pci.c

// SPDX-License-Identifier: GPL-2.0
/*
 * 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
 *   Christoph Raisch
 *   Hannes Hering
 *   Hoang-Nam Nguyen
 *   Jan-Bernd Themann
 *   Stefan Roscher
 *   Thomas Klein
 */

#define KMSG_COMPONENT "zpci"
#define pr_fmt(fmt) KMSG_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 <asm/isc.h>
#include <asm/airq.h>
#include <asm/facility.h>
#include <asm/pci_insn.h>
#include <asm/pci_clp.h>
#include <asm/pci_dma.h>

/* list of all detected zpci devices */
static LIST_HEAD(zpci_list);
static DEFINE_SPINLOCK(zpci_list_lock);

static DECLARE_BITMAP(zpci_domain, ZPCI_NR_DEVICES);
static DEFINE_SPINLOCK(zpci_domain_lock);

#define ZPCI_IOMAP_ENTRIES						\
	min(((unsigned long) ZPCI_NR_DEVICES * PCI_BAR_COUNT / 2),	\
	    ZPCI_IOMAP_MAX_ENTRIES)

static DEFINE_SPINLOCK(zpci_iomap_lock);
static unsigned long *zpci_iomap_bitmap;
struct zpci_iomap_entry *zpci_iomap_start;
EXPORT_SYMBOL_GPL(zpci_iomap_start);

static struct kmem_cache *zdev_fmb_cache;

struct zpci_dev *get_zdev_by_fid(u32 fid)
{
	struct zpci_dev *tmp, *zdev = NULL;

	spin_lock(&zpci_list_lock);
	list_for_each_entry(tmp, &zpci_list, entry) {
		if (tmp->fid == fid) {
			zdev = tmp;
			break;
		}
	}
	spin_unlock(&zpci_list_lock);
	return zdev;
}

void zpci_remove_reserved_devices(void)
{
	struct zpci_dev *tmp, *zdev;
	enum zpci_state state;
	LIST_HEAD(remove);

	spin_lock(&zpci_list_lock);
	list_for_each_entry_safe(zdev, tmp, &zpci_list, entry) {
		if (zdev->state == ZPCI_FN_STATE_STANDBY &&
		    !clp_get_state(zdev->fid, &state) &&
		    state == ZPCI_FN_STATE_RESERVED)
			list_move_tail(&zdev->entry, &remove);
	}
	spin_unlock(&zpci_list_lock);

	list_for_each_entry_safe(zdev, tmp, &remove, entry)
		zpci_remove_device(zdev);
}

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);

/* Modify PCI: Register I/O address translation parameters */
int zpci_register_ioat(struct zpci_dev *zdev, u8 dmaas,
		       u64 base, u64 limit, u64 iota)
{
	u64 req = ZPCI_CREATE_REQ(zdev->fh, dmaas, ZPCI_MOD_FC_REG_IOAT);
	struct zpci_fib fib = {0};
	u8 status;

	WARN_ON_ONCE(iota & 0x3fff);
	fib.pba = base;
	fib.pal = limit;
	fib.iota = iota | ZPCI_IOTA_RTTO_FLAG;
	return zpci_mod_fc(req, &fib, &status) ? -EIO : 0;
}

/* Modify PCI: Unregister I/O address translation parameters */
int zpci_unregister_ioat(struct zpci_dev *zdev, u8 dmaas)
{
	u64 req = ZPCI_CREATE_REQ(zdev->fh, dmaas, ZPCI_MOD_FC_DEREG_IOAT);
	struct zpci_fib fib = {0};
	u8 cc, status;

	cc = zpci_mod_fc(req, &fib, &status);
	if (cc == 3) /* Function already gone. */
		cc = 0;
	return cc ? -EIO : 0;
}

/* Modify PCI: Set PCI function measurement parameters */
int zpci_fmb_enable_device(struct zpci_dev *zdev)
{
	u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_SET_MEASURE);
	struct zpci_fib fib = {0};
	u8 cc, status;

	if (zdev->fmb || sizeof(*zdev->fmb) < zdev->fmb_length)
		return -EINVAL;

	zdev->fmb = kmem_cache_zalloc(zdev_fmb_cache, GFP_KERNEL);
	if (!zdev->fmb)
		return -ENOMEM;
	WARN_ON((u64) zdev->fmb & 0xf);

