qeth: fix page breaks in hw headers

Turning on memory debugging showed there could be page breaks in hardware headers. OSA does not allow this so we had to add code to bounce the header in case there is a page break. This patch also fixes a problem in case the skb->data part of a fragmented skb spreads multiple pages. Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>

qeth: fix page breaks in hw headers
Turning on memory debugging showed there could be page breaks in hardware headers. OSA does not allow this so we had to add code to bounce the header in case there is a page break. This patch also fixes a problem in case the skb->data part of a fragmented skb spreads multiple pages. Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Frank Blaschka · David S. Miller
1 parent 43a65303fe
Showing 4 changed files with 65 additions and 73 deletions Side-by-side Diff
drivers/s390/net/qeth_core.h
drivers/s390/net/qeth_core_main.c
drivers/s390/net/qeth_l2_main.c
drivers/s390/net/qeth_l3_main.c
@@ -869,6 +869,7 @@
 void qeth_dbf_longtext(debug_info_t *id, int level, char *text, ...);
 int qeth_core_ethtool_get_settings(struct net_device *, struct ethtool_cmd *);
 int qeth_set_access_ctrl_online(struct qeth_card *card);
+int qeth_hdr_chk_and_bounce(struct sk_buff *, int);
  
 /* exports for OSN */
 int qeth_osn_assist(struct net_device *, void *, int);
@@ -57,48 +57,6 @@
 static int qeth_qdio_establish(struct qeth_card *);
  
  
-static inline void __qeth_fill_buffer_frag(struct sk_buff *skb,
-		struct qdio_buffer *buffer, int is_tso,
-		int *next_element_to_fill)
-{
-	struct skb_frag_struct *frag;
-	int fragno;
-	unsigned long addr;
-	int element, cnt, dlen;
-
-	fragno = skb_shinfo(skb)->nr_frags;
-	element = *next_element_to_fill;
-	dlen = 0;
-
-	if (is_tso)
-		buffer->element[element].flags =
-			SBAL_FLAGS_MIDDLE_FRAG;
-	else
-		buffer->element[element].flags =
-			SBAL_FLAGS_FIRST_FRAG;
-	dlen = skb->len - skb->data_len;
-	if (dlen) {
-		buffer->element[element].addr = skb->data;
-		buffer->element[element].length = dlen;
-		element++;
-	}
-	for (cnt = 0; cnt < fragno; cnt++) {
-		frag = &skb_shinfo(skb)->frags[cnt];
-		addr = (page_to_pfn(frag->page) << PAGE_SHIFT) +
-			frag->page_offset;
-		buffer->element[element].addr = (char *)addr;
-		buffer->element[element].length = frag->size;
-		if (cnt < (fragno - 1))
-			buffer->element[element].flags =
-				SBAL_FLAGS_MIDDLE_FRAG;
-		else
-			buffer->element[element].flags =
-				SBAL_FLAGS_LAST_FRAG;
-		element++;
-	}
-	*next_element_to_fill = element;
-}
-
 static inline const char *qeth_get_cardname(struct qeth_card *card)
 {
 	if (card->info.guestlan) {
  
@@ -3020,13 +2978,11 @@
 int qeth_get_elements_no(struct qeth_card *card, void *hdr,
 		     struct sk_buff *skb, int elems)
 {
-	int elements_needed = 0;
+	int dlen = skb->len - skb->data_len;
+	int elements_needed = PFN_UP((unsigned long)skb->data + dlen - 1) -
+		PFN_DOWN((unsigned long)skb->data);
  
-	if (skb_shinfo(skb)->nr_frags > 0)
-		elements_needed = (skb_shinfo(skb)->nr_frags + 1);
-	if (elements_needed == 0)
-		elements_needed = 1 + (((((unsigned long) skb->data) %
-				PAGE_SIZE) + skb->len) >> PAGE_SHIFT);
+	elements_needed += skb_shinfo(skb)->nr_frags;
 	if ((elements_needed + elems) > QETH_MAX_BUFFER_ELEMENTS(card)) {
 		QETH_DBF_MESSAGE(2, "Invalid size of IP packet "
 			"(Number=%d / Length=%d). Discarded.\n",
  
  
@@ -3037,15 +2993,35 @@
 }
 EXPORT_SYMBOL_GPL(qeth_get_elements_no);
  
