From: Niklas Schnelle <schnelle@linux.ibm.com>
Date: Fri, 16 Jul 2021 11:53:37 +0200
Subject: s390/pci: improve DMA translation init and exit
Git-commit: 1f3f76812d5dfc791193b39c2140a8bd09962c0e
Patch-mainline: v5.15-rc1
References: jsc#PED-592
Currently zpci_dma_init_device()/zpci_dma_exit_device() is called as
part of zpci_enable_device()/zpci_disable_device() and errors for
zpci_dma_exit_device() are always ignored even if we could abort.
Improve upon this by moving zpci_dma_exit_device() out of
zpci_disable_device() and check for errors whenever we have a way to
abort the current operation. Note that for example in
zpci_event_hard_deconfigured() the device is expected to be gone so we
really can't abort and proceed even in case of error.
Similarly move the cc == 3 special case out of zpci_unregister_ioat()
and into the callers allowing to abort when finding an already disabled
devices precludes proceeding with the operation.
While we are at it log IOAT register/unregister errors in the s390
debugfs log,
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
arch/s390/include/asm/pci.h | 2 +
arch/s390/include/asm/pci_dma.h | 2 -
arch/s390/pci/pci.c | 43 +++++++++++++++++-----------------------
arch/s390/pci/pci_bus.c | 5 ++++
arch/s390/pci/pci_dma.c | 25 +++++++++++++++--------
arch/s390/pci/pci_event.c | 5 +++-
arch/s390/pci/pci_sysfs.c | 19 ++++++++++++++---
drivers/iommu/s390-iommu.c | 18 ++++++++++++----
8 files changed, 76 insertions(+), 43 deletions(-)
--- a/arch/s390/include/asm/pci.h
+++ b/arch/s390/include/asm/pci.h
@@ -272,6 +272,8 @@ struct zpci_dev *get_zdev_by_fid(u32);
/* DMA */
int zpci_dma_init(void);
void zpci_dma_exit(void);
+int zpci_dma_init_device(struct zpci_dev *zdev);
+int zpci_dma_exit_device(struct zpci_dev *zdev);
/* IRQ */
int __init zpci_irq_init(void);
--- a/arch/s390/include/asm/pci_dma.h
+++ b/arch/s390/include/asm/pci_dma.h
@@ -182,8 +182,6 @@ static inline unsigned long *get_st_pto(
}
/* 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 *);
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -113,13 +113,16 @@ int zpci_register_ioat(struct zpci_dev *
{
u64 req = ZPCI_CREATE_REQ(zdev->fh, dmaas, ZPCI_MOD_FC_REG_IOAT);
struct zpci_fib fib = {0};
- u8 status;
+ u8 cc, 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;
+ cc = zpci_mod_fc(req, &fib, &status);
+ if (cc)
+ zpci_dbg(3, "reg ioat fid:%x, cc:%d, status:%d\n", zdev->fid, cc, status);
+ return cc;
}
/* Modify PCI: Unregister I/O address translation parameters */
@@ -130,9 +133,9 @@ int zpci_unregister_ioat(struct zpci_dev
u8 cc, status;
cc = zpci_mod_fc(req, &fib, &status);
- if (cc == 3) /* Function already gone. */
- cc = 0;
- return cc ? -EIO : 0;
+ if (cc)
+ zpci_dbg(3, "unreg ioat fid:%x, cc:%d, status:%d\n", zdev->fid, cc, status);
+ return cc;
}
/* Modify PCI: Set PCI function measurement parameters */
@@ -660,24 +663,12 @@ void zpci_free_domain(int domain)
int zpci_enable_device(struct zpci_dev *zdev)
{
u32 fh = zdev->fh;
- int rc;
+ int rc = 0;
- if (clp_enable_fh(zdev, &fh, ZPCI_NR_DMA_SPACES)) {
+ if (clp_enable_fh(zdev, &fh, ZPCI_NR_DMA_SPACES))
rc = -EIO;
- goto out;
- }
- zdev->fh = fh;
-
- rc = zpci_dma_init_device(zdev);
- if (rc)
- goto out_dma;
-
- return 0;
-
-out_dma:
- clp_disable_fh(zdev, &fh);
-out:
- zdev->fh = fh;
+ else
+ zdev->fh = fh;
return rc;
}
@@ -686,9 +677,6 @@ int zpci_disable_device(struct zpci_dev
u32 fh = zdev->fh;
int cc, rc = 0;
- zpci_dma_exit_device(zdev);
- if (!zdev_enabled(zdev))
- return 0;
cc = clp_disable_fh(zdev, &fh);
if (!cc) {
zdev->fh = fh;
@@ -814,6 +802,11 @@ int zpci_deconfigure_device(struct zpci_
if (zdev->zbus->bus)
zpci_bus_remove_device(zdev, false);
+ if (zdev->dma_table) {
+ rc = zpci_dma_exit_device(zdev);
+ if (rc)
+ return rc;
+ }
if (zdev_enabled(zdev)) {
rc = zpci_disable_device(zdev);
