iommu/s390: Add iommu api for s390 pci devices

This adds an IOMMU API implementation for s390 PCI devices.

Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Gerald Schaefer 2015-08-27 15:33:03 +02:00 committed by Joerg Roedel
parent 049e6dde7e
commit 8128f23c43
8 changed files with 386 additions and 13 deletions

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@ -8943,6 +8943,13 @@ F: drivers/s390/net/*iucv*
F: include/net/iucv/
F: net/iucv/
S390 IOMMU (PCI)
M: Gerald Schaefer <gerald.schaefer@de.ibm.com>
L: linux-s390@vger.kernel.org
W: http://www.ibm.com/developerworks/linux/linux390/
S: Supported
F: drivers/iommu/s390-iommu.c
S3C24XX SD/MMC Driver
M: Ben Dooks <ben-linux@fluff.org>
L: linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)

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@ -582,6 +582,7 @@ menuconfig PCI
bool "PCI support"
select HAVE_DMA_ATTRS
select PCI_MSI
select IOMMU_SUPPORT
help
Enable PCI support.

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@ -62,6 +62,8 @@ struct zpci_bar_struct {
u8 size; /* order 2 exponent */
};
struct s390_domain;
/* Private data per function */
struct zpci_dev {
struct pci_dev *pdev;
@ -118,6 +120,8 @@ struct zpci_dev {
struct dentry *debugfs_dev;
struct dentry *debugfs_perf;
struct s390_domain *s390_domain; /* s390 IOMMU domain data */
};
static inline bool zdev_enabled(struct zpci_dev *zdev)

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@ -192,5 +192,8 @@ static inline unsigned long *get_st_pto(unsigned long entry)
/* Prototypes */
int zpci_dma_init_device(struct zpci_dev *);
void zpci_dma_exit_device(struct zpci_dev *);
void dma_free_seg_table(unsigned long);
unsigned long *dma_alloc_cpu_table(void);
void dma_cleanup_tables(unsigned long *);
void dma_update_cpu_trans(unsigned long *, void *, dma_addr_t, int);
#endif

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@ -24,7 +24,7 @@ static int zpci_refresh_global(struct zpci_dev *zdev)
zdev->iommu_pages * PAGE_SIZE);
}
static unsigned long *dma_alloc_cpu_table(void)
unsigned long *dma_alloc_cpu_table(void)
{
unsigned long *table, *entry;
@ -114,12 +114,12 @@ static unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr
return &pto[px];
}
static void dma_update_cpu_trans(struct zpci_dev *zdev, void *page_addr,
dma_addr_t dma_addr, int flags)
void dma_update_cpu_trans(unsigned long *dma_table, void *page_addr,
dma_addr_t dma_addr, int flags)
{
unsigned long *entry;
entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr);
entry = dma_walk_cpu_trans(dma_table, dma_addr);
if (!entry) {
WARN_ON_ONCE(1);
return;
@ -156,7 +156,8 @@ static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
goto no_refresh;
for (i = 0; i < nr_pages; i++) {
dma_update_cpu_trans(zdev, page_addr, dma_addr, flags);
dma_update_cpu_trans(zdev->dma_table, page_addr, dma_addr,
flags);
page_addr += PAGE_SIZE;
dma_addr += PAGE_SIZE;
}
@ -181,7 +182,7 @@ no_refresh:
return rc;
}
static void dma_free_seg_table(unsigned long entry)
void dma_free_seg_table(unsigned long entry)
{
unsigned long *sto = get_rt_sto(entry);
int sx;
@ -193,21 +194,18 @@ static void dma_free_seg_table(unsigned long entry)
dma_free_cpu_table(sto);
}
static void dma_cleanup_tables(struct zpci_dev *zdev)
void dma_cleanup_tables(unsigned long *table)
{
unsigned long *table;
int rtx;
if (!zdev || !zdev->dma_table)
if (!table)
return;
table = zdev->dma_table;
for (rtx = 0; rtx < ZPCI_TABLE_ENTRIES; rtx++)
if (reg_entry_isvalid(table[rtx]))
dma_free_seg_table(table[rtx]);
dma_free_cpu_table(table);
zdev->dma_table = NULL;
}
static unsigned long __dma_alloc_iommu(struct zpci_dev *zdev,
@ -416,6 +414,13 @@ int zpci_dma_init_device(struct zpci_dev *zdev)
{
int rc;
/*
* At this point, if the device is part of an IOMMU domain, this would
* be a strong hint towards a bug in the IOMMU API (common) code and/or
* simultaneous access via IOMMU and DMA API. So let's issue a warning.
*/
WARN_ON(zdev->s390_domain);
spin_lock_init(&zdev->iommu_bitmap_lock);
spin_lock_init(&zdev->dma_table_lock);
@ -450,8 +455,16 @@ out_clean:
void zpci_dma_exit_device(struct zpci_dev *zdev)
{
/*
* At this point, if the device is part of an IOMMU domain, this would
* be a strong hint towards a bug in the IOMMU API (common) code and/or
* simultaneous access via IOMMU and DMA API. So let's issue a warning.
*/
WARN_ON(zdev->s390_domain);
zpci_unregister_ioat(zdev, 0);
dma_cleanup_tables(zdev);
dma_cleanup_tables(zdev->dma_table);
zdev->dma_table = NULL;
vfree(zdev->iommu_bitmap);
zdev->iommu_bitmap = NULL;
zdev->next_bit = 0;

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@ -369,4 +369,11 @@ config ARM_SMMU_V3
Say Y here if your system includes an IOMMU device implementing
the ARM SMMUv3 architecture.
config S390_IOMMU
def_bool y if S390 && PCI
depends on S390 && PCI
select IOMMU_API
help
Support for the IOMMU API for s390 PCI devices.
endif # IOMMU_SUPPORT

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@ -23,3 +23,4 @@ obj-$(CONFIG_EXYNOS_IOMMU) += exynos-iommu.o
obj-$(CONFIG_SHMOBILE_IOMMU) += shmobile-iommu.o
obj-$(CONFIG_SHMOBILE_IPMMU) += shmobile-ipmmu.o
obj-$(CONFIG_FSL_PAMU) += fsl_pamu.o fsl_pamu_domain.o
obj-$(CONFIG_S390_IOMMU) += s390-iommu.o

337
drivers/iommu/s390-iommu.c Normal file
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@ -0,0 +1,337 @@
/*
* IOMMU API for s390 PCI devices
*
* Copyright IBM Corp. 2015
* Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
*/
#include <linux/pci.h>
#include <linux/iommu.h>
#include <linux/iommu-helper.h>
#include <linux/pci.h>
#include <linux/sizes.h>
#include <asm/pci_dma.h>
/*
* Physically contiguous memory regions can be mapped with 4 KiB alignment,
* we allow all page sizes that are an order of 4KiB (no special large page
* support so far).
*/
#define S390_IOMMU_PGSIZES (~0xFFFUL)
struct s390_domain {
struct iommu_domain domain;
struct list_head devices;
unsigned long *dma_table;
spinlock_t dma_table_lock;
spinlock_t list_lock;
};
struct s390_domain_device {
struct list_head list;
struct zpci_dev *zdev;
};
static struct s390_domain *to_s390_domain(struct iommu_domain *dom)
{
return container_of(dom, struct s390_domain, domain);
}
static bool s390_iommu_capable(enum iommu_cap cap)
{
switch (cap) {
case IOMMU_CAP_CACHE_COHERENCY:
return true;
case IOMMU_CAP_INTR_REMAP:
return true;
default:
return false;
}
}
struct iommu_domain *s390_domain_alloc(unsigned domain_type)
{
struct s390_domain *s390_domain;
if (domain_type != IOMMU_DOMAIN_UNMANAGED)
return NULL;
s390_domain = kzalloc(sizeof(*s390_domain), GFP_KERNEL);
if (!s390_domain)
return NULL;
s390_domain->dma_table = dma_alloc_cpu_table();
if (!s390_domain->dma_table) {
kfree(s390_domain);
return NULL;
}
spin_lock_init(&s390_domain->dma_table_lock);
spin_lock_init(&s390_domain->list_lock);
INIT_LIST_HEAD(&s390_domain->devices);
return &s390_domain->domain;
}
void s390_domain_free(struct iommu_domain *domain)
{
struct s390_domain *s390_domain = to_s390_domain(domain);
dma_cleanup_tables(s390_domain->dma_table);
kfree(s390_domain);
}
static int s390_iommu_attach_device(struct iommu_domain *domain,
struct device *dev)
{
struct s390_domain *s390_domain = to_s390_domain(domain);
struct zpci_dev *zdev = to_pci_dev(dev)->sysdata;
struct s390_domain_device *domain_device;
unsigned long flags;
int rc;
if (!zdev)
return -ENODEV;
domain_device = kzalloc(sizeof(*domain_device), GFP_KERNEL);
if (!domain_device)
return -ENOMEM;
if (zdev->dma_table)
zpci_dma_exit_device(zdev);
zdev->dma_table = s390_domain->dma_table;
