[PATCH v1 07/13] KVM: s390: move some gmap shadowing functions away from mm/gmap.c

[Claudio Imbrenda <imbrenda@linux.ibm.com>]

Move some gmap shadowing functions from mm/gmap.c to kvm/vsie.c and
kvm/kvm-s390.c .

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
 arch/s390/include/asm/gmap.h |   7 +-
 arch/s390/kvm/kvm-s390.c     |  62 +++++++++-
 arch/s390/kvm/kvm-s390.h     |   2 +
 arch/s390/kvm/vsie.c         | 137 +++++++++++++++++++++
 arch/s390/mm/gmap.c          | 232 ++++-------------------------------
 5 files changed, 226 insertions(+), 214 deletions(-)

diff --git a/arch/s390/include/asm/gmap.h b/arch/s390/include/asm/gmap.h
index 3652d8523e1f..8637ebbf618a 100644
--- a/arch/s390/include/asm/gmap.h
+++ b/arch/s390/include/asm/gmap.h
@@ -106,6 +106,8 @@ struct gmap *gmap_create(struct mm_struct *mm, unsigned long limit);
 void gmap_remove(struct gmap *gmap);
 struct gmap *gmap_get(struct gmap *gmap);
 void gmap_put(struct gmap *gmap);
+void gmap_free(struct gmap *gmap);
+struct gmap *gmap_alloc(unsigned long limit);
 
 int gmap_map_segment(struct gmap *gmap, unsigned long from,
 		     unsigned long to, unsigned long len);
@@ -120,7 +122,7 @@ int gmap_read_table(struct gmap *gmap, unsigned long gaddr, unsigned long *val);
 
 struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce,
 			 int edat_level);
-int gmap_shadow_valid(struct gmap *sg, unsigned long asce, int edat_level);
+void gmap_unshadow(struct gmap *sg);
 int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
 		    int fake);
 int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
@@ -136,8 +138,7 @@ int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte);
 void gmap_register_pte_notifier(struct gmap_notifier *);
 void gmap_unregister_pte_notifier(struct gmap_notifier *);
 
-int gmap_mprotect_notify(struct gmap *, unsigned long start,
-			 unsigned long len, int prot);
+int gmap_protect_one(struct gmap *gmap, unsigned long gaddr, int prot, unsigned long bits);
 
 void gmap_sync_dirty_log_pmd(struct gmap *gmap, unsigned long dirty_bitmap[4],
 			     unsigned long gaddr, unsigned long vmaddr);
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 574a9e43f97a..b9e02fb9ae4a 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -4520,6 +4520,63 @@ static bool ibs_enabled(struct kvm_vcpu *vcpu)
 	return kvm_s390_test_cpuflags(vcpu, CPUSTAT_IBS);
 }
 
