[PATCH 8/8] powerpc: Added PCI MSI support using the HSTA module
Alistair Popple
alistair at popple.id.au
Fri Nov 22 13:08:36 EST 2013
The PPC476GTR SoC supports message signalled interrupts (MSI) by writing
to special addresses within the High Speed Transfer Assist (HSTA) module.
This patch adds support for PCI MSI with a new system device. The DMA
window is also updated to allow access to the entire 42-bit address range
to allow PCI devices write access to the HSTA module.
Signed-off-by: Alistair Popple <alistair at popple.id.au>
---
arch/powerpc/boot/dts/akebono.dts | 46 +++++-
arch/powerpc/platforms/44x/Kconfig | 2 +
arch/powerpc/sysdev/Kconfig | 6 +
arch/powerpc/sysdev/Makefile | 1 +
arch/powerpc/sysdev/ppc4xx_hsta_msi.c | 266 +++++++++++++++++++++++++++++++++
arch/powerpc/sysdev/ppc4xx_pci.c | 8 +-
6 files changed, 319 insertions(+), 10 deletions(-)
create mode 100644 arch/powerpc/sysdev/ppc4xx_hsta_msi.c
diff --git a/arch/powerpc/boot/dts/akebono.dts b/arch/powerpc/boot/dts/akebono.dts
index 6dd47e9..4cb917f 100644
--- a/arch/powerpc/boot/dts/akebono.dts
+++ b/arch/powerpc/boot/dts/akebono.dts
@@ -82,6 +82,28 @@
ranges;
clock-frequency = <200000000>; // 200Mhz
+ HSTA0: hsta at 310000e0000 {
+ compatible = "ibm,476gtr-hsta-msi", "ibm,hsta-msi";
+ reg = <0x310 0x000e0000 0x0 0xf0>;
+ interrupt-parent = <&MPIC>;
+ interrupts = <108 0
+ 109 0
+ 110 0
+ 111 0
+ 112 0
+ 113 0
+ 114 0
+ 115 0
+ 116 0
+ 117 0
+ 118 0
+ 119 0
+ 120 0
+ 121 0
+ 122 0
+ 123 0>;
+ };
+
MAL0: mcmal {
compatible = "ibm,mcmal-476gtr", "ibm,mcmal2";
dcr-reg = <0xc0000000 0x062>;
@@ -242,8 +264,10 @@
ranges = <0x02000000 0x00000000 0x80000000 0x00000110 0x80000000 0x0 0x80000000
0x01000000 0x0 0x0 0x00000140 0x0 0x0 0x00010000>;
- /* Inbound starting at 0 to memsize filled in by zImage */
- dma-ranges = <0x42000000 0x0 0x0 0x0 0x0 0x0 0x0>;
+ /* Inbound starting at 0x0 to 0x40000000000. In order to use MSI
+ * PCI devices must be able to write to the HSTA module.
+ */
+ dma-ranges = <0x42000000 0x0 0x0 0x0 0x0 0x400 0x0>;
/* This drives busses 0 to 0xf */
bus-range = <0x0 0xf>;
@@ -280,8 +304,10 @@
ranges = <0x02000000 0x00000000 0x80000000 0x00000210 0x80000000 0x0 0x80000000
0x01000000 0x0 0x0 0x00000240 0x0 0x0 0x00010000>;
- /* Inbound starting at 0 to memsize filled in by zImage */
- dma-ranges = <0x42000000 0x0 0x0 0x0 0x0 0x0 0x0>;
+ /* Inbound starting at 0x0 to 0x40000000000. In order to use MSI
+ * PCI devices must be able to write to the HSTA module.
+ */
+ dma-ranges = <0x42000000 0x0 0x0 0x0 0x0 0x400 0x0>;
/* This drives busses 0 to 0xf */
bus-range = <0x0 0xf>;
@@ -318,8 +344,10 @@
ranges = <0x02000000 0x00000000 0x80000000 0x00000190 0x80000000 0x0 0x80000000
0x01000000 0x0 0x0 0x000001c0 0x0 0x0 0x00010000>;
- /* Inbound starting at 0 to memsize filled in by zImage */
- dma-ranges = <0x42000000 0x0 0x0 0x0 0x0 0x0 0x0>;
+ /* Inbound starting at 0x0 to 0x40000000000. In order to use MSI
+ * PCI devices must be able to write to the HSTA module.
