s390/pci: base support

Add PCI support for s390, (only 64 bit mode is supported by hardware):
- PCI facility tests
- PCI instructions: pcilg, pcistg, pcistb, stpcifc, mpcifc, rpcit
- map readb/w/l/q and writeb/w/l/q to pcilg and pcistg instructions
- pci_iomap implementation
- memcpy_fromio/toio
- pci_root_ops using special pcilg/pcistg
- device, bus and domain allocation

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 562 insertions, 0 deletions

diff --git a/arch/s390/pci/Makefile b/arch/s390/pci/Makefile
new file mode 100644
index 00000000000..78a1344ff7b
--- /dev/null
+++ b/arch/s390/pci/Makefile
@@ -0,0 +1,5 @@
+#
+# Makefile for the s390 PCI subsystem.
+#
+
+obj-$(CONFIG_PCI)	+= pci.o
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
new file mode 100644
index 00000000000..0b80ac7e158
--- /dev/null
+++ b/arch/s390/pci/pci.c
@@ -0,0 +1,557 @@
+/*
+ * Copyright IBM Corp. 2012
+ *
+ * Author(s):
+ *   Jan Glauber <jang@linux.vnet.ibm.com>
+ *
+ * The System z PCI code is a rewrite from a prototype by
+ * the following people (Kudoz!):
+ *   Alexander Schmidt <alexschm@de.ibm.com>
+ *   Christoph Raisch <raisch@de.ibm.com>
+ *   Hannes Hering <hering2@de.ibm.com>
+ *   Hoang-Nam Nguyen <hnguyen@de.ibm.com>
+ *   Jan-Bernd Themann <themann@de.ibm.com>
+ *   Stefan Roscher <stefan.roscher@de.ibm.com>
+ *   Thomas Klein <tklein@de.ibm.com>
+ */
+
+#define COMPONENT "zPCI"
+#define pr_fmt(fmt) COMPONENT ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/delay.h>
+#include <linux/seq_file.h>
+#include <linux/pci.h>
+#include <linux/msi.h>
+
+#include <asm/facility.h>
+#include <asm/pci_insn.h>
+
+#define DEBUG				/* enable pr_debug */
+
+#define ZPCI_NR_DMA_SPACES		1
+#define ZPCI_NR_DEVICES			CONFIG_PCI_NR_FUNCTIONS
+
+/* list of all detected zpci devices */
+LIST_HEAD(zpci_list);
+DEFINE_MUTEX(zpci_list_lock);
+
+static DECLARE_BITMAP(zpci_domain, ZPCI_NR_DEVICES);
+static DEFINE_SPINLOCK(zpci_domain_lock);
+
+/* 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);
+
+struct zpci_dev *get_zdev(struct pci_dev *pdev)
+{
+	return (struct zpci_dev *) pdev->sysdata;
+}
+
+struct zpci_dev *get_zdev_by_fid(u32 fid)
+{
+	struct zpci_dev *tmp, *zdev = NULL;
+
+	mutex_lock(&zpci_list_lock);
+	list_for_each_entry(tmp, &zpci_list, entry) {
+		if (tmp->fid == fid) {
+			zdev = tmp;
+			break;
+		}
+	}
+	mutex_unlock(&zpci_list_lock);
+	return zdev;
+}
+
+bool zpci_fid_present(u32 fid)
+{
+	return (get_zdev_by_fid(fid) != NULL) ? true : false;
+}
+
+static struct zpci_dev *get_zdev_by_bus(struct pci_bus *bus)
+{
