Commit e0bf78b0 authored by Alexey Kardashevskiy's avatar Alexey Kardashevskiy Committed by Michael Ellerman
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powerpc/mm/iommu/vfio_spapr_tce: Change mm_iommu_get to reference a region 



Normally mm_iommu_get() should add a reference and mm_iommu_put() should
remove it. However historically mm_iommu_find() does the referencing and
mm_iommu_get() is doing allocation and referencing.

We are going to add another helper to preregister device memory so
instead of having mm_iommu_new() (which pre-registers the normal memory
and references the region), we need separate helpers for pre-registering
and referencing.

This renames:
- mm_iommu_get to mm_iommu_new;
- mm_iommu_find to mm_iommu_get.

This changes mm_iommu_get() to reference the region so the name now
reflects what it does.

This removes the check for exact match from mm_iommu_new() as we want it
to fail on existing regions; mm_iommu_get() should be used instead.

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 ab7032e7

arch/powerpc/include/asm/mmu_context.h

+2 −2
Original line number Diff line number Diff line
@@ -21,7 +21,7 @@ struct mm_iommu_table_group_mem_t; 


extern int isolate_lru_page(struct page *page);	/* from internal.h */

extern bool mm_iommu_preregistered(struct mm_struct *mm);

extern long mm_iommu_get(struct mm_struct *mm,

extern long mm_iommu_new(struct mm_struct *mm,

		unsigned long ua, unsigned long entries,

		struct mm_iommu_table_group_mem_t **pmem);

extern long mm_iommu_put(struct mm_struct *mm,
@@ -32,7 +32,7 @@ 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,

extern struct mm_iommu_table_group_mem_t *mm_iommu_get(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 int pageshift, unsigned long *hpa);

arch/powerpc/mm/mmu_context_iommu.c

+9 −10
Original line number Diff line number Diff line
@@ -126,7 +126,7 @@ static int mm_iommu_move_page_from_cma(struct page *page) 
	return 0;

}



long mm_iommu_get(struct mm_struct *mm, unsigned long ua, unsigned long entries,

long mm_iommu_new(struct mm_struct *mm, unsigned long ua, unsigned long entries,

		struct mm_iommu_table_group_mem_t **pmem)

{

	struct mm_iommu_table_group_mem_t *mem;
@@ -140,12 +140,6 @@ long mm_iommu_get(struct mm_struct *mm, unsigned long ua, unsigned long entries, 


	list_for_each_entry_rcu(mem, &mm->context.iommu_group_mem_list,

			next) {

		if ((mem->ua == ua) && (mem->entries == entries)) {

			++mem->used;

			*pmem = mem;

			goto unlock_exit;

		}



		/* Overlap? */

		if ((mem->ua < (ua + (entries << PAGE_SHIFT))) &&

				(ua < (mem->ua +
@@ -252,7 +246,7 @@ unlock_exit: 


	return ret;

}

EXPORT_SYMBOL_GPL(mm_iommu_get);

EXPORT_SYMBOL_GPL(mm_iommu_new);



static void mm_iommu_unpin(struct mm_iommu_table_group_mem_t *mem)

{
@@ -368,21 +362,26 @@ struct mm_iommu_table_group_mem_t *mm_iommu_lookup_rm(struct mm_struct *mm, 
	return ret;

}



struct mm_iommu_table_group_mem_t *mm_iommu_find(struct mm_struct *mm,

struct mm_iommu_table_group_mem_t *mm_iommu_get(struct mm_struct *mm,

		unsigned long ua, unsigned long entries)

{

	struct mm_iommu_table_group_mem_t *mem, *ret = NULL;



	mutex_lock(&mem_list_mutex);



	list_for_each_entry_rcu(mem, &mm->context.iommu_group_mem_list, next) {

		if ((mem->ua == ua) && (mem->entries == entries)) {

			ret = mem;

			++mem->used;

			break;

		}

	}



	mutex_unlock(&mem_list_mutex);



	return ret;

}

EXPORT_SYMBOL_GPL(mm_iommu_find);

EXPORT_SYMBOL_GPL(mm_iommu_get);



long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem,

		unsigned long ua, unsigned int pageshift, unsigned long *hpa)

drivers/vfio/vfio_iommu_spapr_tce.c

+23 −12
Original line number Diff line number Diff line
@@ -152,11 +152,12 @@ static long tce_iommu_unregister_pages(struct tce_container *container, 
	struct mm_iommu_table_group_mem_t *mem;

	struct tce_iommu_prereg *tcemem;

	bool found = false;

	long ret;



	if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK))

		return -EINVAL;



	mem = mm_iommu_find(container->mm, vaddr, size >> PAGE_SHIFT);

	mem = mm_iommu_get(container->mm, vaddr, size >> PAGE_SHIFT);

	if (!mem)

		return -ENOENT;
@@ -168,9 +169,13 @@ static long tce_iommu_unregister_pages(struct tce_container *container, 
	}



	if (!found)

		return -ENOENT;

		ret = -ENOENT;

	else

		ret = tce_iommu_prereg_free(container, tcemem);



	mm_iommu_put(container->mm, mem);



	return tce_iommu_prereg_free(container, tcemem);

	return ret;

}



static long tce_iommu_register_pages(struct tce_container *container,
@@ -185,22 +190,24 @@ static long tce_iommu_register_pages(struct tce_container *container, 
			((vaddr + size) < vaddr))

		return -EINVAL;



	mem = mm_iommu_find(container->mm, vaddr, entries);

	mem = mm_iommu_get(container->mm, vaddr, entries);

	if (mem) {

		list_for_each_entry(tcemem, &container->prereg_list, next) {

			if (tcemem->mem == mem)

				return -EBUSY;

			if (tcemem->mem == mem) {

				ret = -EBUSY;

				goto put_exit;

			}

		}



	ret = mm_iommu_get(container->mm, vaddr, entries, &mem);

	} else {

		ret = mm_iommu_new(container->mm, vaddr, entries, &mem);

		if (ret)

			return ret;

	}



	tcemem = kzalloc(sizeof(*tcemem), GFP_KERNEL);

	if (!tcemem) {

		mm_iommu_put(container->mm, mem);

		return -ENOMEM;

		ret = -ENOMEM;

		goto put_exit;

	}



	tcemem->mem = mem;
@@ -209,6 +216,10 @@ static long tce_iommu_register_pages(struct tce_container *container, 
	container->enabled = true;



	return 0;



put_exit:

	mm_iommu_put(container->mm, mem);

	return ret;

}



static bool tce_page_is_contained(struct page *page, unsigned page_shift)

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