+int qeth_hdr_chk_and_bounce(struct sk_buff *skb, int len)
+{
+	int hroom, inpage, rest;
+
+	if (((unsigned long)skb->data & PAGE_MASK) !=
+	    (((unsigned long)skb->data + len - 1) & PAGE_MASK)) {
+		hroom = skb_headroom(skb);
+		inpage = PAGE_SIZE - ((unsigned long) skb->data % PAGE_SIZE);
+		rest = len - inpage;
+		if (rest > hroom)
+			return 1;
+		memmove(skb->data - rest, skb->data, skb->len - skb->data_len);
+		skb->data -= rest;
+		QETH_DBF_MESSAGE(2, "skb bounce len: %d rest: %d\n", len, rest);
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(qeth_hdr_chk_and_bounce);
+
 static inline void __qeth_fill_buffer(struct sk_buff *skb,
 	struct qdio_buffer *buffer, int is_tso, int *next_element_to_fill,
 	int offset)
 {
-	int length = skb->len;
+	int length = skb->len - skb->data_len;
 	int length_here;
 	int element;
 	char *data;
-	int first_lap ;
+	int first_lap, cnt;
+	struct skb_frag_struct *frag;
  
 	element = *next_element_to_fill;
 	data = skb->data;
  
@@ -3068,10 +3044,14 @@
 		length -= length_here;
 		if (!length) {
 			if (first_lap)
-				buffer->element[element].flags = 0;
+				if (skb_shinfo(skb)->nr_frags)
+					buffer->element[element].flags =
+						SBAL_FLAGS_FIRST_FRAG;
+				else
+					buffer->element[element].flags = 0;
 			else
 				buffer->element[element].flags =
-				    SBAL_FLAGS_LAST_FRAG;
+				    SBAL_FLAGS_MIDDLE_FRAG;
 		} else {
 			if (first_lap)
 				buffer->element[element].flags =
@@ -3084,6 +3064,18 @@
 		element++;
 		first_lap = 0;
 	}
+
+	for (cnt = 0; cnt < skb_shinfo(skb)->nr_frags; cnt++) {
+		frag = &skb_shinfo(skb)->frags[cnt];
+		buffer->element[element].addr = (char *)page_to_phys(frag->page)
+			+ frag->page_offset;
+		buffer->element[element].length = frag->size;
+		buffer->element[element].flags = SBAL_FLAGS_MIDDLE_FRAG;
+		element++;
+	}
+
+	if (buffer->element[element - 1].flags)
+		buffer->element[element - 1].flags = SBAL_FLAGS_LAST_FRAG;
 	*next_element_to_fill = element;
 }
  
@@ -3124,12 +3116,8 @@
 		buf->next_element_to_fill++;
 	}
  
-	if (skb_shinfo(skb)->nr_frags == 0)
-		__qeth_fill_buffer(skb, buffer, large_send,
-				(int *)&buf->next_element_to_fill, offset);
-	else
-		__qeth_fill_buffer_frag(skb, buffer, large_send,
-					(int *)&buf->next_element_to_fill);
+	__qeth_fill_buffer(skb, buffer, large_send,
+		(int *)&buf->next_element_to_fill, offset);
  
 	if (!queue->do_pack) {
 		QETH_CARD_TEXT(queue->card, 6, "fillbfnp");
@@ -712,10 +712,13 @@
 		goto tx_drop;
 	}
  
-	if (card->info.type != QETH_CARD_TYPE_IQD)
+	if (card->info.type != QETH_CARD_TYPE_IQD) {
+		if (qeth_hdr_chk_and_bounce(new_skb,
+		    sizeof(struct qeth_hdr_layer2)))
+			goto tx_drop;
 		rc = qeth_do_send_packet(card, queue, new_skb, hdr,
 					 elements);
-	else
+	} else
 		rc = qeth_do_send_packet_fast(card, queue, new_skb, hdr,
 					elements, data_offset, hd_len);
 	if (!rc) {
@@ -2904,19 +2904,11 @@
 	unsigned long tcpd = (unsigned long)tcp_hdr(skb) +
 		tcp_hdr(skb)->doff * 4;
 	int tcpd_len = skb->len - (tcpd - (unsigned long)skb->data);
-	int elements = PFN_UP(tcpd + tcpd_len) - PFN_DOWN(tcpd);
+	int elements = PFN_UP(tcpd + tcpd_len - 1) - PFN_DOWN(tcpd);
 	elements += skb_shinfo(skb)->nr_frags;
 	return elements;
 }
  
