x86/sgx: Rename fallback labels in sgx_init()

It's hard to add new content to this function because it is time consuming to match fallback and its cause. Rename labels in a way that the name of error label refers to the site where failure happened. This way it is easier to keep on track what is going on.

---
v5:
* A new patch.

---
 arch/x86/kernel/cpu/sgx/main.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

index 63d3de02bbcc..a6e313f1a82d 100644
@@ -803,12 +803,12 @@ static int __init sgx_init(void)
 
 	if (!sgx_page_reclaimer_init()) {
 		ret = -ENOMEM;
-		goto err_page_cache;
+		goto err_reclaimer;
 	}
 
 	ret = misc_register(&sgx_dev_provision);
 	if (ret)
-		goto err_kthread;
+		goto err_provision;
 
 	/*
 	 * Always try to initialize the native *and* KVM drivers.

@@ -821,17 +821,17 @@ static int __init sgx_init(void)
 	ret = sgx_drv_init();
 
 	if (sgx_vepc_init() && ret)
-		goto err_provision;
+		goto err_driver;
 
 	return 0;
 
-err_provision:
+err_driver:
 	misc_deregister(&sgx_dev_provision);
 
-err_kthread:
+err_provision:
 	kthread_stop(ksgxd_tsk);
 
-err_page_cache:
+err_reclaimer:
 	for (i = 0; i < sgx_nr_epc_sections; i++) {
 		vfree(sgx_epc_sections[i].pages);
 		memunmap(sgx_epc_sections[i].virt_addr);

2.25.1

The amount of SGX memory on the system is determined by the BIOS and it varies wildly between systems. It can be from dozens of MB's on desktops or VM's, up to many GB's on servers. Just like for regular memory, it is sometimes useful to know the amount of usable SGX memory in the system.

Add an attribute for the amount of SGX memory in bytes to each NUMA node. The path is /sys/devices/system/node/node[0-9]*/sgx/size. Calculate these values by summing up EPC section sizes for each node during the driver initalization.

---
v7:
* Shorten memory_size to size. The prefix makes the name only longer but does not clarify things more than "size" would.
* Use device_attribute instead of kobj_attribute.
* Use named attribute group instead of creating raw kobject just for the "sgx" subdirectory.

v6:
* Initialize node->size to zero in sgx_setup_epc_section(), when the node is first accessed.

v5
* A new patch based on the discussion on
https://lore.kernel.org/linux-sgx/[email protected]/T/#t

---
 Documentation/ABI/stable/sysfs-devices-node |  7 ++
 arch/x86/kernel/cpu/sgx/main.c              | 82 +++++++++++++++++++++
 arch/x86/kernel/cpu/sgx/sgx.h               |  2 +
 3 files changed, 91 insertions(+)

index 484fc04bcc25..12dc2149e8e0 100644
@@ -176,3 +176,10 @@ Contact:	Keith Busch <[email protected]>
 Description:
 		The cache write policy: 0 for write-back, 1 for write-through,
 		other or unknown.
+
+What:		/sys/devices/system/node/nodeX/sgx/size
+Date:		October 2021
+Contact:	Jarkko Sakkinen <[email protected]>
+Description:
+		Total available physical SGX memory, also known as Enclave Page
+		Cache (EPC), in bytes.

index 4628acec0009..1de8c627a286 100644
@@ -39,6 +39,8 @@ struct sgx_epc_page {
  */
 struct sgx_numa_node {
 	struct list_head free_page_list;
+	struct device *dev;
+	unsigned long size;
 	spinlock_t lock;
 };
 

2.25.1