powerpc/4xx: Adding PCIe MSI support

This patch adds MSI support for 440SPe, 460Ex, 460Sx and 405Ex.

Signed-off-by: Rupjyoti Sarmah <rsarmah@apm.com>
Signed-off-by: Tirumala R Marri <tmarri@apm.com>
Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

3 files changed, 284 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/Kconfig b/arch/powerpc/sysdev/Kconfig
index d775fd148d13..7b4df37ac381 100644
--- a/arch/powerpc/sysdev/Kconfig
+++ b/arch/powerpc/sysdev/Kconfig
@@ -7,11 +7,18 @@ config PPC4xx_PCI_EXPRESS
 	depends on PCI && 4xx
 	default n
 
+config PPC4xx_MSI
+	bool
+	depends on PCI_MSI
+	depends on PCI && 4xx
+	default n
+
 config PPC_MSI_BITMAP
 	bool
 	depends on PCI_MSI
 	default y if MPIC
 	default y if FSL_PCI
+	default y if PPC4xx_MSI
 
 source "arch/powerpc/sysdev/xics/Kconfig"
 
diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile
index 6076e0074a87..0efa990e3344 100644
--- a/arch/powerpc/sysdev/Makefile
+++ b/arch/powerpc/sysdev/Makefile
@@ -41,6 +41,7 @@ obj-$(CONFIG_OF_RTC)		+= of_rtc.o
 ifeq ($(CONFIG_PCI),y)
 obj-$(CONFIG_4xx)		+= ppc4xx_pci.o
 endif
+obj-$(CONFIG_PPC4xx_MSI)	+= ppc4xx_msi.o
 obj-$(CONFIG_PPC4xx_CPM)	+= ppc4xx_cpm.o
 obj-$(CONFIG_PPC4xx_GPIO)	+= ppc4xx_gpio.o
 
