq_domain\n");
 		return NULL;
 	}
-	irq_domain->host_data = io_base;
 
 	return irq_domain;
 }
diff --git a/arch/powerpc/platforms/iseries/irq.c b/arch/powerpc/platforms/iseries/irq.c
index b07d4f2e015..5538b593079 100644
--- a/arch/powerpc/platforms/iseries/irq.c
+++ b/arch/powerpc/platforms/iseries/irq.c
@@ -380,8 +380,7 @@ void __init iSeries_init_IRQ(void)
 	/* Create irq host. No need for a revmap since HV will give us
 	 * back our virtual irq number
 	 */
-	host = irq_alloc_host(NULL, IRQ_DOMAIN_MAP_NOMAP, 0,
-			      &iseries_irq_domain_ops, 0);
+	host = irq_domain_add_nomap(NULL, &iseries_irq_domain_ops, NULL);
 	BUG_ON(host == NULL);
 	irq_set_default_host(host);
 
diff --git a/arch/powerpc/platforms/powermac/pic.c b/arch/powerpc/platforms/powermac/pic.c
index cff326ab8ef..646fdf3b9c0 100644
--- a/arch/powerpc/platforms/powermac/pic.c
+++ b/arch/powerpc/platforms/powermac/pic.c
@@ -352,9 +352,8 @@ static void __init pmac_pic_probe_oldstyle(void)
 	/*
 	 * Allocate an irq host
 	 */
-	pmac_pic_host = irq_alloc_host(master, IRQ_DOMAIN_MAP_LINEAR, max_irqs,
-				       &pmac_pic_host_ops,
-				       max_irqs);
+	pmac_pic_host = irq_domain_add_linear(master, max_irqs,
+					      &pmac_pic_host_ops, NULL);
 	BUG_ON(pmac_pic_host == NULL);
 	irq_set_default_host(pmac_pic_host);
 
diff --git a/arch/powerpc/platforms/powermac/smp.c b/arch/powerpc/platforms/powermac/smp.c
index 6b1ef2d4dea..09afd704f07 100644
--- a/arch/powerpc/platforms/powermac/smp.c
+++ b/arch/powerpc/platforms/powermac/smp.c
@@ -192,8 +192,7 @@ static int psurge_secondary_ipi_init(void)
 {
 	int rc = -ENOMEM;
 
-	psurge_host = irq_alloc_host(NULL, IRQ_DOMAIN_MAP_NOMAP, 0,
-		&psurge_host_ops, 0);
+	psurge_host = irq_domain_add_nomap(NULL, &psurge_host_ops, NULL);
 
 	if (psurge_host)
 		psurge_secondary_virq = irq_create_direct_mapping(psurge_host);
diff --git a/arch/powerpc/platforms/ps3/interrupt.c b/arch/powerpc/platforms/ps3/interrupt.c
index c5980e422dc..c05808f2101 100644
--- a/arch/powerpc/platforms/ps3/interrupt.c
+++ b/arch/powerpc/platforms/ps3/interrupt.c
@@ -753,8 +753,7 @@ void __init ps3_init_IRQ(void)
 	unsigned cpu;
 	struct irq_domain *host;
 
-	host = irq_alloc_host(NULL, IRQ_DOMAIN_MAP_NOMAP, 0, &ps3_host_ops,
-		PS3_INVALID_OUTLET);
+	host = irq_domain_add_nomap(NULL, &ps3_host_ops, NULL);
 	irq_set_default_host(host);
 	irq_set_virq_count(PS3_PLUG_MAX + 1);
 
diff --git a/arch/powerpc/platforms/wsp/opb_pic.c b/arch/powerpc/platforms/wsp/opb_pic.c
index 76b33bc3611..4837515c282 100644
--- a/arch/powerpc/platforms/wsp/opb_pic.c
+++ b/arch/powerpc/platforms/wsp/opb_pic.c
@@ -263,13 +263,11 @@ struct opb_pic *opb_pic_init_one(struct device_node *dn)
 		goto free_opb;
 	}
 
-	/* Allocate an irq host so that Linux knows that despite only
+	/* Allocate an irq domain so that Linux knows that despite only
 	 * having one interrupt to issue, we're the controller for multiple
 	 * hardware IRQs, so later we can lookup their virtual IRQs. */
 