if (rc)
@@ -837,6 +830,8 @@ void zpci_release_device(struct kref *kr
if (zdev->zbus->bus)
zpci_bus_remove_device(zdev, false);
+ if (zdev->dma_table)
+ zpci_dma_exit_device(zdev);
if (zdev_enabled(zdev))
zpci_disable_device(zdev);
--- a/arch/s390/pci/pci_bus.c
+++ b/arch/s390/pci/pci_bus.c
@@ -49,6 +49,11 @@ static int zpci_bus_prepare_device(struc
rc = zpci_enable_device(zdev);
if (rc)
return rc;
+ rc = zpci_dma_init_device(zdev);
+ if (rc) {
+ zpci_disable_device(zdev);
+ return rc;
+ }
}
if (!zdev->has_resources) {
--- a/arch/s390/pci/pci_dma.c
+++ b/arch/s390/pci/pci_dma.c
@@ -590,10 +590,11 @@ int zpci_dma_init_device(struct zpci_dev
}
}
- rc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
- (u64) zdev->dma_table);
- if (rc)
+ if (zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
+ (u64)zdev->dma_table)) {
+ rc = -EIO;
goto free_bitmap;
+ }
return 0;
free_bitmap:
@@ -608,17 +609,25 @@ out:
return rc;
}
-void zpci_dma_exit_device(struct zpci_dev *zdev)
+int zpci_dma_exit_device(struct zpci_dev *zdev)
{
+ int cc = 0;
+
/*
* 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);
-
- if (zpci_unregister_ioat(zdev, 0))
- return;
+ if (zdev_enabled(zdev))
+ cc = zpci_unregister_ioat(zdev, 0);
+ /*
+ * cc == 3 indicates the function is gone already. This can happen
+ * if the function was deconfigured/disabled suddenly and we have not
+ * received a new handle yet.
+ */
+ if (cc && cc != 3)
+ return -EIO;
dma_cleanup_tables(zdev->dma_table);
zdev->dma_table = NULL;
@@ -626,8 +635,8 @@ void zpci_dma_exit_device(struct zpci_de
zdev->iommu_bitmap = NULL;
vfree(zdev->lazy_bitmap);
zdev->lazy_bitmap = NULL;
-
zdev->next_bit = 0;
+ return 0;
}
static int __init dma_alloc_cpu_table_caches(void)
--- a/arch/s390/pci/pci_event.c
+++ b/arch/s390/pci/pci_event.c
@@ -84,7 +84,10 @@ static void zpci_event_hard_deconfigured
/* Even though the device is already gone we still
* need to free zPCI resources as part of the disable.
*/
- zpci_disable_device(zdev);
+ if (zdev->dma_table)
+ zpci_dma_exit_device(zdev);
+ if (zdev_enabled(zdev))
+ zpci_disable_device(zdev);
zdev->state = ZPCI_FN_STATE_STANDBY;
}
--- a/arch/s390/pci/pci_sysfs.c
+++ b/arch/s390/pci/pci_sysfs.c
@@ -82,13 +82,26 @@ static ssize_t recover_store(struct devi
pci_lock_rescan_remove();
if (pci_dev_is_added(pdev)) {
pci_stop_and_remove_bus_device(pdev);
- ret = zpci_disable_device(zdev);
- if (ret)
- goto out;
+ if (zdev->dma_table) {
+ ret = zpci_dma_exit_device(zdev);
+ if (ret)
+ goto out;
+ }
+
+ if (zdev_enabled(zdev)) {
+ ret = zpci_disable_device(zdev);
+ if (ret)
+ goto out;
+ }
ret = zpci_enable_device(zdev);
if (ret)
goto out;
+ ret = zpci_dma_init_device(zdev);
+ if (ret) {
+ zpci_disable_device(zdev);
+ goto out;
+ }
pci_rescan_bus(zdev->zbus->bus);
}
out:
--- a/drivers/iommu/s390-iommu.c
+++ b/drivers/iommu/s390-iommu.c
@@ -90,7 +90,7 @@ static int s390_iommu_attach_device(stru
struct zpci_dev *zdev = to_zpci_dev(dev);
struct s390_domain_device *domain_device;
unsigned long flags;
- int rc;
+ int cc, rc;
if (!zdev)
return -ENODEV;
@@ -99,14 +99,21 @@ static int s390_iommu_attach_device(stru
if (!domain_device)
return -ENOMEM;
- if (zdev->dma_table)
- zpci_dma_exit_device(zdev);
+ if (zdev->dma_table) {
+ cc = zpci_dma_exit_device(zdev);
+ if (cc) {
+ rc = -EIO;
+ goto out_free;
+ }
+ }
zdev->dma_table = s390_domain->dma_table;
- rc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
+ cc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
(u64) zdev->dma_table);
- if (rc)
+ if (cc) {
+ rc = -EIO;
goto out_restore;
+ }
spin_lock_irqsave(&s390_domain->list_lock, flags);
/* First device defines the DMA range limits */
@@ -130,6 +137,7 @@ static int s390_iommu_attach_device(stru
out_restore:
zpci_dma_init_device(zdev);
+out_free:
kfree(domain_device);
return rc;