diff --git a/arch/powerpc/sysdev/ppc4xx_msi.c b/arch/powerpc/sysdev/ppc4xx_msi.c
new file mode 100644
index 000000000000..367af0241851
--- /dev/null
+++ b/arch/powerpc/sysdev/ppc4xx_msi.c
@@ -0,0 +1,276 @@
+/*
+ * Adding PCI-E MSI support for PPC4XX SoCs.
+ *
+ * Copyright (c) 2010, Applied Micro Circuits Corporation
+ * Authors:	Tirumala R Marri <tmarri@apm.com>
+ *		Feng Kan <fkan@apm.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <linux/irq.h>
+#include <linux/bootmem.h>
+#include <linux/pci.h>
+#include <linux/msi.h>
+#include <linux/of_platform.h>
+#include <linux/interrupt.h>
+#include <asm/prom.h>
+#include <asm/hw_irq.h>
+#include <asm/ppc-pci.h>
+#include <boot/dcr.h>
+#include <asm/dcr-regs.h>
+#include <asm/msi_bitmap.h>
+
+#define PEIH_TERMADH	0x00
+#define PEIH_TERMADL	0x08
+#define PEIH_MSIED	0x10
+#define PEIH_MSIMK	0x18
+#define PEIH_MSIASS	0x20
+#define PEIH_FLUSH0	0x30
+#define PEIH_FLUSH1	0x38
+#define PEIH_CNTRST	0x48
+#define NR_MSI_IRQS	4
+
+struct ppc4xx_msi {
+	u32 msi_addr_lo;
+	u32 msi_addr_hi;
+	void __iomem *msi_regs;
+	int msi_virqs[NR_MSI_IRQS];
+	struct msi_bitmap bitmap;
+	struct device_node *msi_dev;
+};
+
+static struct ppc4xx_msi ppc4xx_msi;
+
+static int ppc4xx_msi_init_allocator(struct platform_device *dev,
+		struct ppc4xx_msi *msi_data)
+{
+	int err;
+
+	err = msi_bitmap_alloc(&msi_data->bitmap, NR_MSI_IRQS,
+			      dev->dev.of_node);
+	if (err)
+		return err;
+
+	err = msi_bitmap_reserve_dt_hwirqs(&msi_data->bitmap);
+	if (err < 0) {
+		msi_bitmap_free(&msi_data->bitmap);
+		return err;
+	}
+
+	return 0;
+}
+
+static int ppc4xx_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+{
+	int int_no = -ENOMEM;
+	unsigned int virq;
+	struct msi_msg msg;
+	struct msi_desc *entry;
+	struct ppc4xx_msi *msi_data = &ppc4xx_msi;
+
+	list_for_each_entry(entry, &dev->msi_list, list) {
+		int_no = msi_bitmap_alloc_hwirqs(&msi_data->bitmap, 1);
+		if (int_no >= 0)
+			break;
+		if (int_no < 0) {
+			pr_debug("%s: fail allocating msi interrupt\n",
+					__func__);
+		}
+		virq = irq_of_parse_and_map(msi_data->msi_dev, int_no);
+		if (virq == NO_IRQ) {
+			dev_err(&dev->dev, "%s: fail mapping irq\n", __func__);
+			msi_bitmap_free_hwirqs(&msi_data->bitmap, int_no, 1);
+			return -ENOSPC;
+		}
+		dev_dbg(&dev->dev, "%s: virq = %d\n", __func__, virq);
+
+		/* Setup msi address space */
+		msg.address_hi = msi_data->msi_addr_hi;
+		msg.address_lo = msi_data->msi_addr_lo;
+
+		irq_set_msi_desc(virq, entry);
+		msg.data = int_no;
+		write_msi_msg(virq, &msg);
+	}
+	return 0;
+}
+
+void ppc4xx_teardown_msi_irqs(struct pci_dev *dev)
+{
+	struct msi_desc *entry;
+	struct ppc4xx_msi *msi_data = &ppc4xx_msi;
+
+	dev_dbg(&dev->dev, "PCIE-MSI: tearing down msi irqs\n");
+
+	list_for_each_entry(entry, &dev->msi_list, list) {
+		if (entry->irq == NO_IRQ)
+			continue;
+		irq_set_msi_desc(entry->irq, NULL);
+		msi_bitmap_free_hwirqs(&msi_data->bitmap,
+				virq_to_hw(entry->irq), 1);
+		irq_dispose_mapping(entry->irq);
+	}
+}
+
+static int ppc4xx_msi_check_device(struct pci_dev *pdev, int nvec, int type)
+{
+	dev_dbg(&pdev->dev, "PCIE-MSI:%s called. vec %x type %d\n",
+		__func__, nvec, type);
+	if (type == PCI_CAP_ID_MSIX)
+		pr_debug("ppc4xx msi: MSI-X untested, trying anyway.\n");
+
+	return 0;
+}
+
+static int ppc4xx_setup_pcieh_hw(struct platform_device *dev,
+				 struct resource res, struct ppc4xx_msi *msi)
+{
+	const u32 *msi_data;
