Merge branch 'dev-5.10' into dev-5.10-inteldev-5.10-intel

Pull 5.10.67 stable from OpenBMC upstream.

Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>

13 files changed, 179 insertions, 121 deletions

diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 463c24e26000..171913b9a925 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -957,6 +957,7 @@ struct kvm_arch{
 	atomic64_t cmma_dirty_pages;
 	/* subset of available cpu features enabled by user space */
 	DECLARE_BITMAP(cpu_feat, KVM_S390_VM_CPU_FEAT_NR_BITS);
+	/* indexed by vcpu_idx */
 	DECLARE_BITMAP(idle_mask, KVM_MAX_VCPUS);
 	struct kvm_s390_gisa_interrupt gisa_int;
 	struct kvm_s390_pv pv;
diff --git a/arch/s390/include/asm/setup.h b/arch/s390/include/asm/setup.h
index bdb242a1544e..75a2ecec2ab8 100644
--- a/arch/s390/include/asm/setup.h
+++ b/arch/s390/include/asm/setup.h
@@ -38,6 +38,7 @@
 #define MACHINE_FLAG_NX		BIT(15)
 #define MACHINE_FLAG_GS		BIT(16)
 #define MACHINE_FLAG_SCC	BIT(17)
+#define MACHINE_FLAG_PCI_MIO	BIT(18)
 
 #define LPP_MAGIC		BIT(31)
 #define LPP_PID_MASK		_AC(0xffffffff, UL)
@@ -113,6 +114,7 @@ extern unsigned long mio_wb_bit_mask;
 #define MACHINE_HAS_NX		(S390_lowcore.machine_flags & MACHINE_FLAG_NX)
 #define MACHINE_HAS_GS		(S390_lowcore.machine_flags & MACHINE_FLAG_GS)
 #define MACHINE_HAS_SCC		(S390_lowcore.machine_flags & MACHINE_FLAG_SCC)
+#define MACHINE_HAS_PCI_MIO	(S390_lowcore.machine_flags & MACHINE_FLAG_PCI_MIO)
 
 /*
  * Console mode. Override with conmode=
diff --git a/arch/s390/kernel/debug.c b/arch/s390/kernel/debug.c
index b6619ae9a3e0..89fbfb3b1e01 100644
--- a/arch/s390/kernel/debug.c
+++ b/arch/s390/kernel/debug.c
@@ -24,6 +24,7 @@
 #include <linux/export.h>
 #include <linux/init.h>
 #include <linux/fs.h>
+#include <linux/minmax.h>
 #include <linux/debugfs.h>
 
 #include <asm/debug.h>
@@ -92,6 +93,8 @@ static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view,
 				     char *out_buf, const char *in_buf);
 static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view,
 				   char *out_buf, debug_sprintf_entry_t *curr_event);
+static void debug_areas_swap(debug_info_t *a, debug_info_t *b);
+static void debug_events_append(debug_info_t *dest, debug_info_t *src);
 
 /* globals */
 
@@ -311,24 +314,6 @@ static debug_info_t *debug_info_create(const char *name, int pages_per_area,
 		goto out;
 
 	rc->mode = mode & ~S_IFMT;
-
-	/* create root directory */
-	rc->debugfs_root_entry = debugfs_create_dir(rc->name,
-						    debug_debugfs_root_entry);
-
-	/* append new element to linked list */
-	if (!debug_area_first) {
-		/* first element in list */
-		debug_area_first = rc;
-		rc->prev = NULL;
-	} else {
-		/* append element to end of list */
-		debug_area_last->next = rc;
-		rc->prev = debug_area_last;
-	}
-	debug_area_last = rc;
-	rc->next = NULL;
-
 	refcount_set(&rc->ref_count, 1);
 out:
 	return rc;
@@ -388,27 +373,10 @@ static void debug_info_get(debug_info_t *db_info)
  */
 static void debug_info_put(debug_info_t *db_info)
 {
-	int i;
-
 	if (!db_info)
 		return;
-	if (refcount_dec_and_test(&db_info->ref_count)) {
-		for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
-			if (!db_info->views[i])
-				continue;
-			debugfs_remove(db_info->debugfs_entries[i]);
-		}
-		debugfs_remove(db_info->debugfs_root_entry);
-		if (db_info == debug_area_first)
-			debug_area_first = db_info->next;
-		if (db_info == debug_area_last)
-			debug_area_last = db_info->prev;
-		if (db_info->prev)
-			db_info->prev->next = db_info->next;
-		if (db_info->next)
-			db_info->next->prev = db_info->prev;
+	if (refcount_dec_and_test(&db_info->ref_count))
 		debug_info_free(db_info);
-	}
 }
 