+	return (bus && bus->sysdata) ? (struct zpci_dev *) bus->sysdata : NULL;
+}
+
+int pci_domain_nr(struct pci_bus *bus)
+{
+	return ((struct zpci_dev *) bus->sysdata)->domain;
+}
+EXPORT_SYMBOL_GPL(pci_domain_nr);
+
+int pci_proc_domain(struct pci_bus *bus)
+{
+	return pci_domain_nr(bus);
+}
+EXPORT_SYMBOL_GPL(pci_proc_domain);
+
+/* Store PCI function information block */
+static int zpci_store_fib(struct zpci_dev *zdev, u8 *fc)
+{
+	struct zpci_fib *fib;
+	u8 status, cc;
+
+	fib = (void *) get_zeroed_page(GFP_KERNEL);
+	if (!fib)
+		return -ENOMEM;
+
+	do {
+		cc = __stpcifc(zdev->fh, 0, fib, &status);
+		if (cc == 2) {
+			msleep(ZPCI_INSN_BUSY_DELAY);
+			memset(fib, 0, PAGE_SIZE);
+		}
+	} while (cc == 2);
+
+	if (cc)
+		pr_err_once("%s: cc: %u  status: %u\n",
+			    __func__, cc, status);
+
+	/* Return PCI function controls */
+	*fc = fib->fc;
+
+	free_page((unsigned long) fib);
+	return (cc) ? -EIO : 0;
+}
+
+#define ZPCI_PCIAS_CFGSPC	15
+
+static int zpci_cfg_load(struct zpci_dev *zdev, int offset, u32 *val, u8 len)
+{
+	u64 req = ZPCI_CREATE_REQ(zdev->fh, ZPCI_PCIAS_CFGSPC, len);
+	u64 data;
+	int rc;
+
+	rc = pcilg_instr(&data, req, offset);
+	data = data << ((8 - len) * 8);
+	data = le64_to_cpu(data);
+	if (!rc)
+		*val = (u32) data;
+	else
+		*val = 0xffffffff;
+	return rc;
+}
+
+static int zpci_cfg_store(struct zpci_dev *zdev, int offset, u32 val, u8 len)
+{
+	u64 req = ZPCI_CREATE_REQ(zdev->fh, ZPCI_PCIAS_CFGSPC, len);
+	u64 data = val;
+	int rc;
+
+	data = cpu_to_le64(data);
+	data = data >> ((8 - len) * 8);
+	rc = pcistg_instr(data, req, offset);
+	return rc;
+}
+
+void __devinit pcibios_fixup_bus(struct pci_bus *bus)
+{
+}
+
+resource_size_t pcibios_align_resource(void *data, const struct resource *res,
+				       resource_size_t size,
+				       resource_size_t align)
+{
+	return 0;
+}
+
+/* Create a virtual mapping cookie for a PCI BAR */
+void __iomem *pci_iomap(struct pci_dev *pdev, int bar, unsigned long max)
+{
+	struct zpci_dev *zdev =	get_zdev(pdev);
+	u64 addr;
+	int idx;
+
+	if ((bar & 7) != bar)
+		return NULL;
+
+	idx = zdev->bars[bar].map_idx;
+	spin_lock(&zpci_iomap_lock);
+	zpci_iomap_start[idx].fh = zdev->fh;
+	zpci_iomap_start[idx].bar = bar;
+	spin_unlock(&zpci_iomap_lock);
+
+	addr = ZPCI_IOMAP_ADDR_BASE | ((u64) idx << 48);
+	return (void __iomem *) addr;
+}
+EXPORT_SYMBOL_GPL(pci_iomap);
+
+void pci_iounmap(struct pci_dev *pdev, void __iomem *addr)
+{
+	unsigned int idx;
+
+	idx = (((__force u64) addr) & ~ZPCI_IOMAP_ADDR_BASE) >> 48;
+	spin_lock(&zpci_iomap_lock);
+	zpci_iomap_start[idx].fh = 0;
+	zpci_iomap_start[idx].bar = 0;