+static int __kvm_s390_fixup_fault_sync(struct gmap *gmap, gpa_t gaddr, unsigned int flags)
+{
+	struct kvm *kvm = gmap->private;
+	gfn_t gfn = gpa_to_gfn(gaddr);
+	bool unlocked;
+	hva_t vmaddr;
+	gpa_t tmp;
+	int rc;
+
+	if (kvm_is_ucontrol(kvm)) {
+		tmp = __gmap_translate(gmap, gaddr);
+		gfn = gpa_to_gfn(tmp);
+	}
+
+	vmaddr = gfn_to_hva(kvm, gfn);
+	rc = fixup_user_fault(gmap->mm, vmaddr, FAULT_FLAG_WRITE, &unlocked);
+	if (!rc)
+		rc = __gmap_link(gmap, gaddr, vmaddr);
+	return rc;
+}
+
+int __kvm_s390_mprotect_many(struct gmap *gmap, gpa_t gpa, u8 npages, unsigned int prot,
+			     unsigned long bits)
+{
+	unsigned int fault_flag = (prot & PROT_WRITE) ? FAULT_FLAG_WRITE : 0;
+	gpa_t end = gpa + npages * PAGE_SIZE;
+	int rc;
+
+	for (; gpa < end; gpa = ALIGN(gpa + 1, rc ? HPAGE_SIZE : PAGE_SIZE)) {
+		rc = gmap_protect_one(gmap, gpa, prot, bits);
+		if (rc == -EAGAIN) {
+			__kvm_s390_fixup_fault_sync(gmap, gpa, fault_flag);
+			rc = gmap_protect_one(gmap, gpa, prot, bits);
+		}
+		if (rc < 0)
+			return rc;
+	}
+
+	return 0;
+}
+
+static int kvm_s390_mprotect_notify_prefix(struct kvm_vcpu *vcpu)
+{
+	gpa_t gaddr = kvm_s390_get_prefix(vcpu);
+	int idx, rc;
+
+	idx = srcu_read_lock(&vcpu->kvm->srcu);
+	mmap_read_lock(vcpu->arch.gmap->mm);
+
+	rc = __kvm_s390_mprotect_many(vcpu->arch.gmap, gaddr, 2, PROT_WRITE, GMAP_NOTIFY_MPROT);
+
+	mmap_read_unlock(vcpu->arch.gmap->mm);
+	srcu_read_unlock(&vcpu->kvm->srcu, idx);
+
+	return rc;
+}
+
 static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu)
 {
 retry:
@@ -4535,9 +4592,8 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu)
 	 */
 	if (kvm_check_request(KVM_REQ_REFRESH_GUEST_PREFIX, vcpu)) {
 		int rc;
-		rc = gmap_mprotect_notify(vcpu->arch.gmap,
-					  kvm_s390_get_prefix(vcpu),
-					  PAGE_SIZE * 2, PROT_WRITE);
+
+		rc = kvm_s390_mprotect_notify_prefix(vcpu);
 		if (rc) {
 			kvm_make_request(KVM_REQ_REFRESH_GUEST_PREFIX, vcpu);
 			return rc;
diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index 37c9ab52ecaa..f77a3829d182 100644
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -418,6 +418,8 @@ void kvm_s390_set_cpu_timer(struct kvm_vcpu *vcpu, __u64 cputm);
 __u64 kvm_s390_get_cpu_timer(struct kvm_vcpu *vcpu);
 int kvm_s390_cpus_from_pv(struct kvm *kvm, u16 *rc, u16 *rrc);
 int __kvm_s390_handle_dat_fault(struct kvm_vcpu *vcpu, gfn_t gfn, gpa_t gaddr, unsigned int flags);
+int __kvm_s390_mprotect_many(struct gmap *gmap, gpa_t gpa, u8 npages, unsigned int prot,
+			     unsigned long bits);
 
 static inline int kvm_s390_handle_dat_fault(struct kvm_vcpu *vcpu, gpa_t gaddr, unsigned int flags)
 {
diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c
index 150b9387860a..314e9baf2120 100644
--- a/arch/s390/kvm/vsie.c
+++ b/arch/s390/kvm/vsie.c
@@ -13,6 +13,7 @@
 #include <linux/bitmap.h>
 #include <linux/sched/signal.h>
 #include <linux/io.h>
+#include <linux/mman.h>
 
 #include <asm/gmap.h>
 #include <asm/mmu_context.h>
@@ -1207,6 +1208,142 @@ static void release_gmap_shadow(struct vsie_page *vsie_page)
 	prefix_unmapped(vsie_page);
 }
 
+/**
+ * gmap_find_shadow - find a specific asce in the list of shadow tables
+ * @parent: pointer to the parent gmap
+ * @asce: ASCE for which the shadow table is created
+ * @edat_level: edat level to be used for the shadow translation
+ *
+ * Returns the pointer to a gmap if a shadow table with the given asce is
+ * already available, ERR_PTR(-EAGAIN) if another one is just being created,
+ * otherwise NULL
+ */
+static struct gmap *gmap_find_shadow(struct gmap *parent, unsigned long asce,
+				     int edat_level)
+{
+	struct gmap *sg;
+
+	list_for_each_entry(sg, &parent->children, list) {
+		if (sg->orig_asce != asce || sg->edat_level != edat_level ||
+		    sg->removed)
+			continue;
+		if (!sg->initialized)
+			return ERR_PTR(-EAGAIN);
+		refcount_inc(&sg->ref_count);
+		return sg;
+	}
+	return NULL;
+}
+
+/**
+ * gmap_shadow_valid - check if a shadow guest address space matches the
+ *                     given properties and is still valid
+ * @sg: pointer to the shadow guest address space structure
+ * @asce: ASCE for which the shadow table is requested
+ * @edat_level: edat level to be used for the shadow translation
+ *
+ * Returns 1 if the gmap shadow is still valid and matches the given
+ * properties, the caller can continue using it. Returns 0 otherwise, the
+ * caller has to request a new shadow gmap in this case.
+ *
+ */
+static int gmap_shadow_valid(struct gmap *sg, unsigned long asce, int edat_level)
+{
+	if (sg->removed)
+		return 0;
+	return sg->orig_asce == asce && sg->edat_level == edat_level;
+}
+
+/**
+ * gmap_shadow - create/find a shadow guest address space
+ * @parent: pointer to the parent gmap
+ * @asce: ASCE for which the shadow table is created
+ * @edat_level: edat level to be used for the shadow translation
+ *
+ * The pages of the top level page table referred by the asce parameter
+ * will be set to read-only and marked in the PGSTEs of the kvm process.
+ * The shadow table will be removed automatically on any change to the
+ * PTE mapping for the source table.
+ *
+ * Returns a guest address space structure, ERR_PTR(-ENOMEM) if out of memory,
+ * ERR_PTR(-EAGAIN) if the caller has to retry and ERR_PTR(-EFAULT) if the
+ * parent gmap table could not be protected.
+ */
+struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce,
+			 int edat_level)
+{
+	struct gmap *sg, *new;
+	unsigned long limit;
+	int rc;
+
+	if (KVM_BUG_ON(parent->mm->context.allow_gmap_hpage_1m, (struct kvm *)parent->private) ||
+	    KVM_BUG_ON(gmap_is_shadow(parent), (struct kvm *)parent->private))
+		return ERR_PTR(-EFAULT);
+	spin_lock(&parent->shadow_lock);
+	sg = gmap_find_shadow(parent, asce, edat_level);
+	spin_unlock(&parent->shadow_lock);
+	if (sg)
+		return sg;
+	/* Create a new shadow gmap */
+	limit = -1UL >> (33 - (((asce & _ASCE_TYPE_MASK) >> 2) * 11));
+	if (asce & _ASCE_REAL_SPACE)
+		limit = -1UL;
+	new = gmap_alloc(limit);
+	if (!new)
+		return ERR_PTR(-ENOMEM);
+	new->mm = parent->mm;
+	new->parent = gmap_get(parent);
+	new->private = parent->private;
+	new->orig_asce = asce;
+	new->edat_level = edat_level;
+	new->initialized = false;
+	spin_lock(&parent->shadow_lock);
+	/* Recheck if another CPU created the same shadow */
+	sg = gmap_find_shadow(parent, asce, edat_level);
+	if (sg) {
+		spin_unlock(&parent->shadow_lock);
+		gmap_free(new);
+		return sg;
+	}
+	if (asce & _ASCE_REAL_SPACE) {
+		/* only allow one real-space gmap shadow */
+		list_for_each_entry(sg, &parent->children, list) {
+			if (sg->orig_asce & _ASCE_REAL_SPACE) {
+				spin_lock(&sg->guest_table_lock);
+				gmap_unshadow(sg);
+				spin_unlock(&sg->guest_table_lock);
+				list_del(&sg->list);
+				gmap_put(sg);
+				break;
+			}
+		}
+	}
+	refcount_set(&new->ref_count, 2);
+	list_add(&new->list, &parent->children);
+	if (asce & _ASCE_REAL_SPACE) {
+		/* nothing to protect, return right away */
+		new->initialized = true;
+		spin_unlock(&parent->shadow_lock);
+		return new;
+	}
+	spin_unlock(&parent->shadow_lock);
+	/* protect after insertion, so it will get properly invalidated */
+	mmap_read_lock(parent->mm);
+	rc = __kvm_s390_mprotect_many(parent, asce & _ASCE_ORIGIN,
+				      ((asce & _ASCE_TABLE_LENGTH) + 1),
+				      PROT_READ, GMAP_NOTIFY_SHADOW);
+	mmap_read_unlock(parent->mm);
+	spin_lock(&parent->shadow_lock);
+	new->initialized = true;
+	if (rc) {
+		list_del(&new->list);
+		gmap_free(new);
+		new = ERR_PTR(rc);
+	}
+	spin_unlock(&parent->shadow_lock);
+	return new;
+}
+
 static int acquire_gmap_shadow(struct kvm_vcpu *vcpu,
 			       struct vsie_page *vsie_page)
 {
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index ae6ccf034378..12d681b657b4 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -43,7 +43,7 @@ static struct page *gmap_alloc_crst(void)
  *
  * Returns a guest address space structure.
  */
-static struct gmap *gmap_alloc(unsigned long limit)
+struct gmap *gmap_alloc(unsigned long limit)
 {
 	struct gmap *gmap;
 	struct page *page;
@@ -97,6 +97,7 @@ static struct gmap *gmap_alloc(unsigned long limit)
 out:
 	return NULL;
 }
+EXPORT_SYMBOL_GPL(gmap_alloc);
 
