[PULL 19/30] hw/block/nvme: remove pointless rw indirection

[Klaus Jensen]

From: Keith Busch <kbusch@kernel.org>

The code switches on the opcode to invoke a function specific to that
opcode. There's no point in consolidating back to a common function that
just switches on that same opcode without any actual common code.
Restore the opcode specific behavior without going back through another
level of switches.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
---
 hw/block/nvme.c       | 91 ++++++++++++++-----------------------------
 hw/block/trace-events |  1 -
 2 files changed, 29 insertions(+), 63 deletions(-)

diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index 2225b944f935..a168f0bf4adb 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -927,68 +927,12 @@ static void nvme_rw_cb(void *opaque, int ret)
     nvme_enqueue_req_completion(nvme_cq(req), req);
 }
 
-static uint16_t nvme_do_aio(BlockBackend *blk, int64_t offset, size_t len,
-                            NvmeRequest *req)
-{
-    BlockAcctCookie *acct = &req->acct;
-    BlockAcctStats *stats = blk_get_stats(blk);
-
-    bool is_write = false;
-
-    trace_pci_nvme_do_aio(nvme_cid(req), req->cmd.opcode,
-                          nvme_io_opc_str(req->cmd.opcode), blk_name(blk),
-                          offset, len);
-
-    switch (req->cmd.opcode) {
-    case NVME_CMD_FLUSH:
-        block_acct_start(stats, acct, 0, BLOCK_ACCT_FLUSH);
-        req->aiocb = blk_aio_flush(blk, nvme_rw_cb, req);
-        break;
-
-    case NVME_CMD_WRITE_ZEROES:
-        block_acct_start(stats, acct, len, BLOCK_ACCT_WRITE);
-        req->aiocb = blk_aio_pwrite_zeroes(blk, offset, len,
-                                           BDRV_REQ_MAY_UNMAP, nvme_rw_cb,
-                                           req);
-        break;
-
-    case NVME_CMD_WRITE:
-        is_write = true;
-
-        /* fallthrough */
-
-    case NVME_CMD_READ:
-        block_acct_start(stats, acct, len,
-                         is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ);
-
-        if (req->qsg.sg) {
-            if (is_write) {
-                req->aiocb = dma_blk_write(blk, &req->qsg, offset,
-                                           BDRV_SECTOR_SIZE, nvme_rw_cb, req);
-            } else {
-                req->aiocb = dma_blk_read(blk, &req->qsg, offset,
-                                          BDRV_SECTOR_SIZE, nvme_rw_cb, req);
-            }
-        } else {
-            if (is_write) {
-                req->aiocb = blk_aio_pwritev(blk, offset, &req->iov, 0,
-                                             nvme_rw_cb, req);
-            } else {
-                req->aiocb = blk_aio_preadv(blk, offset, &req->iov, 0,
-                                            nvme_rw_cb, req);
-            }
-        }
-
-        break;
-    }
-
-    return NVME_NO_COMPLETE;
-}
-
 static uint16_t nvme_flush(NvmeCtrl *n, NvmeRequest *req)
 {
-    NvmeNamespace *ns = req->ns;
-    return nvme_do_aio(ns->blkconf.blk, 0, 0, req);
+    block_acct_start(blk_get_stats(req->ns->blkconf.blk), &req->acct, 0,
+                     BLOCK_ACCT_FLUSH);
+    req->aiocb = blk_aio_flush(req->ns->blkconf.blk, nvme_rw_cb, req);
+    return NVME_NO_COMPLETE;
 }
 
 static uint16_t nvme_write_zeroes(NvmeCtrl *n, NvmeRequest *req)
@@ -1009,7 +953,11 @@ static uint16_t nvme_write_zeroes(NvmeCtrl *n, 
NvmeRequest *req)
         return status;
     }
 