-	opb->host = irq_alloc_host(dn, IRQ_DOMAIN_MAP_LINEAR,
-			OPB_NR_IRQS, &opb_host_ops, -1);
-
+	opb->host = irq_domain_add_linear(dn, OPB_NR_IRQS, &opb_host_ops, opb);
 	if (!opb->host) {
 		printk(KERN_ERR "opb: Failed to allocate IRQ host!\n");
 		goto free_regs;
@@ -277,7 +275,6 @@ struct opb_pic *opb_pic_init_one(struct device_node *dn)
 
 	opb->index = opb_index++;
 	spin_lock_init(&opb->lock);
-	opb->host->host_data = opb;
 
 	/* Disable all interrupts by default */
 	opb_out(opb, OPB_MLSASIER, 0);
diff --git a/arch/powerpc/sysdev/cpm1.c b/arch/powerpc/sysdev/cpm1.c
index 0877a757c20..53f39dbbfb9 100644
--- a/arch/powerpc/sysdev/cpm1.c
+++ b/arch/powerpc/sysdev/cpm1.c
@@ -164,8 +164,7 @@ unsigned int cpm_pic_init(void)
 
 	out_be32(&cpic_reg->cpic_cimr, 0);
 
-	cpm_pic_host = irq_alloc_host(np, IRQ_DOMAIN_MAP_LINEAR,
-				      64, &cpm_pic_host_ops, 64);
+	cpm_pic_host = irq_domain_add_linear(np, 64, &cpm_pic_host_ops, NULL);
 	if (cpm_pic_host == NULL) {
 		printk(KERN_ERR "CPM2 PIC: failed to allocate irq host!\n");
 		sirq = NO_IRQ;
diff --git a/arch/powerpc/sysdev/cpm2_pic.c b/arch/powerpc/sysdev/cpm2_pic.c
index b149baae5d3..b3643322c52 100644
--- a/arch/powerpc/sysdev/cpm2_pic.c
+++ b/arch/powerpc/sysdev/cpm2_pic.c
@@ -275,8 +275,7 @@ void cpm2_pic_init(struct device_node *node)
 	out_be32(&cpm2_intctl->ic_scprrl, 0x05309770);
 
 	/* create a legacy host */
-	cpm2_pic_host = irq_alloc_host(node, IRQ_DOMAIN_MAP_LINEAR,
-				       64, &cpm2_pic_host_ops, 64);
+	cpm2_pic_host = irq_domain_add_linear(node, 64, &cpm2_pic_host_ops, NULL);
 	if (cpm2_pic_host == NULL) {
 		printk(KERN_ERR "CPM2 PIC: failed to allocate irq host!\n");
 		return;
diff --git a/arch/powerpc/sysdev/ehv_pic.c b/arch/powerpc/sysdev/ehv_pic.c
index 48d3ba1220d..adea322ea18 100644
--- a/arch/powerpc/sysdev/ehv_pic.c
+++ b/arch/powerpc/sysdev/ehv_pic.c
@@ -275,9 +275,8 @@ void __init ehv_pic_init(void)
 		return;
 	}
 
-	ehv_pic->irqhost = irq_alloc_host(np, IRQ_DOMAIN_MAP_LINEAR,
-		NR_EHV_PIC_INTS, &ehv_pic_host_ops, 0);
-
+	ehv_pic->irqhost = irq_domain_add_linear(np, NR_EHV_PIC_INTS,
+						 &ehv_pic_host_ops, ehv_pic);
 	if (!ehv_pic->irqhost) {
 		of_node_put(np);
 		kfree(ehv_pic);
@@ -293,7 +292,6 @@ void __init ehv_pic_init(void)
 		of_node_put(np2);
 	}
 
-	ehv_pic->irqhost->host_data = ehv_pic;
 	ehv_pic->hc_irq = ehv_pic_irq_chip;
 	ehv_pic->hc_irq.irq_set_affinity = ehv_pic_set_affinity;
 	ehv_pic->coreint_flag = coreint_flag;
diff --git a/arch/powerpc/sysdev/fsl_msi.c b/arch/powerpc/sysdev/fsl_msi.c
index 3f9a301c455..f4fd95bc127 100644
--- a/arch/powerpc/sysdev/fsl_msi.c
+++ b/arch/powerpc/sysdev/fsl_msi.c
@@ -387,8 +387,8 @@ static int __devinit fsl_of_msi_probe(struct platform_device *dev)
 	}
 	platform_set_drvdata(dev, msi);
 