-static inline int qeth_l3_tso_check(struct sk_buff *skb)
-{
-	int len = ((unsigned long)tcp_hdr(skb) + tcp_hdr(skb)->doff * 4) -
-		(unsigned long)skb->data;
-	return (((unsigned long)skb->data & PAGE_MASK) !=
-		(((unsigned long)skb->data + len) & PAGE_MASK));
-}
-
 static int qeth_l3_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	int rc;
@@ -3016,8 +3008,6 @@
 	    (cast_type == RTN_UNSPEC)) {
 		hdr = (struct qeth_hdr *)skb_push(new_skb,
 						sizeof(struct qeth_hdr_tso));
-		if (qeth_l3_tso_check(new_skb))
-			QETH_DBF_MESSAGE(2, "tso skb misaligned\n");
 		memset(hdr, 0, sizeof(struct qeth_hdr_tso));
 		qeth_l3_fill_header(card, hdr, new_skb, ipv, cast_type);
 		qeth_tso_fill_header(card, hdr, new_skb);
  
@@ -3048,10 +3038,20 @@
 	elements_needed += elems;
 	nr_frags = skb_shinfo(new_skb)->nr_frags;
  
-	if (card->info.type != QETH_CARD_TYPE_IQD)
+	if (card->info.type != QETH_CARD_TYPE_IQD) {
+		int len;
+		if (large_send == QETH_LARGE_SEND_TSO)
+			len = ((unsigned long)tcp_hdr(new_skb) +
+				tcp_hdr(new_skb)->doff * 4) -
+				(unsigned long)new_skb->data;
+		else
+			len = sizeof(struct qeth_hdr_layer3);
+
+		if (qeth_hdr_chk_and_bounce(new_skb, len))
+			goto tx_drop;
 		rc = qeth_do_send_packet(card, queue, new_skb, hdr,
 					 elements_needed);
-	else
+	} else
 		rc = qeth_do_send_packet_fast(card, queue, new_skb, hdr,
 					elements_needed, data_offset, 0);
...	...	@@ -869,6 +869,7 @@
869	869	void qeth_dbf_longtext(debug_info_t id, int level, char text, ...);
870	870	int qeth_core_ethtool_get_settings(struct net_device , struct ethtool_cmd );
871	871	int qeth_set_access_ctrl_online(struct qeth_card *card);
	872	+int qeth_hdr_chk_and_bounce(struct sk_buff *, int);
872	873
873	874	/* exports for OSN */
874	875	int qeth_osn_assist(struct net_device , void , int);
...	...	@@ -57,48 +57,6 @@
57	57	static int qeth_qdio_establish(struct qeth_card *);
58	58
59	59
60		-static inline void __qeth_fill_buffer_frag(struct sk_buff *skb,
61		- struct qdio_buffer *buffer, int is_tso,
62		- int *next_element_to_fill)
63		-{
64		- struct skb_frag_struct *frag;
65		- int fragno;
66		- unsigned long addr;
67		- int element, cnt, dlen;
68		-
69		- fragno = skb_shinfo(skb)->nr_frags;
70		- element = *next_element_to_fill;
71		- dlen = 0;
72		-
73		- if (is_tso)
74		- buffer->element[element].flags =
75		- SBAL_FLAGS_MIDDLE_FRAG;
76		- else
77		- buffer->element[element].flags =
78		- SBAL_FLAGS_FIRST_FRAG;
79		- dlen = skb->len - skb->data_len;
80		- if (dlen) {
81		- buffer->element[element].addr = skb->data;
82		- buffer->element[element].length = dlen;
83		- element++;
84		- }
85		- for (cnt = 0; cnt < fragno; cnt++) {
86		- frag = &skb_shinfo(skb)->frags[cnt];
87		- addr = (page_to_pfn(frag->page) << PAGE_SHIFT) +
88		- frag->page_offset;
89		- buffer->element[element].addr = (char *)addr;
90		- buffer->element[element].length = frag->size;
91		- if (cnt < (fragno - 1))
92		- buffer->element[element].flags =
93		- SBAL_FLAGS_MIDDLE_FRAG;
94		- else
95		- buffer->element[element].flags =
96		- SBAL_FLAGS_LAST_FRAG;
97		- element++;
98		- }
99		- *next_element_to_fill = element;
100		-}
101		-
102	60	static inline const char qeth_get_cardname(struct qeth_card card)
103	61	{
104	62	if (card->info.guestlan) {
105	63
...	...	@@ -3020,13 +2978,11 @@
3020	2978	int qeth_get_elements_no(struct qeth_card card, void hdr,
3021	2979	struct sk_buff *skb, int elems)
3022	2980	{
3023		- int elements_needed = 0;
	2981	+ int dlen = skb->len - skb->data_len;
	2982	+ int elements_needed = PFN_UP((unsigned long)skb->data + dlen - 1) -
	2983	+ PFN_DOWN((unsigned long)skb->data);
3024	2984
3025		- if (skb_shinfo(skb)->nr_frags > 0)
3026		- elements_needed = (skb_shinfo(skb)->nr_frags + 1);
3027		- if (elements_needed == 0)
3028		- elements_needed = 1 + (((((unsigned long) skb->data) %
3029		- PAGE_SIZE) + skb->len) >> PAGE_SHIFT);
	2985	+ elements_needed += skb_shinfo(skb)->nr_frags;
3030	2986	if ((elements_needed + elems) > QETH_MAX_BUFFER_ELEMENTS(card)) {
3031	2987	QETH_DBF_MESSAGE(2, "Invalid size of IP packet "
3032	2988	"(Number=%d / Length=%d). Discarded.\n",
3033	2989
3034	2990
...	...	@@ -3037,15 +2993,35 @@
3037	2993	}
3038	2994	EXPORT_SYMBOL_GPL(qeth_get_elements_no);
3039	2995
	2996	+int qeth_hdr_chk_and_bounce(struct sk_buff *skb, int len)
	2997	+{
	2998	+ int hroom, inpage, rest;
	2999	+
	3000	+ if (((unsigned long)skb->data & PAGE_MASK) !=
	3001	+ (((unsigned long)skb->data + len - 1) & PAGE_MASK)) {
	3002	+ hroom = skb_headroom(skb);
	3003	+ inpage = PAGE_SIZE - ((unsigned long) skb->data % PAGE_SIZE);
	3004	+ rest = len - inpage;
	3005	+ if (rest > hroom)
	3006	+ return 1;
	3007	+ memmove(skb->data - rest, skb->data, skb->len - skb->data_len);
	3008	+ skb->data -= rest;
	3009	+ QETH_DBF_MESSAGE(2, "skb bounce len: %d rest: %d\n", len, rest);
	3010	+ }
	3011	+ return 0;
	3012	+}
	3013	+EXPORT_SYMBOL_GPL(qeth_hdr_chk_and_bounce);
	3014	+
3040	3015	static inline void __qeth_fill_buffer(struct sk_buff *skb,
3041	3016	struct qdio_buffer buffer, int is_tso, int next_element_to_fill,
3042	3017	int offset)
3043	3018	{
3044		- int length = skb->len;
	3019	+ int length = skb->len - skb->data_len;
3045	3020	int length_here;
3046	3021	int element;
3047	3022	char *data;
3048		- int first_lap ;
	3023	+ int first_lap, cnt;
	3024	+ struct skb_frag_struct *frag;
3049	3025
3050	3026	element = *next_element_to_fill;
3051	3027	data = skb->data;
3052	3028
...	...	@@ -3068,10 +3044,14 @@
3068	3044	length -= length_here;
3069	3045	if (!length) {
3070	3046	if (first_lap)
3071		- buffer->element[element].flags = 0;
	3047	+ if (skb_shinfo(skb)->nr_frags)
	3048	+ buffer->element[element].flags =
	3049	+ SBAL_FLAGS_FIRST_FRAG;
	3050	+ else
	3051	+ buffer->element[element].flags = 0;
3072	3052	else
3073	3053	buffer->element[element].flags =
3074		- SBAL_FLAGS_LAST_FRAG;
	3054	+ SBAL_FLAGS_MIDDLE_FRAG;
3075	3055	} else {
3076	3056	if (first_lap)
3077	3057	buffer->element[element].flags =
...	...	@@ -3084,6 +3064,18 @@
3084	3064	element++;
3085	3065	first_lap = 0;
3086	3066	}
	3067	+
	3068	+ for (cnt = 0; cnt < skb_shinfo(skb)->nr_frags; cnt++) {
	3069	+ frag = &skb_shinfo(skb)->frags[cnt];
	3070	+ buffer->element[element].addr = (char *)page_to_phys(frag->page)
	3071	+ + frag->page_offset;
	3072	+ buffer->element[element].length = frag->size;
	3073	+ buffer->element[element].flags = SBAL_FLAGS_MIDDLE_FRAG;
	3074	+ element++;
	3075	+ }
	3076	+
	3077	+ if (buffer->element[element - 1].flags)
	3078	+ buffer->element[element - 1].flags = SBAL_FLAGS_LAST_FRAG;
3087	3079	*next_element_to_fill = element;
3088	3080	}
3089	3081
...	...	@@ -3124,12 +3116,8 @@
3124	3116	buf->next_element_to_fill++;
3125	3117	}
3126	3118
3127		- if (skb_shinfo(skb)->nr_frags == 0)
3128		- __qeth_fill_buffer(skb, buffer, large_send,
3129		- (int *)&buf->next_element_to_fill, offset);
3130		- else
3131		- __qeth_fill_buffer_frag(skb, buffer, large_send,
3132		- (int *)&buf->next_element_to_fill);
	3119	+ __qeth_fill_buffer(skb, buffer, large_send,
	3120	+ (int *)&buf->next_element_to_fill, offset);
3133	3121
3134	3122	if (!queue->do_pack) {
3135	3123	QETH_CARD_TEXT(queue->card, 6, "fillbfnp");
...	...	@@ -712,10 +712,13 @@
712	712	goto tx_drop;
713	713	}
714	714
715		- if (card->info.type != QETH_CARD_TYPE_IQD)
	715	+ if (card->info.type != QETH_CARD_TYPE_IQD) {
	716	+ if (qeth_hdr_chk_and_bounce(new_skb,
	717	+ sizeof(struct qeth_hdr_layer2)))
	718	+ goto tx_drop;
716	719	rc = qeth_do_send_packet(card, queue, new_skb, hdr,
717	720	elements);
718		- else
	721	+ } else
719	722	rc = qeth_do_send_packet_fast(card, queue, new_skb, hdr,
720	723	elements, data_offset, hd_len);
721	724	if (!rc) {
...	...	@@ -2904,19 +2904,11 @@
2904	2904	unsigned long tcpd = (unsigned long)tcp_hdr(skb) +
2905	2905	tcp_hdr(skb)->doff * 4;
2906	2906	int tcpd_len = skb->len - (tcpd - (unsigned long)skb->data);
2907		- int elements = PFN_UP(tcpd + tcpd_len) - PFN_DOWN(tcpd);
	2907	+ int elements = PFN_UP(tcpd + tcpd_len - 1) - PFN_DOWN(tcpd);
2908	2908	elements += skb_shinfo(skb)->nr_frags;
2909	2909	return elements;
2910	2910	}
2911	2911
2912		-static inline int qeth_l3_tso_check(struct sk_buff *skb)
2913		-{
2914		- int len = ((unsigned long)tcp_hdr(skb) + tcp_hdr(skb)->doff * 4) -
2915		- (unsigned long)skb->data;
2916		- return (((unsigned long)skb->data & PAGE_MASK) !=
2917		- (((unsigned long)skb->data + len) & PAGE_MASK));
2918		-}
2919		-
2920	2912	static int qeth_l3_hard_start_xmit(struct sk_buff skb, struct net_device dev)
2921	2913	{
2922	2914	int rc;
...	...	@@ -3016,8 +3008,6 @@
3016	3008	(cast_type == RTN_UNSPEC)) {
3017	3009	hdr = (struct qeth_hdr *)skb_push(new_skb,
3018	3010	sizeof(struct qeth_hdr_tso));
3019		- if (qeth_l3_tso_check(new_skb))
3020		- QETH_DBF_MESSAGE(2, "tso skb misaligned\n");
3021	3011	memset(hdr, 0, sizeof(struct qeth_hdr_tso));
3022	3012	qeth_l3_fill_header(card, hdr, new_skb, ipv, cast_type);
3023	3013	qeth_tso_fill_header(card, hdr, new_skb);
3024	3014
...	...	@@ -3048,10 +3038,20 @@
3048	3038	elements_needed += elems;
3049	3039	nr_frags = skb_shinfo(new_skb)->nr_frags;
3050	3040
3051		- if (card->info.type != QETH_CARD_TYPE_IQD)
	3041	+ if (card->info.type != QETH_CARD_TYPE_IQD) {
	3042	+ int len;
	3043	+ if (large_send == QETH_LARGE_SEND_TSO)
	3044	+ len = ((unsigned long)tcp_hdr(new_skb) +
	3045	+ tcp_hdr(new_skb)->doff * 4) -
	3046	+ (unsigned long)new_skb->data;
	3047	+ else
	3048	+ len = sizeof(struct qeth_hdr_layer3);
	3049	+
	3050	+ if (qeth_hdr_chk_and_bounce(new_skb, len))
	3051	+ goto tx_drop;
3052	3052	rc = qeth_do_send_packet(card, queue, new_skb, hdr,
3053	3053	elements_needed);
3054		- else
	3054	+ } else
3055	3055	rc = qeth_do_send_packet_fast(card, queue, new_skb, hdr,
3056	3056	elements_needed, data_offset, 0);
3057	3057