-    return nvme_do_aio(ns->blkconf.blk, offset, count, req);
+    block_acct_start(blk_get_stats(req->ns->blkconf.blk), &req->acct, 0,
+                     BLOCK_ACCT_WRITE);
+    req->aiocb = blk_aio_pwrite_zeroes(req->ns->blkconf.blk, offset, count,
+                                       BDRV_REQ_MAY_UNMAP, nvme_rw_cb, req);
+    return NVME_NO_COMPLETE;
 }
 
 static uint16_t nvme_rw(NvmeCtrl *n, NvmeRequest *req)
@@ -1023,6 +971,7 @@ static uint16_t nvme_rw(NvmeCtrl *n, NvmeRequest *req)
     uint64_t data_offset = nvme_l2b(ns, slba);
     enum BlockAcctType acct = req->cmd.opcode == NVME_CMD_WRITE ?
         BLOCK_ACCT_WRITE : BLOCK_ACCT_READ;
+    BlockBackend *blk = ns->blkconf.blk;
     uint16_t status;
 
     trace_pci_nvme_rw(nvme_cid(req), nvme_io_opc_str(rw->opcode),
@@ -1045,7 +994,25 @@ static uint16_t nvme_rw(NvmeCtrl *n, NvmeRequest *req)
         goto invalid;
     }
 
-    return nvme_do_aio(ns->blkconf.blk, data_offset, data_size, req);
+    block_acct_start(blk_get_stats(blk), &req->acct, data_size, acct);
+    if (req->qsg.sg) {
+        if (acct == BLOCK_ACCT_WRITE) {
+            req->aiocb = dma_blk_write(blk, &req->qsg, data_offset,
+                                       BDRV_SECTOR_SIZE, nvme_rw_cb, req);
+        } else {
+            req->aiocb = dma_blk_read(blk, &req->qsg, data_offset,
+                                      BDRV_SECTOR_SIZE, nvme_rw_cb, req);
+        }
+    } else {
+        if (acct == BLOCK_ACCT_WRITE) {
+            req->aiocb = blk_aio_pwritev(blk, data_offset, &req->iov, 0,
+                                         nvme_rw_cb, req);
+        } else {
+            req->aiocb = blk_aio_preadv(blk, data_offset, &req->iov, 0,
+                                        nvme_rw_cb, req);
+        }
+    }
+    return NVME_NO_COMPLETE;
 
 invalid:
     block_acct_invalid(blk_get_stats(ns->blkconf.blk), acct);
diff --git a/hw/block/trace-events b/hw/block/trace-events
index 446cca08e9ab..e56d688b88d3 100644
--- a/hw/block/trace-events
+++ b/hw/block/trace-events
@@ -43,7 +43,6 @@ pci_nvme_admin_cmd(uint16_t cid, uint16_t sqid, uint8_t 
opcode, const char *opna
 pci_nvme_rw(uint16_t cid, const char *verb, uint32_t nsid, uint32_t nlb, 
uint64_t count, uint64_t lba) "cid %"PRIu16" opname '%s' nsid %"PRIu32" nlb 
%"PRIu32" count %"PRIu64" lba 0x%"PRIx64""
 pci_nvme_rw_cb(uint16_t cid, const char *blkname) "cid %"PRIu16" blk '%s'"
 pci_nvme_write_zeroes(uint16_t cid, uint32_t nsid, uint64_t slba, uint32_t 
nlb) "cid %"PRIu16" nsid %"PRIu32" slba %"PRIu64" nlb %"PRIu32""
-pci_nvme_do_aio(uint16_t cid, uint8_t opc, const char *opname, const char 
*blkname, int64_t offset, size_t len) "cid %"PRIu16" opc 0x%"PRIx8" opname '%s' 
blk '%s' offset %"PRId64" len %zu"
 pci_nvme_create_sq(uint64_t addr, uint16_t sqid, uint16_t cqid, uint16_t 
qsize, uint16_t qflags) "create submission queue, addr=0x%"PRIx64", 
sqid=%"PRIu16", cqid=%"PRIu16", qsize=%"PRIu16", qflags=%"PRIu16""
 pci_nvme_create_cq(uint64_t addr, uint16_t cqid, uint16_t vector, uint16_t 
size, uint16_t qflags, int ien) "create completion queue, addr=0x%"PRIx64", 
cqid=%"PRIu16", vector=%"PRIu16", qsize=%"PRIu16", qflags=%"PRIu16", ien=%d"
 pci_nvme_del_sq(uint16_t qid) "deleting submission queue sqid=%"PRIu16""
-- 
2.29.1