nvme-core: replace ctrl page size with a macro

Saving the nvme controller's page size was from a time when the driver
tried to use different sized pages, but this value is always set to
a constant, and has been this way for some time. Remove the 'page_size'
field and replace its usage with the constant value.

This also lets the compiler make some micro-optimizations in the io
path, and that's always a good thing.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 23 insertions, 24 deletions

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 45e94f016ec2..0ab0dcf84d5e 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -348,8 +348,8 @@ static bool nvme_dbbuf_update_and_check_event(u16 value, u32 *dbbuf_db,
  */
 static int nvme_npages(unsigned size, struct nvme_dev *dev)
 {
-	unsigned nprps = DIV_ROUND_UP(size + dev->ctrl.page_size,
-				      dev->ctrl.page_size);
+	unsigned nprps = DIV_ROUND_UP(size + NVME_CTRL_PAGE_SIZE,
+				      NVME_CTRL_PAGE_SIZE);
 	return DIV_ROUND_UP(8 * nprps, PAGE_SIZE - 8);
 }
 
@@ -515,7 +515,7 @@ static inline bool nvme_pci_use_sgls(struct nvme_dev *dev, struct request *req)
 static void nvme_unmap_data(struct nvme_dev *dev, struct request *req)
 {
 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
-	const int last_prp = dev->ctrl.page_size / sizeof(__le64) - 1;
+	const int last_prp = NVME_CTRL_PAGE_SIZE / sizeof(__le64) - 1;
 	dma_addr_t dma_addr = iod->first_dma, next_dma_addr;
 	int i;
 
@@ -582,34 +582,33 @@ static blk_status_t nvme_pci_setup_prps(struct nvme_dev *dev,
 	struct scatterlist *sg = iod->sg;
 	int dma_len = sg_dma_len(sg);
 	u64 dma_addr = sg_dma_address(sg);
-	u32 page_size = dev->ctrl.page_size;
-	int offset = dma_addr & (page_size - 1);
+	int offset = dma_addr & (NVME_CTRL_PAGE_SIZE - 1);
 	__le64 *prp_list;
 	void **list = nvme_pci_iod_list(req);
 	dma_addr_t prp_dma;
 	int nprps, i;
 
-	length -= (page_size - offset);
+	length -= (NVME_CTRL_PAGE_SIZE - offset);
 	if (length <= 0) {
 		iod->first_dma = 0;
 		goto done;
 	}
 
-	dma_len -= (page_size - offset);
+	dma_len -= (NVME_CTRL_PAGE_SIZE - offset);
 	if (dma_len) {
-		dma_addr += (page_size - offset);
+		dma_addr += (NVME_CTRL_PAGE_SIZE - offset);
 	} else {
 		sg = sg_next(sg);
 		dma_addr = sg_dma_address(sg);
 		dma_len = sg_dma_len(sg);
 	}
 
-	if (length <= page_size) {
+	if (length <= NVME_CTRL_PAGE_SIZE) {
 		iod->first_dma = dma_addr;
 		goto done;
 	}
 
-	nprps = DIV_ROUND_UP(length, page_size);
+	nprps = DIV_ROUND_UP(length, NVME_CTRL_PAGE_SIZE);
 	if (nprps <= (256 / 8)) {
 		pool = dev->prp_small_pool;
 		iod->npages = 0;
@@ -628,7 +627,7 @@ static blk_status_t nvme_pci_setup_prps(struct nvme_dev *dev,
 	iod->first_dma = prp_dma;
 	i = 0;
 	for (;;) {
-		if (i == page_size >> 3) {
+		if (i == NVME_CTRL_PAGE_SIZE >> 3) {
 			__le64 *old_prp_list = prp_list;
 			prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);
 			if (!prp_list)
@@ -639,9 +638,9 @@ static blk_status_t nvme_pci_setup_prps(struct nvme_dev *dev,
 			i = 1;
 		}
 		prp_list[i++] = cpu_to_le64(dma_addr);
-		dma_len -= page_size;
-		dma_addr += page_size;
-		length -= page_size;
+		dma_len -= NVME_CTRL_PAGE_SIZE;
+		dma_addr += NVME_CTRL_PAGE_SIZE;
+		length -= NVME_CTRL_PAGE_SIZE;
 		if (length <= 0)
 			break;
 		if (dma_len > 0)
@@ -751,8 +750,8 @@ static blk_status_t nvme_setup_prp_simple(struct nvme_dev *dev,
 		struct bio_vec *bv)
 {
 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
-	unsigned int offset = bv->bv_offset & (dev->ctrl.page_size - 1);
-	unsigned int first_prp_len = dev->ctrl.page_size - offset;
+	unsigned int offset = bv->bv_offset & (NVME_CTRL_PAGE_SIZE - 1);
+	unsigned int first_prp_len = NVME_CTRL_PAGE_SIZE - offset;
 
