Commit e7eaf91b authored by Eric Farman's avatar Eric Farman Committed by Cornelia Huck
Browse files

vfio-ccw: Remove pfn_array_table 



Now that both CCW codepaths build this nested array:

  ccwchain->pfn_array_table[1]->pfn_array[#idaws/#pages]

We can collapse this into simply:

  ccwchain->pfn_array[#idaws/#pages]

Let's do that, so that we don't have to continually navigate two
nested arrays when the first array always has a count of one.

Signed-off-by: default avatarEric Farman <farman@linux.ibm.com>
Reviewed-by: default avatarCornelia Huck <cohuck@redhat.com>
Message-Id: <20190606202831.44135-8-farman@linux.ibm.com>
Signed-off-by: default avatarCornelia Huck <cohuck@redhat.com>
parent 8aabf0ed

drivers/s390/cio/vfio_ccw_cp.c

+33 −85
Original line number Diff line number Diff line
@@ -33,11 +33,6 @@ struct pfn_array { 
	int			pa_nr;

};



struct pfn_array_table {

	struct pfn_array	*pat_pa;

	int			pat_nr;

};



struct ccwchain {

	struct list_head	next;

	struct ccw1		*ch_ccw;
@@ -46,7 +41,7 @@ struct ccwchain { 
	/* Count of the valid ccws in chain. */

	int			ch_len;

	/* Pinned PAGEs for the original data. */

	struct pfn_array_table	*ch_pat;

	struct pfn_array	*ch_pa;

};



/*
@@ -139,55 +134,23 @@ static void pfn_array_unpin_free(struct pfn_array *pa, struct device *mdev) 
	kfree(pa->pa_iova_pfn);

}



static int pfn_array_table_init(struct pfn_array_table *pat, int nr)

{

	pat->pat_pa = kcalloc(nr, sizeof(*pat->pat_pa), GFP_KERNEL);

	if (unlikely(ZERO_OR_NULL_PTR(pat->pat_pa))) {

		pat->pat_nr = 0;

		return -ENOMEM;

	}



	pat->pat_nr = nr;



	return 0;

}



static void pfn_array_table_unpin_free(struct pfn_array_table *pat,

				       struct device *mdev)

{

	int i;



	for (i = 0; i < pat->pat_nr; i++)

		pfn_array_unpin_free(pat->pat_pa + i, mdev);



	if (pat->pat_nr) {

		kfree(pat->pat_pa);

		pat->pat_pa = NULL;

		pat->pat_nr = 0;

	}

}



static bool pfn_array_table_iova_pinned(struct pfn_array_table *pat,

					unsigned long iova)

static bool pfn_array_iova_pinned(struct pfn_array *pa, unsigned long iova)

{

	struct pfn_array *pa = pat->pat_pa;

	unsigned long iova_pfn = iova >> PAGE_SHIFT;

	int i, j;

	int i;



	for (i = 0; i < pat->pat_nr; i++, pa++)

		for (j = 0; j < pa->pa_nr; j++)

			if (pa->pa_iova_pfn[j] == iova_pfn)

	for (i = 0; i < pa->pa_nr; i++)

		if (pa->pa_iova_pfn[i] == iova_pfn)

			return true;



	return false;

}

/* Create the list idal words for a pfn_array_table. */

static inline void pfn_array_table_idal_create_words(

	struct pfn_array_table *pat,

/* Create the list of IDAL words for a pfn_array. */

static inline void pfn_array_idal_create_words(

	struct pfn_array *pa,

	unsigned long *idaws)

{

	struct pfn_array *pa;

	int i, j, k;

	int i;



	/*

	 * Idal words (execept the first one) rely on the memory being 4k
@@ -196,17 +159,12 @@ static inline void pfn_array_table_idal_create_words( 
	 * there will be no problem here to simply use the phys to create an

	 * idaw.

	 */

	k = 0;

	for (i = 0; i < pat->pat_nr; i++) {

		pa = pat->pat_pa + i;

		for (j = 0; j < pa->pa_nr; j++) {

			idaws[k] = pa->pa_pfn[j] << PAGE_SHIFT;

			k++;

		}

	}



	for (i = 0; i < pa->pa_nr; i++)

		idaws[i] = pa->pa_pfn[i] << PAGE_SHIFT;



	/* Adjust the first IDAW, since it may not start on a page boundary */

	idaws[0] += pat->pat_pa->pa_iova & (PAGE_SIZE - 1);

	idaws[0] += pa->pa_iova & (PAGE_SIZE - 1);

}
@@ -378,7 +336,7 @@ static struct ccwchain *ccwchain_alloc(struct channel_program *cp, int len) 
	/* Make ccw address aligned to 8. */

	size = ((sizeof(*chain) + 7L) & -8L) +

		sizeof(*chain->ch_ccw) * len +

		sizeof(*chain->ch_pat) * len;

		sizeof(*chain->ch_pa) * len;

	chain = kzalloc(size, GFP_DMA | GFP_KERNEL);

	if (!chain)

		return NULL;
@@ -387,7 +345,7 @@ static struct ccwchain *ccwchain_alloc(struct channel_program *cp, int len) 
	chain->ch_ccw = (struct ccw1 *)data;



	data = (u8 *)(chain->ch_ccw) + sizeof(*chain->ch_ccw) * len;

	chain->ch_pat = (struct pfn_array_table *)data;

	chain->ch_pa = (struct pfn_array *)data;



	chain->ch_len = len;
@@ -575,7 +533,7 @@ static int ccwchain_fetch_direct(struct ccwchain *chain, 
				 struct channel_program *cp)

{

	struct ccw1 *ccw;

	struct pfn_array_table *pat;

	struct pfn_array *pa;

	unsigned long *idaws;

	int ret;

	int bytes = 1;
@@ -593,21 +551,17 @@ static int ccwchain_fetch_direct(struct ccwchain *chain, 
	 * The number of pages actually is the count of the idaws which will be

	 * needed when translating a direct ccw to a idal ccw.