 /**
  * gmap_create - create a guest address space
@@ -191,7 +192,7 @@ static void gmap_rmap_radix_tree_free(struct radix_tree_root *root)
  *
  * No locks required. There are no references to this gmap anymore.
  */
-static void gmap_free(struct gmap *gmap)
+void gmap_free(struct gmap *gmap)
 {
 	struct page *page, *next;
 
@@ -218,6 +219,7 @@ static void gmap_free(struct gmap *gmap)
 
 	kfree(gmap);
 }
+EXPORT_SYMBOL_GPL(gmap_free);
 
 /**
  * gmap_get - increase reference counter for guest address space
@@ -958,86 +960,36 @@ static int gmap_protect_pte(struct gmap *gmap, unsigned long gaddr,
  * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
  * @bits: pgste notification bits to set
  *
- * Returns 0 if successfully protected, -ENOMEM if out of memory and
- * -EFAULT if gaddr is invalid (or mapping for shadows is missing).
+ * Returns 0 if successfully protected, -ENOMEM if out of memory,
+ * -EFAULT if gaddr is invalid (or mapping for shadows is missing),
+ * -EAGAIN if the guest mapping is missing and should be fixed by the
+ * caller.
  *
  * Called with sg->mm->mmap_lock in read.
  */
-static int gmap_protect_range(struct gmap *gmap, unsigned long gaddr,
-			      unsigned long len, int prot, unsigned long bits)
+int gmap_protect_one(struct gmap *gmap, unsigned long gaddr, int prot, unsigned long bits)
 {
-	unsigned long vmaddr, dist;
 	pmd_t *pmdp;
-	int rc;
+	int rc = 0;
 
 	BUG_ON(gmap_is_shadow(gmap));
-	while (len) {
-		rc = -EAGAIN;
-		pmdp = gmap_pmd_op_walk(gmap, gaddr);
-		if (pmdp) {
-			if (!pmd_leaf(*pmdp)) {
-				rc = gmap_protect_pte(gmap, gaddr, pmdp, prot,
-						      bits);
-				if (!rc) {
-					len -= PAGE_SIZE;
-					gaddr += PAGE_SIZE;
-				}
-			} else {
-				rc = gmap_protect_pmd(gmap, gaddr, pmdp, prot,
-						      bits);
-				if (!rc) {
-					dist = HPAGE_SIZE - (gaddr & ~HPAGE_MASK);
-					len = len < dist ? 0 : len - dist;
-					gaddr = (gaddr & HPAGE_MASK) + HPAGE_SIZE;
-				}
-			}
-			gmap_pmd_op_end(gmap, pmdp);
-		}
-		if (rc) {
-			if (rc == -EINVAL)
-				return rc;
 