-	msi->irqhost = irq_alloc_host(dev->dev.of_node, IRQ_DOMAIN_MAP_LINEAR,
-				      NR_MSI_IRQS, &fsl_msi_host_ops, 0);
+	msi->irqhost = irq_domain_add_linear(dev->dev.of_node,
+				      NR_MSI_IRQS, &fsl_msi_host_ops, msi);
 
 	if (msi->irqhost == NULL) {
 		dev_err(&dev->dev, "No memory for MSI irqhost\n");
@@ -420,8 +420,6 @@ static int __devinit fsl_of_msi_probe(struct platform_device *dev)
 
 	msi->feature = features->fsl_pic_ip;
 
-	msi->irqhost->host_data = msi;
-
 	/*
 	 * Remember the phandle, so that we can match with any PCI nodes
 	 * that have an "fsl,msi" property.
diff --git a/arch/powerpc/sysdev/i8259.c b/arch/powerpc/sysdev/i8259.c
index 7e67890b8fc..573a73bd954 100644
--- a/arch/powerpc/sysdev/i8259.c
+++ b/arch/powerpc/sysdev/i8259.c
@@ -263,8 +263,7 @@ void i8259_init(struct device_node *node, unsigned long intack_addr)
 	raw_spin_unlock_irqrestore(&i8259_lock, flags);
 
 	/* create a legacy host */
-	i8259_host = irq_alloc_host(node, IRQ_DOMAIN_MAP_LEGACY,
-				    0, &i8259_host_ops, 0);
+	i8259_host = irq_domain_add_legacy(node, &i8259_host_ops, NULL);
 	if (i8259_host == NULL) {
 		printk(KERN_ERR "i8259: failed to allocate irq host !\n");
 		return;
diff --git a/arch/powerpc/sysdev/ipic.c b/arch/powerpc/sysdev/ipic.c
index 9abed376054..0eaaa01c11b 100644
--- a/arch/powerpc/sysdev/ipic.c
+++ b/arch/powerpc/sysdev/ipic.c
@@ -728,9 +728,8 @@ struct ipic * __init ipic_init(struct device_node *node, unsigned int flags)
 	if (ipic == NULL)
 		return NULL;
 
-	ipic->irqhost = irq_alloc_host(node, IRQ_DOMAIN_MAP_LINEAR,
-				       NR_IPIC_INTS,
-				       &ipic_host_ops, 0);
+	ipic->irqhost = irq_domain_add_linear(node, NR_IPIC_INTS,
+					      &ipic_host_ops, ipic);
 	if (ipic->irqhost == NULL) {
 		kfree(ipic);
 		return NULL;
@@ -738,8 +737,6 @@ struct ipic * __init ipic_init(struct device_node *node, unsigned int flags)
 
 	ipic->regs = ioremap(res.start, resource_size(&res));
 
-	ipic->irqhost->host_data = ipic;
-
 	/* init hw */
 	ipic_write(ipic->regs, IPIC_SICNR, 0x0);
 
diff --git a/arch/powerpc/sysdev/mpc8xx_pic.c b/arch/powerpc/sysdev/mpc8xx_pic.c
index 978dfc4c312..d5f5416be31 100644
--- a/arch/powerpc/sysdev/mpc8xx_pic.c
+++ b/arch/powerpc/sysdev/mpc8xx_pic.c
@@ -171,8 +171,7 @@ int mpc8xx_pic_init(void)
 		goto out;
 	}
 
