2022-11-11 18:48:27

by Kristen Carlson Accardi

Subject: [PATCH 12/26] x86/sgx: Add helper to retrieve SGX EPC LRU given an EPC page

From: Sean Christopherson <[email protected]>

Introduce a function that will be used to retrieve an LRU
from an EPC page.

Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Kristen Carlson Accardi <[email protected]>
Cc: Sean Christopherson <[email protected]>
---
arch/x86/kernel/cpu/sgx/main.c | 30 ++++++++++++++++++++----------
1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index b72b5868dd01..c33966eafab6 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -31,6 +31,10 @@ static DEFINE_XARRAY(sgx_epc_address_space);
* with sgx_global_lru.lock acquired.
*/
static struct sgx_epc_lru sgx_global_lru;
+static inline struct sgx_epc_lru *sgx_lru(struct sgx_epc_page *epc_page)
+{
+ return &sgx_global_lru;
+}

static atomic_long_t sgx_nr_free_pages = ATOMIC_LONG_INIT(0);

@@ -297,6 +301,7 @@ static int __sgx_reclaim_pages(int nr_to_scan, bool ignore_age)
struct sgx_backing backing[SGX_MAX_NR_TO_RECLAIM];
struct sgx_epc_page *epc_page, *tmp;
struct sgx_encl_page *encl_page;
+ struct sgx_epc_lru *lru;
pgoff_t page_index;
LIST_HEAD(iso);
int ret;
@@ -352,10 +357,11 @@ static int __sgx_reclaim_pages(int nr_to_scan, bool ignore_age)
continue;

skip:
- spin_lock(&sgx_global_lru.lock);
+ lru = sgx_lru(epc_page);
+ spin_lock(&lru->lock);
epc_page->flags &= ~SGX_EPC_PAGE_RECLAIM_IN_PROGRESS;
- sgx_epc_move_reclaimable(&sgx_global_lru, epc_page);
- spin_unlock(&sgx_global_lru.lock);
+ sgx_epc_move_reclaimable(lru, epc_page);
+ spin_unlock(&lru->lock);

kref_put(&encl_page->encl->refcount, sgx_encl_release);
}
@@ -521,14 +527,16 @@ struct sgx_epc_page *__sgx_alloc_epc_page(void)
*/
void sgx_record_epc_page(struct sgx_epc_page *page, unsigned long flags)
{
- spin_lock(&sgx_global_lru.lock);
+ struct sgx_epc_lru *lru = sgx_lru(page);
+
+ spin_lock(&lru->lock);
WARN_ON(page->flags & SGX_EPC_PAGE_RECLAIM_FLAGS);
page->flags |= flags;
if (flags & SGX_EPC_PAGE_RECLAIMER_TRACKED)
- sgx_epc_push_reclaimable(&sgx_global_lru, page);
+ sgx_epc_push_reclaimable(lru, page);
else
- sgx_epc_push_unreclaimable(&sgx_global_lru, page);
- spin_unlock(&sgx_global_lru.lock);
+ sgx_epc_push_unreclaimable(lru, page);
+ spin_unlock(&lru->lock);
}

/**
@@ -543,14 +551,16 @@ void sgx_record_epc_page(struct sgx_epc_page *page, unsigned long flags)
*/
int sgx_drop_epc_page(struct sgx_epc_page *page)
{
- spin_lock(&sgx_global_lru.lock);
+ struct sgx_epc_lru *lru = sgx_lru(page);
+
+ spin_lock(&lru->lock);
if ((page->flags & SGX_EPC_PAGE_RECLAIMER_TRACKED) &&
(page->flags & SGX_EPC_PAGE_RECLAIM_IN_PROGRESS)) {
- spin_unlock(&sgx_global_lru.lock);
+ spin_unlock(&lru->lock);
return -EBUSY;
}
list_del(&page->list);
- spin_unlock(&sgx_global_lru.lock);
+ spin_unlock(&lru->lock);

page->flags &= ~SGX_EPC_PAGE_RECLAIM_FLAGS;

--
2.37.3