On Wed, 12 Dec 2018 at 07:25, Ashish Mhetre <amhetre@xxxxxxxxxx> wrote:
>
> From: Krishna Reddy <vdumpa@xxxxxxxxxx>
>
> In the cases where greater than 4GB allocations are required, current
> definition of scatterlist doesn't support it. For example, Tegra devices
> have more than 4GB of system memory available. So they are expected to
> support larger allocation requests.
> This patch updates the type of scatterlist members to support creating
> scatterlist for allocations of size greater than 4GB size.
Can you explain what the use case is? We have had systems with more
than 4 GB for a while now, so where does this new requirement come
from?
Also, you are changing 'length' to size_t and 'offset' to unsigned
long. What is the rationale behind that? Did you consider 32-bit
architectures with PAE at all?
> Updated the files that are necessary to fix compilation issues with updated
> type of variables.
>
> With definition of scatterlist changed in this patch, size of sg has
> increased from 28 bytes to 40 bytes because of which allocations in nvme
> driver are crossing order-0( as sizeof(struct scatterlist) is used in nvme
> driver allocations ) i.e. they are not able to fit into single page.
>
> Recently a patch to limit the nvme allocations to order-0 is mergerd.
> 'commit 943e942e6266f22babee5efeb00f8f672fbff5bd ("nvme-pci: limit
> max IO size and segments to avoid high order allocations")'
> Because of that patch, WARN log is getting printed in our case as
> definition of scatterlist has changed. Alloc size of nvme is calculated as
> NVME_MAX_SEGS * sizeof(struct scatterlist). As sizeof(struct scatterlist)
> has changed from 28 bytes to 40 bytes, so updating NVME_MAX_SEGS from 127
> to 88 to correspond to original nvme alloc size value.
>
> Signed-off-by: Krishna Reddy <vdumpa@xxxxxxxxxx>
> Signed-off-by: Ashish Mhetre <amhetre@xxxxxxxxxx>
> ---
> crypto/shash.c | 2 +-
> drivers/ata/libata-sff.c | 2 +-
> drivers/mmc/host/sdhci.c | 2 +-
> drivers/mmc/host/toshsd.c | 2 +-
> drivers/mmc/host/usdhi6rol0.c | 14 +++++++-------
> drivers/nvme/host/pci.c | 8 ++++----
> include/linux/nvme.h | 2 +-
> include/linux/scatterlist.h | 8 ++++----
> 8 files changed, 20 insertions(+), 20 deletions(-)
>
> diff --git a/crypto/shash.c b/crypto/shash.c
> index d21f04d..434970e 100644
> --- a/crypto/shash.c
> +++ b/crypto/shash.c
> @@ -298,7 +298,7 @@ int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
>
> if (nbytes &&
> (sg = req->src, offset = sg->offset,
> - nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) {
> + nbytes < min(sg->length, ((size_t)(PAGE_SIZE)) - offset))) {
> void *data;
>
> data = kmap_atomic(sg_page(sg));
> diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
> index c5ea0fc..675def6 100644
> --- a/drivers/ata/libata-sff.c
> +++ b/drivers/ata/libata-sff.c
> @@ -810,7 +810,7 @@ static int __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)
> offset %= PAGE_SIZE;
>
> /* don't overrun current sg */
> - count = min(sg->length - qc->cursg_ofs, bytes);
> + count = min(sg->length - qc->cursg_ofs, (size_t)bytes);
>
> /* don't cross page boundaries */
> count = min(count, (unsigned int)PAGE_SIZE - offset);
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 99bdae5..bd84c0c 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1025,7 +1025,7 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
> if (unlikely(length_mask | offset_mask)) {
> for_each_sg(data->sg, sg, data->sg_len, i) {
> if (sg->length & length_mask) {
> - DBG("Reverting to PIO because of transfer size (%d)\n",
> + DBG("Reverting to PIO because of transfer size (%zd)\n",
> sg->length);
> host->flags &= ~SDHCI_REQ_USE_DMA;
> break;
> diff --git a/drivers/mmc/host/toshsd.c b/drivers/mmc/host/toshsd.c
> index dd961c5..af00936 100644
> --- a/drivers/mmc/host/toshsd.c
> +++ b/drivers/mmc/host/toshsd.c
> @@ -479,7 +479,7 @@ static void toshsd_start_data(struct toshsd_host *host, struct mmc_data *data)
> {
> unsigned int flags = SG_MITER_ATOMIC;
>
> - dev_dbg(&host->pdev->dev, "setup data transfer: blocksize %08x nr_blocks %d, offset: %08x\n",
> + dev_dbg(&host->pdev->dev, "setup data transfer: blocksize %08x nr_blocks %d, offset: %08lx\n",
> data->blksz, data->blocks, data->sg->offset);
>
> host->data = data;
> diff --git a/drivers/mmc/host/usdhi6rol0.c b/drivers/mmc/host/usdhi6rol0.c
> index cd8b1b9..5fce5ff 100644
> --- a/drivers/mmc/host/usdhi6rol0.c
> +++ b/drivers/mmc/host/usdhi6rol0.c
> @@ -316,7 +316,7 @@ static void usdhi6_blk_bounce(struct usdhi6_host *host,
> struct mmc_data *data = host->mrq->data;
> size_t blk_head = host->head_len;
>
> - dev_dbg(mmc_dev(host->mmc), "%s(): CMD%u of %u SG: %ux%u @ 0x%x\n",
> + dev_dbg(mmc_dev(host->mmc), "%s(): CMD%u of %u SG: %ux%u @ 0x%lx\n",
> __func__, host->mrq->cmd->opcode, data->sg_len,
> data->blksz, data->blocks, sg->offset);
>
> @@ -360,7 +360,7 @@ static void *usdhi6_sg_map(struct usdhi6_host *host)
>
> WARN(host->pg.page, "%p not properly unmapped!\n", host->pg.page);
> if (WARN(sg_dma_len(sg) % data->blksz,
> - "SG size %u isn't a multiple of block size %u\n",
> + "SG size %zu isn't a multiple of block size %u\n",
> sg_dma_len(sg), data->blksz))
> return NULL;
>
> @@ -383,7 +383,7 @@ static void *usdhi6_sg_map(struct usdhi6_host *host)
> else
> host->blk_page = host->pg.mapped;
>
> - dev_dbg(mmc_dev(host->mmc), "Mapped %p (%lx) at %p + %u for CMD%u @ 0x%p\n",
> + dev_dbg(mmc_dev(host->mmc), "Mapped %p (%lx) at %p + %lu for CMD%u @ 0x%p\n",
> host->pg.page, page_to_pfn(host->pg.page), host->pg.mapped,
> sg->offset, host->mrq->cmd->opcode, host->mrq);
>
> @@ -492,7 +492,7 @@ static void usdhi6_sg_advance(struct usdhi6_host *host)
> host->sg = next;
>
> if (WARN(next && sg_dma_len(next) % data->blksz,
> - "SG size %u isn't a multiple of block size %u\n",
> + "SG size %zu isn't a multiple of block size %u\n",
> sg_dma_len(next), data->blksz))
> data->error = -EINVAL;
>
> @@ -1044,7 +1044,7 @@ static int usdhi6_rq_start(struct usdhi6_host *host)
> (data->blksz % 4 ||
> data->sg->offset % 4))
> dev_dbg(mmc_dev(host->mmc),
> - "Bad SG of %u: %ux%u @ %u\n", data->sg_len,
> + "Bad SG of %u: %ux%u @ %lu\n", data->sg_len,
> data->blksz, data->blocks, data->sg->offset);
>
> /* Enable DMA for USDHI6_MIN_DMA bytes or more */