-	mpc8xx_pic_host = irq_alloc_host(np, IRQ_DOMAIN_MAP_LINEAR,
-					 64, &mpc8xx_pic_host_ops, 64);
+	mpc8xx_pic_host = irq_domain_add_linear(np, 64, &mpc8xx_pic_host_ops, NULL);
 	if (mpc8xx_pic_host == NULL) {
 		printk(KERN_ERR "MPC8xx PIC: failed to allocate irq host!\n");
 		ret = -ENOMEM;
diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index c844d343bf3..c83a512fa17 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -1345,10 +1345,9 @@ struct mpic * __init mpic_alloc(struct device_node *node,
 	mpic->isu_shift = 1 + __ilog2(mpic->isu_size - 1);
 	mpic->isu_mask = (1 << mpic->isu_shift) - 1;
 
-	mpic->irqhost = irq_alloc_host(mpic->node, IRQ_DOMAIN_MAP_LINEAR,
+	mpic->irqhost = irq_domain_add_linear(mpic->node,
 				       isu_size ? isu_size : mpic->num_sources,
-				       &mpic_host_ops,
-				       flags & MPIC_LARGE_VECTORS ? 2048 : 256);
+				       &mpic_host_ops, mpic);
 
 	/*
 	 * FIXME: The code leaks the MPIC object and mappings here; this
@@ -1357,8 +1356,6 @@ struct mpic * __init mpic_alloc(struct device_node *node,
 	if (mpic->irqhost == NULL)
 		return NULL;
 
-	mpic->irqhost->host_data = mpic;
-
 	/* Display version */
 	switch (greg_feature & MPIC_GREG_FEATURE_VERSION_MASK) {
 	case 1:
diff --git a/arch/powerpc/sysdev/mv64x60_pic.c b/arch/powerpc/sysdev/mv64x60_pic.c
index 45124a1959d..8848e99a83f 100644
--- a/arch/powerpc/sysdev/mv64x60_pic.c
+++ b/arch/powerpc/sysdev/mv64x60_pic.c
@@ -250,9 +250,8 @@ void __init mv64x60_init_irq(void)
 	paddr = of_translate_address(np, reg);
 	mv64x60_irq_reg_base = ioremap(paddr, reg[1]);
 
-	mv64x60_irq_host = irq_alloc_host(np, IRQ_DOMAIN_MAP_LINEAR,
-					  MV64x60_NUM_IRQS,
-					  &mv64x60_host_ops, MV64x60_NUM_IRQS);
+	mv64x60_irq_host = irq_domain_add_linear(np, MV64x60_NUM_IRQS,
+					  &mv64x60_host_ops, NULL);
 
 	spin_lock_irqsave(&mv64x60_lock, flags);
 	out_le32(mv64x60_gpp_reg_base + MV64x60_GPP_INTR_MASK,
diff --git a/arch/powerpc/sysdev/qe_lib/qe_ic.c b/arch/powerpc/sysdev/qe_lib/qe_ic.c
index 78e90192c34..e9b3d5cc65d 100644
--- a/arch/powerpc/sysdev/qe_lib/qe_ic.c
+++ b/arch/powerpc/sysdev/qe_lib/qe_ic.c
@@ -339,8 +339,8 @@ void __init qe_ic_init(struct device_node *node, unsigned int flags,
 	if (qe_ic == NULL)
 		return;
 
-	qe_ic->irqhost = irq_alloc_host(node, IRQ_DOMAIN_MAP_LINEAR,
-					NR_QE_IC_INTS, &qe_ic_host_ops, 0);
+	qe_ic->irqhost = irq_domain_add_linear(node, NR_QE_IC_INTS,
+					       &qe_ic_host_ops, qe_ic);
 	if (qe_ic->irqhost == NULL) {
 		kfree(qe_ic);
 		return;
@@ -348,7 +348,6 @@ void __init qe_ic_init(struct device_node *node, unsigned int flags,
 
 	qe_ic->regs = ioremap(res.start, resource_size(&res));
 
-	qe_ic->irqhost->host_data = qe_ic;
 	qe_ic->hc_irq = qe_ic_irq_chip;
 
 	qe_ic->virq_high = irq_of_parse_and_map(node, 0);
diff --git a/arch/powerpc/sysdev/tsi108_pci.c b/arch/powerpc/sysdev/tsi108_pci.c
index f3757236e66..1be26f4b9c9 100644
--- a/arch/powerpc/sysdev/tsi108_pci.c
+++ b/arch/powerpc/sysdev/tsi108_pci.c
@@ -419,8 +419,7 @@ void __init tsi108_pci_int_init(struct device_node *node)
 {
 	DBG("Tsi108_pci_int_init: initializing PCI interrupts\n");
 
