Hi Will,
On 2025/1/14 00:26, Will Deacon wrote:
On Wed, Jan 08, 2025 at 02:57:21PM +0800, Qi Zheng wrote:
Like other levels of page tables, also use mmu gather mechanism to free
p4d level page table.
Signed-off-by: Qi Zheng <zhengqi.a...@bytedance.com>
Originally-by: Peter Zijlstra (Intel) <pet...@infradead.org>
Reviewed-by: Kevin Brodsky <kevin.brod...@arm.com>
Cc: linux-arm-ker...@lists.infradead.org
---
arch/arm64/include/asm/pgalloc.h | 1 -
arch/arm64/include/asm/tlb.h | 14 ++++++++++++++
2 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/pgalloc.h b/arch/arm64/include/asm/pgalloc.h
index 2965f5a7e39e3..1b4509d3382c6 100644
--- a/arch/arm64/include/asm/pgalloc.h
+++ b/arch/arm64/include/asm/pgalloc.h
@@ -85,7 +85,6 @@ static inline void pgd_populate(struct mm_struct *mm, pgd_t
*pgdp, p4d_t *p4dp)
__pgd_populate(pgdp, __pa(p4dp), pgdval);
}
-#define __p4d_free_tlb(tlb, p4d, addr) p4d_free((tlb)->mm, p4d)
#else
static inline void __pgd_populate(pgd_t *pgdp, phys_addr_t p4dp, pgdval_t
prot)
{
diff --git a/arch/arm64/include/asm/tlb.h b/arch/arm64/include/asm/tlb.h
index a947c6e784ed2..445282cde9afb 100644
--- a/arch/arm64/include/asm/tlb.h
+++ b/arch/arm64/include/asm/tlb.h
@@ -111,4 +111,18 @@ static inline void __pud_free_tlb(struct mmu_gather *tlb,
pud_t *pudp,
}
#endif
+#if CONFIG_PGTABLE_LEVELS > 4
+static inline void __p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4dp,
+ unsigned long addr)
+{
+ struct ptdesc *ptdesc = virt_to_ptdesc(p4dp);
+
+ if (!pgtable_l5_enabled())
+ return;
+
+ pagetable_p4d_dtor(ptdesc);
+ tlb_remove_ptdesc(tlb, ptdesc);
+}
Should we update p4d_free() to call the destructor, too? It looks like
it just does free_page() atm.
The patch #3 introduces the generic p4d_free() and lets arm64 to use it.
The patch #4 adds the destructor to generic p4d_free(). So IIUC, there
is no problem here.
Thanks!
Will