+ */
+ dma-ranges = <0x42000000 0x0 0x0 0x0 0x0 0x400 0x0>;
/* This drives busses 0 to 0xf */
bus-range = <0x0 0xf>;
@@ -356,8 +384,10 @@
ranges = <0x02000000 0x00000000 0x80000000 0x00000290 0x80000000 0x0 0x80000000
0x01000000 0x0 0x0 0x000002c0 0x0 0x0 0x00010000>;
- /* Inbound starting at 0 to memsize filled in by zImage */
- dma-ranges = <0x42000000 0x0 0x0 0x0 0x0 0x0 0x0>;
+ /* Inbound starting at 0x0 to 0x40000000000. In order to use MSI
+ * PCI devices must be able to write to the HSTA module.
+ */
+ dma-ranges = <0x42000000 0x0 0x0 0x0 0x0 0x400 0x0>;
/* This drives busses 0 to 0xf */
bus-range = <0x0 0xf>;
diff --git a/arch/powerpc/platforms/44x/Kconfig b/arch/powerpc/platforms/44x/Kconfig
index 9d20800..7bc993e 100644
--- a/arch/powerpc/platforms/44x/Kconfig
+++ b/arch/powerpc/platforms/44x/Kconfig
@@ -206,6 +206,8 @@ config AKEBONO
select SWIOTLB
select 476
select PPC4xx_PCI_EXPRESS
+ select PCI_MSI
+ select PPC4xx_HSTA_MSI
select I2C
select I2C_IBM_IIC
select NETDEVICES
diff --git a/arch/powerpc/sysdev/Kconfig b/arch/powerpc/sysdev/Kconfig
index ab4cb54..d3d91ca 100644
--- a/arch/powerpc/sysdev/Kconfig
+++ b/arch/powerpc/sysdev/Kconfig
@@ -7,6 +7,12 @@ config PPC4xx_PCI_EXPRESS
depends on PCI && 4xx
default n
+config PPC4xx_HSTA_MSI
+ bool
+ depends on PCI_MSI
+ depends on PCI && 4xx
+ default n
+
config PPC4xx_MSI
bool
depends on PCI_MSI
diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile
index f67ac90..7657fb7 100644
--- a/arch/powerpc/sysdev/Makefile
+++ b/arch/powerpc/sysdev/Makefile
@@ -46,6 +46,7 @@ obj-$(CONFIG_OF_RTC) += of_rtc.o
ifeq ($(CONFIG_PCI),y)
obj-$(CONFIG_4xx) += ppc4xx_pci.o
endif
+obj-$(CONFIG_PPC4xx_HSTA_MSI) += ppc4xx_hsta_msi.o
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_hsta_msi.c b/arch/powerpc/sysdev/ppc4xx_hsta_msi.c
new file mode 100644
index 0000000..dac3f3b
--- /dev/null
+++ b/arch/powerpc/sysdev/ppc4xx_hsta_msi.c
@@ -0,0 +1,266 @@
+/*
+ * MSI support for PPC4xx SoCs using High Speed Transfer Assist (HSTA) for
+ * generation of the interrupt.
+ *
+ * Copyright © 2013 Alistair Popple <alistair at popple.id.au> IBM Corporation
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/msi.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/pci.h>
+#include <linux/semaphore.h>
+#include <asm/msi_bitmap.h>
+
+/*
+ * If TEST_IRQ is defined the driver will test that all MSI interrupts
+ * can be generated by writing to the HSTA module from the CPU before
+ * allowing MSI to be used. This increases system boot time and is
+ * only needed to test correct operation of the HSTA so it isn't
+ * enabled by default.