 /*
@@ -632,6 +600,31 @@ static int debug_close(struct inode *inode, struct file *file)
 	return 0; /* success */
 }
 
+/* Create debugfs entries and add to internal list. */
+static void _debug_register(debug_info_t *id)
+{
+	/* create root directory */
+	id->debugfs_root_entry = debugfs_create_dir(id->name,
+						    debug_debugfs_root_entry);
+
+	/* append new element to linked list */
+	if (!debug_area_first) {
+		/* first element in list */
+		debug_area_first = id;
+		id->prev = NULL;
+	} else {
+		/* append element to end of list */
+		debug_area_last->next = id;
+		id->prev = debug_area_last;
+	}
+	debug_area_last = id;
+	id->next = NULL;
+
+	debug_register_view(id, &debug_level_view);
+	debug_register_view(id, &debug_flush_view);
+	debug_register_view(id, &debug_pages_view);
+}
+
 /**
  * debug_register_mode() - creates and initializes debug area.
  *
@@ -661,19 +654,16 @@ debug_info_t *debug_register_mode(const char *name, int pages_per_area,
 	if ((uid != 0) || (gid != 0))
 		pr_warn("Root becomes the owner of all s390dbf files in sysfs\n");
 	BUG_ON(!initialized);
-	mutex_lock(&debug_mutex);
 
 	/* create new debug_info */
 	rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
-	if (!rc)
-		goto out;
-	debug_register_view(rc, &debug_level_view);
-	debug_register_view(rc, &debug_flush_view);
-	debug_register_view(rc, &debug_pages_view);
-out:
-	if (!rc)
+	if (rc) {
+		mutex_lock(&debug_mutex);
+		_debug_register(rc);
+		mutex_unlock(&debug_mutex);
+	} else {
 		pr_err("Registering debug feature %s failed\n", name);
-	mutex_unlock(&debug_mutex);
+	}
 	return rc;
 }
 EXPORT_SYMBOL(debug_register_mode);
@@ -702,6 +692,27 @@ debug_info_t *debug_register(const char *name, int pages_per_area,
 }
 EXPORT_SYMBOL(debug_register);
 
+/* Remove debugfs entries and remove from internal list. */
+static void _debug_unregister(debug_info_t *id)
+{
+	int i;
+
+	for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
+		if (!id->views[i])
+			continue;
+		debugfs_remove(id->debugfs_entries[i]);
+	}
+	debugfs_remove(id->debugfs_root_entry);
+	if (id == debug_area_first)
+		debug_area_first = id->next;
+	if (id == debug_area_last)
+		debug_area_last = id->prev;
+	if (id->prev)
+		id->prev->next = id->next;
+	if (id->next)
+		id->next->prev = id->prev;
+}
+
 /**
  * debug_unregister() - give back debug area.
  *
@@ -715,8 +726,10 @@ void debug_unregister(debug_info_t *id)
 	if (!id)
 		return;
 	mutex_lock(&debug_mutex);
-	debug_info_put(id);
+	_debug_unregister(id);
 	mutex_unlock(&debug_mutex);
+
+	debug_info_put(id);
 }
 EXPORT_SYMBOL(debug_unregister);
 
@@ -726,35 +739,28 @@ EXPORT_SYMBOL(debug_unregister);
  */
 static int debug_set_size(debug_info_t *id, int nr_areas, int pages_per_area)
 {
-	debug_entry_t ***new_areas;
+	debug_info_t *new_id;
 	unsigned long flags;
-	int rc = 0;
 
 	if (!id || (nr_areas <= 0) || (pages_per_area < 0))
 		return -EINVAL;
-	if (pages_per_area > 0) {
-		new_areas = debug_areas_alloc(pages_per_area, nr_areas);
-		if (!new_areas) {
-			pr_info("Allocating memory for %i pages failed\n",
-				pages_per_area);
-			rc = -ENOMEM;
-			goto out;
-		}
-	} else {
-		new_areas = NULL;
+
+	new_id = debug_info_alloc("", pages_per_area, nr_areas, id->buf_size,
+				  id->level, ALL_AREAS);
+	if (!new_id) {
+		pr_info("Allocating memory for %i pages failed\n",
+			pages_per_area);
+		return -ENOMEM;
 	}
+
 	spin_lock_irqsave(&id->lock, flags);
-	debug_areas_free(id);
-	id->areas = new_areas;
-	id->nr_areas = nr_areas;
-	id->pages_per_area = pages_per_area;
-	id->active_area = 0;
-	memset(id->active_entries, 0, sizeof(int)*id->nr_areas);
-	memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
+	debug_events_append(new_id, id);
+	debug_areas_swap(new_id, id);
+	debug_info_free(new_id);
 	spin_unlock_irqrestore(&id->lock, flags);
 	pr_info("%s: set new size (%i pages)\n", id->name, pages_per_area);
-out:
-	return rc;
+
+	return 0;
 }
 
 /**
@@ -821,6 +827,42 @@ static inline debug_entry_t *get_active_entry(debug_info_t *id)
 				  id->active_entries[id->active_area]);
 }
 
+/* Swap debug areas of a and b. */
+static void debug_areas_swap(debug_info_t *a, debug_info_t *b)
+{
+	swap(a->nr_areas, b->nr_areas);
+	swap(a->pages_per_area, b->pages_per_area);
+	swap(a->areas, b->areas);
+	swap(a->active_area, b->active_area);
+	swap(a->active_pages, b->active_pages);
+	swap(a->active_entries, b->active_entries);
+}
+
+/* Append all debug events in active area from source to destination log. */
+static void debug_events_append(debug_info_t *dest, debug_info_t *src)
+{
+	debug_entry_t *from, *to, *last;
+
+	if (!src->areas || !dest->areas)
+		return;
+
+	/* Loop over all entries in src, starting with oldest. */
+	from = get_active_entry(src);
+	last = from;
+	do {
+		if (from->clock != 0LL) {
+			to = get_active_entry(dest);
+			memset(to, 0, dest->entry_size);
+			memcpy(to, from, min(src->entry_size,
+					     dest->entry_size));
+			proceed_active_entry(dest);
+		}
+
+		proceed_active_entry(src);
+		from = get_active_entry(src);
+	} while (from != last);
+}
+
 /*
  * debug_finish_entry:
  * - set timestamp, caller address, cpu number etc.
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index 705844f73934..985e1e755333 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -238,6 +238,10 @@ static __init void detect_machine_facilities(void)
 		clock_comparator_max = -1ULL >> 1;
 		__ctl_set_bit(0, 53);
 	}
+	if (IS_ENABLED(CONFIG_PCI) && test_facility(153)) {
+		S390_lowcore.machine_flags |= MACHINE_FLAG_PCI_MIO;
+		/* the control bit is set during PCI initialization */
+	}
 }
 
 static inline void save_vector_registers(void)
diff --git a/arch/s390/kernel/jump_label.c b/arch/s390/kernel/jump_label.c
index ab584e8e3527..9156653b56f6 100644
--- a/arch/s390/kernel/jump_label.c
+++ b/arch/s390/kernel/jump_label.c
@@ -36,7 +36,7 @@ static void jump_label_bug(struct jump_entry *entry, struct insn *expected,
 	unsigned char *ipe = (unsigned char *)expected;
 	unsigned char *ipn = (unsigned char *)new;
 
-	pr_emerg("Jump label code mismatch at %pS [%p]\n", ipc, ipc);
+	pr_emerg("Jump label code mismatch at %pS [%px]\n", ipc, ipc);
 	pr_emerg("Found:    %6ph\n", ipc);
 	pr_emerg("Expected: %6ph\n", ipe);
 	pr_emerg("New:      %6ph\n", ipn);
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 2f177298c663..2bb9996ff09b 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -419,13 +419,13 @@ static unsigned long deliverable_irqs(struct kvm_vcpu *vcpu)
 static void __set_cpu_idle(struct kvm_vcpu *vcpu)
 {
 	kvm_s390_set_cpuflags(vcpu, CPUSTAT_WAIT);
-	set_bit(vcpu->vcpu_id, vcpu->kvm->arch.idle_mask);
+	set_bit(kvm_vcpu_get_idx(vcpu), vcpu->kvm->arch.idle_mask);
 }
 
