[PATCH v2 11/11] m68k/tlb: Fix __p*_free_tlb()

Peter Zijlstra
2020-07-17T11:10:16Z

The Motorola MMU has funny PMD stuff, so use a custom table freeer.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
arch/m68k/Kconfig | 1 +
arch/m68k/include/asm/mcf_pgalloc.h | 14 ++++++--------
arch/m68k/include/asm/motorola_pgalloc.h | 10 ++++++----
arch/m68k/mm/motorola.c | 17 +++++++++++++++++
4 files changed, 30 insertions(+), 12 deletions(-)

--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -32,6 +32,7 @@ config M68K
select OLD_SIGSUSPEND3
select OLD_SIGACTION
select MMU_GATHER_NO_RANGE if MMU
+ select MMU_GATHER_TABLE_FREE if MMU_MOTOROLA

config CPU_BIG_ENDIAN
def_bool y
--- a/arch/m68k/include/asm/mcf_pgalloc.h
+++ b/arch/m68k/include/asm/mcf_pgalloc.h
@@ -34,14 +34,12 @@ extern inline pmd_t *pmd_alloc_kernel(pg

#define pmd_pgtable(pmd) pfn_to_virt(pmd_val(pmd) >> PAGE_SHIFT)

-static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pgtable,
- unsigned long address)
-{
- struct page *page = virt_to_page(pgtable);
-
- pgtable_pte_page_dtor(page);
- __free_page(page);
-}
+#define __pte_free_tlb(tlb, pgtable, addr) \
+do { \
+ struct page *page = virt_to_page(pgtable); \
+ pgtable_pte_page_dtor(page); \
+ tlb_remove_page((tlb), page); \
+} while (0)

static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
{
--- a/arch/m68k/include/asm/motorola_pgalloc.h
+++ b/arch/m68k/include/asm/motorola_pgalloc.h
@@ -14,6 +14,8 @@ enum m68k_table_types {
TABLE_PTE = 1,
};

+extern void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int type);
+extern void __tlb_remove_table(void *table);
extern void init_pointer_table(void *table, int type);
extern void *get_pointer_table(int type);
extern int free_pointer_table(void *table, int type);
@@ -47,7 +49,7 @@ static inline void pte_free(struct mm_st
static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pgtable,
unsigned long address)
{
- free_pointer_table(pgtable, TABLE_PTE);
+ pgtable_free_tlb(tlb, pgtable, TABLE_PTE);
}

@@ -61,10 +63,10 @@ static inline int pmd_free(struct mm_str
return free_pointer_table(pmd, TABLE_PMD);
}

-static inline int __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
- unsigned long address)
+static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
+ unsigned long address)
{
- return free_pointer_table(pmd, TABLE_PMD);
+ pgtable_free_tlb(tlb, pmd, TABLE_PMD);
}

--- a/arch/m68k/mm/motorola.c
+++ b/arch/m68k/mm/motorola.c
@@ -215,6 +215,23 @@ int free_pointer_table(void *table, int
return 0;
}

+void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int type)
+{
+ unsigned long ptr = (unsigned long)table;
+ BUG_ON(type > 1);
+ BUG_ON(ptr & 1);
+ ptr |= type;
+ tlb_remove_table(tlb, (void *)ptr);
+}
+
+void __tlb_remove_table(void *table)
+{
+ int type = (unsigned long)table & 1;
+ table = (void *)((unsigned long)table & ~1);
+
+ free_pointer_table(table, type);
+}
+
/* size of memory already mapped in head.S */
extern __initdata unsigned long m68k_init_mapped_size;