 	iod->first_dma = dma_map_bvec(dev->dev, bv, rq_dma_dir(req), 0);
 	if (dma_mapping_error(dev->dev, iod->first_dma))
@@ -794,7 +793,7 @@ static blk_status_t nvme_map_data(struct nvme_dev *dev, struct request *req,
 		struct bio_vec bv = req_bvec(req);
 
 		if (!is_pci_p2pdma_page(bv.bv_page)) {
-			if (bv.bv_offset + bv.bv_len <= dev->ctrl.page_size * 2)
+			if (bv.bv_offset + bv.bv_len <= NVME_CTRL_PAGE_SIZE * 2)
 				return nvme_setup_prp_simple(dev, req,
 							     &cmnd->rw, &bv);
 
@@ -1396,12 +1395,12 @@ static int nvme_cmb_qdepth(struct nvme_dev *dev, int nr_io_queues,
 {
 	int q_depth = dev->q_depth;
 	unsigned q_size_aligned = roundup(q_depth * entry_size,
-					  dev->ctrl.page_size);
+					  NVME_CTRL_PAGE_SIZE);
 
 	if (q_size_aligned * nr_io_queues > dev->cmb_size) {
 		u64 mem_per_q = div_u64(dev->cmb_size, nr_io_queues);
 
-		mem_per_q = round_down(mem_per_q, dev->ctrl.page_size);
+		mem_per_q = round_down(mem_per_q, NVME_CTRL_PAGE_SIZE);
 		q_depth = div_u64(mem_per_q, entry_size);
 
 		/*
@@ -1816,6 +1815,7 @@ static inline void nvme_release_cmb(struct nvme_dev *dev)
 
 static int nvme_set_host_mem(struct nvme_dev *dev, u32 bits)
 {
+	u32 host_mem_size = dev->host_mem_size >> NVME_CTRL_PAGE_SHIFT;
 	u64 dma_addr = dev->host_mem_descs_dma;
 	struct nvme_command c;
 	int ret;
@@ -1824,8 +1824,7 @@ static int nvme_set_host_mem(struct nvme_dev *dev, u32 bits)
 	c.features.opcode	= nvme_admin_set_features;
 	c.features.fid		= cpu_to_le32(NVME_FEAT_HOST_MEM_BUF);
 	c.features.dword11	= cpu_to_le32(bits);
-	c.features.dword12	= cpu_to_le32(dev->host_mem_size >>
-					      ilog2(dev->ctrl.page_size));
+	c.features.dword12	= cpu_to_le32(host_mem_size);
 	c.features.dword13	= cpu_to_le32(lower_32_bits(dma_addr));
 	c.features.dword14	= cpu_to_le32(upper_32_bits(dma_addr));
 	c.features.dword15	= cpu_to_le32(dev->nr_host_mem_descs);
@@ -1845,7 +1844,7 @@ static void nvme_free_host_mem(struct nvme_dev *dev)
 
 	for (i = 0; i < dev->nr_host_mem_descs; i++) {
 		struct nvme_host_mem_buf_desc *desc = &dev->host_mem_descs[i];
-		size_t size = le32_to_cpu(desc->size) * dev->ctrl.page_size;
+		size_t size = le32_to_cpu(desc->size) * NVME_CTRL_PAGE_SIZE;
 
 		dma_free_attrs(dev->dev, size, dev->host_mem_desc_bufs[i],
 			       le64_to_cpu(desc->addr),
@@ -1897,7 +1896,7 @@ static int __nvme_alloc_host_mem(struct nvme_dev *dev, u64 preferred,
 			break;
 
 		descs[i].addr = cpu_to_le64(dma_addr);
-		descs[i].size = cpu_to_le32(len / dev->ctrl.page_size);
+		descs[i].size = cpu_to_le32(len / NVME_CTRL_PAGE_SIZE);
 		i++;
 	}
 
@@ -1913,7 +1912,7 @@ static int __nvme_alloc_host_mem(struct nvme_dev *dev, u64 preferred,
 
 out_free_bufs:
 	while (--i >= 0) {
-		size_t size = le32_to_cpu(descs[i].size) * dev->ctrl.page_size;
+		size_t size = le32_to_cpu(descs[i].size) * NVME_CTRL_PAGE_SIZE;
 
 		dma_free_attrs(dev->dev, size, bufs[i],
 			       le64_to_cpu(descs[i].addr),