-			/* -EAGAIN, fixup of userspace mm and gmap */
-			vmaddr = __gmap_translate(gmap, gaddr);
-			if (IS_ERR_VALUE(vmaddr))
-				return vmaddr;
-			rc = gmap_pte_op_fixup(gmap, gaddr, vmaddr, prot);
-			if (rc)
-				return rc;
-		}
-	}
-	return 0;
-}
+	pmdp = gmap_pmd_op_walk(gmap, gaddr);
+	if (!pmdp)
+		return -EAGAIN;
 
-/**
- * gmap_mprotect_notify - change access rights for a range of ptes and
- *                        call the notifier if any pte changes again
- * @gmap: pointer to guest mapping meta data structure
- * @gaddr: virtual address in the guest address space
- * @len: size of area
- * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
- *
- * Returns 0 if for each page in the given range a gmap mapping exists,
- * the new access rights could be set and the notifier could be armed.
- * If the gmap mapping is missing for one or more pages -EFAULT is
- * returned. If no memory could be allocated -ENOMEM is returned.
- * This function establishes missing page table entries.
- */
-int gmap_mprotect_notify(struct gmap *gmap, unsigned long gaddr,
-			 unsigned long len, int prot)
-{
-	int rc;
+	if (!pmd_leaf(*pmdp)) {
+		rc = gmap_protect_pte(gmap, gaddr, pmdp, prot, bits);
+	} else {
+		rc = gmap_protect_pmd(gmap, gaddr, pmdp, prot, bits);
+		if (!rc)
+			rc = 1;
+	}
+	gmap_pmd_op_end(gmap, pmdp);
 
-	if ((gaddr & ~PAGE_MASK) || (len & ~PAGE_MASK) || gmap_is_shadow(gmap))
-		return -EINVAL;
-	if (!MACHINE_HAS_ESOP && prot == PROT_READ)
-		return -EINVAL;
-	mmap_read_lock(gmap->mm);
-	rc = gmap_protect_range(gmap, gaddr, len, prot, GMAP_NOTIFY_MPROT);
-	mmap_read_unlock(gmap->mm);
 	return rc;
 }
-EXPORT_SYMBOL_GPL(gmap_mprotect_notify);
+EXPORT_SYMBOL_GPL(gmap_protect_one);
 
 /**
  * gmap_read_table - get an unsigned long value from a guest page table using
@@ -1488,7 +1440,7 @@ static void __gmap_unshadow_r1t(struct gmap *sg, unsigned long raddr,
  *
  * Called with sg->guest_table_lock
  */
-static void gmap_unshadow(struct gmap *sg)
+void gmap_unshadow(struct gmap *sg)
 {
 	unsigned long *table;
 
@@ -1514,143 +1466,7 @@ static void gmap_unshadow(struct gmap *sg)
 		break;
 	}
 }
-
-/**
- * gmap_find_shadow - find a specific asce in the list of shadow tables
- * @parent: pointer to the parent gmap
- * @asce: ASCE for which the shadow table is created
- * @edat_level: edat level to be used for the shadow translation
- *
- * Returns the pointer to a gmap if a shadow table with the given asce is
- * already available, ERR_PTR(-EAGAIN) if another one is just being created,
- * otherwise NULL
- */
-static struct gmap *gmap_find_shadow(struct gmap *parent, unsigned long asce,
-				     int edat_level)
-{
-	struct gmap *sg;
-
-	list_for_each_entry(sg, &parent->children, list) {
-		if (sg->orig_asce != asce || sg->edat_level != edat_level ||
-		    sg->removed)
-			continue;
-		if (!sg->initialized)
-			return ERR_PTR(-EAGAIN);
-		refcount_inc(&sg->ref_count);
-		return sg;
-	}
-	return NULL;
-}
-
-/**
- * gmap_shadow_valid - check if a shadow guest address space matches the
- *                     given properties and is still valid
- * @sg: pointer to the shadow guest address space structure
- * @asce: ASCE for which the shadow table is requested
- * @edat_level: edat level to be used for the shadow translation
- *
- * Returns 1 if the gmap shadow is still valid and matches the given
- * properties, the caller can continue using it. Returns 0 otherwise, the
- * caller has to request a new shadow gmap in this case.
- *
- */
-int gmap_shadow_valid(struct gmap *sg, unsigned long asce, int edat_level)
-{
-	if (sg->removed)
-		return 0;
-	return sg->orig_asce == asce && sg->edat_level == edat_level;
-}
-EXPORT_SYMBOL_GPL(gmap_shadow_valid);
-
-/**
- * gmap_shadow - create/find a shadow guest address space
- * @parent: pointer to the parent gmap
- * @asce: ASCE for which the shadow table is created
- * @edat_level: edat level to be used for the shadow translation
- *
- * The pages of the top level page table referred by the asce parameter
- * will be set to read-only and marked in the PGSTEs of the kvm process.
- * The shadow table will be removed automatically on any change to the
- * PTE mapping for the source table.
- *
- * Returns a guest address space structure, ERR_PTR(-ENOMEM) if out of memory,
- * ERR_PTR(-EAGAIN) if the caller has to retry and ERR_PTR(-EFAULT) if the
- * parent gmap table could not be protected.
- */
-struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce,
-			 int edat_level)
-{
-	struct gmap *sg, *new;
-	unsigned long limit;
-	int rc;
-
-	BUG_ON(parent->mm->context.allow_gmap_hpage_1m);
-	BUG_ON(gmap_is_shadow(parent));
-	spin_lock(&parent->shadow_lock);
-	sg = gmap_find_shadow(parent, asce, edat_level);
-	spin_unlock(&parent->shadow_lock);
-	if (sg)
-		return sg;
-	/* Create a new shadow gmap */
-	limit = -1UL >> (33 - (((asce & _ASCE_TYPE_MASK) >> 2) * 11));
-	if (asce & _ASCE_REAL_SPACE)
-		limit = -1UL;
-	new = gmap_alloc(limit);
-	if (!new)
-		return ERR_PTR(-ENOMEM);
-	new->mm = parent->mm;
-	new->parent = gmap_get(parent);
-	new->private = parent->private;
-	new->orig_asce = asce;
-	new->edat_level = edat_level;
-	new->initialized = false;
-	spin_lock(&parent->shadow_lock);
-	/* Recheck if another CPU created the same shadow */
-	sg = gmap_find_shadow(parent, asce, edat_level);
-	if (sg) {
-		spin_unlock(&parent->shadow_lock);
-		gmap_free(new);
-		return sg;
-	}
-	if (asce & _ASCE_REAL_SPACE) {
-		/* only allow one real-space gmap shadow */
-		list_for_each_entry(sg, &parent->children, list) {
-			if (sg->orig_asce & _ASCE_REAL_SPACE) {
-				spin_lock(&sg->guest_table_lock);
-				gmap_unshadow(sg);
-				spin_unlock(&sg->guest_table_lock);
-				list_del(&sg->list);
-				gmap_put(sg);
-				break;
-			}
-		}
-	}
-	refcount_set(&new->ref_count, 2);
-	list_add(&new->list, &parent->children);
-	if (asce & _ASCE_REAL_SPACE) {
-		/* nothing to protect, return right away */
-		new->initialized = true;
-		spin_unlock(&parent->shadow_lock);
-		return new;
-	}
-	spin_unlock(&parent->shadow_lock);
-	/* protect after insertion, so it will get properly invalidated */
-	mmap_read_lock(parent->mm);
-	rc = gmap_protect_range(parent, asce & _ASCE_ORIGIN,
-				((asce & _ASCE_TABLE_LENGTH) + 1) * PAGE_SIZE,
-				PROT_READ, GMAP_NOTIFY_SHADOW);
-	mmap_read_unlock(parent->mm);
-	spin_lock(&parent->shadow_lock);
-	new->initialized = true;
-	if (rc) {
-		list_del(&new->list);
-		gmap_free(new);
-		new = ERR_PTR(rc);
-	}
-	spin_unlock(&parent->shadow_lock);
-	return new;
-}
-EXPORT_SYMBOL_GPL(gmap_shadow);
+EXPORT_SYMBOL(gmap_unshadow);
 
 /**
  * gmap_shadow_r2t - create an empty shadow region 2 table
-- 
2.47.1