1 files changed, 54 insertions, 35 deletions

diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index 88f72745fa59..cd6676c2d602 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -31,6 +31,7 @@
 #include <linux/lockdep.h>
 #include <linux/list_sort.h>
 
+#include <asm/machine.h>
 #include <asm/isc.h>
 #include <asm/airq.h>
 #include <asm/facility.h>
@@ -44,6 +45,7 @@
 /* list of all detected zpci devices */
 static LIST_HEAD(zpci_list);
 static DEFINE_SPINLOCK(zpci_list_lock);
+static DEFINE_MUTEX(zpci_add_remove_lock);
 
 static DECLARE_BITMAP(zpci_domain, ZPCI_DOMAIN_BITMAP_SIZE);
 static DEFINE_SPINLOCK(zpci_domain_lock);
@@ -69,6 +71,15 @@ EXPORT_SYMBOL_GPL(zpci_aipb);
 struct airq_iv *zpci_aif_sbv;
 EXPORT_SYMBOL_GPL(zpci_aif_sbv);
 
+void zpci_zdev_put(struct zpci_dev *zdev)
+{
+	if (!zdev)
+		return;
+	mutex_lock(&zpci_add_remove_lock);
+	kref_put_lock(&zdev->kref, zpci_release_device, &zpci_list_lock);
+	mutex_unlock(&zpci_add_remove_lock);
+}
+
 struct zpci_dev *get_zdev_by_fid(u32 fid)
 {
 	struct zpci_dev *tmp, *zdev = NULL;
@@ -124,14 +135,13 @@ int zpci_register_ioat(struct zpci_dev *zdev, u8 dmaas,
 	struct zpci_fib fib = {0};
 	u8 cc;
 
-	WARN_ON_ONCE(iota & 0x3fff);
 	fib.pba = base;
 	/* Work around off by one in ISM virt device */
 	if (zdev->pft == PCI_FUNC_TYPE_ISM && limit > base)
 		fib.pal = limit + (1 << 12);
 	else
 		fib.pal = limit;
-	fib.iota = iota | ZPCI_IOTA_RTTO_FLAG;
+	fib.iota = iota;
 	fib.gd = zdev->gisa;
 	cc = zpci_mod_fc(req, &fib, status);
 	if (cc)
@@ -255,7 +265,7 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
 }
 
 void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
-			   unsigned long prot)
+			   pgprot_t prot)
 {
 	/*
 	 * When PCI MIO instructions are unavailable the "physical" address
@@ -265,7 +275,7 @@ void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
 	if (!static_branch_unlikely(&have_mio))
 		return (void __iomem *)phys_addr;
 
-	return generic_ioremap_prot(phys_addr, size, __pgprot(prot));
+	return generic_ioremap_prot(phys_addr, size, prot);
 }
 EXPORT_SYMBOL(ioremap_prot);
 
@@ -690,6 +700,23 @@ int zpci_enable_device(struct zpci_dev *zdev)
 }
 EXPORT_SYMBOL_GPL(zpci_enable_device);
 
+int zpci_reenable_device(struct zpci_dev *zdev)
+{
+	u8 status;
+	int rc;
+
+	rc = zpci_enable_device(zdev);
+	if (rc)
+		return rc;
+
+	rc = zpci_iommu_register_ioat(zdev, &status);
+	if (rc)
+		zpci_disable_device(zdev);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(zpci_reenable_device);
+
 int zpci_disable_device(struct zpci_dev *zdev)
 {
 	u32 fh = zdev->fh;
@@ -739,7 +766,6 @@ EXPORT_SYMBOL_GPL(zpci_disable_device);
  */
 int zpci_hot_reset_device(struct zpci_dev *zdev)
 {
-	u8 status;
 	int rc;
 
 	lockdep_assert_held(&zdev->state_lock);
@@ -758,19 +784,9 @@ int zpci_hot_reset_device(struct zpci_dev *zdev)
 			return rc;
 	}
 
-	rc = zpci_enable_device(zdev);
-	if (rc)
-		return rc;
+	rc = zpci_reenable_device(zdev);
 