rc = zpci_register_ioat(zdev, 0, zdev->start_dma + PAGE_OFFSET,
zdev->start_dma + zdev->iommu_size - 1,
(u64) zdev->dma_table);
if (rc)
goto out_restore;
spin_lock_irqsave(&s390_domain->list_lock, flags);
/* First device defines the DMA range limits */
if (list_empty(&s390_domain->devices)) {
domain->geometry.aperture_start = zdev->start_dma;
domain->geometry.aperture_end = zdev->end_dma;
domain->geometry.force_aperture = true;
/* Allow only devices with identical DMA range limits */
} else if (domain->geometry.aperture_start != zdev->start_dma ||
domain->geometry.aperture_end != zdev->end_dma) {
rc = -EINVAL;
spin_unlock_irqrestore(&s390_domain->list_lock, flags);
goto out_restore;
}
domain_device->zdev = zdev;
zdev->s390_domain = s390_domain;
list_add(&domain_device->list, &s390_domain->devices);
spin_unlock_irqrestore(&s390_domain->list_lock, flags);
return 0;
out_restore:
zpci_dma_init_device(zdev);
kfree(domain_device);
return rc;
}
static void s390_iommu_detach_device(struct iommu_domain *domain,
struct device *dev)
{
struct s390_domain *s390_domain = to_s390_domain(domain);
struct zpci_dev *zdev = to_pci_dev(dev)->sysdata;
struct s390_domain_device *domain_device, *tmp;
unsigned long flags;
int found = 0;
if (!zdev)
return;
spin_lock_irqsave(&s390_domain->list_lock, flags);
list_for_each_entry_safe(domain_device, tmp, &s390_domain->devices,
list) {
if (domain_device->zdev == zdev) {
list_del(&domain_device->list);
kfree(domain_device);
found = 1;
break;
}
}
spin_unlock_irqrestore(&s390_domain->list_lock, flags);
if (found) {
zdev->s390_domain = NULL;
zpci_unregister_ioat(zdev, 0);
zpci_dma_init_device(zdev);
}
}
static int s390_iommu_add_device(struct device *dev)
{
struct iommu_group *group;
int rc;
group = iommu_group_get(dev);
if (!group) {
group = iommu_group_alloc();
if (IS_ERR(group))
return PTR_ERR(group);
}
rc = iommu_group_add_device(group, dev);
iommu_group_put(group);
return rc;
}
static void s390_iommu_remove_device(struct device *dev)
{
struct zpci_dev *zdev = to_pci_dev(dev)->sysdata;
struct iommu_domain *domain;
/*
* This is a workaround for a scenario where the IOMMU API common code
* "forgets" to call the detach_dev callback: After binding a device
* to vfio-pci and completing the VFIO_SET_IOMMU ioctl (which triggers
* the attach_dev), removing the device via
* "echo 1 > /sys/bus/pci/devices/.../remove" won't trigger detach_dev,
* only remove_device will be called via the BUS_NOTIFY_REMOVED_DEVICE
* notifier.
*
* So let's call detach_dev from here if it hasn't been called before.
*/
if (zdev && zdev->s390_domain) {
domain = iommu_get_domain_for_dev(dev);
if (domain)
s390_iommu_detach_device(domain, dev);
}
iommu_group_remove_device(dev);
}
static int s390_iommu_update_trans(struct s390_domain *s390_domain,
unsigned long pa, dma_addr_t dma_addr,
size_t size, int flags)
{
struct s390_domain_device *domain_device;
u8 *page_addr = (u8 *) (pa & PAGE_MASK);
dma_addr_t start_dma_addr = dma_addr;