+ */
+#undef TEST_IRQ
+
+struct ppc4xx_hsta_msi {
+ struct device *dev;
+
+ /* The ioremapped HSTA MSI IO space */
+ u32 __iomem *data;
+
+ /* Physical address of HSTA MSI IO space */
+ u64 address;
+ struct msi_bitmap bmp;
+
+ /* An array mapping offsets to hardware IRQs */
+ int *irq_map;
+
+#ifdef TEST_IRQ
+ struct semaphore sem;
+#endif
+};
+static struct ppc4xx_hsta_msi ppc4xx_hsta_msi;
+
+#ifdef TEST_IRQ
+static irqreturn_t hsta_test_msi_irq(int irq, void *data)
+{
+ pr_debug("HSTA MSI: Got test irq %d\n", irq);
+ up(&ppc4xx_hsta_msi.sem);
+ return IRQ_HANDLED;
+}
+#endif
+
+static int hsta_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+{
+ struct msi_msg msg;
+ struct msi_desc *entry;
+ int irq, hwirq;
+ u64 addr;
+
+ list_for_each_entry(entry, &dev->msi_list, list) {
+ irq = msi_bitmap_alloc_hwirqs(&ppc4xx_hsta_msi.bmp, 1);
+ if (irq < 0) {
+ pr_debug("%s: Failed to allocate msi interrupt\n",
+ __func__);
+ return irq;
+ }
+
+ hwirq = ppc4xx_hsta_msi.irq_map[irq];
+ if (hwirq == NO_IRQ) {
+ pr_err("%s: Failed mapping irq %d\n", __func__, irq);
+ return -EINVAL;
+ }
+
+ /*
+ * HSTA generates interrupts on writes to 128-bit aligned
+ * addresses.
+ */
+ addr = ppc4xx_hsta_msi.address + irq*0x10;
+ msg.address_hi = upper_32_bits(addr);
+ msg.address_lo = lower_32_bits(addr);
+
+ /* Data is not used by the HSTA. */
+ msg.data = 0;
+
+ pr_debug("%s: Setup irq %d (0x%0llx)\n", __func__, hwirq,
+ (((u64) msg.address_hi) << 32) | msg.address_lo);
+
+ if (irq_set_msi_desc(hwirq, entry)) {
+ pr_err(
+ "%s: Invalid hwirq %d specified in device tree\n",
+ __func__, hwirq);
+ msi_bitmap_free_hwirqs(&ppc4xx_hsta_msi.bmp, irq, 1);
+ return -EINVAL;
+ }
+ write_msi_msg(hwirq, &msg);
+ }
+
+ return 0;
+}
+
+static int hsta_find_hwirq_offset(int hwirq)
+{
+ int irq;
+
+ /* Find the offset given the hwirq */
+ for (irq = 0; ppc4xx_hsta_msi.irq_map[irq] != hwirq;
+ irq++)
+ ;
+
+ if (ppc4xx_hsta_msi.irq_map[irq] != hwirq)
+ irq = -EINVAL;
+
+ return irq;
+}
+
+static void hsta_teardown_msi_irqs(struct pci_dev *dev)
+{
+ struct msi_desc *entry;
+ int irq;
+
+ list_for_each_entry(entry, &dev->msi_list, list) {
+ if (entry->irq == NO_IRQ)
+ continue;
+
+ irq = hsta_find_hwirq_offset(entry->irq);
+
+ /* entry->irq should always be in irq_map */
+ BUG_ON(irq < 0);
+ irq_set_msi_desc(entry->irq, NULL);
+ msi_bitmap_free_hwirqs(&ppc4xx_hsta_msi.bmp, irq, 1);
+ pr_debug("%s: Teardown IRQ %u (index %u)\n", __func__,
+ entry->irq, irq);
+ }
+}
+
+static int hsta_msi_check_device(struct pci_dev *pdev, int nvec, int type)
+{
+ /* We don't support MSI-X */
+ if (type == PCI_CAP_ID_MSIX) {
+ pr_debug("%s: MSI-X not supported.\n", __func__);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int hsta_msi_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct resource *mem;
+ int irq, ret, irq_count;
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (IS_ERR(mem)) {
+ dev_err(dev, "Unable to get mmio space\n");
+ return -EINVAL;
+ }
+
+ irq_count = of_irq_count(dev->of_node);
+ if (!irq_count) {
+ dev_err(dev, "Unable to find IRQ range\n");
+ return -EINVAL;
+ }
+
+ ppc4xx_hsta_msi.dev = dev;
+ ppc4xx_hsta_msi.address = mem->start;
