Allocate subpage protect related variables only if we use the feature.
This helps in reducing the hash related mm context struct by around 4K
Before the patch
sizeof(struct hash_mm_context) = 8288
After the patch
sizeof(struct hash_mm_context) = 4160
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
#define SBP_L3_SHIFT (SBP_L2_SHIFT + SBP_L2_BITS)
extern void subpage_prot_free(struct mm_struct *mm);
-extern void subpage_prot_init_new_context(struct mm_struct *mm);
#else
static inline void subpage_prot_free(struct mm_struct *mm) {}
-static inline void subpage_prot_init_new_context(struct mm_struct *mm) { }
#endif /* CONFIG_PPC_SUBPAGE_PROT */
/*
#endif
#ifdef CONFIG_PPC_SUBPAGE_PROT
- struct subpage_prot_table spt;
+ struct subpage_prot_table *spt;
#endif /* CONFIG_PPC_SUBPAGE_PROT */
};
#ifdef CONFIG_PPC_SUBPAGE_PROT
static inline struct subpage_prot_table *mm_ctx_subpage_prot(mm_context_t *ctx)
{
- return &ctx->hash_context->spt;
+ return ctx->hash_context->spt;
}
#endif
u32 spp = 0;
u32 **sbpm, *sbpp;
+ if (!spt)
+ return 0;
+
if (ea >= spt->maxaddr)
return 0;
if (ea < 0x100000000UL) {
if (index < 0)
return index;
- mm->context.hash_context = kmalloc(sizeof(struct hash_mm_context), GFP_KERNEL);
+ mm->context.hash_context = kmalloc(sizeof(struct hash_mm_context),
+ GFP_KERNEL);
if (!mm->context.hash_context) {
ida_free(&mmu_context_ida, index);
return -ENOMEM;
} else {
/* This is fork. Copy hash_context details from current->mm */
memcpy(mm->context.hash_context, current->mm->context.hash_context, sizeof(struct hash_mm_context));
+#ifdef CONFIG_PPC_SUBPAGE_PROT
+ /* inherit subpage prot detalis if we have one. */
+ if (current->mm->context.hash_context->spt) {
+ mm->context.hash_context->spt = kmalloc(sizeof(struct subpage_prot_table),
+ GFP_KERNEL);
+ if (!mm->context.hash_context->spt) {
+ ida_free(&mmu_context_ida, index);
+ kfree(mm->context.hash_context);
+ return -ENOMEM;
+ }
+ }
+#endif
}
- subpage_prot_init_new_context(mm);
-
pkey_mm_init(mm);
return index;
}
unsigned long i, j, addr;
u32 **p;
+ if (!spt)
+ return;
+
for (i = 0; i < 4; ++i) {
if (spt->low_prot[i]) {
free_page((unsigned long)spt->low_prot[i]);
free_page((unsigned long)p);
}
spt->maxaddr = 0;
-}
-
-void subpage_prot_init_new_context(struct mm_struct *mm)
-{
- struct subpage_prot_table *spt = mm_ctx_subpage_prot(&mm->context);
-
- memset(spt, 0, sizeof(*spt));
+ kfree(spt);
}
static void hpte_flush_range(struct mm_struct *mm, unsigned long addr,
size_t nw;
unsigned long next, limit;
+ if (!spt)
+ return ;
+
down_write(&mm->mmap_sem);
limit = addr + len;
if (limit > spt->maxaddr)
return -EFAULT;
down_write(&mm->mmap_sem);
+
+ if (!spt) {
+ /*
+ * Allocate subpage prot table if not already done.
+ * Do this with mmap_sem held
+ */
+ spt = kzalloc(sizeof(struct subpage_prot_table), GFP_KERNEL);
+ if (!spt) {
+ err = -ENOMEM;
+ goto out;
+ }
+ mm->context.hash_context->spt = spt;
+ }
+
subpage_mark_vma_nohuge(mm, addr, len);
for (limit = addr + len; addr < limit; addr = next) {
next = pmd_addr_end(addr, limit);