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Commit 89907779 authored by Arnd Bergmann's avatar Arnd Bergmann Committed by David S. Miller
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netcp: try to reduce type confusion in descriptors 



The netcp driver produces tons of warnings when CONFIG_LPAE is enabled
on ARM:

drivers/net/ethernet/ti/netcp_core.c: In function 'netcp_tx_map_skb':
drivers/net/ethernet/ti/netcp_core.c:1084:13: warning: passing argument 1 of 'set_words' from incompatible pointer type [-Wincompatible-pointer-types]

This is the result of trying to pass a pointer to a dma_addr_t to
a function that expects a u32 pointer to copy that into a DMA descriptor.

Looking at that code in more detail to fix the warnings, I see multiple
related problems:

* The conversion functions are not endian-safe, as the DMA descriptors
  are almost certainly fixed-endian, but the CPU is not.

* On 64-bit machines, passing a pointer through a u32 variable is a
  bug, accessing an indirect pointer as a u32 pointer even more so.

* The handling of epib and psdata mixes native-endian and device-endian
  data.

In this patch, I try to sort out the types for most accesses here,
adding le32_to_cpu/cpu_to_le32 where appropriate, and passing pointers
through two 32-bit words in the descriptor padding, to make it plausible
that the driver does the right thing if compiled for big-endian or
64-bit systems.

Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ad2c8c73

drivers/net/ethernet/ti/netcp_core.c

+71 −52
Original line number Diff line number Diff line
@@ -109,69 +109,80 @@ module_param(netcp_debug_level, int, 0); 
MODULE_PARM_DESC(netcp_debug_level, "Netcp debug level (NETIF_MSG bits) (0=none,...,16=all)");



/* Helper functions - Get/Set */

static void get_pkt_info(u32 *buff, u32 *buff_len, u32 *ndesc,

static void get_pkt_info(dma_addr_t *buff, u32 *buff_len, dma_addr_t *ndesc,

			 struct knav_dma_desc *desc)

{

	*buff_len = desc->buff_len;

	*buff = desc->buff;

	*ndesc = desc->next_desc;

	*buff_len = le32_to_cpu(desc->buff_len);

	*buff = le32_to_cpu(desc->buff);

	*ndesc = le32_to_cpu(desc->next_desc);

}



static void get_pad_info(u32 *pad0, u32 *pad1, struct knav_dma_desc *desc)

static void get_pad_info(u32 *pad0, u32 *pad1, u32 *pad2, struct knav_dma_desc *desc)

{

	*pad0 = desc->pad[0];

	*pad1 = desc->pad[1];

	*pad0 = le32_to_cpu(desc->pad[0]);

	*pad1 = le32_to_cpu(desc->pad[1]);

	*pad2 = le32_to_cpu(desc->pad[2]);

}



static void get_org_pkt_info(u32 *buff, u32 *buff_len,

static void get_pad_ptr(void **padptr, struct knav_dma_desc *desc)

{

	u64 pad64;



	pad64 = le32_to_cpu(desc->pad[0]) +

		((u64)le32_to_cpu(desc->pad[1]) << 32);

	*padptr = (void *)(uintptr_t)pad64;

}



static void get_org_pkt_info(dma_addr_t *buff, u32 *buff_len,

			     struct knav_dma_desc *desc)

{

	*buff = desc->orig_buff;

	*buff_len = desc->orig_len;

	*buff = le32_to_cpu(desc->orig_buff);

	*buff_len = le32_to_cpu(desc->orig_len);

}



static void get_words(u32 *words, int num_words, u32 *desc)

static void get_words(dma_addr_t *words, int num_words, __le32 *desc)

{

	int i;



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

		words[i] = desc[i];

		words[i] = le32_to_cpu(desc[i]);

}



static void set_pkt_info(u32 buff, u32 buff_len, u32 ndesc,

static void set_pkt_info(dma_addr_t buff, u32 buff_len, u32 ndesc,

			 struct knav_dma_desc *desc)

{

	desc->buff_len = buff_len;

	desc->buff = buff;

	desc->next_desc = ndesc;

	desc->buff_len = cpu_to_le32(buff_len);

	desc->buff = cpu_to_le32(buff);

	desc->next_desc = cpu_to_le32(ndesc);

}



static void set_desc_info(u32 desc_info, u32 pkt_info,

			  struct knav_dma_desc *desc)