+	const u32 *msi_mask;
+	const u32 *sdr_addr;
+	dma_addr_t msi_phys;
+	void *msi_virt;
+
+	sdr_addr = of_get_property(dev->dev.of_node, "sdr-base", NULL);
+	if (!sdr_addr)
+		return -1;
+
+	SDR0_WRITE(sdr_addr, (u64)res.start >> 32);	 /*HIGH addr */
+	SDR0_WRITE(sdr_addr + 1, res.start & 0xFFFFFFFF); /* Low addr */
+
+
+	msi->msi_dev = of_find_node_by_name(NULL, "ppc4xx-msi");
+	if (msi->msi_dev)
+		return -ENODEV;
+
+	msi->msi_regs = of_iomap(msi->msi_dev, 0);
+	if (!msi->msi_regs) {
+		dev_err(&dev->dev, "of_iomap problem failed\n");
+		return -ENOMEM;
+	}
+	dev_dbg(&dev->dev, "PCIE-MSI: msi register mapped 0x%x 0x%x\n",
+		(u32) (msi->msi_regs + PEIH_TERMADH), (u32) (msi->msi_regs));
+
+	msi_virt = dma_alloc_coherent(&dev->dev, 64, &msi_phys, GFP_KERNEL);
+	msi->msi_addr_hi = 0x0;
+	msi->msi_addr_lo = (u32) msi_phys;
+	dev_dbg(&dev->dev, "PCIE-MSI: msi address 0x%x\n", msi->msi_addr_lo);
+
+	/* Progam the Interrupt handler Termination addr registers */
+	out_be32(msi->msi_regs + PEIH_TERMADH, msi->msi_addr_hi);
+	out_be32(msi->msi_regs + PEIH_TERMADL, msi->msi_addr_lo);
+
+	msi_data = of_get_property(dev->dev.of_node, "msi-data", NULL);
+	if (!msi_data)
+		return -1;
+	msi_mask = of_get_property(dev->dev.of_node, "msi-mask", NULL);
+	if (!msi_mask)
+		return -1;
+	/* Program MSI Expected data and Mask bits */
+	out_be32(msi->msi_regs + PEIH_MSIED, *msi_data);
+	out_be32(msi->msi_regs + PEIH_MSIMK, *msi_mask);
+
+	return 0;
+}
+
+static int ppc4xx_of_msi_remove(struct platform_device *dev)
+{
+	struct ppc4xx_msi *msi = dev->dev.platform_data;
+	int i;
+	int virq;
+
+	for (i = 0; i < NR_MSI_IRQS; i++) {
+		virq = msi->msi_virqs[i];
+		if (virq != NO_IRQ)
+			irq_dispose_mapping(virq);
+	}
+
+	if (msi->bitmap.bitmap)
+		msi_bitmap_free(&msi->bitmap);
+	iounmap(msi->msi_regs);
+	of_node_put(msi->msi_dev);
+	kfree(msi);
+
+	return 0;
+}
+
+static int __devinit ppc4xx_msi_probe(struct platform_device *dev)
+{
+	struct ppc4xx_msi *msi;
+	struct resource res;
+	int err = 0;
+
+	msi = &ppc4xx_msi;/*keep the msi data for further use*/
+
+	dev_dbg(&dev->dev, "PCIE-MSI: Setting up MSI support...\n");
+
+	msi = kzalloc(sizeof(struct ppc4xx_msi), GFP_KERNEL);
+	if (!msi) {
+		dev_err(&dev->dev, "No memory for MSI structure\n");
+		return -ENOMEM;
+	}
+	dev->dev.platform_data = msi;
+
+	/* Get MSI ranges */
+	err = of_address_to_resource(dev->dev.of_node, 0, &res);
+	if (err) {
+		dev_err(&dev->dev, "%s resource error!\n",
+			dev->dev.of_node->full_name);
+		goto error_out;
+	}
+
+	if (ppc4xx_setup_pcieh_hw(dev, res, msi))
+		goto error_out;
+
+	err = ppc4xx_msi_init_allocator(dev, msi);
+	if (err) {
+		dev_err(&dev->dev, "Error allocating MSI bitmap\n");
+		goto error_out;
+	}
+
+	ppc_md.setup_msi_irqs = ppc4xx_setup_msi_irqs;
+	ppc_md.teardown_msi_irqs = ppc4xx_teardown_msi_irqs;
+	ppc_md.msi_check_device = ppc4xx_msi_check_device;
+	return err;
+
+error_out:
+	ppc4xx_of_msi_remove(dev);
+	return err;
+}
+static const struct of_device_id ppc4xx_msi_ids[] = {
+	{
+		.compatible = "amcc,ppc4xx-msi",
+	},
+	{}
+};
+static struct platform_driver ppc4xx_msi_driver = {
+	.probe = ppc4xx_msi_probe,
+	.remove = ppc4xx_of_msi_remove,
+	.driver = {
+		   .name = "ppc4xx-msi",
+		   .owner = THIS_MODULE,
+		   .of_match_table = ppc4xx_msi_ids,
+		   },
+
+};
+
+static __init int ppc4xx_msi_init(void)
+{
+	return platform_driver_register(&ppc4xx_msi_driver);
+}
+
+subsys_initcall(ppc4xx_msi_init);