	/* reset software counters */
	atomic64_set(&zdev->allocated_pages, 0);
	atomic64_set(&zdev->mapped_pages, 0);
	atomic64_set(&zdev->unmapped_pages, 0);

	fib.fmb_addr = virt_to_phys(zdev->fmb);
	cc = zpci_mod_fc(req, &fib, &status);
	if (cc) {
		kmem_cache_free(zdev_fmb_cache, zdev->fmb);
		zdev->fmb = NULL;
	}
	return cc ? -EIO : 0;
}

/* Modify PCI: Disable PCI function measurement */
int zpci_fmb_disable_device(struct zpci_dev *zdev)
{
	u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_SET_MEASURE);
	struct zpci_fib fib = {0};
	u8 cc, status;

	if (!zdev->fmb)
		return -EINVAL;

	/* Function measurement is disabled if fmb address is zero */
	cc = zpci_mod_fc(req, &fib, &status);
	if (cc == 3) /* Function already gone. */
		cc = 0;

	if (!cc) {
		kmem_cache_free(zdev_fmb_cache, zdev->fmb);
		zdev->fmb = NULL;
	}
	return cc ? -EIO : 0;
}

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 = zpci_load(&data, req, offset);
	if (!rc) {
		data = le64_to_cpu((__force __le64) data);
		data >>= (8 - len) * 8;
		*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 <<= (8 - len) * 8;
	data = (__force u64) cpu_to_le64(data);
	rc = zpci_store(data, req, offset);
	return rc;
}

resource_size_t pcibios_align_resource(void *data, const struct resource *res,
				       resource_size_t size,
				       resource_size_t align)
{
	return 0;
}

/* combine single writes by using store-block insn */
void __iowrite64_copy(void __iomem *to, const void *from, size_t count)
{
       zpci_memcpy_toio(to, from, count);
}

/* Create a virtual mapping cookie for a PCI BAR */
void __iomem *pci_iomap_range(struct pci_dev *pdev,
			      int bar,
			      unsigned long offset,
			      unsigned long max)
{
	struct zpci_dev *zdev =	to_zpci(pdev);
	int idx;

	if (!pci_resource_len(pdev, bar) || bar >= PCI_BAR_COUNT)
		return NULL;

	idx = zdev->bars[bar].map_idx;
	spin_lock(&zpci_iomap_lock);
	/* Detect overrun */
	WARN_ON(!++zpci_iomap_start[idx].count);
	zpci_iomap_start[idx].fh = zdev->fh;
	zpci_iomap_start[idx].bar = bar;
	spin_unlock(&zpci_iomap_lock);

	return (void __iomem *) ZPCI_ADDR(idx) + offset;
}
EXPORT_SYMBOL(pci_iomap_range);

void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
{
	return pci_iomap_range(dev, bar, 0, maxlen);
}
EXPORT_SYMBOL(pci_iomap);

void pci_iounmap(struct pci_dev *pdev, void __iomem *addr)
{
	unsigned int idx = ZPCI_IDX(addr);

	spin_lock(&zpci_iomap_lock);
	/* Detect underrun */
	WARN_ON(!zpci_iomap_start[idx].count);
	if (!--zpci_iomap_start[idx].count) {
		zpci_iomap_start[idx].fh = 0;
		zpci_iomap_start[idx].bar = 0;
	}
	spin_unlock(&zpci_iomap_lock);
}
EXPORT_SYMBOL(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);
	int ret;

	if (!zdev || devfn != ZPCI_DEVFN)
		ret = -ENODEV;
	else
		ret = zpci_cfg_load(zdev, where, val, size);

	return ret;
}

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);
	int ret;

	if (!zdev || devfn != ZPCI_DEVFN)
		ret = -ENODEV;
	else
		ret = zpci_cfg_store(zdev, where, val, size);

	return ret;
}

static struct pci_ops pci_root_ops = {
	.read = pci_read,
	.write = pci_write,
};

#ifdef CONFIG_PCI_IOV
static struct resource iov_res = {
	.name	= "PCI IOV res",
	.start	= 0,
	.end	= -1,
	.flags	= IORESOURCE_MEM,
};
#endif

static void zpci_map_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;
		pdev->resource[i].start =
			(resource_size_t __force) pci_iomap(pdev, i, 0);
		pdev->resource[i].end = pdev->resource[i].start + len - 1;
	}

#ifdef CONFIG_PCI_IOV
	i = PCI_IOV_RESOURCES;

	for (; i < PCI_SRIOV_NUM_BARS + PCI_IOV_RESOURCES; i++) {
		len = pci_resource_len(pdev, i);
		if (!len)
			continue;
		pdev->resource[i].parent = &iov_res;
	}
#endif
}

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 __iomem __force *)
			    pdev->resource[i].start);
	}
}

static int zpci_alloc_iomap(struct zpci_dev *zdev)
{
	unsigned long entry;

	spin_lock(&zpci_iomap_lock);
	entry = find_first_zero_bit(zpci_iomap_bitmap, ZPCI_IOMAP_ENTRIES);
	if (entry == ZPCI_IOMAP_ENTRIES) {
		spin_unlock(&zpci_iomap_lock);
		return -ENOSPC;
	}
	set_bit(entry, zpci_iomap_bitmap);
	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_bitmap);
	spin_unlock(&zpci_iomap_lock);
}

static struct resource *__alloc_res(struct zpci_dev *zdev, unsigned long start,
				    unsigned long size, unsigned long flags)
{
	struct resource *r;

	r = kzalloc(sizeof(*r), GFP_KERNEL);
	if (!r)
		return NULL;

	r->start = start;
	r->end = r->start + size - 1;
	r->flags = flags;
	r->name = zdev->res_name;

	if (request_resource(&iomem_resource, r)) {
		kfree(r);
		return NULL;
	}
	return r;
}

static int zpci_setup_bus_resources(struct zpci_dev *zdev,
				    struct list_head *resources)
{
	unsigned long addr, size, flags;
	struct resource *res;
	int i, entry;

	snprintf(zdev->res_name, sizeof(zdev->res_name),
		 "PCI Bus %04x:%02x", zdev->domain, ZPCI_BUS_NR);

	for (i = 0; i < PCI_BAR_COUNT; i++) {
		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_ADDR(entry);
		size = 1UL << zdev->bars[i].size;

		res = __alloc_res(zdev, addr, size, flags);
		if (!res) {
			zpci_free_iomap(zdev, entry);
			return -ENOMEM;
		}
		zdev->bars[i].res = res;
		pci_add_resource(resources, res);
	}

	return 0;
}

static void zpci_cleanup_bus_resources(struct zpci_dev *zdev)
{
	int i;

	for (i = 0; i < PCI_BAR_COUNT; i++) {
		if (!zdev->bars[i].size || !zdev->bars[i].res)
			continue;

		zpci_free_iomap(zdev, zdev->bars[i].map_idx);
		release_resource(zdev->bars[i].res);
		kfree(zdev->bars[i].res);
	}
}

int pcibios_add_device(struct pci_dev *pdev)
{
	struct resource *res;
	int i;

	if (pdev->is_physfn)
		pdev->no_vf_scan = 1;

	pdev->dev.groups = zpci_attr_groups;
	pdev->dev.dma_ops = &s390_pci_dma_ops;
	zpci_map_resources(pdev);

	for (i = 0; i < PCI_BAR_COUNT; i++) {
		res = &pdev->resource[i];
		if (res->parent || !res->flags)
			continue;
		pci_claim_resource(pdev, i);
	}

	return 0;
}

void pcibios_release_device(struct pci_dev *pdev)
{
	zpci_unmap_resources(pdev);
}

int pcibios_enable_device(struct pci_dev *pdev, int mask)
{
	struct zpci_dev *zdev = to_zpci(pdev);

	zpci_debug_init_device(zdev, dev_name(&pdev->dev));
	zpci_fmb_enable_device(zdev);

	return pci_enable_resources(pdev, mask);
}

void pcibios_disable_device(struct pci_dev *pdev)
{
	struct zpci_dev *zdev = to_zpci(pdev);

	zpci_fmb_disable_device(zdev);
	zpci_debug_exit_device(zdev);
}

#ifdef CONFIG_HIBERNATE_CALLBACKS
static int zpci_restore(struct device *dev)
{
	struct pci_dev *pdev = to_pci_dev(dev);
	struct zpci_dev *zdev = to_zpci(pdev);
	int ret = 0;

	if (zdev->state != ZPCI_FN_STATE_ONLINE)
		goto out;

	ret = clp_enable_fh(zdev, ZPCI_NR_DMA_SPACES);
	if (ret)
		goto out;

	zpci_map_resources(pdev);
	zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
			   (u64) zdev->dma_table);

out:
	return ret;
}

static int zpci_freeze(struct device *dev)
{
	struct pci_dev *pdev = to_pci_dev(dev);
	struct zpci_dev *zdev = to_zpci(pdev);

	if (zdev->state != ZPCI_FN_STATE_ONLINE)
		return 0;

	zpci_unregister_ioat(zdev, 0);
	zpci_unmap_resources(pdev);
	return clp_disable_fh(zdev);
}

struct dev_pm_ops pcibios_pm_ops = {
	.thaw_noirq = zpci_restore,
	.freeze_noirq = zpci_freeze,
	.restore_noirq = zpci_restore,
	.poweroff_noirq = zpci_freeze,
};
#endif /* CONFIG_HIBERNATE_CALLBACKS */

static int zpci_alloc_domain(struct zpci_dev *zdev)
{
	if (zpci_unique_uid) {
		zdev->domain = (u16) zdev->uid;
		if (zdev->domain >= ZPCI_NR_DEVICES)
			return 0;

		spin_lock(&zpci_domain_lock);
		if (test_bit(zdev->domain, zpci_domain)) {
			spin_unlock(&zpci_domain_lock);
			return -EEXIST;
		}
		set_bit(zdev->domain, zpci_domain);
		spin_unlock(&zpci_domain_lock);
		return 0;
	}

	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)
{
	if (zdev->domain >= ZPCI_NR_DEVICES)
		return;

	spin_lock(&zpci_domain_lock);
	clear_bit(zdev->domain, zpci_domain);
	spin_unlock(&zpci_domain_lock);
}

void pcibios_remove_bus(struct pci_bus *bus)
{
	struct zpci_dev *zdev = get_zdev_by_bus(bus);

	zpci_exit_slot(zdev);
	zpci_cleanup_bus_resources(zdev);
	zpci_destroy_iommu(zdev);
	zpci_free_domain(zdev);

	spin_lock(&zpci_list_lock);
	list_del(&zdev->entry);
	spin_unlock(&zpci_list_lock);

	zpci_dbg(3, "rem fid:%x\n", zdev->fid);
	kfree(zdev);
}

static int zpci_scan_bus(struct zpci_dev *zdev)
{
	LIST_HEAD(resources);
	int ret;

	ret = zpci_setup_bus_resources(zdev, &resources);
	if (ret)
		goto error;

	zdev->bus = pci_scan_root_bus(NULL, ZPCI_BUS_NR, &pci_root_ops,
				      zdev, &resources);
	if (!zdev->bus) {
		ret = -EIO;
		goto error;
	}
	zdev->bus->max_bus_speed = zdev->max_bus_speed;
	pci_bus_add_devices(zdev->bus);
	return 0;

error:
	zpci_cleanup_bus_resources(zdev);
	pci_free_resource_list(&resources);
	return ret;
}

int zpci_enable_device(struct zpci_dev *zdev)
{
	int rc;

	rc = clp_enable_fh(zdev, ZPCI_NR_DMA_SPACES);
	if (rc)
		goto out;

	rc = zpci_dma_init_device(zdev);
	if (rc)
		goto out_dma;

	zdev->state = ZPCI_FN_STATE_ONLINE;
	return 0;

out_dma:
	clp_disable_fh(zdev);
out:
	return rc;
}
EXPORT_SYMBOL_GPL(zpci_enable_device);

int zpci_disable_device(struct zpci_dev *zdev)
{
	zpci_dma_exit_device(zdev);
	return clp_disable_fh(zdev);
}
EXPORT_SYMBOL_GPL(zpci_disable_device);

int zpci_create_device(struct zpci_dev *zdev)
{
	int rc;

