linuxkit/kernel/5.11.x-rt/patches/0001-highmem-Don-t-disable-preemption-on-RT-in-kmap_atomi.patch
Avi Deitcher cd12a8613d restructure kernel builds into directories
Signed-off-by: Avi Deitcher <avi@deitcher.net>
2024-02-27 15:14:06 +02:00

78 lines
2.0 KiB
Diff

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Fri, 30 Oct 2020 13:59:06 +0100
Subject: [PATCH] highmem: Don't disable preemption on RT in kmap_atomic()
Disabling preemption makes it impossible to acquire sleeping locks within
kmap_atomic() section.
For PREEMPT_RT it is sufficient to disable migration.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
include/linux/highmem-internal.h | 27 ++++++++++++++++++++++-----
1 file changed, 22 insertions(+), 5 deletions(-)
--- a/include/linux/highmem-internal.h
+++ b/include/linux/highmem-internal.h
@@ -90,7 +90,11 @@ static inline void __kunmap_local(void *
static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{
- preempt_disable();
+ if (IS_ENABLED(CONFIG_PREEMPT_RT))
+ migrate_disable();
+ else
+ preempt_disable();
+
pagefault_disable();
return __kmap_local_page_prot(page, prot);
}
@@ -102,7 +106,11 @@ static inline void *kmap_atomic(struct p
static inline void *kmap_atomic_pfn(unsigned long pfn)
{
- preempt_disable();
+ if (IS_ENABLED(CONFIG_PREEMPT_RT))
+ migrate_disable();
+ else
+ preempt_disable();
+
pagefault_disable();
return __kmap_local_pfn_prot(pfn, kmap_prot);
}
@@ -111,7 +119,10 @@ static inline void __kunmap_atomic(void
{
kunmap_local_indexed(addr);
pagefault_enable();
- preempt_enable();
+ if (IS_ENABLED(CONFIG_PREEMPT_RT))
+ migrate_enable();
+ else
+ preempt_enable();
}
unsigned int __nr_free_highpages(void);
@@ -184,7 +195,10 @@ static inline void __kunmap_local(void *
static inline void *kmap_atomic(struct page *page)
{
- preempt_disable();
+ if (IS_ENABLED(CONFIG_PREEMPT_RT))
+ migrate_disable();
+ else
+ preempt_disable();
pagefault_disable();
return page_address(page);
}
@@ -205,7 +219,10 @@ static inline void __kunmap_atomic(void
kunmap_flush_on_unmap(addr);
#endif
pagefault_enable();
- preempt_enable();
+ if (IS_ENABLED(CONFIG_PREEMPT_RT))
+ migrate_enable();
+ else
+ preempt_enable();
}
static inline unsigned int nr_free_highpages(void) { return 0; }