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netcp: try to reduce type confusion in descriptors
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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: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Arnd Bergmann authored and David S. Miller committed Dec 12, 2015
1 parent ad2c8c7 commit 8990777
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Showing 2 changed files with 82 additions and 63 deletions.
123 changes: 71 additions & 52 deletions drivers/net/ethernet/ti/netcp_core.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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 */
Expand Down Expand Up @@ -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);

Expand All @@ -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);
Expand Down Expand Up @@ -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)
Expand All @@ -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");
Expand All @@ -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)) {
Expand All @@ -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;
}

Expand Down Expand Up @@ -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))) {
Expand All @@ -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");
Expand Down Expand Up @@ -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);
Expand All @@ -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,
Expand All @@ -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 */
Expand All @@ -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;
Expand All @@ -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 */
Expand Down Expand Up @@ -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;
Expand All @@ -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);
Expand All @@ -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");
Expand Down Expand Up @@ -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,
Expand All @@ -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,
Expand Down Expand Up @@ -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 */
Expand Down
22 changes: 11 additions & 11 deletions include/linux/soc/ti/knav_dma.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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)
Expand Down

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