 static void __unset_cpu_idle(struct kvm_vcpu *vcpu)
 {
 	kvm_s390_clear_cpuflags(vcpu, CPUSTAT_WAIT);
-	clear_bit(vcpu->vcpu_id, vcpu->kvm->arch.idle_mask);
+	clear_bit(kvm_vcpu_get_idx(vcpu), vcpu->kvm->arch.idle_mask);
 }
 
 static void __reset_intercept_indicators(struct kvm_vcpu *vcpu)
@@ -3050,18 +3050,18 @@ int kvm_s390_get_irq_state(struct kvm_vcpu *vcpu, __u8 __user *buf, int len)
 
 static void __airqs_kick_single_vcpu(struct kvm *kvm, u8 deliverable_mask)
 {
-	int vcpu_id, online_vcpus = atomic_read(&kvm->online_vcpus);
+	int vcpu_idx, online_vcpus = atomic_read(&kvm->online_vcpus);
 	struct kvm_s390_gisa_interrupt *gi = &kvm->arch.gisa_int;
 	struct kvm_vcpu *vcpu;
 
-	for_each_set_bit(vcpu_id, kvm->arch.idle_mask, online_vcpus) {
-		vcpu = kvm_get_vcpu(kvm, vcpu_id);
+	for_each_set_bit(vcpu_idx, kvm->arch.idle_mask, online_vcpus) {
+		vcpu = kvm_get_vcpu(kvm, vcpu_idx);
 		if (psw_ioint_disabled(vcpu))
 			continue;
 		deliverable_mask &= (u8)(vcpu->arch.sie_block->gcr[6] >> 24);
 		if (deliverable_mask) {
 			/* lately kicked but not yet running */
-			if (test_and_set_bit(vcpu_id, gi->kicked_mask))
+			if (test_and_set_bit(vcpu_idx, gi->kicked_mask))
 				return;
 			kvm_s390_vcpu_wakeup(vcpu);
 			return;
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index f94b4f78d4da..7f719b468b44 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -4015,7 +4015,7 @@ static int vcpu_pre_run(struct kvm_vcpu *vcpu)
 		kvm_s390_patch_guest_per_regs(vcpu);
 	}
 
-	clear_bit(vcpu->vcpu_id, vcpu->kvm->arch.gisa_int.kicked_mask);
+	clear_bit(kvm_vcpu_get_idx(vcpu), vcpu->kvm->arch.gisa_int.kicked_mask);
 
 	vcpu->arch.sie_block->icptcode = 0;
 	cpuflags = atomic_read(&vcpu->arch.sie_block->cpuflags);
diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index 79dcd647b378..2d134833bca6 100644
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -79,7 +79,7 @@ static inline int is_vcpu_stopped(struct kvm_vcpu *vcpu)
 
 static inline int is_vcpu_idle(struct kvm_vcpu *vcpu)
 {
-	return test_bit(vcpu->vcpu_id, vcpu->kvm->arch.idle_mask);
+	return test_bit(kvm_vcpu_get_idx(vcpu), vcpu->kvm->arch.idle_mask);
 }
 
 static inline int kvm_is_ucontrol(struct kvm *kvm)
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 77767850d0d0..9d5960bbc45f 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -180,9 +180,9 @@ static void pv_init(void)
 		return;
 
 	/* make sure bounce buffers are shared */
+	swiotlb_force = SWIOTLB_FORCE;
 	swiotlb_init(1);
 	swiotlb_update_mem_attributes();
-	swiotlb_force = SWIOTLB_FORCE;
 }
 
 void __init mem_init(void)
diff --git a/arch/s390/mm/kasan_init.c b/arch/s390/mm/kasan_init.c
index 5646b39c728a..e9a9b7b616bc 100644
--- a/arch/s390/mm/kasan_init.c
+++ b/arch/s390/mm/kasan_init.c
@@ -108,6 +108,9 @@ static void __init kasan_early_vmemmap_populate(unsigned long address,
 		sgt_prot &= ~_SEGMENT_ENTRY_NOEXEC;
 	}
 
