Commit 1a3a7d64 authored by Niklas Schnelle's avatar Niklas Schnelle Committed by Joerg Roedel
Browse files

iommu/s390: Get rid of s390_domain_device 



The struct s390_domain_device serves the sole purpose as list entry for
the devices list of a struct s390_domain. As it contains no additional
information besides a list_head and a pointer to the struct zpci_dev we
can simplify things and just thread the device list through struct
zpci_dev directly. This removes the need to allocate during domain
attach and gets rid of one level of indirection during mapping
operations.

Reviewed-by: default avatarMatthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Signed-off-by: default avatarNiklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20221025115657.1666860-3-schnelle@linux.ibm.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent bf8d2dd2

arch/s390/include/asm/pci.h

+1 −0
Original line number Diff line number Diff line
@@ -117,6 +117,7 @@ struct zpci_bus { 
struct zpci_dev {

	struct zpci_bus *zbus;

	struct list_head entry;		/* list of all zpci_devices, needed for hotplug, etc. */

	struct list_head iommu_list;

	struct kref kref;

	struct hotplug_slot hotplug_slot;

drivers/iommu/s390-iommu.c

+7 −30
Original line number Diff line number Diff line
@@ -29,11 +29,6 @@ struct s390_domain { 
	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);
@@ -87,21 +82,13 @@ static void s390_domain_free(struct iommu_domain *domain) 
static void __s390_iommu_detach_device(struct zpci_dev *zdev)

{

	struct s390_domain *s390_domain = zdev->s390_domain;

	struct s390_domain_device *domain_device, *tmp;

	unsigned long flags;



	if (!s390_domain)

		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);

			break;

		}

	}

	list_del_init(&zdev->iommu_list);

	spin_unlock_irqrestore(&s390_domain->list_lock, flags);



	zpci_unregister_ioat(zdev, 0);
@@ -114,17 +101,12 @@ static int s390_iommu_attach_device(struct iommu_domain *domain, 
{

	struct s390_domain *s390_domain = to_s390_domain(domain);

	struct zpci_dev *zdev = to_zpci_dev(dev);

	struct s390_domain_device *domain_device;

	unsigned long flags;

	int cc, rc = 0;



	if (!zdev)

		return -ENODEV;



	domain_device = kzalloc(sizeof(*domain_device), GFP_KERNEL);

	if (!domain_device)

		return -ENOMEM;



	if (zdev->s390_domain)

		__s390_iommu_detach_device(zdev);

	else if (zdev->dma_table)
@@ -132,10 +114,8 @@ static int s390_iommu_attach_device(struct iommu_domain *domain, 


	cc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,

				virt_to_phys(s390_domain->dma_table));

	if (cc) {

		rc = -EIO;

		goto out_free;

	}

	if (cc)

		return -EIO;

	zdev->dma_table = s390_domain->dma_table;



	spin_lock_irqsave(&s390_domain->list_lock, flags);
@@ -151,9 +131,8 @@ static int s390_iommu_attach_device(struct iommu_domain *domain, 
		rc = -EINVAL;

		goto out_unregister;

	}

	domain_device->zdev = zdev;

	zdev->s390_domain = s390_domain;

	list_add(&domain_device->list, &s390_domain->devices);

	list_add(&zdev->iommu_list, &s390_domain->devices);

	spin_unlock_irqrestore(&s390_domain->list_lock, flags);



	return 0;
@@ -161,8 +140,6 @@ static int s390_iommu_attach_device(struct iommu_domain *domain, 
out_unregister:

	zpci_unregister_ioat(zdev, 0);

	zdev->dma_table = NULL;

out_free:

	kfree(domain_device);



	return rc;

}
@@ -206,10 +183,10 @@ static int s390_iommu_update_trans(struct s390_domain *s390_domain, 
				   phys_addr_t pa, dma_addr_t dma_addr,

				   size_t size, int flags)

{

	struct s390_domain_device *domain_device;

	phys_addr_t page_addr = pa & PAGE_MASK;

	dma_addr_t start_dma_addr = dma_addr;

	unsigned long irq_flags, nr_pages, i;

	struct zpci_dev *zdev;

	unsigned long *entry;

	int rc = 0;
@@ -234,8 +211,8 @@ static int s390_iommu_update_trans(struct s390_domain *s390_domain, 
	}



	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,

	list_for_each_entry(zdev, &s390_domain->devices, iommu_list) {

		rc = zpci_refresh_trans((u64)zdev->fh << 32,

					start_dma_addr, nr_pages * PAGE_SIZE);

		if (rc)

			break;