{

	desc->desc_info = desc_info;

	desc->packet_info = pkt_info;

	desc->desc_info = cpu_to_le32(desc_info);

	desc->packet_info = cpu_to_le32(pkt_info);

}



static void set_pad_info(u32 pad0, u32 pad1, struct knav_dma_desc *desc)

static void set_pad_info(u32 pad0, u32 pad1, u32 pad2, struct knav_dma_desc *desc)

{

	desc->pad[0] = pad0;

	desc->pad[1] = pad1;

	desc->pad[0] = cpu_to_le32(pad0);

	desc->pad[1] = cpu_to_le32(pad1);

	desc->pad[2] = cpu_to_le32(pad1);

}



static void set_org_pkt_info(u32 buff, u32 buff_len,

static void set_org_pkt_info(dma_addr_t buff, u32 buff_len,

			     struct knav_dma_desc *desc)

{

	desc->orig_buff = buff;

	desc->orig_len = buff_len;

	desc->orig_buff = cpu_to_le32(buff);

	desc->orig_len = cpu_to_le32(buff_len);

}



static void set_words(u32 *words, int num_words, u32 *desc)

static void set_words(u32 *words, int num_words, __le32 *desc)

{

	int i;



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

		desc[i] = words[i];

		desc[i] = cpu_to_le32(words[i]);

}



/* Read the e-fuse value as 32 bit values to be endian independent */
@@ -570,7 +581,7 @@ static void netcp_free_rx_desc_chain(struct netcp_intf *netcp, 
	dma_addr_t dma_desc, dma_buf;

	unsigned int buf_len, dma_sz = sizeof(*ndesc);

	void *buf_ptr;

	u32 tmp;

	u32 pad[2];



	get_words(&dma_desc, 1, &desc->next_desc);
@@ -580,14 +591,15 @@ static void netcp_free_rx_desc_chain(struct netcp_intf *netcp, 
			dev_err(netcp->ndev_dev, "failed to unmap Rx desc\n");

			break;

		}

		get_pkt_info(&dma_buf, &tmp, &dma_desc, ndesc);

		get_pad_info((u32 *)&buf_ptr, &tmp, ndesc);

		get_pad_ptr(&buf_ptr, ndesc);

		dma_unmap_page(netcp->dev, dma_buf, PAGE_SIZE, DMA_FROM_DEVICE);

		__free_page(buf_ptr);

		knav_pool_desc_put(netcp->rx_pool, desc);

	}



	get_pad_info((u32 *)&buf_ptr, &buf_len, desc);

	get_pad_info(&pad[0], &pad[1], &buf_len, desc);

	buf_ptr = (void *)(uintptr_t)(pad[0] + ((u64)pad[1] << 32));



	if (buf_ptr)

		netcp_frag_free(buf_len <= PAGE_SIZE, buf_ptr);

	knav_pool_desc_put(netcp->rx_pool, desc);
@@ -626,7 +638,6 @@ static int netcp_process_one_rx_packet(struct netcp_intf *netcp) 
	struct netcp_packet p_info;

	struct sk_buff *skb;

	void *org_buf_ptr;

	u32 tmp;



	dma_desc = knav_queue_pop(netcp->rx_queue, &dma_sz);

	if (!dma_desc)
@@ -639,7 +650,7 @@ static int netcp_process_one_rx_packet(struct netcp_intf *netcp) 
	}



	get_pkt_info(&dma_buff, &buf_len, &dma_desc, desc);

	get_pad_info((u32 *)&org_buf_ptr, &org_buf_len, desc);

	get_pad_ptr(&org_buf_ptr, desc);



	if (unlikely(!org_buf_ptr)) {

		dev_err(netcp->ndev_dev, "NULL bufptr in desc\n");
@@ -664,6 +675,7 @@ static int netcp_process_one_rx_packet(struct netcp_intf *netcp) 
	/* Fill in the page fragment list */

	while (dma_desc) {

		struct page *page;

		void *ptr;



		ndesc = knav_pool_desc_unmap(netcp->rx_pool, dma_desc, dma_sz);

		if (unlikely(!ndesc)) {
@@ -672,14 +684,15 @@ static int netcp_process_one_rx_packet(struct netcp_intf *netcp) 
		}



		get_pkt_info(&dma_buff, &buf_len, &dma_desc, ndesc);

		get_pad_info((u32 *)&page, &tmp, ndesc);

		get_pad_ptr(ptr, ndesc);

		page = ptr;



		if (likely(dma_buff && buf_len && page)) {

			dma_unmap_page(netcp->dev, dma_buff, PAGE_SIZE,

				       DMA_FROM_DEVICE);

