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authorNiklas Schnelle <schnelle@linux.ibm.com>2021-07-16 11:53:37 +0200
committerHeiko Carstens <hca@linux.ibm.com>2021-08-25 11:03:34 +0200
commit1f3f76812d5dfc791193b39c2140a8bd09962c0e (patch)
tree8f61dd33029e218e765af3ad8753856ad6d5881b /arch/s390
parents390/pci: simplify CLP List PCI handling (diff)
downloadlinux-1f3f76812d5dfc791193b39c2140a8bd09962c0e.tar.xz
linux-1f3f76812d5dfc791193b39c2140a8bd09962c0e.zip
s390/pci: improve DMA translation init and exit
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>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/include/asm/pci.h2
-rw-r--r--arch/s390/include/asm/pci_dma.h2
-rw-r--r--arch/s390/pci/pci.c43
-rw-r--r--arch/s390/pci/pci_bus.c5
-rw-r--r--arch/s390/pci/pci_dma.c25
-rw-r--r--arch/s390/pci/pci_event.c5
-rw-r--r--arch/s390/pci/pci_sysfs.c19
7 files changed, 63 insertions, 38 deletions
diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
index c51e64d49d4e..e4803ec51110 100644
--- 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);
diff --git a/arch/s390/include/asm/pci_dma.h b/arch/s390/include/asm/pci_dma.h
index f62cd3ed2d44..3b8e89d4578a 100644
--- 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(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 *);
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index b05b86e2d2c0..728508da999d 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -113,13 +113,16 @@ int zpci_register_ioat(struct zpci_dev *zdev, u8 dmaas,
{
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 *zdev, u8 dmaas)
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 */
@@ -654,24 +657,12 @@ 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;
}
@@ -680,9 +671,6 @@ int zpci_disable_device(struct zpci_dev *zdev)
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;
@@ -808,6 +796,11 @@ int zpci_deconfigure_device(struct zpci_dev *zdev)
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)
@@ -831,6 +824,8 @@ void zpci_release_device(struct kref *kref)
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);
diff --git a/arch/s390/pci/pci_bus.c b/arch/s390/pci/pci_bus.c
index 3c9ad518712e..5d77acbd1c87 100644
--- a/arch/s390/pci/pci_bus.c
+++ b/arch/s390/pci/pci_bus.c
@@ -49,6 +49,11 @@ static int zpci_bus_prepare_device(struct zpci_dev *zdev)
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) {
diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c
index ebc9a49523aa..58f2f7abea96 100644
--- 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 *zdev)
}
}
- 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_dev *zdev)
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)
diff --git a/arch/s390/pci/pci_event.c b/arch/s390/pci/pci_event.c
index cd447b96b4b1..c856f80cb21b 100644
--- a/arch/s390/pci/pci_event.c
+++ b/arch/s390/pci/pci_event.c
@@ -84,7 +84,10 @@ static void zpci_event_hard_deconfigured(struct zpci_dev *zdev, u32 fh)
/* 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;
}
diff --git a/arch/s390/pci/pci_sysfs.c b/arch/s390/pci/pci_sysfs.c
index 6e2450c2b9c1..335c281811c7 100644
--- a/arch/s390/pci/pci_sysfs.c
+++ b/arch/s390/pci/pci_sysfs.c
@@ -82,13 +82,26 @@ static ssize_t recover_store(struct device *dev, struct device_attribute *attr,
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: