Commit 3e7ccca0 authored by Arthur Kepner's avatar Arthur Kepner Committed by Greg Kroah-Hartman

staging/rdma/hfi1: don't cache "prescan head"

When HFI1_CAP_DMA_RTAIL is toggled off the "prescan head" can get out of sync
with the receive context's "head". This happens when, after prescan_rxq() newly
arrived packets are then received, and processed by an RX interrupt handler.
This is an unavoidable race, and to avoid getting out of sync we always start
prescanning at the current "rcd->head" entry.
Reviewed-by: default avatarMike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: default avatarDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: default avatarArthur Kepner <arthur.kepner@intel.com>
Signed-off-by: default avatarIra Weiny <ira.weiny@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 701e441d
...@@ -509,14 +509,10 @@ static inline void init_ps_mdata(struct ps_mdata *mdata, ...@@ -509,14 +509,10 @@ static inline void init_ps_mdata(struct ps_mdata *mdata,
mdata->rsize = packet->rsize; mdata->rsize = packet->rsize;
mdata->maxcnt = packet->maxcnt; mdata->maxcnt = packet->maxcnt;
if (rcd->ps_state.initialized == 0) {
mdata->ps_head = packet->rhqoff; mdata->ps_head = packet->rhqoff;
rcd->ps_state.initialized++;
} else
mdata->ps_head = rcd->ps_state.ps_head;
if (HFI1_CAP_IS_KSET(DMA_RTAIL)) { if (HFI1_CAP_IS_KSET(DMA_RTAIL)) {
mdata->ps_tail = packet->hdrqtail; mdata->ps_tail = get_rcvhdrtail(rcd);
mdata->ps_seq = 0; /* not used with DMA_RTAIL */ mdata->ps_seq = 0; /* not used with DMA_RTAIL */
} else { } else {
mdata->ps_tail = 0; /* used only with DMA_RTAIL*/ mdata->ps_tail = 0; /* used only with DMA_RTAIL*/
...@@ -533,12 +529,9 @@ static inline int ps_done(struct ps_mdata *mdata, u64 rhf) ...@@ -533,12 +529,9 @@ static inline int ps_done(struct ps_mdata *mdata, u64 rhf)
static inline void update_ps_mdata(struct ps_mdata *mdata) static inline void update_ps_mdata(struct ps_mdata *mdata)
{ {
struct hfi1_ctxtdata *rcd = mdata->rcd;
mdata->ps_head += mdata->rsize; mdata->ps_head += mdata->rsize;
if (mdata->ps_head > mdata->maxcnt) if (mdata->ps_head >= mdata->maxcnt)
mdata->ps_head = 0; mdata->ps_head = 0;
rcd->ps_state.ps_head = mdata->ps_head;
if (!HFI1_CAP_IS_KSET(DMA_RTAIL)) { if (!HFI1_CAP_IS_KSET(DMA_RTAIL)) {
if (++mdata->ps_seq > 13) if (++mdata->ps_seq > 13)
mdata->ps_seq = 1; mdata->ps_seq = 1;
......
...@@ -139,15 +139,6 @@ extern const struct pci_error_handlers hfi1_pci_err_handler; ...@@ -139,15 +139,6 @@ extern const struct pci_error_handlers hfi1_pci_err_handler;
struct hfi1_opcode_stats_perctx; struct hfi1_opcode_stats_perctx;
#endif #endif
/*
* struct ps_state keeps state associated with RX queue "prescanning"
* (prescanning for FECNs, and BECNs), if prescanning is in use.
*/
struct ps_state {
u32 ps_head;
int initialized;
};
struct ctxt_eager_bufs { struct ctxt_eager_bufs {
ssize_t size; /* total size of eager buffers */ ssize_t size; /* total size of eager buffers */
u32 count; /* size of buffers array */ u32 count; /* size of buffers array */
...@@ -302,10 +293,6 @@ struct hfi1_ctxtdata { ...@@ -302,10 +293,6 @@ struct hfi1_ctxtdata {
struct list_head sdma_queues; struct list_head sdma_queues;
spinlock_t sdma_qlock; spinlock_t sdma_qlock;
#ifdef CONFIG_PRESCAN_RXQ
struct ps_state ps_state;
#endif /* CONFIG_PRESCAN_RXQ */
/* /*
* The interrupt handler for a particular receive context can vary * The interrupt handler for a particular receive context can vary
* throughout it's lifetime. This is not a lock protected data member so * throughout it's lifetime. This is not a lock protected data member so
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment