x86/sgx: Rename sgx_encl_ewb_cpumask() as sgx_encl_cpumask()

sgx_encl_ewb_cpumask() is no longer unique to the reclaimer where it
is used during the EWB ENCLS leaf function when EPC pages are written
out to main memory and sgx_encl_ewb_cpumask() is used to learn which
CPUs might have executed the enclave to ensure that TLBs are cleared.

Upcoming SGX2 enabling will use sgx_encl_ewb_cpumask() during the
EMODPR and EMODT ENCLS leaf functions that make changes to enclave
pages. The function is needed for the same reason it is used now: to
learn which CPUs might have executed the enclave to ensure that TLBs
no longer point to the changed pages.

Rename sgx_encl_ewb_cpumask() to sgx_encl_cpumask() to reflect the
broader usage.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/d4d08c449450a13d8dd3bb6c2b1af03895586d4f.1652137848.git.reinette.chatre@intel.com

arch/x86/kernel/cpu/sgx/encl.c

@@ -715,7 +715,7 @@ int sgx_encl_mm_add(struct sgx_encl *encl, struct mm_struct *mm)
 }
 
 /**
- * sgx_encl_ewb_cpumask() - Query which CPUs might be accessing the enclave
+ * sgx_encl_cpumask() - Query which CPUs might be accessing the enclave
  * @encl: the enclave
  *
  * Some SGX functions require that no cached linear-to-physical address
@@ -740,7 +740,7 @@ int sgx_encl_mm_add(struct sgx_encl *encl, struct mm_struct *mm)
  * The following flow is used to support SGX functions that require that
  * no cached linear-to-physical address mappings are present:
  * 1) Execute ENCLS[ETRACK] to initiate hardware tracking.
- * 2) Use this function (sgx_encl_ewb_cpumask()) to query which CPUs might be
+ * 2) Use this function (sgx_encl_cpumask()) to query which CPUs might be
  *    accessing the enclave.
  * 3) Send IPI to identified CPUs, kicking them out of the enclave and
  *    thus flushing all locally cached linear-to-physical address mappings.
@@ -757,7 +757,7 @@ int sgx_encl_mm_add(struct sgx_encl *encl, struct mm_struct *mm)
  *
  * Return: cpumask of CPUs that might be accessing @encl
  */
-const cpumask_t *sgx_encl_ewb_cpumask(struct sgx_encl *encl)
+const cpumask_t *sgx_encl_cpumask(struct sgx_encl *encl)
 {
 	cpumask_t *cpumask = &encl->cpumask;
 	struct sgx_encl_mm *encl_mm;

arch/x86/kernel/cpu/sgx/encl.h

@@ -105,7 +105,7 @@ int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start,
 
 void sgx_encl_release(struct kref *ref);
 int sgx_encl_mm_add(struct sgx_encl *encl, struct mm_struct *mm);
-const cpumask_t *sgx_encl_ewb_cpumask(struct sgx_encl *encl);
+const cpumask_t *sgx_encl_cpumask(struct sgx_encl *encl);
 int sgx_encl_get_backing(struct sgx_encl *encl, unsigned long page_index,
 			 struct sgx_backing *backing);
 void sgx_encl_put_backing(struct sgx_backing *backing);

arch/x86/kernel/cpu/sgx/main.c

@@ -251,7 +251,7 @@ static void sgx_encl_ewb(struct sgx_epc_page *epc_page,
 			 * miss cpus that entered the enclave between
 			 * generating the mask and incrementing epoch.
 			 */
-			on_each_cpu_mask(sgx_encl_ewb_cpumask(encl),
+			on_each_cpu_mask(sgx_encl_cpumask(encl),
 					 sgx_ipi_cb, NULL, 1);
 			ret = __sgx_encl_ewb(epc_page, va_slot, backing);
 		}