-	if (zdev->dma_table)
-		rc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
-					virt_to_phys(zdev->dma_table), &status);
-	if (rc) {
-		zpci_disable_device(zdev);
-		return rc;
-	}
-
-	return 0;
+	return rc;
 }
 
 /**
@@ -831,6 +847,7 @@ int zpci_add_device(struct zpci_dev *zdev)
 {
 	int rc;
 
+	mutex_lock(&zpci_add_remove_lock);
 	zpci_dbg(1, "add fid:%x, fh:%x, c:%d\n", zdev->fid, zdev->fh, zdev->state);
 	rc = zpci_init_iommu(zdev);
 	if (rc)
@@ -844,12 +861,14 @@ int zpci_add_device(struct zpci_dev *zdev)
 	spin_lock(&zpci_list_lock);
 	list_add_tail(&zdev->entry, &zpci_list);
 	spin_unlock(&zpci_list_lock);
+	mutex_unlock(&zpci_add_remove_lock);
 	return 0;
 
 error_destroy_iommu:
 	zpci_destroy_iommu(zdev);
 error:
 	zpci_dbg(0, "add fid:%x, rc:%d\n", zdev->fid, rc);
+	mutex_unlock(&zpci_add_remove_lock);
 	return rc;
 }
 
@@ -919,21 +938,20 @@ int zpci_deconfigure_device(struct zpci_dev *zdev)
  * @zdev: the zpci_dev that was reserved
  *
  * Handle the case that a given zPCI function was reserved by another system.
- * After a call to this function the zpci_dev can not be found via
- * get_zdev_by_fid() anymore but may still be accessible via existing
- * references though it will not be functional anymore.
  */
 void zpci_device_reserved(struct zpci_dev *zdev)
 {
-	/*
-	 * Remove device from zpci_list as it is going away. This also
-	 * makes sure we ignore subsequent zPCI events for this device.
-	 */
-	spin_lock(&zpci_list_lock);
-	list_del(&zdev->entry);
-	spin_unlock(&zpci_list_lock);
+	lockdep_assert_held(&zdev->state_lock);
+	/* We may declare the device reserved multiple times */
+	if (zdev->state == ZPCI_FN_STATE_RESERVED)
+		return;
 	zdev->state = ZPCI_FN_STATE_RESERVED;
 	zpci_dbg(3, "rsv fid:%x\n", zdev->fid);
+	/*
+	 * The underlying device is gone. Allow the zdev to be freed
+	 * as soon as all other references are gone by accounting for
+	 * the removal as a dropped reference.
+	 */
 	zpci_zdev_put(zdev);
 }
 
@@ -941,13 +959,14 @@ void zpci_release_device(struct kref *kref)
 {
 	struct zpci_dev *zdev = container_of(kref, struct zpci_dev, kref);
 
+	lockdep_assert_held(&zpci_add_remove_lock);
 	WARN_ON(zdev->state != ZPCI_FN_STATE_RESERVED);
-
-	if (zdev->zbus->bus)
-		zpci_bus_remove_device(zdev, false);
-
-	if (zdev_enabled(zdev))
-		zpci_disable_device(zdev);
+	/*
+	 * We already hold zpci_list_lock thanks to kref_put_lock().
+	 * This makes sure no new reference can be taken from the list.
+	 */
+	list_del(&zdev->entry);
+	spin_unlock(&zpci_list_lock);
 
 	if (zdev->has_hp_slot)
 		zpci_exit_slot(zdev);
@@ -1073,7 +1092,7 @@ char * __init pcibios_setup(char *str)
 		return NULL;
 	}
 	if (!strcmp(str, "nomio")) {
-		get_lowcore()->machine_flags &= ~MACHINE_FLAG_PCI_MIO;
+		clear_machine_feature(MFEATURE_PCI_MIO);
 		return NULL;
 	}
 	if (!strcmp(str, "force_floating")) {
@@ -1148,7 +1167,7 @@ static int __init pci_base_init(void)
 		return 0;
 	}
 
-	if (MACHINE_HAS_PCI_MIO) {
+	if (test_machine_feature(MFEATURE_PCI_MIO)) {
 		static_branch_enable(&have_mio);
 		system_ctl_set_bit(2, CR2_MIO_ADDRESSING_BIT);
 	}