	rc = zpci_alloc_domain(zdev);
	if (rc)
		goto out;

	rc = zpci_init_iommu(zdev);
	if (rc)
		goto out_free;

	mutex_init(&zdev->lock);
	if (zdev->state == ZPCI_FN_STATE_CONFIGURED) {
		rc = zpci_enable_device(zdev);
		if (rc)
			goto out_destroy_iommu;
	}
	rc = zpci_scan_bus(zdev);
	if (rc)
		goto out_disable;

	spin_lock(&zpci_list_lock);
	list_add_tail(&zdev->entry, &zpci_list);
	spin_unlock(&zpci_list_lock);

	zpci_init_slot(zdev);

	return 0;

out_disable:
	if (zdev->state == ZPCI_FN_STATE_ONLINE)
		zpci_disable_device(zdev);
out_destroy_iommu:
	zpci_destroy_iommu(zdev);
out_free:
	zpci_free_domain(zdev);
out:
	return rc;
}

void zpci_remove_device(struct zpci_dev *zdev)
{
	if (!zdev->bus)
		return;

	pci_stop_root_bus(zdev->bus);
	pci_remove_root_bus(zdev->bus);
}

int zpci_report_error(struct pci_dev *pdev,
		      struct zpci_report_error_header *report)
{
	struct zpci_dev *zdev = to_zpci(pdev);

	return sclp_pci_report(report, zdev->fh, zdev->fid);
}
EXPORT_SYMBOL(zpci_report_error);

static int zpci_mem_init(void)
{
	BUILD_BUG_ON(!is_power_of_2(__alignof__(struct zpci_fmb)) ||
		     __alignof__(struct zpci_fmb) < sizeof(struct zpci_fmb));

	zdev_fmb_cache = kmem_cache_create("PCI_FMB_cache", sizeof(struct zpci_fmb),
					   __alignof__(struct zpci_fmb), 0, NULL);
	if (!zdev_fmb_cache)
		goto error_fmb;

	zpci_iomap_start = kcalloc(ZPCI_IOMAP_ENTRIES,
				   sizeof(*zpci_iomap_start), GFP_KERNEL);
	if (!zpci_iomap_start)
		goto error_iomap;

	zpci_iomap_bitmap = kcalloc(BITS_TO_LONGS(ZPCI_IOMAP_ENTRIES),
				    sizeof(*zpci_iomap_bitmap), GFP_KERNEL);
	if (!zpci_iomap_bitmap)
		goto error_iomap_bitmap;

	return 0;
error_iomap_bitmap:
	kfree(zpci_iomap_start);
error_iomap:
	kmem_cache_destroy(zdev_fmb_cache);
error_fmb:
	return -ENOMEM;
}

static void zpci_mem_exit(void)
{
	kfree(zpci_iomap_bitmap);
	kfree(zpci_iomap_start);
	kmem_cache_destroy(zdev_fmb_cache);
}

static unsigned int s390_pci_probe __initdata = 1;
static unsigned int s390_pci_initialized;

char * __init pcibios_setup(char *str)
{
	if (!strcmp(str, "off")) {
		s390_pci_probe = 0;
		return NULL;
	}
	return str;
}

bool zpci_is_enabled(void)
{
	return s390_pci_initialized;
}

static int __init pci_base_init(void)
{
	int rc;

	if (!s390_pci_probe)
		return 0;

	if (!test_facility(69) || !test_facility(71))
		return 0;

	rc = zpci_debug_init();
	if (rc)
		goto out;

	rc = zpci_mem_init();
	if (rc)
		goto out_mem;

	rc = zpci_irq_init();
	if (rc)
		goto out_irq;

	rc = zpci_dma_init();
	if (rc)
		goto out_dma;

	rc = clp_scan_pci_devices();
	if (rc)
		goto out_find;

	s390_pci_initialized = 1;
	return 0;

out_find:
	zpci_dma_exit();
out_dma:
	zpci_irq_exit();
out_irq:
	zpci_mem_exit();
out_mem:
	zpci_debug_exit();
out:
	return rc;
}
subsys_initcall_sync(pci_base_init);

void zpci_rescan(void)
{
	if (zpci_is_enabled())
		clp_rescan_pci_devices_simple();
}