> @@ -1056,7 +1056,7 @@ static int usdhi6_rq_start(struct usdhi6_host *host)
> usdhi6_write(host, USDHI6_CC_EXT_MODE, USDHI6_CC_EXT_MODE_SDRW);
>
> dev_dbg(mmc_dev(host->mmc),
> - "%s(): request opcode %u, %u blocks of %u bytes in %u segments, %s %s @+0x%x%s\n",
> + "%s(): request opcode %u, %u blocks of %u bytes in %u segments, %s %s @+0x%lx%s\n",
> __func__, cmd->opcode, data->blocks, data->blksz,
> data->sg_len, use_dma ? "DMA" : "PIO",
> data->flags & MMC_DATA_READ ? "read" : "write",
> @@ -1704,7 +1704,7 @@ static void usdhi6_timeout_work(struct work_struct *work)
> case USDHI6_WAIT_FOR_WRITE:
> sg = host->sg ?: data->sg;
> dev_dbg(mmc_dev(host->mmc),
> - "%c: page #%u @ +0x%zx %ux%u in SG%u. Current SG %u bytes @ %u\n",
> + "%c: page #%u @ +0x%zx %ux%u in SG%u. Current SG %zu bytes @ %lu\n",
> data->flags & MMC_DATA_READ ? 'R' : 'W', host->page_idx,
> host->offset, data->blocks, data->blksz, data->sg_len,
> sg_dma_len(sg), sg->offset);
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index d668682..57ef89d 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -43,7 +43,7 @@
> * require an sg allocation that needs more than a page of data.
> */
> #define NVME_MAX_KB_SZ 4096
> -#define NVME_MAX_SEGS 127
> +#define NVME_MAX_SEGS 88
>
> static int use_threaded_interrupts;
> module_param(use_threaded_interrupts, int, 0);
> @@ -552,8 +552,8 @@ static void nvme_print_sgl(struct scatterlist *sgl, int nents)
>
> for_each_sg(sgl, sg, nents, i) {
> dma_addr_t phys = sg_phys(sg);
> - pr_warn("sg[%d] phys_addr:%pad offset:%d length:%d "
> - "dma_address:%pad dma_length:%d\n",
> + pr_warn("sg[%d] phys_addr:%pad offset:%lu length:%zu "
> + "dma_address:%pad dma_length:%zu\n",
> i, &phys, sg->offset, sg->length, &sg_dma_address(sg),
> sg_dma_len(sg));
> }
> @@ -566,7 +566,7 @@ static blk_status_t nvme_pci_setup_prps(struct nvme_dev *dev,
> struct dma_pool *pool;
> int length = blk_rq_payload_bytes(req);
> struct scatterlist *sg = iod->sg;
> - int dma_len = sg_dma_len(sg);
> + u64 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);
> diff --git a/include/linux/nvme.h b/include/linux/nvme.h
> index 68e91ef..0a07a29 100644
> --- a/include/linux/nvme.h
> +++ b/include/linux/nvme.h
> @@ -587,7 +587,7 @@ enum {
>
> struct nvme_sgl_desc {
> __le64 addr;
> - __le32 length;
> + __le64 length;
> __u8 rsvd[3];
> __u8 type;
> };
> diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
> index 093aa57..f6d3482 100644
> --- a/include/linux/scatterlist.h
> +++ b/include/linux/scatterlist.h
> @@ -10,11 +10,11 @@
>
> struct scatterlist {
> unsigned long page_link;
> - unsigned int offset;
> - unsigned int length;
> + unsigned long offset;
> + size_t length;
> dma_addr_t dma_address;
> #ifdef CONFIG_NEED_SG_DMA_LENGTH
> - unsigned int dma_length;
> + size_t dma_length;
> #endif
> };
>
> @@ -114,7 +114,7 @@ static inline void sg_assign_page(struct scatterlist *sg, struct page *page)
> *
> **/
> static inline void sg_set_page(struct scatterlist *sg, struct page *page,
> - unsigned int len, unsigned int offset)
> + size_t len, unsigned long offset)
> {
> sg_assign_page(sg, page);
> sg->offset = offset;
> --
> 2.7.4
>
