crypto: omap-sham - split up data to multiple sg elements with huge data

When using huge data amount, allocating free pages fails as the kernel
isn't able to process get_free_page requests larger than MAX_ORDER.
Also, the DMA subsystem has an inherent limitation that data size
larger than some 2MB can't be handled properly. In these cases,
split up the data instead to smaller requests so that the kernel
can allocate the data, and also so that the DMA driver can handle
the separate SG elements.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Tested-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/omap-sham.c b/drivers/crypto/omap-sham.c
index ac80bc6af093059565ac03960dba01f1ef92e91b..2e9435577ceae50c1c55439520ff0ec12a46bd62 100644 (file)
--- a/drivers/crypto/omap-sham.c
+++ b/drivers/crypto/omap-sham.c
@@ -112,6 +112,8 @@
 #define FLAGS_BE32_SHA1                8
 #define FLAGS_SGS_COPIED       9
 #define FLAGS_SGS_ALLOCED      10
+#define FLAGS_HUGE             11
+
 /* context flags */
 #define FLAGS_FINUP            16
 
@@ -136,6 +138,8 @@
 #define BUFLEN                 SHA512_BLOCK_SIZE
 #define OMAP_SHA_DMA_THRESHOLD 256
 
+#define OMAP_SHA_MAX_DMA_LEN   (1024 * 2048)
+
 struct omap_sham_dev;
 
 struct omap_sham_reqctx {
@@ -689,21 +693,20 @@ static int omap_sham_copy_sg_lists(struct omap_sham_reqctx *ctx,
 
        set_bit(FLAGS_SGS_ALLOCED, &ctx->dd->flags);
 
+       ctx->offset += new_len - ctx->bufcnt;
        ctx->bufcnt = 0;
 
        return 0;
 }
 
 static int omap_sham_copy_sgs(struct omap_sham_reqctx *ctx,
-                             struct scatterlist *sg, int bs, int new_len)
+                             struct scatterlist *sg, int bs,
+                             unsigned int new_len)
 {
        int pages;
        void *buf;
-       int len;
-
-       len = new_len + ctx->bufcnt;
 
-       pages = get_order(ctx->total);
+       pages = get_order(new_len);
 
        buf = (void *)__get_free_pages(GFP_ATOMIC, pages);
        if (!buf) {
@@ -715,14 +718,14 @@ static int omap_sham_copy_sgs(struct omap_sham_reqctx *ctx,
                memcpy(buf, ctx->dd->xmit_buf, ctx->bufcnt);
 
        scatterwalk_map_and_copy(buf + ctx->bufcnt, sg, ctx->offset,
-                                ctx->total - ctx->bufcnt, 0);
+                                min(new_len, ctx->total) - ctx->bufcnt, 0);
        sg_init_table(ctx->sgl, 1);
-       sg_set_buf(ctx->sgl, buf, len);
+       sg_set_buf(ctx->sgl, buf, new_len);
        ctx->sg = ctx->sgl;
        set_bit(FLAGS_SGS_COPIED, &ctx->dd->flags);
        ctx->sg_len = 1;
+       ctx->offset += new_len - ctx->bufcnt;
        ctx->bufcnt = 0;
-       ctx->offset = 0;
 
        return 0;
 }
@@ -741,7 +744,7 @@ static int omap_sham_align_sgs(struct scatterlist *sg,
        if (!sg || !sg->length || !nbytes)
                return 0;
 
-       new_len = nbytes;
+       new_len = nbytes - offset;
 
        if (offset)
                list_ok = false;
@@ -751,6 +754,9 @@ static int omap_sham_align_sgs(struct scatterlist *sg,
        else
                new_len = (new_len - 1) / bs * bs;
 
+       if (!new_len)
+               return 0;
+
        if (nbytes != new_len)
                list_ok = false;
 
@@ -794,10 +800,17 @@ static int omap_sham_align_sgs(struct scatterlist *sg,
                }
        }
 
+       if (new_len > OMAP_SHA_MAX_DMA_LEN) {
+               new_len = OMAP_SHA_MAX_DMA_LEN;
+               aligned = false;
+       }
+
        if (!aligned)
                return omap_sham_copy_sgs(rctx, sg, bs, new_len);
        else if (!list_ok)
                return omap_sham_copy_sg_lists(rctx, sg, bs, new_len);
+       else
+               rctx->offset += new_len;
 
        rctx->sg_len = n;
        rctx->sg = sg;
@@ -821,7 +834,12 @@ static int omap_sham_prepare_request(struct ahash_request *req, bool update)
        else
                nbytes = 0;
 
-       rctx->total = nbytes + rctx->bufcnt;
+       rctx->total = nbytes + rctx->bufcnt - rctx->offset;
+
+       dev_dbg(rctx->dd->dev,
+               "%s: nbytes=%d, bs=%d, total=%d, offset=%d, bufcnt=%d\n",
+               __func__, nbytes, bs, rctx->total, rctx->offset,
+               rctx->bufcnt);
 
        if (!rctx->total)
                return 0;
@@ -847,12 +865,15 @@ static int omap_sham_prepare_request(struct ahash_request *req, bool update)
 
        xmit_len = rctx->total;
 
+       if (xmit_len > OMAP_SHA_MAX_DMA_LEN)
+               xmit_len = OMAP_SHA_MAX_DMA_LEN;
+
        if (!IS_ALIGNED(xmit_len, bs)) {
                if (final)
                        xmit_len = DIV_ROUND_UP(xmit_len, bs) * bs;
                else
                        xmit_len = xmit_len / bs * bs;
-       } else if (!final) {
+       } else if (!final && rctx->total == xmit_len) {
                xmit_len -= bs;
        }
 
@@ -880,7 +901,7 @@ static int omap_sham_prepare_request(struct ahash_request *req, bool update)
                rctx->sg_len = 1;
        }
 
-       if (hash_later) {
+       if (hash_later && hash_later <= rctx->buflen) {
                int offset = 0;
 
                if (hash_later > req->nbytes) {
@@ -901,6 +922,9 @@ static int omap_sham_prepare_request(struct ahash_request *req, bool update)
                rctx->bufcnt = 0;
        }
 
+       if (hash_later > rctx->buflen)
+               set_bit(FLAGS_HUGE, &rctx->dd->flags);
+
        if (!final)
                rctx->total = xmit_len;
 
@@ -998,10 +1022,11 @@ static int omap_sham_update_req(struct omap_sham_dev *dd)
        struct ahash_request *req = dd->req;
        struct omap_sham_reqctx *ctx = ahash_request_ctx(req);
        int err;
-       bool final = ctx->flags & BIT(FLAGS_FINUP);
+       bool final = (ctx->flags & BIT(FLAGS_FINUP)) &&
+                       !(dd->flags & BIT(FLAGS_HUGE));
 
-       dev_dbg(dd->dev, "update_req: total: %u, digcnt: %d, finup: %d\n",
-                ctx->total, ctx->digcnt, (ctx->flags & BIT(FLAGS_FINUP)) != 0);
+       dev_dbg(dd->dev, "update_req: total: %u, digcnt: %d, final: %d",
+               ctx->total, ctx->digcnt, final);
 
        if (ctx->total < get_block_size(ctx) ||
            ctx->total < dd->fallback_sz)
@@ -1024,6 +1049,9 @@ static int omap_sham_final_req(struct omap_sham_dev *dd)
        struct omap_sham_reqctx *ctx = ahash_request_ctx(req);
        int err = 0, use_dma = 1;
 
+       if (dd->flags & BIT(FLAGS_HUGE))
+               return 0;
+
        if ((ctx->total <= get_block_size(ctx)) || dd->polling_mode)
                /*
                 * faster to handle last block with cpu or
@@ -1083,7 +1111,7 @@ static void omap_sham_finish_req(struct ahash_request *req, int err)
 
        if (test_bit(FLAGS_SGS_COPIED, &dd->flags))
                free_pages((unsigned long)sg_virt(ctx->sg),
-                          get_order(ctx->sg->length + ctx->bufcnt));
+                          get_order(ctx->sg->length));
 
        if (test_bit(FLAGS_SGS_ALLOCED, &dd->flags))
                kfree(ctx->sg);
@@ -1092,6 +1120,21 @@ static void omap_sham_finish_req(struct ahash_request *req, int err)
 
        dd->flags &= ~(BIT(FLAGS_SGS_ALLOCED) | BIT(FLAGS_SGS_COPIED));
 
+       if (dd->flags & BIT(FLAGS_HUGE)) {
+               dd->flags &= ~(BIT(FLAGS_CPU) | BIT(FLAGS_DMA_READY) |
+                               BIT(FLAGS_OUTPUT_READY) | BIT(FLAGS_HUGE));
+               omap_sham_prepare_request(req, ctx->op == OP_UPDATE);
+               if (ctx->op == OP_UPDATE || (dd->flags & BIT(FLAGS_HUGE))) {
+                       err = omap_sham_update_req(dd);
+                       if (err != -EINPROGRESS &&
+                           (ctx->flags & BIT(FLAGS_FINUP)))
+                               err = omap_sham_final_req(dd);
+               } else if (ctx->op == OP_FINAL) {
+                       omap_sham_final_req(dd);
+               }
+               return;
+       }
+
        if (!err) {
                dd->pdata->copy_hash(req, 1);
                if (test_bit(FLAGS_FINAL, &dd->flags))
@@ -1107,6 +1150,8 @@ static void omap_sham_finish_req(struct ahash_request *req, int err)
        pm_runtime_mark_last_busy(dd->dev);
        pm_runtime_put_autosuspend(dd->dev);
 
+       ctx->offset = 0;
+
        if (req->base.complete)
                req->base.complete(&req->base, err);
 }
@@ -1158,7 +1203,7 @@ retry:
                /* request has changed - restore hash */
                dd->pdata->copy_hash(req, 0);
 
-       if (ctx->op == OP_UPDATE) {
+       if (ctx->op == OP_UPDATE || (dd->flags & BIT(FLAGS_HUGE))) {
                err = omap_sham_update_req(dd);
                if (err != -EINPROGRESS && (ctx->flags & BIT(FLAGS_FINUP)))
                        /* no final() after finup() */
@@ -1730,6 +1775,8 @@ static void omap_sham_done_task(unsigned long data)
        struct omap_sham_dev *dd = (struct omap_sham_dev *)data;
        int err = 0;
 
+       dev_dbg(dd->dev, "%s: flags=%lx\n", __func__, dd->flags);
+
        if (!test_bit(FLAGS_BUSY, &dd->flags)) {
                omap_sham_handle_queue(dd, NULL);
                return;