-	pci_irq_host = irq_alloc_host(node, IRQ_DOMAIN_MAP_LEGACY,
-				      0, &pci_irq_domain_ops, 0);
+	pci_irq_host = irq_domain_add_legacy(node, &pci_irq_domain_ops, NULL);
 	if (pci_irq_host == NULL) {
 		printk(KERN_ERR "pci_irq_host: failed to allocate irq domain!\n");
 		return;
diff --git a/arch/powerpc/sysdev/uic.c b/arch/powerpc/sysdev/uic.c
index 7eea3a64bdf..84e59c97391 100644
--- a/arch/powerpc/sysdev/uic.c
+++ b/arch/powerpc/sysdev/uic.c
@@ -270,13 +270,11 @@ static struct uic * __init uic_init_one(struct device_node *node)
 	}
 	uic->dcrbase = *dcrreg;
 
-	uic->irqhost = irq_alloc_host(node, IRQ_DOMAIN_MAP_LINEAR,
-				      NR_UIC_INTS, &uic_host_ops, -1);
+	uic->irqhost = irq_domain_add_linear(node, NR_UIC_INTS, &uic_host_ops,
+					     uic);
 	if (! uic->irqhost)
 		return NULL; /* FIXME: panic? */
 
-	uic->irqhost->host_data = uic;
-
 	/* Start with all interrupts disabled, level and non-critical */
 	mtdcr(uic->dcrbase + UIC_ER, 0);
 	mtdcr(uic->dcrbase + UIC_CR, 0);
diff --git a/arch/powerpc/sysdev/xics/xics-common.c b/arch/powerpc/sysdev/xics/xics-common.c
index fb2e303d25f..ea5e204e345 100644
--- a/arch/powerpc/sysdev/xics/xics-common.c
+++ b/arch/powerpc/sysdev/xics/xics-common.c
@@ -374,8 +374,7 @@ static struct irq_domain_ops xics_host_ops = {
 
 static void __init xics_init_host(void)
 {
-	xics_host = irq_alloc_host(NULL, IRQ_DOMAIN_MAP_TREE, 0, &xics_host_ops,
-				   XICS_IRQ_SPURIOUS);
+	xics_host = irq_domain_add_tree(NULL, &xics_host_ops, NULL);
 	BUG_ON(xics_host == NULL);
 	irq_set_default_host(xics_host);
 }
diff --git a/arch/powerpc/sysdev/xilinx_intc.c b/arch/powerpc/sysdev/xilinx_intc.c
index 92e7d4db9fd..8d73c3c0bee 100644
--- a/arch/powerpc/sysdev/xilinx_intc.c
+++ b/arch/powerpc/sysdev/xilinx_intc.c
@@ -201,11 +201,10 @@ xilinx_intc_init(struct device_node *np)
 	out_be32(regs + XINTC_MER, 0x3UL); /* Turn on the Master Enable. */
 
 	/* Allocate and initialize an irq_domain structure. */
-	irq = irq_alloc_host(np, IRQ_DOMAIN_MAP_LINEAR, XILINX_INTC_MAXIRQS,
-			     &xilinx_intc_ops, -1);
+	irq = irq_domain_add_linear(np, XILINX_INTC_MAXIRQS, &xilinx_intc_ops,
+				    regs);
 	if (!irq)
 		panic(__FILE__ ": Cannot allocate IRQ host\n");
-	irq->host_data = regs;
 
 	return irq;
 }
diff --git a/drivers/gpio/gpio-mpc8xxx.c b/drivers/gpio/gpio-mpc8xxx.c
index 9efd59732ee..149d9876fca 100644
--- a/drivers/gpio/gpio-mpc8xxx.c
+++ b/drivers/gpio/gpio-mpc8xxx.c
@@ -364,9 +364,8 @@ static void __init mpc8xxx_add_controller(struct device_node *np)
 	if (hwirq == NO_IRQ)
 		goto skip_irq;
 