		} else {

			dev_err(netcp->ndev_dev, "Bad Rx desc dma_buff(%p), len(%d), page(%p)\n",

				(void *)dma_buff, buf_len, page);

			dev_err(netcp->ndev_dev, "Bad Rx desc dma_buff(%pad), len(%d), page(%p)\n",

				&dma_buff, buf_len, page);

			goto free_desc;

		}
@@ -750,7 +763,6 @@ static void netcp_free_rx_buf(struct netcp_intf *netcp, int fdq) 
	unsigned int buf_len, dma_sz;

	dma_addr_t dma;

	void *buf_ptr;

	u32 tmp;



	/* Allocate descriptor */

	while ((dma = knav_queue_pop(netcp->rx_fdq[fdq], &dma_sz))) {
@@ -761,7 +773,7 @@ static void netcp_free_rx_buf(struct netcp_intf *netcp, int fdq) 
		}



		get_org_pkt_info(&dma, &buf_len, desc);

		get_pad_info((u32 *)&buf_ptr, &tmp, desc);

		get_pad_ptr(buf_ptr, desc);



		if (unlikely(!dma)) {

			dev_err(netcp->ndev_dev, "NULL orig_buff in desc\n");
@@ -813,7 +825,7 @@ static int netcp_allocate_rx_buf(struct netcp_intf *netcp, int fdq) 
	struct page *page;

	dma_addr_t dma;

	void *bufptr;

	u32 pad[2];

	u32 pad[3];



	/* Allocate descriptor */

	hwdesc = knav_pool_desc_get(netcp->rx_pool);
@@ -830,7 +842,7 @@ static int netcp_allocate_rx_buf(struct netcp_intf *netcp, int fdq) 
				SKB_DATA_ALIGN(sizeof(struct skb_shared_info));



		bufptr = netdev_alloc_frag(primary_buf_len);

		pad[1] = primary_buf_len;

		pad[2] = primary_buf_len;



		if (unlikely(!bufptr)) {

			dev_warn_ratelimited(netcp->ndev_dev,
@@ -842,7 +854,8 @@ static int netcp_allocate_rx_buf(struct netcp_intf *netcp, int fdq) 
		if (unlikely(dma_mapping_error(netcp->dev, dma)))

			goto fail;



		pad[0] = (u32)bufptr;

		pad[0] = lower_32_bits((uintptr_t)bufptr);

		pad[1] = upper_32_bits((uintptr_t)bufptr);



	} else {

		/* Allocate a secondary receive queue entry */
@@ -853,8 +866,9 @@ static int netcp_allocate_rx_buf(struct netcp_intf *netcp, int fdq) 
		}

		buf_len = PAGE_SIZE;

		dma = dma_map_page(netcp->dev, page, 0, buf_len, DMA_TO_DEVICE);

		pad[0] = (u32)page;

		pad[1] = 0;

		pad[0] = lower_32_bits(dma);

		pad[1] = upper_32_bits(dma);

		pad[2] = 0;

	}



	desc_info =  KNAV_DMA_DESC_PS_INFO_IN_DESC;
@@ -864,7 +878,7 @@ static int netcp_allocate_rx_buf(struct netcp_intf *netcp, int fdq) 
	pkt_info |= (netcp->rx_queue_id & KNAV_DMA_DESC_RETQ_MASK) <<

		    KNAV_DMA_DESC_RETQ_SHIFT;

	set_org_pkt_info(dma, buf_len, hwdesc);

	set_pad_info(pad[0], pad[1], hwdesc);

	set_pad_info(pad[0], pad[1], pad[2], hwdesc);

	set_desc_info(desc_info, pkt_info, hwdesc);



	/* Push to FDQs */
@@ -935,8 +949,8 @@ static void netcp_free_tx_desc_chain(struct netcp_intf *netcp, 
			dma_unmap_single(netcp->dev, dma_buf, buf_len,

					 DMA_TO_DEVICE);

		else

			dev_warn(netcp->ndev_dev, "bad Tx desc buf(%p), len(%d)\n",

				 (void *)dma_buf, buf_len);

			dev_warn(netcp->ndev_dev, "bad Tx desc buf(%pad), len(%d)\n",

				 &dma_buf, buf_len);



		knav_pool_desc_put(netcp->tx_pool, ndesc);

		ndesc = NULL;
@@ -953,11 +967,11 @@ static int netcp_process_tx_compl_packets(struct netcp_intf *netcp, 
					  unsigned int budget)

