[PATCH RFC PKS/PMEM 51/58] kernel: Utilize new kmap_thread()

From: ira . weiny
Date: Fri Oct 09 2020 - 15:56:37 EST


From: Ira Weiny <ira.weiny@xxxxxxxxx>

This kmap() call is localized to a single thread. To avoid the over
head of global PKRS updates use the new kmap_thread() call.

Cc: Eric Biederman <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
---
kernel/kexec_core.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index c19c0dad1ebe..272a9920c0d6 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -815,7 +815,7 @@ static int kimage_load_normal_segment(struct kimage *image,
if (result < 0)
goto out;

- ptr = kmap(page);
+ ptr = kmap_thread(page);
/* Start with a clear page */
clear_page(ptr);
ptr += maddr & ~PAGE_MASK;
@@ -828,7 +828,7 @@ static int kimage_load_normal_segment(struct kimage *image,
memcpy(ptr, kbuf, uchunk);
else
result = copy_from_user(ptr, buf, uchunk);
- kunmap(page);
+ kunmap_thread(page);
if (result) {
result = -EFAULT;
goto out;
@@ -879,7 +879,7 @@ static int kimage_load_crash_segment(struct kimage *image,
goto out;
}
arch_kexec_post_alloc_pages(page_address(page), 1, 0);
- ptr = kmap(page);
+ ptr = kmap_thread(page);
ptr += maddr & ~PAGE_MASK;
mchunk = min_t(size_t, mbytes,
PAGE_SIZE - (maddr & ~PAGE_MASK));
@@ -895,7 +895,7 @@ static int kimage_load_crash_segment(struct kimage *image,
else
result = copy_from_user(ptr, buf, uchunk);
kexec_flush_icache_page(page);
- kunmap(page);
+ kunmap_thread(page);
arch_kexec_pre_free_pages(page_address(page), 1);
if (result) {
result = -EFAULT;
--
2.28.0.rc0.12.gb6a658bd00c9