-	mpc8xxx_gc->irq =
-		irq_alloc_host(np, IRQ_DOMAIN_MAP_LINEAR, MPC8XXX_GPIO_PINS,
-			       &mpc8xxx_gpio_irq_ops, MPC8XXX_GPIO_PINS);
+	mpc8xxx_gc->irq = irq_domain_add_linear(np, MPC8XXX_GPIO_PINS,
+					&mpc8xxx_gpio_irq_ops, mpc8xxx_gc);
 	if (!mpc8xxx_gc->irq)
 		goto skip_irq;
 
@@ -374,8 +373,6 @@ static void __init mpc8xxx_add_controller(struct device_node *np)
 	if (id)
 		mpc8xxx_gc->of_dev_id_data = id->data;
 
-	mpc8xxx_gc->irq->host_data = mpc8xxx_gc;
-
 	/* ack and mask all irqs */
 	out_be32(mm_gc->regs + GPIO_IER, 0xffffffff);
 	out_be32(mm_gc->regs + GPIO_IMR, 0);
diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index 18f4ab002d2..f95553fa687 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -95,10 +95,6 @@ struct irq_domain {
 
 	/* type of reverse mapping_technique */
 	unsigned int revmap_type;
-#define IRQ_DOMAIN_MAP_LEGACY 0 /* legacy 8259, gets irqs 1..15 */
-#define IRQ_DOMAIN_MAP_NOMAP 1 /* no fast reverse mapping */
-#define IRQ_DOMAIN_MAP_LINEAR 2 /* linear map of interrupts */
-#define IRQ_DOMAIN_MAP_TREE 3 /* radix tree */
 	union {
 		struct {
 			unsigned int size;
@@ -120,11 +116,21 @@ struct irq_domain {
 
 #ifdef CONFIG_IRQ_DOMAIN
 #ifdef CONFIG_PPC
-extern struct irq_domain *irq_alloc_host(struct device_node *of_node,
-				       unsigned int revmap_type,
-				       unsigned int revmap_arg,
-				       struct irq_domain_ops *ops,
-				       irq_hw_number_t inval_irq);
+struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
+					 struct irq_domain_ops *ops,
+					 void *host_data);
+struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
+					 unsigned int size,
+					 struct irq_domain_ops *ops,
+					 void *host_data);
+struct irq_domain *irq_domain_add_nomap(struct device_node *of_node,
+					 struct irq_domain_ops *ops,
+					 void *host_data);
+struct irq_domain *irq_domain_add_tree(struct device_node *of_node,
+					 struct irq_domain_ops *ops,
+					 void *host_data);
+
+
 extern struct irq_domain *irq_find_host(struct device_node *node);
 extern void irq_set_default_host(struct irq_domain *host);
 extern void irq_set_virq_count(unsigned int count);
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 432d292b33f..acedba1a265 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -13,6 +13,11 @@
 #include <linux/smp.h>
 #include <linux/fs.h>
 
+#define IRQ_DOMAIN_MAP_LEGACY 0 /* legacy 8259, gets irqs 1..15 */
+#define IRQ_DOMAIN_MAP_NOMAP 1 /* no fast reverse mapping */
+#define IRQ_DOMAIN_MAP_LINEAR 2 /* linear map of interrupts */
+#define IRQ_DOMAIN_MAP_TREE 3 /* radix tree */
+
 static LIST_HEAD(irq_domain_list);
 static DEFINE_MUTEX(irq_domain_mutex);
 
@@ -27,100 +32,158 @@ static int default_irq_domain_match(struct irq_domain *d, struct device_node *np
 }
 
