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nfp: remove pessimistic NFP_QCP_MAX_ADD limits

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Multiple writes cause intermediate pointer values that do not
end on complete TX descriptors.

The QCP peripheral on the NFP provides a number of access
modes.  In some access modes, the maximum amount to add must
be restricted to a 6bit value.  The particular access mode
used by _nfp_qcp_ptr_add() has no such restrictions, so the
"< NFP_QCP_MAX_ADD" test is unnecessary.

Note that trying to add more that the configured ring size
in a single add will cause a QCP overflow, caught and handled
by the QCP peripheral.

Signed-off-by: Christo du Toit <christo.du.toit@netronome.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Fei Qin <fei.qin@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Christo du Toit
2022-03-11 11:42:57 +01:00
committed by Jakub Kicinski
parent 940ea0eae3
commit f6df1aa628
1 changed files with 2 additions and 30 deletions
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32
drivers/net/ethernet/netronome/nfp/nfp_net.h
View File

@@ -814,41 +814,15 @@ enum nfp_qcp_ptr {
NFP_QCP_WRITE_PTR
};
/* There appear to be an *undocumented* upper limit on the value which
* one can add to a queue and that value is either 0x3f or 0x7f. We
* go with 0x3f as a conservative measure.
*/
#define NFP_QCP_MAX_ADD 0x3f
static inline void _nfp_qcp_ptr_add(u8 __iomem *q,
enum nfp_qcp_ptr ptr, u32 val)
{
u32 off;
if (ptr == NFP_QCP_READ_PTR)
off = NFP_QCP_QUEUE_ADD_RPTR;
else
off = NFP_QCP_QUEUE_ADD_WPTR;
while (val > NFP_QCP_MAX_ADD) {
writel(NFP_QCP_MAX_ADD, q + off);
val -= NFP_QCP_MAX_ADD;
}
writel(val, q + off);
}
/**
* nfp_qcp_rd_ptr_add() - Add the value to the read pointer of a queue
*
* @q: Base address for queue structure
* @val: Value to add to the queue pointer
*
* If @val is greater than @NFP_QCP_MAX_ADD multiple writes are performed.
*/
static inline void nfp_qcp_rd_ptr_add(u8 __iomem *q, u32 val)
{
_nfp_qcp_ptr_add(q, NFP_QCP_READ_PTR, val);
writel(val, q + NFP_QCP_QUEUE_ADD_RPTR);
}
/**
@@ -856,12 +830,10 @@ static inline void nfp_qcp_rd_ptr_add(u8 __iomem *q, u32 val)
*
* @q: Base address for queue structure
* @val: Value to add to the queue pointer
*
* If @val is greater than @NFP_QCP_MAX_ADD multiple writes are performed.
*/
static inline void nfp_qcp_wr_ptr_add(u8 __iomem *q, u32 val)
{
_nfp_qcp_ptr_add(q, NFP_QCP_WRITE_PTR, val);
writel(val, q + NFP_QCP_QUEUE_ADD_WPTR);
}
static inline u32 _nfp_qcp_read(u8 __iomem *q, enum nfp_qcp_ptr ptr)