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Commit 0d82044e authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'powerpc-5.1-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux 

Pull powerpc fixes from Michael Ellerman:
 "A one-liner to make our Radix MMU support depend on HUGETLB_PAGE. We
  use some of the hugetlb inlines (eg. pud_huge()) when operating on the
  linear mapping and if they're compiled into empty wrappers we can
  corrupt memory.

  Then two fixes to our VFIO IOMMU code. The first is not a regression
  but fixes the locking to avoid a user-triggerable deadlock.

  The second does fix a regression since rc1, and depends on the first
  fix. It makes it possible to run guests with large amounts of memory
  again (~256GB).

  Thanks to Alexey Kardashevskiy"

* tag 'powerpc-5.1-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/mm_iommu: Allow pinning large regions
  powerpc/mm_iommu: Fix potential deadlock
  powerpc/mm/radix: Make Radix require HUGETLB_PAGE
parents 975a0f40 7a3a4d76

arch/powerpc/configs/skiroot_defconfig

+1 −0
Original line number Diff line number Diff line
@@ -266,6 +266,7 @@ CONFIG_UDF_FS=m 
CONFIG_MSDOS_FS=m

CONFIG_VFAT_FS=m

CONFIG_PROC_KCORE=y

CONFIG_HUGETLBFS=y

# CONFIG_MISC_FILESYSTEMS is not set

# CONFIG_NETWORK_FILESYSTEMS is not set

CONFIG_NLS=y

arch/powerpc/mm/mmu_context_iommu.c

+58 −39
Original line number Diff line number Diff line
@@ -95,28 +95,15 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua, 
			      unsigned long entries, unsigned long dev_hpa,

			      struct mm_iommu_table_group_mem_t **pmem)

{

	struct mm_iommu_table_group_mem_t *mem;

	long i, ret, locked_entries = 0;

	struct mm_iommu_table_group_mem_t *mem, *mem2;

	long i, ret, locked_entries = 0, pinned = 0;

	unsigned int pageshift;



	mutex_lock(&mem_list_mutex);



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

			next) {

		/* Overlap? */

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

				(ua < (mem->ua +

				       (mem->entries << PAGE_SHIFT)))) {

			ret = -EINVAL;

			goto unlock_exit;

		}



	}

	unsigned long entry, chunk;



	if (dev_hpa == MM_IOMMU_TABLE_INVALID_HPA) {

		ret = mm_iommu_adjust_locked_vm(mm, entries, true);

		if (ret)

			goto unlock_exit;

			return ret;



		locked_entries = entries;

	}
@@ -148,17 +135,27 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua, 
	}



	down_read(&mm->mmap_sem);

	ret = get_user_pages_longterm(ua, entries, FOLL_WRITE, mem->hpages, NULL);

	chunk = (1UL << (PAGE_SHIFT + MAX_ORDER - 1)) /

			sizeof(struct vm_area_struct *);

	chunk = min(chunk, entries);

	for (entry = 0; entry < entries; entry += chunk) {

		unsigned long n = min(entries - entry, chunk);



		ret = get_user_pages_longterm(ua + (entry << PAGE_SHIFT), n,

				FOLL_WRITE, mem->hpages + entry, NULL);

		if (ret == n) {

			pinned += n;

			continue;

		}

		if (ret > 0)

			pinned += ret;

		break;

	}

	up_read(&mm->mmap_sem);

	if (ret != entries) {

		/* free the reference taken */

		for (i = 0; i < ret; i++)

			put_page(mem->hpages[i]);



		vfree(mem->hpas);

		kfree(mem);

	if (pinned != entries) {

		if (!ret)

			ret = -EFAULT;

		goto unlock_exit;

		goto free_exit;

	}



	pageshift = PAGE_SHIFT;
@@ -183,21 +180,43 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua, 
	}



good_exit:

	ret = 0;

	atomic64_set(&mem->mapped, 1);

	mem->used = 1;

	mem->ua = ua;

	mem->entries = entries;

	*pmem = mem;



	mutex_lock(&mem_list_mutex);



	list_for_each_entry_rcu(mem2, &mm->context.iommu_group_mem_list, next) {

		/* Overlap? */

		if ((mem2->ua < (ua + (entries << PAGE_SHIFT))) &&

				(ua < (mem2->ua +

				       (mem2->entries << PAGE_SHIFT)))) {

			ret = -EINVAL;

			mutex_unlock(&mem_list_mutex);

			goto free_exit;

		}

	}



	list_add_rcu(&mem->next, &mm->context.iommu_group_mem_list);



	mutex_unlock(&mem_list_mutex);



	*pmem = mem;



	return 0;



free_exit:

	/* free the reference taken */

	for (i = 0; i < pinned; i++)

		put_page(mem->hpages[i]);



	vfree(mem->hpas);

	kfree(mem);



unlock_exit:

	if (locked_entries && ret)

	mm_iommu_adjust_locked_vm(mm, locked_entries, false);



	mutex_unlock(&mem_list_mutex);



	return ret;

}
@@ -266,7 +285,7 @@ static void mm_iommu_release(struct mm_iommu_table_group_mem_t *mem) 
long mm_iommu_put(struct mm_struct *mm, struct mm_iommu_table_group_mem_t *mem)

{

	long ret = 0;

	unsigned long entries, dev_hpa;

	unsigned long unlock_entries = 0;



	mutex_lock(&mem_list_mutex);
@@ -287,17 +306,17 @@ long mm_iommu_put(struct mm_struct *mm, struct mm_iommu_table_group_mem_t *mem) 
		goto unlock_exit;

	}



	if (mem->dev_hpa == MM_IOMMU_TABLE_INVALID_HPA)

		unlock_entries = mem->entries;



	/* @mapped became 0 so now mappings are disabled, release the region */

	entries = mem->entries;

	dev_hpa = mem->dev_hpa;

	mm_iommu_release(mem);



	if (dev_hpa == MM_IOMMU_TABLE_INVALID_HPA)

		mm_iommu_adjust_locked_vm(mm, entries, false);



unlock_exit:

	mutex_unlock(&mem_list_mutex);



	mm_iommu_adjust_locked_vm(mm, unlock_entries, false);



	return ret;

}

EXPORT_SYMBOL_GPL(mm_iommu_put);

arch/powerpc/platforms/Kconfig.cputype

+1 −1
Original line number Diff line number Diff line
@@ -324,7 +324,7 @@ config ARCH_ENABLE_SPLIT_PMD_PTLOCK 


config PPC_RADIX_MMU

	bool "Radix MMU Support"

	depends on PPC_BOOK3S_64

	depends on PPC_BOOK3S_64 && HUGETLB_PAGE

	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA

	default y

	help