+ ppc4xx_hsta_msi.data = ioremap(mem->start, resource_size(mem));
+ if (IS_ERR(ppc4xx_hsta_msi.data)) {
+ dev_err(dev, "Unable to map memory\n");
+ return -ENOMEM;
+ }
+
+ ret = msi_bitmap_alloc(&ppc4xx_hsta_msi.bmp, irq_count, dev->of_node);
+ if (ret)
+ goto out;
+
+ ppc4xx_hsta_msi.irq_map = kmalloc(sizeof(int) * irq_count, GFP_KERNEL);
+ if (IS_ERR(ppc4xx_hsta_msi.irq_map)) {
+ ret = -ENOMEM;
+ goto out1;
+ }
+
+ /* Setup a mapping from irq offsets to hardware irq numbers */
+ for (irq = 0; irq < irq_count; irq++) {
+ ppc4xx_hsta_msi.irq_map[irq] =
+ irq_of_parse_and_map(dev->of_node, irq);
+ if (ppc4xx_hsta_msi.irq_map[irq] == NO_IRQ) {
+ dev_err(dev, "Unable to map IRQ\n");
+ ret = -EINVAL;
+ goto out2;
+ }
+ }
+
+#ifdef TEST_IRQ
+ /* Test generation of MSI interrupts */
+ semaphore_init(&ppc4xx_hsta_msi.sem, 0);
+ pr_info("HSTA MSI: Testing irq generation.\n");
+ for (irq = 0; irq < irq_count; irq++) {
+ int hwirq = ppc4xx_hsta_msi.irq_map[irq];
+ ret = request_irq(hwirq, hsta_test_msi_irq, 0,
+ "hsta-test-msi-irq", NULL);
+ if (ret) {
+ pr_err("HSTA MSI: Can't get interrupt %d.\n", hwirq);
+ goto out2;
+ }
+
+ /*
+ * Interrupts are generated by writes to the HSTA memory space
+ * at 128-bit aligned offsets.
+ */
+ ppc4xx_hsta_msi.data[irq*4] = 0x0;
+ if (down_timeout(&ppc4xx_hsta_msi.sem, 0.5 * HZ)) {
+ pr_err("HSTA MSI: Timeout waiting for interrupt %d.\n",
+ hwirq);
+ ret = -ETIME;
+ free_irq(hwirq, NULL);
+ goto out2;
+ }
+ free_irq(hwirq, NULL);
+ }
+ pr_info("HSTA MSI: Irq test completed successfully.\n");
+#endif
+
+ ppc_md.setup_msi_irqs = hsta_setup_msi_irqs;
+ ppc_md.teardown_msi_irqs = hsta_teardown_msi_irqs;
+ ppc_md.msi_check_device = hsta_msi_check_device;
+ return 0;
+
+out2:
+ kfree(ppc4xx_hsta_msi.irq_map);
+
+out1:
+ msi_bitmap_free(&ppc4xx_hsta_msi.bmp);
+
+out:
+ iounmap(ppc4xx_hsta_msi.data);
+ return ret;
+}
+
+static const struct of_device_id hsta_msi_ids[] = {
+ {
+ .compatible = "ibm,hsta-msi",
+ },
+ {}
+};
+
+static struct platform_driver hsta_msi_driver = {
+ .probe = hsta_msi_probe,
+ .driver = {
+ .name = "hsta-msi",
+ .owner = THIS_MODULE,
+ .of_match_table = hsta_msi_ids,
+ },
+};
+
+static int hsta_msi_init(void)
+{
+ return platform_driver_register(&hsta_msi_driver);
+}
+subsys_initcall(hsta_msi_init);
diff --git a/arch/powerpc/sysdev/ppc4xx_pci.c b/arch/powerpc/sysdev/ppc4xx_pci.c
index 771a0ba..fad9031 100644
--- a/arch/powerpc/sysdev/ppc4xx_pci.c
+++ b/arch/powerpc/sysdev/ppc4xx_pci.c
@@ -176,8 +176,12 @@ static int __init ppc4xx_parse_dma_ranges(struct pci_controller *hose,
return -ENXIO;
}
- /* Check that we are fully contained within 32 bits space */
- if (res->end > 0xffffffff) {
+ /* Check that we are fully contained within 32 bits space if we are not
+ * running on a 460sx or 476fpe which have 64 bit bus addresses.
+ */
+ if (res->end > 0xffffffff &&
+ !(of_device_is_compatible(hose->dn, "ibm,plb-pciex-460sx")
+ || of_device_is_compatible(hose->dn, "ibm,plb-pciex-476fpe"))) {
printk(KERN_ERR "%s: dma-ranges outside of 32 bits space\n",
hose->dn->full_name);
return -ENXIO;
--
1.7.10.4
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