+	spin_unlock(&zpci_iomap_lock);
+}
+EXPORT_SYMBOL_GPL(pci_iounmap);
+
+static int pci_read(struct pci_bus *bus, unsigned int devfn, int where,
+		    int size, u32 *val)
+{
+	struct zpci_dev *zdev = get_zdev_by_bus(bus);
+
+	if (!zdev || devfn != ZPCI_DEVFN)
+		return 0;
+	return zpci_cfg_load(zdev, where, val, size);
+}
+
+static int pci_write(struct pci_bus *bus, unsigned int devfn, int where,
+		     int size, u32 val)
+{
+	struct zpci_dev *zdev = get_zdev_by_bus(bus);
+
+	if (!zdev || devfn != ZPCI_DEVFN)
+		return 0;
+	return zpci_cfg_store(zdev, where, val, size);
+}
+
+static struct pci_ops pci_root_ops = {
+	.read = pci_read,
+	.write = pci_write,
+};
+
+static void zpci_map_resources(struct zpci_dev *zdev)
+{
+	struct pci_dev *pdev = zdev->pdev;
+	resource_size_t len;
+	int i;
+
+	for (i = 0; i < PCI_BAR_COUNT; i++) {
+		len = pci_resource_len(pdev, i);
+		if (!len)
+			continue;
+		pdev->resource[i].start = (resource_size_t) pci_iomap(pdev, i, 0);
+		pdev->resource[i].end = pdev->resource[i].start + len - 1;
+		pr_debug("BAR%i: -> start: %Lx  end: %Lx\n",
+			i, pdev->resource[i].start, pdev->resource[i].end);
+	}
+};
+
+static void zpci_unmap_resources(struct pci_dev *pdev)
+{
+	resource_size_t len;
+	int i;
+
+	for (i = 0; i < PCI_BAR_COUNT; i++) {
+		len = pci_resource_len(pdev, i);
+		if (!len)
+			continue;
+		pci_iounmap(pdev, (void *) pdev->resource[i].start);
+	}
+};
+
+struct zpci_dev *zpci_alloc_device(void)
+{
+	struct zpci_dev *zdev;
+
+	/* Alloc memory for our private pci device data */
+	zdev = kzalloc(sizeof(*zdev), GFP_KERNEL);
+	if (!zdev)
+		return ERR_PTR(-ENOMEM);
+	return zdev;
+}
+
+void zpci_free_device(struct zpci_dev *zdev)
+{
+	kfree(zdev);
+}
+
+/* Called on removal of pci_dev, leaves zpci and bus device */
+static void zpci_remove_device(struct pci_dev *pdev)
+{
+	struct zpci_dev *zdev = get_zdev(pdev);
+
+	dev_info(&pdev->dev, "Removing device %u\n", zdev->domain);
+	zdev->state = ZPCI_FN_STATE_CONFIGURED;
+	zpci_unmap_resources(pdev);
+	list_del(&zdev->entry);		/* can be called from init */
+	zdev->pdev = NULL;
+}
+
+static void zpci_scan_devices(void)
+{
+	struct zpci_dev *zdev;
+
+	mutex_lock(&zpci_list_lock);
+	list_for_each_entry(zdev, &zpci_list, entry)
+		if (zdev->state == ZPCI_FN_STATE_CONFIGURED)
+			zpci_scan_device(zdev);
+	mutex_unlock(&zpci_list_lock);
+}
+
+/*
+ * Too late for any s390 specific setup, since interrupts must be set up
+ * already which requires DMA setup too and the pci scan will access the
+ * config space, which only works if the function handle is enabled.