 /**
- * irq_alloc_host() - Allocate a new irq_domain data structure
+ * irq_domain_alloc() - Allocate a new irq_domain data structure
  * @of_node: optional device-tree node of the interrupt controller
  * @revmap_type: type of reverse mapping to use
- * @revmap_arg: for IRQ_DOMAIN_MAP_LINEAR linear only: size of the map
  * @ops: map/unmap domain callbacks
- * @inval_irq: provide a hw number in that domain space that is always invalid
+ * @host_data: Controller private data pointer
  *
- * Allocates and initialize and irq_domain structure. Note that in the case of
- * IRQ_DOMAIN_MAP_LEGACY, the map() callback will be called before this returns
- * for all legacy interrupts except 0 (which is always the invalid irq for
- * a legacy controller). For a IRQ_DOMAIN_MAP_LINEAR, the map is allocated by
- * this call as well. For a IRQ_DOMAIN_MAP_TREE, the radix tree will be
- * allocated later during boot automatically (the reverse mapping will use the
- * slow path until that happens).
+ * Allocates and initialize and irq_domain structure.  Caller is expected to
+ * register allocated irq_domain with irq_domain_register().  Returns pointer
+ * to IRQ domain, or NULL on failure.
  */
-struct irq_domain *irq_alloc_host(struct device_node *of_node,
-				unsigned int revmap_type,
-				unsigned int revmap_arg,
-				struct irq_domain_ops *ops,
-				irq_hw_number_t inval_irq)
+static struct irq_domain *irq_domain_alloc(struct device_node *of_node,
+					   unsigned int revmap_type,
+					   struct irq_domain_ops *ops,
+					   void *host_data)
 {
-	struct irq_domain *domain, *h;
-	unsigned int size = sizeof(struct irq_domain);
-	unsigned int i;
-	unsigned int *rmap;
+	struct irq_domain *domain;
 
-	/* Allocate structure and revmap table if using linear mapping */
-	if (revmap_type == IRQ_DOMAIN_MAP_LINEAR)
-		size += revmap_arg * sizeof(unsigned int);
-	domain = kzalloc(size, GFP_KERNEL);
-	if (domain == NULL)
+	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+	if (WARN_ON(!domain))
 		return NULL;
 
 	/* Fill structure */
 	domain->revmap_type = revmap_type;
-	domain->inval_irq = inval_irq;
 	domain->ops = ops;
+	domain->host_data = host_data;
 	domain->of_node = of_node_get(of_node);
 
 	if (domain->ops->match == NULL)
 		domain->ops->match = default_irq_domain_match;
 
+	return domain;
+}
+
+static void irq_domain_add(struct irq_domain *domain)
+{
+	mutex_lock(&irq_domain_mutex);
+	list_add(&domain->link, &irq_domain_list);
+	mutex_unlock(&irq_domain_mutex);
+	pr_debug("irq: Allocated domain of type %d @0x%p\n",
+		 domain->revmap_type, domain);
+}
+
+/**
+ * irq_domain_add_legacy() - Allocate and register a legacy revmap irq_domain.
+ * @of_node: pointer to interrupt controller's device tree node.
+ * @ops: map/unmap domain callbacks
+ * @host_data: Controller private data pointer
+ *
+ * Note: the map() callback will be called before this function returns
+ * for all legacy interrupts except 0 (which is always the invalid irq for
+ * a legacy controller).
+ */
+struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
+					 struct irq_domain_ops *ops,
+					 void *host_data)
+{
+	struct irq_domain *domain, *h;
+	unsigned int i;
+
+	domain = irq_domain_alloc(of_node, IRQ_DOMAIN_MAP_LEGACY, ops, host_data);
+	if (!domain)
+		return NULL;
+
 	mutex_lock(&irq_domain_mutex);
 	/* Make sure only one legacy controller can be created */
-	if (revmap_type == IRQ_DOMAIN_MAP_LEGACY) {
-		list_for_each_entry(h, &irq_domain_list, link) {
-			if (WARN_ON(h->revmap_type == IRQ_DOMAIN_MAP_LEGACY)) {
-				mutex_unlock(&irq_domain_mutex);
-				of_node_put(domain->of_node);
-				kfree(domain);
-				return NULL;
-			}
+	list_for_each_entry(h, &irq_domain_list, link) {
+		if (WARN_ON(h->revmap_type == IRQ_DOMAIN_MAP_LEGACY)) {
+			mutex_unlock(&irq_domain_mutex);
+			of_node_put(domain->of_node);
+			kfree(domain);
+			return NULL;
 		}
 	}
 	list_add(&domain->link, &irq_domain_list);
 	mutex_unlock(&irq_domain_mutex);
 