{

	struct knav_dma_desc *desc;

	void *ptr;

	struct sk_buff *skb;

	unsigned int dma_sz;

	dma_addr_t dma;

	int pkts = 0;

	u32 tmp;



	while (budget--) {

		dma = knav_queue_pop(netcp->tx_compl_q, &dma_sz);
@@ -970,7 +984,8 @@ static int netcp_process_tx_compl_packets(struct netcp_intf *netcp, 
			continue;

		}



		get_pad_info((u32 *)&skb, &tmp, desc);

		get_pad_ptr(&ptr, desc);

		skb = ptr;

		netcp_free_tx_desc_chain(netcp, desc, dma_sz);

		if (!skb) {

			dev_err(netcp->ndev_dev, "No skb in Tx desc\n");
@@ -1059,6 +1074,7 @@ netcp_tx_map_skb(struct sk_buff *skb, struct netcp_intf *netcp) 
		u32 page_offset = frag->page_offset;

		u32 buf_len = skb_frag_size(frag);

		dma_addr_t desc_dma;

		u32 desc_dma_32;

		u32 pkt_info;



		dma_addr = dma_map_page(dev, page, page_offset, buf_len,
@@ -1075,13 +1091,13 @@ netcp_tx_map_skb(struct sk_buff *skb, struct netcp_intf *netcp) 
			goto free_descs;

		}



		desc_dma = knav_pool_desc_virt_to_dma(netcp->tx_pool,

						      (void *)ndesc);

		desc_dma = knav_pool_desc_virt_to_dma(netcp->tx_pool, ndesc);

		pkt_info =

			(netcp->tx_compl_qid & KNAV_DMA_DESC_RETQ_MASK) <<

				KNAV_DMA_DESC_RETQ_SHIFT;

		set_pkt_info(dma_addr, buf_len, 0, ndesc);

		set_words(&desc_dma, 1, &pdesc->next_desc);

		desc_dma_32 = (u32)desc_dma;

		set_words(&desc_dma_32, 1, &pdesc->next_desc);

		pkt_len += buf_len;

		if (pdesc != desc)

			knav_pool_desc_map(netcp->tx_pool, pdesc,
@@ -1173,11 +1189,14 @@ static int netcp_tx_submit_skb(struct netcp_intf *netcp, 
	}



	set_words(&tmp, 1, &desc->packet_info);

	set_words((u32 *)&skb, 1, &desc->pad[0]);

	tmp = lower_32_bits((uintptr_t)&skb);

	set_words(&tmp, 1, &desc->pad[0]);

	tmp = upper_32_bits((uintptr_t)&skb);

	set_words(&tmp, 1, &desc->pad[1]);



	if (tx_pipe->flags & SWITCH_TO_PORT_IN_TAGINFO) {

		tmp = tx_pipe->switch_to_port;

		set_words((u32 *)&tmp, 1, &desc->tag_info);

		set_words(&tmp, 1, &desc->tag_info);

	}



	/* submit packet descriptor */

include/linux/soc/ti/knav_dma.h

+11 −11
Original line number Diff line number Diff line
@@ -144,17 +144,17 @@ struct knav_dma_cfg { 
 * @psdata:			Protocol specific

 */

struct knav_dma_desc {

	u32	desc_info;

	u32	tag_info;

	u32	packet_info;

	u32	buff_len;

	u32	buff;

	u32	next_desc;

	u32	orig_len;

	u32	orig_buff;

	u32	epib[KNAV_DMA_NUM_EPIB_WORDS];

	u32	psdata[KNAV_DMA_NUM_PS_WORDS];

	u32	pad[4];

	__le32	desc_info;

	__le32	tag_info;

	__le32	packet_info;

	__le32	buff_len;

	__le32	buff;

	__le32	next_desc;

	__le32	orig_len;

	__le32	orig_buff;

	__le32	epib[KNAV_DMA_NUM_EPIB_WORDS];

	__le32	psdata[KNAV_DMA_NUM_PS_WORDS];

	__le32	pad[4];

} ____cacheline_aligned;



#if IS_ENABLED(CONFIG_KEYSTONE_NAVIGATOR_DMA)