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IB/hfi1: Eliminate allocation while atomic

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The PIO trailing buffer was being dynamically allocated
but the kcalloc return value was not being checked. Further,
the GFP_KERNEL was being used even though the send engine
might be called with interrupts disabled.

Since the maximum size of the trailing buffer is only 12
bytes (CRC = 4, LT = 1, Pad = 0 to 7 bytes) just statically
allocate the buffer, remove the alloc entirely and share it
with the SDMA engine by making it global.

Reported-by: Leon Romanovsky <leon@kernel.org>
Fixes: 566d53a826 ("IB/hfi1: Enhance PIO/SDMA send for 16B")
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Don Hiatt <don.hiatt@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Reviewed-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This commit is contained in:
Don Hiatt 2017-10-09 12:38:19 -07:00 • committed by Doug Ledford
parent d0a2f45471
commit f8195f3b14
2 changed files with 9 additions and 14 deletions
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1
drivers/infiniband/hw/hfi1/common.h
View file

@ -328,6 +328,7 @@ struct diag_pkt {
#define SC15_PACKET 0xF #define SC15_PACKET 0xF
#define SIZE_OF_CRC 1 #define SIZE_OF_CRC 1
#define SIZE_OF_LT 1 #define SIZE_OF_LT 1
#define MAX_16B_PADDING 12 /* CRC = 4, LT = 1, Pad = 0 to 7 bytes */
#define LIM_MGMT_P_KEY 0x7FFF #define LIM_MGMT_P_KEY 0x7FFF
#define FULL_MGMT_P_KEY 0xFFFF #define FULL_MGMT_P_KEY 0xFFFF

22
drivers/infiniband/hw/hfi1/verbs.c
View file

@ -146,6 +146,9 @@ static int pio_wait(struct rvt_qp *qp,
/* Length of buffer to create verbs txreq cache name */ /* Length of buffer to create verbs txreq cache name */
#define TXREQ_NAME_LEN 24 #define TXREQ_NAME_LEN 24
/* 16B trailing buffer */
static const u8 trail_buf[MAX_16B_PADDING];
static uint wss_threshold; static uint wss_threshold;
module_param(wss_threshold, uint, S_IRUGO); module_param(wss_threshold, uint, S_IRUGO);
MODULE_PARM_DESC(wss_threshold, "Percentage (1-100) of LLC to use as a threshold for a cacheless copy"); MODULE_PARM_DESC(wss_threshold, "Percentage (1-100) of LLC to use as a threshold for a cacheless copy");
@ -814,7 +817,6 @@ static int build_verbs_tx_desc(
u16 hdrbytes = tx->hdr_dwords << 2; u16 hdrbytes = tx->hdr_dwords << 2;
u32 *hdr; u32 *hdr;
u8 extra_bytes = 0; u8 extra_bytes = 0;
static char trail_buf[12]; /* CRC = 4, LT = 1, Pad = 0 to 7 bytes */
if (tx->phdr.hdr.hdr_type) { if (tx->phdr.hdr.hdr_type) {
/* /*
@ -869,9 +871,9 @@ static int build_verbs_tx_desc(
} }
/* add icrc, lt byte, and padding to flit */ /* add icrc, lt byte, and padding to flit */
if (extra_bytes != 0) if (extra_bytes)
ret = sdma_txadd_kvaddr(sde->dd, &tx->txreq, ret = sdma_txadd_kvaddr(sde->dd, &tx->txreq,
trail_buf, extra_bytes); (void *)trail_buf, extra_bytes);
bail_txadd: bail_txadd:
return ret; return ret;
@ -1128,18 +1130,10 @@ int hfi1_verbs_send_pio(struct rvt_qp *qp, struct hfi1_pkt_state *ps,
len -= slen; len -= slen;
} }
} }
/* /* add icrc, lt byte, and padding to flit */
* Bypass packet will need to copy additional if (extra_bytes)
* bytes to accommodate for CRC and LT bytes seg_pio_copy_mid(pbuf, trail_buf, extra_bytes);
*/
if (extra_bytes) {
u8 *empty_buf;
empty_buf = kcalloc(extra_bytes, sizeof(u8),
GFP_KERNEL);
seg_pio_copy_mid(pbuf, empty_buf, extra_bytes);
kfree(empty_buf);
}
seg_pio_copy_end(pbuf); seg_pio_copy_end(pbuf);
} }