+	/*
+	 * The first 1MB of 1:1 mapping is mapped with 4KB pages
+	 */
 	while (address < end) {
 		pg_dir = pgd_offset_k(address);
 		if (pgd_none(*pg_dir)) {
@@ -165,30 +168,26 @@ static void __init kasan_early_vmemmap_populate(unsigned long address,
 
 		pm_dir = pmd_offset(pu_dir, address);
 		if (pmd_none(*pm_dir)) {
-			if (mode == POPULATE_ZERO_SHADOW &&
-			    IS_ALIGNED(address, PMD_SIZE) &&
+			if (IS_ALIGNED(address, PMD_SIZE) &&
 			    end - address >= PMD_SIZE) {
-				pmd_populate(&init_mm, pm_dir,
-						kasan_early_shadow_pte);
-				address = (address + PMD_SIZE) & PMD_MASK;
-				continue;
-			}
-			/* the first megabyte of 1:1 is mapped with 4k pages */
-			if (has_edat && address && end - address >= PMD_SIZE &&
-			    mode != POPULATE_ZERO_SHADOW) {
-				void *page;
-
-				if (mode == POPULATE_ONE2ONE) {
-					page = (void *)address;
-				} else {
-					page = kasan_early_alloc_segment();
-					memset(page, 0, _SEGMENT_SIZE);
+				if (mode == POPULATE_ZERO_SHADOW) {
+					pmd_populate(&init_mm, pm_dir, kasan_early_shadow_pte);
+					address = (address + PMD_SIZE) & PMD_MASK;
+					continue;
+				} else if (has_edat && address) {
+					void *page;
+
+					if (mode == POPULATE_ONE2ONE) {
+						page = (void *)address;
+					} else {
+						page = kasan_early_alloc_segment();
+						memset(page, 0, _SEGMENT_SIZE);
+					}
+					pmd_val(*pm_dir) = __pa(page) | sgt_prot;
+					address = (address + PMD_SIZE) & PMD_MASK;
+					continue;
 				}
-				pmd_val(*pm_dir) = __pa(page) | sgt_prot;
-				address = (address + PMD_SIZE) & PMD_MASK;
-				continue;
 			}
-
 			pt_dir = kasan_early_pte_alloc();
 			pmd_populate(&init_mm, pm_dir, pt_dir);
 		} else if (pmd_large(*pm_dir)) {
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index 1ae7a76ae97b..f5ddbc625c1a 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -558,9 +558,12 @@ static void zpci_cleanup_bus_resources(struct zpci_dev *zdev)
 
 int pcibios_add_device(struct pci_dev *pdev)
 {
+	struct zpci_dev *zdev = to_zpci(pdev);
 	struct resource *res;
 	int i;
 
+	/* The pdev has a reference to the zdev via its bus */
+	zpci_zdev_get(zdev);
 	if (pdev->is_physfn)
 		pdev->no_vf_scan = 1;
 
@@ -580,7 +583,10 @@ int pcibios_add_device(struct pci_dev *pdev)
 
 void pcibios_release_device(struct pci_dev *pdev)
 {
+	struct zpci_dev *zdev = to_zpci(pdev);
+
 	zpci_unmap_resources(pdev);
+	zpci_zdev_put(zdev);
 }
 
 int pcibios_enable_device(struct pci_dev *pdev, int mask)
@@ -653,9 +659,10 @@ int zpci_enable_device(struct zpci_dev *zdev)
 {
 	int rc;
 
-	rc = clp_enable_fh(zdev, ZPCI_NR_DMA_SPACES);
-	if (rc)
+	if (clp_enable_fh(zdev, ZPCI_NR_DMA_SPACES)) {
+		rc = -EIO;
 		goto out;
+	}
 
 	rc = zpci_dma_init_device(zdev);
 	if (rc)
@@ -678,7 +685,7 @@ int zpci_disable_device(struct zpci_dev *zdev)
 	 * The zPCI function may already be disabled by the platform, this is
 	 * detected in clp_disable_fh() which becomes a no-op.
 	 */
-	return clp_disable_fh(zdev);
+	return clp_disable_fh(zdev) ? -EIO : 0;
 }
 EXPORT_SYMBOL_GPL(zpci_disable_device);
 
@@ -859,7 +866,6 @@ static void zpci_mem_exit(void)
 }
 
 static unsigned int s390_pci_probe __initdata = 1;
-static unsigned int s390_pci_no_mio __initdata;
 unsigned int s390_pci_force_floating __initdata;
 static unsigned int s390_pci_initialized;
 
@@ -870,7 +876,7 @@ char * __init pcibios_setup(char *str)
 		return NULL;
 	}
 	if (!strcmp(str, "nomio")) {
-		s390_pci_no_mio = 1;
+		S390_lowcore.machine_flags &= ~MACHINE_FLAG_PCI_MIO;
 		return NULL;
 	}
 	if (!strcmp(str, "force_floating")) {
@@ -899,7 +905,7 @@ static int __init pci_base_init(void)
 	if (!test_facility(69) || !test_facility(71))
 		return 0;
 
-	if (test_facility(153) && !s390_pci_no_mio) {
+	if (MACHINE_HAS_PCI_MIO) {
 		static_branch_enable(&have_mio);
 		ctl_set_bit(2, 5);
 	}
diff --git a/arch/s390/pci/pci_bus.h b/arch/s390/pci/pci_bus.h
index f8dfac0b5b71..55c9488e504c 100644
--- a/arch/s390/pci/pci_bus.h
+++ b/arch/s390/pci/pci_bus.h
@@ -16,6 +16,11 @@ static inline void zpci_zdev_put(struct zpci_dev *zdev)
 	kref_put(&zdev->kref, zpci_release_device);
 }
 
+static inline void zpci_zdev_get(struct zpci_dev *zdev)
+{
+	kref_get(&zdev->kref);
+}
+
 int zpci_alloc_domain(int domain);
 void zpci_free_domain(int domain);
 int zpci_setup_bus_resources(struct zpci_dev *zdev,
diff --git a/arch/s390/pci/pci_clp.c b/arch/s390/pci/pci_clp.c
index d3331596ddbe..0a0e8b8293be 100644
--- a/arch/s390/pci/pci_clp.c
+++ b/arch/s390/pci/pci_clp.c
@@ -213,15 +213,19 @@ out:
 }
 
 static int clp_refresh_fh(u32 fid);
-/*
- * Enable/Disable a given PCI function and update its function handle if
- * necessary
+/**
+ * clp_set_pci_fn() - Execute a command on a PCI function
+ * @zdev: Function that will be affected
+ * @nr_dma_as: DMA address space number
+ * @command: The command code to execute
+ *
+ * Returns: 0 on success, < 0 for Linux errors (e.g. -ENOMEM), and
+ * > 0 for non-success platform responses
  */
 static int clp_set_pci_fn(struct zpci_dev *zdev, u8 nr_dma_as, u8 command)
 {
 	struct clp_req_rsp_set_pci *rrb;
 	int rc, retries = 100;
-	u32 fid = zdev->fid;
 
 	rrb = clp_alloc_block(GFP_KERNEL);
 	if (!rrb)
@@ -245,17 +249,16 @@ static int clp_set_pci_fn(struct zpci_dev *zdev, u8 nr_dma_as, u8 command)
 		}
 	} while (rrb->response.hdr.rsp == CLP_RC_SETPCIFN_BUSY);
 
-	if (rc || rrb->response.hdr.rsp != CLP_RC_OK) {
-		zpci_err("Set PCI FN:\n");
-		zpci_err_clp(rrb->response.hdr.rsp, rc);
-	}
-
 	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK) {
 		zdev->fh = rrb->response.fh;
-	} else if (!rc && rrb->response.hdr.rsp == CLP_RC_SETPCIFN_ALRDY &&
-			rrb->response.fh == 0) {
+	} else if (!rc && rrb->response.hdr.rsp == CLP_RC_SETPCIFN_ALRDY) {
 		/* Function is already in desired state - update handle */
-		rc = clp_refresh_fh(fid);
+		rc = clp_refresh_fh(zdev->fid);
+	} else {
+		zpci_err("Set PCI FN:\n");
+		zpci_err_clp(rrb->response.hdr.rsp, rc);
+		if (!rc)
+			rc = rrb->response.hdr.rsp;
 	}
 	clp_free_block(rrb);
 	return rc;
@@ -301,17 +304,13 @@ int clp_enable_fh(struct zpci_dev *zdev, u8 nr_dma_as)
 
 	rc = clp_set_pci_fn(zdev, nr_dma_as, CLP_SET_ENABLE_PCI_FN);
 	zpci_dbg(3, "ena fid:%x, fh:%x, rc:%d\n", zdev->fid, zdev->fh, rc);
-	if (rc)
-		goto out;
-
-	if (zpci_use_mio(zdev)) {
+	if (!rc && zpci_use_mio(zdev)) {
 		rc = clp_set_pci_fn(zdev, nr_dma_as, CLP_SET_ENABLE_MIO);
 		zpci_dbg(3, "ena mio fid:%x, fh:%x, rc:%d\n",
 				zdev->fid, zdev->fh, rc);
 		if (rc)
 			clp_disable_fh(zdev);
 	}
-out:
 	return rc;
 }