+ */
+int pcibios_enable_device(struct pci_dev *pdev, int mask)
+{
+	struct resource *res;
+	u16 cmd;
+	int i;
+
+	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
+
+	for (i = 0; i < PCI_BAR_COUNT; i++) {
+		res = &pdev->resource[i];
+
+		if (res->flags & IORESOURCE_IO)
+			return -EINVAL;
+
+		if (res->flags & IORESOURCE_MEM)
+			cmd |= PCI_COMMAND_MEMORY;
+	}
+	pci_write_config_word(pdev, PCI_COMMAND, cmd);
+	return 0;
+}
+
+void pcibios_disable_device(struct pci_dev *pdev)
+{
+	zpci_remove_device(pdev);
+	pdev->sysdata = NULL;
+}
+
+static struct resource *zpci_alloc_bus_resource(unsigned long start, unsigned long size,
+						unsigned long flags, int domain)
+{
+	struct resource *r;
+	char *name;
+	int rc;
+
+	r = kzalloc(sizeof(*r), GFP_KERNEL);
+	if (!r)
+		return ERR_PTR(-ENOMEM);
+	r->start = start;
+	r->end = r->start + size - 1;
+	r->flags = flags;
+	r->parent = &iomem_resource;
+	name = kmalloc(18, GFP_KERNEL);
+	if (!name) {
+		kfree(r);
+		return ERR_PTR(-ENOMEM);
+	}
+	sprintf(name, "PCI Bus: %04x:%02x", domain, ZPCI_BUS_NR);
+	r->name = name;
+
+	rc = request_resource(&iomem_resource, r);
+	if (rc)
+		pr_debug("request resource %pR failed\n", r);
+	return r;
+}
+
+static int zpci_alloc_iomap(struct zpci_dev *zdev)
+{
+	int entry;
+
+	spin_lock(&zpci_iomap_lock);
+	entry = find_first_zero_bit(zpci_iomap, ZPCI_IOMAP_MAX_ENTRIES);
+	if (entry == ZPCI_IOMAP_MAX_ENTRIES) {
+		spin_unlock(&zpci_iomap_lock);
+		return -ENOSPC;
+	}
+	set_bit(entry, zpci_iomap);
+	spin_unlock(&zpci_iomap_lock);
+	return entry;
+}
+
+static void zpci_free_iomap(struct zpci_dev *zdev, int entry)
+{
+	spin_lock(&zpci_iomap_lock);
+	memset(&zpci_iomap_start[entry], 0, sizeof(struct zpci_iomap_entry));
+	clear_bit(entry, zpci_iomap);
+	spin_unlock(&zpci_iomap_lock);
+}
+
+static int zpci_create_device_bus(struct zpci_dev *zdev)
+{
+	struct resource *res;
+	LIST_HEAD(resources);
+	int i;
+
+	/* allocate mapping entry for each used bar */
+	for (i = 0; i < PCI_BAR_COUNT; i++) {
+		unsigned long addr, size, flags;
+		int entry;
+
+		if (!zdev->bars[i].size)
+			continue;
+		entry = zpci_alloc_iomap(zdev);
+		if (entry < 0)
+			return entry;
+		zdev->bars[i].map_idx = entry;
+
+		/* only MMIO is supported */
+		flags = IORESOURCE_MEM;
+		if (zdev->bars[i].val & 8)
+			flags |= IORESOURCE_PREFETCH;
+		if (zdev->bars[i].val & 4)
+			flags |= IORESOURCE_MEM_64;
+
+		addr = ZPCI_IOMAP_ADDR_BASE + ((u64) entry << 48);
+
+		size = 1UL << zdev->bars[i].size;
+
+		res = zpci_alloc_bus_resource(addr, size, flags, zdev->domain);
+		if (IS_ERR(res)) {
+			zpci_free_iomap(zdev, entry);
+			return PTR_ERR(res);
+		}
+		pci_add_resource(&resources, res);
+	}
+
+	zdev->bus = pci_create_root_bus(NULL, ZPCI_BUS_NR, &pci_root_ops,
+					zdev, &resources);