unsigned long irq_flags, nr_pages, i;
int rc = 0;
if (dma_addr < s390_domain->domain.geometry.aperture_start ||
dma_addr + size > s390_domain->domain.geometry.aperture_end)
return -EINVAL;
nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
if (!nr_pages)
return 0;
spin_lock_irqsave(&s390_domain->dma_table_lock, irq_flags);
for (i = 0; i < nr_pages; i++) {
dma_update_cpu_trans(s390_domain->dma_table, page_addr,
dma_addr, flags);
page_addr += PAGE_SIZE;
dma_addr += PAGE_SIZE;
}
spin_lock(&s390_domain->list_lock);
list_for_each_entry(domain_device, &s390_domain->devices, list) {
rc = zpci_refresh_trans((u64) domain_device->zdev->fh << 32,
start_dma_addr, nr_pages * PAGE_SIZE);
if (rc)
break;
}
spin_unlock(&s390_domain->list_lock);
spin_unlock_irqrestore(&s390_domain->dma_table_lock, irq_flags);
return rc;
}
static int s390_iommu_map(struct iommu_domain *domain, unsigned long iova,
phys_addr_t paddr, size_t size, int prot)
{
struct s390_domain *s390_domain = to_s390_domain(domain);
int flags = ZPCI_PTE_VALID, rc = 0;
if (!(prot & IOMMU_READ))
return -EINVAL;
if (!(prot & IOMMU_WRITE))
flags |= ZPCI_TABLE_PROTECTED;
rc = s390_iommu_update_trans(s390_domain, (unsigned long) paddr, iova,
size, flags);
return rc;
}
static phys_addr_t s390_iommu_iova_to_phys(struct iommu_domain *domain,
dma_addr_t iova)
{
struct s390_domain *s390_domain = to_s390_domain(domain);
unsigned long *sto, *pto, *rto, flags;
unsigned int rtx, sx, px;
phys_addr_t phys = 0;
if (iova < domain->geometry.aperture_start ||
iova > domain->geometry.aperture_end)
return 0;
rtx = calc_rtx(iova);
sx = calc_sx(iova);
px = calc_px(iova);
rto = s390_domain->dma_table;
spin_lock_irqsave(&s390_domain->dma_table_lock, flags);
if (rto && reg_entry_isvalid(rto[rtx])) {
sto = get_rt_sto(rto[rtx]);
if (sto && reg_entry_isvalid(sto[sx])) {
pto = get_st_pto(sto[sx]);
if (pto && pt_entry_isvalid(pto[px]))
phys = pto[px] & ZPCI_PTE_ADDR_MASK;
}
}
spin_unlock_irqrestore(&s390_domain->dma_table_lock, flags);
return phys;
}
static size_t s390_iommu_unmap(struct iommu_domain *domain,
unsigned long iova, size_t size)
{
struct s390_domain *s390_domain = to_s390_domain(domain);
int flags = ZPCI_PTE_INVALID;
phys_addr_t paddr;
int rc;
paddr = s390_iommu_iova_to_phys(domain, iova);
if (!paddr)
return 0;
rc = s390_iommu_update_trans(s390_domain, (unsigned long) paddr, iova,
size, flags);
if (rc)
return 0;
return size;
}
static struct iommu_ops s390_iommu_ops = {
.capable = s390_iommu_capable,
.domain_alloc = s390_domain_alloc,
.domain_free = s390_domain_free,
.attach_dev = s390_iommu_attach_device,
.detach_dev = s390_iommu_detach_device,
.map = s390_iommu_map,
.unmap = s390_iommu_unmap,
.iova_to_phys = s390_iommu_iova_to_phys,
.add_device = s390_iommu_add_device,
.remove_device = s390_iommu_remove_device,
.pgsize_bitmap = S390_IOMMU_PGSIZES,
};
static int __init s390_iommu_init(void)
{
return bus_set_iommu(&pci_bus_type, &s390_iommu_ops);
}
subsys_initcall(s390_iommu_init);