	 */

	pat = chain->ch_pat + idx;

	ret = pfn_array_table_init(pat, 1);

	if (ret)

		goto out_init;



	ret = pfn_array_alloc(pat->pat_pa, ccw->cda, bytes);

	pa = chain->ch_pa + idx;

	ret = pfn_array_alloc(pa, ccw->cda, bytes);

	if (ret < 0)

		goto out_unpin;



	if (ccw_does_data_transfer(ccw)) {

		ret = pfn_array_pin(pat->pat_pa, cp->mdev);

		ret = pfn_array_pin(pa, cp->mdev);

		if (ret < 0)

			goto out_unpin;

	} else {

		pat->pat_pa->pa_nr = 0;

		pa->pa_nr = 0;

	}



	/* Translate this direct ccw to a idal ccw. */
@@ -619,12 +573,12 @@ static int ccwchain_fetch_direct(struct ccwchain *chain, 
	ccw->cda = (__u32) virt_to_phys(idaws);

	ccw->flags |= CCW_FLAG_IDA;



	pfn_array_table_idal_create_words(pat, idaws);

	pfn_array_idal_create_words(pa, idaws);



	return 0;



out_unpin:

	pfn_array_table_unpin_free(pat, cp->mdev);

	pfn_array_unpin_free(pa, cp->mdev);

out_init:

	ccw->cda = 0;

	return ret;
@@ -635,7 +589,7 @@ static int ccwchain_fetch_idal(struct ccwchain *chain, 
			       struct channel_program *cp)

{

	struct ccw1 *ccw;

	struct pfn_array_table *pat;

	struct pfn_array *pa;

	unsigned long *idaws;

	u64 idaw_iova;

	unsigned int idaw_nr, idaw_len;
@@ -655,15 +609,11 @@ static int ccwchain_fetch_idal(struct ccwchain *chain, 
	idaw_len = idaw_nr * sizeof(*idaws);



	/* Pin data page(s) in memory. */

	pat = chain->ch_pat + idx;

	ret = pfn_array_table_init(pat, 1);

	pa = chain->ch_pa + idx;

	ret = pfn_array_alloc(pa, idaw_iova, bytes);

	if (ret)

		goto out_init;



	ret = pfn_array_alloc(pat->pat_pa, idaw_iova, bytes);

	if (ret)

		goto out_unpin;



	/* Translate idal ccw to use new allocated idaws. */

	idaws = kzalloc(idaw_len, GFP_DMA | GFP_KERNEL);

	if (!idaws) {
@@ -678,24 +628,24 @@ static int ccwchain_fetch_idal(struct ccwchain *chain, 
	ccw->cda = virt_to_phys(idaws);



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

		pat->pat_pa->pa_iova_pfn[i] = idaws[i] >> PAGE_SHIFT;

		pa->pa_iova_pfn[i] = idaws[i] >> PAGE_SHIFT;



	if (ccw_does_data_transfer(ccw)) {

		ret = pfn_array_pin(pat->pat_pa, cp->mdev);

		ret = pfn_array_pin(pa, cp->mdev);

		if (ret < 0)

			goto out_free_idaws;

	} else {

		pat->pat_pa->pa_nr = 0;

		pa->pa_nr = 0;

	}



	pfn_array_table_idal_create_words(pat, idaws);

	pfn_array_idal_create_words(pa, idaws);



	return 0;



out_free_idaws:

	kfree(idaws);

out_unpin:

	pfn_array_table_unpin_free(pat, cp->mdev);

	pfn_array_unpin_free(pa, cp->mdev);

out_init:

	ccw->cda = 0;

	return ret;
@@ -790,8 +740,7 @@ void cp_free(struct channel_program *cp) 
	cp->initialized = false;

	list_for_each_entry_safe(chain, temp, &cp->ccwchain_list, next) {

		for (i = 0; i < chain->ch_len; i++) {

			pfn_array_table_unpin_free(chain->ch_pat + i,

						   cp->mdev);

			pfn_array_unpin_free(chain->ch_pa + i, cp->mdev);

			ccwchain_cda_free(chain, i);

		}

		ccwchain_free(chain);
@@ -967,8 +916,7 @@ bool cp_iova_pinned(struct channel_program *cp, u64 iova) 


	list_for_each_entry(chain, &cp->ccwchain_list, next) {

		for (i = 0; i < chain->ch_len; i++)

			if (pfn_array_table_iova_pinned(chain->ch_pat + i,

							iova))

			if (pfn_array_iova_pinned(chain->ch_pa + i, iova))

				return true;

	}

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