Complete the split of the radix vs hash mm context initialisation.
This is mostly code movement, with the exception that we now limit the
context allocation to PRTB_ENTRIES - 1 on radix.
Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
---
arch/powerpc/include/asm/book3s/64/mmu.h | 2 +
arch/powerpc/mm/mmu_context_book3s64.c | 67 ++++++++++++++++++++------------
2 files changed, 45 insertions(+), 24 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h
b/arch/powerpc/include/asm/book3s/64/mmu.h
index 805d4105e9bb..cce434e7de06 100644
--- a/arch/powerpc/include/asm/book3s/64/mmu.h
+++ b/arch/powerpc/include/asm/book3s/64/mmu.h
@@ -65,6 +65,8 @@ extern struct patb_entry *partition_tb;
* MAX_USER_CONTEXT * 16 bytes of space.
*/
#define PRTB_SIZE_SHIFT (CONTEXT_BITS + 4)
+#define PRTB_ENTRIES (1ul << CONTEXT_BITS)
+
/*
* Power9 currently only support 64K partition table size.
*/
diff --git a/arch/powerpc/mm/mmu_context_book3s64.c
b/arch/powerpc/mm/mmu_context_book3s64.c
index 981c3b02e46a..e5da551edde3 100644
--- a/arch/powerpc/mm/mmu_context_book3s64.c
+++ b/arch/powerpc/mm/mmu_context_book3s64.c
@@ -63,47 +63,66 @@ int hash__alloc_context_id(void)
}
EXPORT_SYMBOL_GPL(hash__alloc_context_id);
-static int radix__init_new_context(struct mm_struct *mm, int index)
+static int hash__init_new_context(struct mm_struct *mm)
+{
+ int index;
+
+ index = hash__alloc_context_id();
+ if (index < 0)
+ return index;
+
+ /*
+ * The old code would re-promote on fork, we don't do that when using
+ * slices as it could cause problem promoting slices that have been
+ * forced down to 4K.
+ *
+ * For book3s we have MMU_NO_CONTEXT set to be ~0. Hence check
+ * explicitly against context.id == 0. This ensures that we properly
+ * initialize context slice details for newly allocated mm's (which will
+ * have id == 0) and don't alter context slice inherited via fork (which
+ * will have id != 0).
+ *
+ * We should not be calling init_new_context() on init_mm. Hence a
+ * check against 0 is OK.
+ */
+ if (mm->context.id == 0)
+ slice_set_user_psize(mm, mmu_virtual_psize);
+
+ subpage_prot_init_new_context(mm);
+
+ return index;
+}
+
+static int radix__init_new_context(struct mm_struct *mm)
{
unsigned long rts_field;
+ int index;
+
+ index = alloc_context_id(1, PRTB_ENTRIES - 1);
+ if (index < 0)
+ return index;
/*
* set the process table entry,
*/
rts_field = radix__get_tree_size();
process_tb[index].prtb0 = cpu_to_be64(rts_field | __pa(mm->pgd) |
RADIX_PGD_INDEX_SIZE);
- return 0;
+
+ return index;
}
int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
{
int index;
- index = hash__alloc_context_id();
+ if (radix_enabled())
+ index = radix__init_new_context(mm);
+ else
+ index = hash__init_new_context(mm);
+
if (index < 0)
return index;
- if (radix_enabled()) {
- radix__init_new_context(mm, index);
- } else {
-
- /* The old code would re-promote on fork, we don't do that
- * when using slices as it could cause problem promoting slices
- * that have been forced down to 4K
- *
- * For book3s we have MMU_NO_CONTEXT set to be ~0. Hence check
- * explicitly against context.id == 0. This ensures that we
- * properly initialize context slice details for newly allocated
- * mm's (which will have id == 0) and don't alter context slice
- * inherited via fork (which will have id != 0).
- *
- * We should not be calling init_new_context() on init_mm.
Hence a
- * check against 0 is ok.
- */
- if (mm->context.id == 0)
- slice_set_user_psize(mm, mmu_virtual_psize);
- subpage_prot_init_new_context(mm);
- }
mm->context.id = index;
#ifdef CONFIG_PPC_ICSWX
mm->context.cop_lockp = kmalloc(sizeof(spinlock_t), GFP_KERNEL);
--
2.7.4
