From: Don Hiatt <don.hiatt@intel.com>
Date: Mon, 9 Oct 2017 12:38:19 -0700
Subject: IB/hfi1: Eliminate allocation while atomic
Patch-mainline: v4.15-rc1
Git-commit: f8195f3b14a046ae33d9c369ffb59b4192f29e08
References: bsc#1060463 FATE#323043
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: 566d53a82644 ("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>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/infiniband/hw/hfi1/common.h | 1 +
drivers/infiniband/hw/hfi1/verbs.c | 22 ++++++++--------------
2 files changed, 9 insertions(+), 14 deletions(-)
--- a/drivers/infiniband/hw/hfi1/common.h
+++ b/drivers/infiniband/hw/hfi1/common.h
@@ -328,6 +328,7 @@ struct diag_pkt {
#define SC15_PACKET 0xF
#define SIZE_OF_CRC 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 FULL_MGMT_P_KEY 0xFFFF
--- a/drivers/infiniband/hw/hfi1/verbs.c
+++ b/drivers/infiniband/hw/hfi1/verbs.c
@@ -146,6 +146,9 @@ static int pio_wait(struct rvt_qp *qp,
/* Length of buffer to create verbs txreq cache name */
#define TXREQ_NAME_LEN 24
+/* 16B trailing buffer */
+static const u8 trail_buf[MAX_16B_PADDING];
+
static uint wss_threshold;
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");
@@ -814,7 +817,6 @@ static int build_verbs_tx_desc(
u16 hdrbytes = tx->hdr_dwords << 2;
u32 *hdr;
u8 extra_bytes = 0;
- static char trail_buf[12]; /* CRC = 4, LT = 1, Pad = 0 to 7 bytes */
if (tx->phdr.hdr.hdr_type) {
/*
@@ -869,9 +871,9 @@ static int build_verbs_tx_desc(
}
/* add icrc, lt byte, and padding to flit */
- if (extra_bytes != 0)
+ if (extra_bytes)
ret = sdma_txadd_kvaddr(sde->dd, &tx->txreq,
- trail_buf, extra_bytes);
+ (void *)trail_buf, extra_bytes);
bail_txadd:
return ret;
@@ -1128,18 +1130,10 @@ int hfi1_verbs_send_pio(struct rvt_qp *q
len -= slen;
}
}
- /*
- * Bypass packet will need to copy additional
- * bytes to accommodate for CRC and LT bytes
- */
- if (extra_bytes) {
- u8 *empty_buf;
+ /* add icrc, lt byte, and padding to flit */
+ if (extra_bytes)
+ seg_pio_copy_mid(pbuf, trail_buf, extra_bytes);
- 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);
}