-	/* Additional setups per revmap type */
-	switch(revmap_type) {
-	case IRQ_DOMAIN_MAP_LEGACY:
-		/* 0 is always the invalid number for legacy */
-		domain->inval_irq = 0;
-		/* setup us as the domain for all legacy interrupts */
-		for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
-			struct irq_data *irq_data = irq_get_irq_data(i);
-			irq_data->hwirq = i;
-			irq_data->domain = domain;
-
-			/* Legacy flags are left to default at this point,
-			 * one can then use irq_create_mapping() to
-			 * explicitly change them
-			 */
-			ops->map(domain, i, i);
-
-			/* Clear norequest flags */
-			irq_clear_status_flags(i, IRQ_NOREQUEST);
-		}
-		break;
-	case IRQ_DOMAIN_MAP_LINEAR:
-		rmap = (unsigned int *)(domain + 1);
-		for (i = 0; i < revmap_arg; i++)
-			rmap[i] = 0;
-		domain->revmap_data.linear.size = revmap_arg;
-		domain->revmap_data.linear.revmap = rmap;
-		break;
-	case IRQ_DOMAIN_MAP_TREE:
-		INIT_RADIX_TREE(&domain->revmap_data.tree, GFP_KERNEL);
-		break;
-	default:
-		break;
+	/* setup us as the domain for all legacy interrupts */
+	for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
+		struct irq_data *irq_data = irq_get_irq_data(i);
+		irq_data->hwirq = i;
+		irq_data->domain = domain;
+
+		/* Legacy flags are left to default at this point,
+		 * one can then use irq_create_mapping() to
+		 * explicitly change them
+		 */
+		ops->map(domain, i, i);
+
+		/* Clear norequest flags */
+		irq_clear_status_flags(i, IRQ_NOREQUEST);
 	}
+	return domain;
+}
 
-	pr_debug("irq: Allocated domain of type %d @0x%p\n", revmap_type, domain);
+/**
+ * irq_domain_add_linear() - Allocate and register a legacy revmap irq_domain.
+ * @of_node: pointer to interrupt controller's device tree node.
+ * @ops: map/unmap domain callbacks
+ * @host_data: Controller private data pointer
+ */
+struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
+					 unsigned int size,
+					 struct irq_domain_ops *ops,
+					 void *host_data)
+{
+	struct irq_domain *domain;
+	unsigned int *revmap;
+
+	revmap = kzalloc(sizeof(*revmap) * size, GFP_KERNEL);
+	if (WARN_ON(!revmap))
+		return NULL;
 
+	domain = irq_domain_alloc(of_node, IRQ_DOMAIN_MAP_LINEAR, ops, host_data);
+	if (!domain) {
+		kfree(revmap);
+		return NULL;
+	}
+	domain->revmap_data.linear.size = size;
+	domain->revmap_data.linear.revmap = revmap;
+	irq_domain_add(domain);
+	return domain;
+}
+
+struct irq_domain *irq_domain_add_nomap(struct device_node *of_node,
+					 struct irq_domain_ops *ops,
+					 void *host_data)
+{
+	struct irq_domain *domain = irq_domain_alloc(of_node,
+					IRQ_DOMAIN_MAP_NOMAP, ops, host_data);
+	if (domain)
+		irq_domain_add(domain);
+	return domain;
+}
+
+/**
+ * irq_domain_add_tree()
+ * @of_node: pointer to interrupt controller's device tree node.
+ * @ops: map/unmap domain callbacks
+ *
+ * Note: The radix tree will be allocated later during boot automatically
+ * (the reverse mapping will use the slow path until that happens).
+ */
+struct irq_domain *irq_domain_add_tree(struct device_node *of_node,
+					 struct irq_domain_ops *ops,
+					 void *host_data)
+{
+	struct irq_domain *domain = irq_domain_alloc(of_node,
+					IRQ_DOMAIN_MAP_TREE, ops, host_data);
+	if (domain) {
+		INIT_RADIX_TREE(&domain->revmap_data.tree, GFP_KERNEL);
+		irq_domain_add(domain);
+	}
 	return domain;
 }
 
@@ -393,9 +456,6 @@ void irq_dispose_mapping(unsigned int virq)
 		break;
 	}
 
-	/* Destroy map */
-	irq_data->hwirq = domain->inval_irq;
-
 	irq_free_desc(virq);
 }
 EXPORT_SYMBOL_GPL(irq_dispose_mapping);