Commit 81244074 authored by Matthew Rosato's avatar Matthew Rosato Committed by Joerg Roedel
Browse files

iommu/s390: allow larger region tables 



Extend the aperture calculation to consider sizes beyond the maximum
size of a region third table.  Attempt to always use the smallest
table size possible to avoid unnecessary extra steps during translation.
Update reserved region calculations to use the appropriate table size.

Signed-off-by: default avatarMatthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: default avatarNiklas Schnelle <schnelle@linux.ibm.com>
Tested-by: default avatarNiklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20250411202433.181683-6-mjrosato@linux.ibm.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent d5fbc5ef

arch/s390/include/asm/pci_dma.h

+1 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ enum zpci_ioat_dtype { 
#define ZPCI_KEY			(PAGE_DEFAULT_KEY << 5)



#define ZPCI_TABLE_SIZE_RT	(1UL << 42)

#define ZPCI_TABLE_SIZE_RS	(1UL << 53)



#define ZPCI_IOTA_STO_FLAG	(ZPCI_IOTA_IOT_ENABLED | ZPCI_KEY | ZPCI_IOTA_DT_ST)

#define ZPCI_IOTA_RTTO_FLAG	(ZPCI_IOTA_IOT_ENABLED | ZPCI_KEY | ZPCI_IOTA_DT_RT)

drivers/iommu/s390-iommu.c

+52 −18
Original line number Diff line number Diff line
@@ -511,9 +511,25 @@ static bool s390_iommu_capable(struct device *dev, enum iommu_cap cap) 
	}

}



static inline u64 max_tbl_size(struct s390_domain *domain)

{

	switch (domain->origin_type) {

	case ZPCI_TABLE_TYPE_RTX:

		return ZPCI_TABLE_SIZE_RT - 1;

	case ZPCI_TABLE_TYPE_RSX:

		return ZPCI_TABLE_SIZE_RS - 1;

	case ZPCI_TABLE_TYPE_RFX:

		return U64_MAX;

	default:

		return 0;

	}

}



static struct iommu_domain *s390_domain_alloc_paging(struct device *dev)

{

	struct zpci_dev *zdev = to_zpci_dev(dev);

	struct s390_domain *s390_domain;

	u64 aperture_size;



	s390_domain = kzalloc(sizeof(*s390_domain), GFP_KERNEL);

	if (!s390_domain)
@@ -524,10 +540,26 @@ static struct iommu_domain *s390_domain_alloc_paging(struct device *dev) 
		kfree(s390_domain);

		return NULL;

	}



	aperture_size = min(s390_iommu_aperture,

			    zdev->end_dma - zdev->start_dma + 1);

	if (aperture_size <= (ZPCI_TABLE_SIZE_RT - zdev->start_dma)) {

		s390_domain->origin_type = ZPCI_TABLE_TYPE_RTX;

	} else if (aperture_size <= (ZPCI_TABLE_SIZE_RS - zdev->start_dma) &&

		  (zdev->dtsm & ZPCI_IOTA_DT_RS)) {

		s390_domain->origin_type = ZPCI_TABLE_TYPE_RSX;

	} else if (zdev->dtsm & ZPCI_IOTA_DT_RF) {

		s390_domain->origin_type = ZPCI_TABLE_TYPE_RFX;

	} else {

		/* Assume RTX available */

		s390_domain->origin_type = ZPCI_TABLE_TYPE_RTX;

		aperture_size = ZPCI_TABLE_SIZE_RT - zdev->start_dma;

	}

	zdev->end_dma = zdev->start_dma + aperture_size - 1;



	s390_domain->domain.geometry.force_aperture = true;

	s390_domain->domain.geometry.aperture_start = 0;

	s390_domain->domain.geometry.aperture_end = ZPCI_TABLE_SIZE_RT - 1;

	s390_domain->origin_type = ZPCI_TABLE_TYPE_RTX;

	s390_domain->domain.geometry.aperture_end = max_tbl_size(s390_domain);



	spin_lock_init(&s390_domain->list_lock);

	INIT_LIST_HEAD_RCU(&s390_domain->devices);
@@ -680,6 +712,8 @@ static void s390_iommu_get_resv_regions(struct device *dev, 
{

	struct zpci_dev *zdev = to_zpci_dev(dev);

	struct iommu_resv_region *region;

	u64 max_size, end_resv;

	unsigned long flags;



	if (zdev->start_dma) {

		region = iommu_alloc_resv_region(0, zdev->start_dma, 0,
@@ -689,10 +723,21 @@ static void s390_iommu_get_resv_regions(struct device *dev, 
		list_add_tail(&region->list, list);

	}



	if (zdev->end_dma < ZPCI_TABLE_SIZE_RT - 1) {

		region = iommu_alloc_resv_region(zdev->end_dma + 1,

						 ZPCI_TABLE_SIZE_RT - zdev->end_dma - 1,

						 0, IOMMU_RESV_RESERVED, GFP_KERNEL);

	spin_lock_irqsave(&zdev->dom_lock, flags);

	if (zdev->s390_domain->type == IOMMU_DOMAIN_BLOCKED ||

	    zdev->s390_domain->type == IOMMU_DOMAIN_IDENTITY) {

		spin_unlock_irqrestore(&zdev->dom_lock, flags);

		return;

	}



	max_size = max_tbl_size(to_s390_domain(zdev->s390_domain));

	spin_unlock_irqrestore(&zdev->dom_lock, flags);



	if (zdev->end_dma < max_size) {

		end_resv = max_size - zdev->end_dma;

		region = iommu_alloc_resv_region(zdev->end_dma + 1, end_resv,

						 0, IOMMU_RESV_RESERVED,

						 GFP_KERNEL);

		if (!region)

			return;

		list_add_tail(&region->list, list);
@@ -708,13 +753,9 @@ static struct iommu_device *s390_iommu_probe_device(struct device *dev) 


	zdev = to_zpci_dev(dev);



	if (zdev->start_dma > zdev->end_dma ||

	    zdev->start_dma > ZPCI_TABLE_SIZE_RT - 1)

	if (zdev->start_dma > zdev->end_dma)

		return ERR_PTR(-EINVAL);



	if (zdev->end_dma > ZPCI_TABLE_SIZE_RT - 1)

		zdev->end_dma = ZPCI_TABLE_SIZE_RT - 1;



	if (zdev->tlb_refresh)

		dev->iommu->shadow_on_flush = 1;
@@ -999,7 +1040,6 @@ struct zpci_iommu_ctrs *zpci_get_iommu_ctrs(struct zpci_dev *zdev) 


int zpci_init_iommu(struct zpci_dev *zdev)

{

	u64 aperture_size;

	int rc = 0;



	rc = iommu_device_sysfs_add(&zdev->iommu_dev, NULL, NULL,
@@ -1017,12 +1057,6 @@ int zpci_init_iommu(struct zpci_dev *zdev) 
	if (rc)

		goto out_sysfs;



	zdev->start_dma = PAGE_ALIGN(zdev->start_dma);

	aperture_size = min3(s390_iommu_aperture,

			     ZPCI_TABLE_SIZE_RT - zdev->start_dma,

			     zdev->end_dma - zdev->start_dma + 1);

	zdev->end_dma = zdev->start_dma + aperture_size - 1;



	return 0;



out_sysfs: