[PATCH for_v22 v2 6/8] x86/sgx: Allocate encl_page prior to taking encl->lock

[Sean Christopherson <sean.j.christopherson@intel.com>]

Refactor sgx_encl_add_page() to allocate the encl_page prior to taking
encl->lock so that the encl_page can be used to allocate its associated
EPC page without having to drop and retake encl->lock.  Removal of the
add page worker will move EPC page allocation to sgx_encl_add_page().

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kernel/cpu/sgx/driver/ioctl.c | 29 ++++++++++++--------------
 1 file changed, 13 insertions(+), 16 deletions(-)

diff --git a/arch/x86/kernel/cpu/sgx/driver/ioctl.c b/arch/x86/kernel/cpu/sgx/driver/ioctl.c
index 55e0fe261b8c..49407ccb26c8 100644
--- a/arch/x86/kernel/cpu/sgx/driver/ioctl.c
+++ b/arch/x86/kernel/cpu/sgx/driver/ioctl.c
@@ -518,24 +518,22 @@ static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long addr,
 			return ret;
 	}
 
-	mutex_lock(&encl->lock);
-
-	va_page = sgx_encl_grow(encl, SGX_ENCL_INITIALIZED | SGX_ENCL_DEAD);
-	if (IS_ERR(va_page)) {
-		ret = PTR_ERR(va_page);
-		goto err_out_unlock;
-	}
-
 	encl_page = sgx_encl_page_alloc(encl, addr, prot, page_type);
-	if (IS_ERR(encl_page)) {
-		ret = PTR_ERR(encl_page);
-		goto err_out_shrink;
+	if (IS_ERR(encl_page))
+		return PTR_ERR(encl_page);
+
+	mutex_lock(&encl->lock);
+
+	va_page = sgx_encl_grow(encl, SGX_ENCL_INITIALIZED | SGX_ENCL_DEAD);
+	if (IS_ERR(va_page)) {
+		ret = PTR_ERR(va_page);
+		goto err_out_free;
 	}
 
 	ret = radix_tree_insert(&encl->page_tree, PFN_DOWN(encl_page->desc),
 				encl_page);
 	if (ret)
-		goto err_out_free;
+		goto err_out_shrink;
 
 	ret = __sgx_encl_add_page(encl, encl_page, data, secinfo, mrmask);
 	if (ret)
@@ -547,13 +545,12 @@ static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long addr,
 err_out:
 	radix_tree_delete(&encl_page->encl->page_tree,
 			  PFN_DOWN(encl_page->desc));
+err_out_shrink:
+	sgx_encl_shrink(encl, va_page);
+
 err_out_free:
 	kfree(encl_page);
 
-err_out_shrink:
-	sgx_encl_shrink(encl, va_page);
-
-err_out_unlock:
 	mutex_unlock(&encl->lock);
 	return ret;
 }
-- 
2.22.0