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powerpc/mmu: Add real mode support for IOMMU preregistered memory 

This makes mm_iommu_lookup() able to work in realmode by replacing
list_for_each_entry_rcu() (which can do debug stuff which can fail in
real mode) with list_for_each_entry_lockless().

This adds realmode version of mm_iommu_ua_to_hpa() which adds
explicit vmalloc'd-to-linear address conversion.
Unlike mm_iommu_ua_to_hpa(), mm_iommu_ua_to_hpa_rm() can fail.

This changes mm_iommu_preregistered() to receive @mm as in real mode
@current does not always have a correct pointer.

This adds realmode version of mm_iommu_lookup() which receives @mm
(for the same reason as for mm_iommu_preregistered()) and uses
lockless version of list_for_each_entry_rcu().

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
hifive-unleashed-5.1
Alexey Kardashevskiy 2017-03-22 15:21:47 +11:00 committed by Michael Ellerman
parent 97da3854c5
commit 6b5c19c552
2 changed files with 43 additions and 0 deletions
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4
arch/powerpc/include/asm/mmu_context.h
View File

@ -29,10 +29,14 @@ extern void mm_iommu_init(struct mm_struct *mm);
extern void mm_iommu_cleanup(struct mm_struct *mm);
extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup(struct mm_struct *mm,
unsigned long ua, unsigned long size);
extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup_rm(
struct mm_struct *mm, unsigned long ua, unsigned long size);
extern struct mm_iommu_table_group_mem_t *mm_iommu_find(struct mm_struct *mm,
unsigned long ua, unsigned long entries);
extern long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem,
unsigned long ua, unsigned long *hpa);
extern long mm_iommu_ua_to_hpa_rm(struct mm_iommu_table_group_mem_t *mem,
unsigned long ua, unsigned long *hpa);
extern long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem);
extern void mm_iommu_mapped_dec(struct mm_iommu_table_group_mem_t *mem);
#endif

39
arch/powerpc/mm/mmu_context_iommu.c
View File

@ -314,6 +314,25 @@ struct mm_iommu_table_group_mem_t *mm_iommu_lookup(struct mm_struct *mm,
}
EXPORT_SYMBOL_GPL(mm_iommu_lookup);
struct mm_iommu_table_group_mem_t *mm_iommu_lookup_rm(struct mm_struct *mm,
unsigned long ua, unsigned long size)
{
struct mm_iommu_table_group_mem_t *mem, *ret = NULL;
list_for_each_entry_lockless(mem, &mm->context.iommu_group_mem_list,
next) {
if ((mem->ua <= ua) &&
(ua + size <= mem->ua +
(mem->entries << PAGE_SHIFT))) {
ret = mem;
break;
}
}
return ret;
}
EXPORT_SYMBOL_GPL(mm_iommu_lookup_rm);
struct mm_iommu_table_group_mem_t *mm_iommu_find(struct mm_struct *mm,
unsigned long ua, unsigned long entries)
{
@ -345,6 +364,26 @@ long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem,
}
EXPORT_SYMBOL_GPL(mm_iommu_ua_to_hpa);
long mm_iommu_ua_to_hpa_rm(struct mm_iommu_table_group_mem_t *mem,
unsigned long ua, unsigned long *hpa)
{
const long entry = (ua - mem->ua) >> PAGE_SHIFT;
void *va = &mem->hpas[entry];
unsigned long *pa;
if (entry >= mem->entries)
return -EFAULT;
pa = (void *) vmalloc_to_phys(va);
if (!pa)
return -EFAULT;
*hpa = *pa | (ua & ~PAGE_MASK);
return 0;
}
EXPORT_SYMBOL_GPL(mm_iommu_ua_to_hpa_rm);
long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem)
{
if (atomic64_inc_not_zero(&mem->mapped))