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Commit b0a8d1a0 authored by Arnd Bergmann's avatar Arnd Bergmann Committed by David S. Miller
Browse files

net: ezchip: fix address space confusion in nps_enet.c 



The nps_enet driver happily mixes virtual, physical and __iomem
addresses, which are all different depending on the architecture
and configuration.  That causes a warning when building the code
on ARM with LPAE mode enabled:

drivers/net/ethernet/ezchip/nps_enet.c: In function 'nps_enet_send_frame':
drivers/net/ethernet/ezchip/nps_enet.c:370:13: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]

but will also fail to work for other reasons.

In this patch, I'm trying to change the code to use only normal
kernel pointers, which I assume is what the author actually meant:

* For reading or writing a 32-bit word that may be unaligned when
  an SKB contains unaligned data, I'm using get_unaligned/put_unaligned()
  rather than memcpy_fromio/toio.

* For converting a u8 pointer to a u32 pointer, I use a cast rather
  than the incorrect virt_to_phys.

* For copying a couple of bytes from one place to another while respecting
  alignment, I use memcpy instead of memcpy_toio.

Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8cde3e44

drivers/net/ethernet/ezchip/nps_enet.c

+9 −21
Original line number Diff line number Diff line
@@ -48,21 +48,15 @@ static void nps_enet_read_rx_fifo(struct net_device *ndev, 
			*reg = nps_enet_reg_get(priv, NPS_ENET_REG_RX_BUF);

	else { /* !dst_is_aligned */

		for (i = 0; i < len; i++, reg++) {

			u32 buf =

				nps_enet_reg_get(priv, NPS_ENET_REG_RX_BUF);



			/* to accommodate word-unaligned address of "reg"

			 * we have to do memcpy_toio() instead of simple "=".

			 */

			memcpy_toio((void __iomem *)reg, &buf, sizeof(buf));

			u32 buf = nps_enet_reg_get(priv, NPS_ENET_REG_RX_BUF);

			put_unaligned(buf, reg);

		}

	}



	/* copy last bytes (if any) */

	if (last) {

		u32 buf = nps_enet_reg_get(priv, NPS_ENET_REG_RX_BUF);



		memcpy_toio((void __iomem *)reg, &buf, last);

		memcpy((u8*)reg, &buf, last);

	}

}
@@ -367,7 +361,7 @@ static void nps_enet_send_frame(struct net_device *ndev, 
	struct nps_enet_tx_ctl tx_ctrl;

	short length = skb->len;

	u32 i, len = DIV_ROUND_UP(length, sizeof(u32));

	u32 *src = (u32 *)virt_to_phys(skb->data);

	u32 *src = (void *)skb->data;

	bool src_is_aligned = IS_ALIGNED((unsigned long)src, sizeof(u32));



	tx_ctrl.value = 0;
@@ -375,17 +369,11 @@ static void nps_enet_send_frame(struct net_device *ndev, 
	if (src_is_aligned)

		for (i = 0; i < len; i++, src++)

			nps_enet_reg_set(priv, NPS_ENET_REG_TX_BUF, *src);

	else { /* !src_is_aligned */

		for (i = 0; i < len; i++, src++) {

			u32 buf;

	else /* !src_is_aligned */

		for (i = 0; i < len; i++, src++)

			nps_enet_reg_set(priv, NPS_ENET_REG_TX_BUF,

					 get_unaligned(src));



			/* to accommodate word-unaligned address of "src"

			 * we have to do memcpy_fromio() instead of simple "="

			 */

			memcpy_fromio(&buf, (void __iomem *)src, sizeof(buf));

			nps_enet_reg_set(priv, NPS_ENET_REG_TX_BUF, buf);

		}

	}

	/* Write the length of the Frame */

	tx_ctrl.nt = length;