+	if (!zdev->bus)
+		return -EIO;
+
+	zdev->bus->max_bus_speed = zdev->max_bus_speed;
+	return 0;
+}
+
+static int zpci_alloc_domain(struct zpci_dev *zdev)
+{
+	spin_lock(&zpci_domain_lock);
+	zdev->domain = find_first_zero_bit(zpci_domain, ZPCI_NR_DEVICES);
+	if (zdev->domain == ZPCI_NR_DEVICES) {
+		spin_unlock(&zpci_domain_lock);
+		return -ENOSPC;
+	}
+	set_bit(zdev->domain, zpci_domain);
+	spin_unlock(&zpci_domain_lock);
+	return 0;
+}
+
+static void zpci_free_domain(struct zpci_dev *zdev)
+{
+	spin_lock(&zpci_domain_lock);
+	clear_bit(zdev->domain, zpci_domain);
+	spin_unlock(&zpci_domain_lock);
+}
+
+int zpci_create_device(struct zpci_dev *zdev)
+{
+	int rc;
+
+	rc = zpci_alloc_domain(zdev);
+	if (rc)
+		goto out;
+
+	rc = zpci_create_device_bus(zdev);
+	if (rc)
+		goto out_bus;
+
+	mutex_lock(&zpci_list_lock);
+	list_add_tail(&zdev->entry, &zpci_list);
+	mutex_unlock(&zpci_list_lock);
+
+	if (zdev->state == ZPCI_FN_STATE_STANDBY)
+		return 0;
+
+	return 0;
+
+out_bus:
+	zpci_free_domain(zdev);
+out:
+	return rc;
+}
+
+void zpci_stop_device(struct zpci_dev *zdev)
+{
+	/*
+	 * Note: SCLP disables fh via set-pci-fn so don't
+	 * do that here.
+	 */
+}
+EXPORT_SYMBOL_GPL(zpci_stop_device);
+
+int zpci_scan_device(struct zpci_dev *zdev)
+{
+	zdev->pdev = pci_scan_single_device(zdev->bus, ZPCI_DEVFN);
+	if (!zdev->pdev) {
+		pr_err("pci_scan_single_device failed for fid: 0x%x\n",
+			zdev->fid);
+		goto out;
+	}
+
+	zpci_map_resources(zdev);
+	pci_bus_add_devices(zdev->bus);
+
+	/* now that pdev was added to the bus mark it as used */
+	zdev->state = ZPCI_FN_STATE_ONLINE;
+	return 0;
+
+out:
+	return -EIO;
+}
+EXPORT_SYMBOL_GPL(zpci_scan_device);
+
+static inline int barsize(u8 size)
+{
+	return (size) ? (1 << size) >> 10 : 0;
+}
+
+static int zpci_mem_init(void)
+{
+	/* TODO: use realloc */
+	zpci_iomap_start = kzalloc(ZPCI_IOMAP_MAX_ENTRIES * sizeof(*zpci_iomap_start),
+				   GFP_KERNEL);
+	if (!zpci_iomap_start)
+		goto error_zdev;
+	return 0;
+
+error_zdev:
+	return -ENOMEM;
+}
+
+static void zpci_mem_exit(void)
+{
+	kfree(zpci_iomap_start);
+}
+
+unsigned int pci_probe = 1;
+EXPORT_SYMBOL_GPL(pci_probe);
+
+char * __init pcibios_setup(char *str)
+{
+	if (!strcmp(str, "off")) {
+		pci_probe = 0;
+		return NULL;
+	}
+	return str;
+}
+
+static int __init pci_base_init(void)
+{
+	int rc;
+
+	if (!pci_probe)
+		return 0;
+
+	if (!test_facility(2) || !test_facility(69)
+	    || !test_facility(71) || !test_facility(72))
+		return 0;
+
+	pr_info("Probing PCI hardware: PCI:%d  SID:%d  AEN:%d\n",
+		test_facility(69), test_facility(70),
+		test_facility(71));
+
+	rc = zpci_mem_init();
+	if (rc)
+		goto out_mem;
+
+	zpci_scan_devices();
+	return 0;
+
+	zpci_mem_exit();
+out_mem:
+	return rc;
+}
+subsys_initcall(pci_base_init);