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Commit 6b5c19c5 authored by Alexey Kardashevskiy's avatar Alexey Kardashevskiy Committed by Michael Ellerman
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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: default avatarAlexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 97da3854

arch/powerpc/include/asm/mmu_context.h

+4 −0
Original line number Diff line number Diff line
@@ -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

arch/powerpc/mm/mmu_context_iommu.c

+39 −0
Original line number Diff line number Diff line
@@ -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))