Pause remote CPUs so that the local CPU can follow the proper BBM
sequence to safely update the vmemmap mapping `struct page` areas.
While updating the vmemmap, it is guaranteed that neither the local
CPU nor the remote ones will access the `struct page` area being
updated, and therefore they should not trigger (non-spurious) kernel
PFs.
Signed-off-by: Yu Zhao <yuzhao@xxxxxxxxxx>
---
arch/arm64/include/asm/pgalloc.h | 69 ++++++++++++++++++++++++++++++++
1 file changed, 69 insertions(+)
diff --git a/arch/arm64/include/asm/pgalloc.h b/arch/arm64/include/asm/pgalloc.h
index 8ff5f2a2579e..f50f79f57c1e 100644
--- a/arch/arm64/include/asm/pgalloc.h
+++ b/arch/arm64/include/asm/pgalloc.h
@@ -12,6 +12,7 @@
#include <asm/processor.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
+#include <asm/cpu.h>
#define __HAVE_ARCH_PGD_FREE
#define __HAVE_ARCH_PUD_FREE
@@ -137,4 +138,72 @@ pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep)
__pmd_populate(pmdp, page_to_phys(ptep), PMD_TYPE_TABLE | PMD_TABLE_PXN);
}
+#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
+
+#define VMEMMAP_ARCH_TLB_FLUSH_FLAGS (VMEMMAP_SPLIT_NO_TLB_FLUSH | VMEMMAP_REMAP_NO_TLB_FLUSH)
+
+#define vmemmap_update_supported vmemmap_update_supported
+static inline bool vmemmap_update_supported(void)
+{
+ return system_uses_irq_prio_masking();
+}
+
+#define vmemmap_update_lock vmemmap_update_lock
+static inline void vmemmap_update_lock(void)
+{
+ cpus_read_lock();
+}
+
+#define vmemmap_update_unlock vmemmap_update_unlock
+static inline void vmemmap_update_unlock(void)
+{
+ cpus_read_unlock();
+}
+
+#define vmemmap_update_pte_range_start vmemmap_update_pte_range_start
+static inline void vmemmap_update_pte_range_start(pte_t *pte,
+ unsigned long start, unsigned long end)
+{
+ unsigned long addr;
+
+ local_irq_disable();
+ pause_remote_cpus();
+
+ for (addr = start; addr != end; addr += PAGE_SIZE, pte++)
+ pte_clear(&init_mm, addr, pte);
+
+ flush_tlb_kernel_range(start, end);
+}
+
+#define vmemmap_update_pte_range_end vmemmap_update_pte_range_end
+static inline void vmemmap_update_pte_range_end(void)
+{
+ resume_remote_cpus();
+ local_irq_enable();
+}
+
+#define vmemmap_update_pmd_range_start vmemmap_update_pmd_range_start
+static inline void vmemmap_update_pmd_range_start(pmd_t *pmd,
+ unsigned long start, unsigned long end)
+{
+ unsigned long addr;
+
+ local_irq_disable();
+ pause_remote_cpus();
+
+ for (addr = start; addr != end; addr += PMD_SIZE, pmd++)
+ pmd_clear(pmd);
+
+ flush_tlb_kernel_range(start, end);
+}
+
+#define vmemmap_update_pmd_range_end vmemmap_update_pmd_range_end
+static inline void vmemmap_update_pmd_range_end(void)
+{
+ resume_remote_cpus();
+ local_irq_enable();
+}
+
+#endif /* CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP */
+
#endif
--
2.47.0.rc1.288.g06298d1525-goog
