crypto: omap - add base support library for common routines
This contains the generic APIs for aligning SG buffers.
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/drivers/crypto/omap-crypto.c b/drivers/crypto/omap-crypto.c
new file mode 100644
index 0000000..23e3777
--- /dev/null
+++ b/drivers/crypto/omap-crypto.c
@@ -0,0 +1,184 @@
+/*
+ * OMAP Crypto driver common support routines.
+ *
+ * Copyright (c) 2017 Texas Instruments Incorporated
+ * Tero Kristo <t-kristo@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/scatterlist.h>
+#include <crypto/scatterwalk.h>
+
+#include "omap-crypto.h"
+
+static int omap_crypto_copy_sg_lists(int total, int bs,
+ struct scatterlist **sg,
+ struct scatterlist *new_sg, u16 flags)
+{
+ int n = sg_nents(*sg);
+ struct scatterlist *tmp;
+
+ if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY)) {
+ new_sg = kmalloc_array(n, sizeof(*sg), GFP_KERNEL);
+ if (!new_sg)
+ return -ENOMEM;
+
+ sg_init_table(new_sg, n);
+ }
+
+ tmp = new_sg;
+
+ while (*sg && total) {
+ int len = (*sg)->length;
+
+ if (total < len)
+ len = total;
+
+ if (len > 0) {
+ total -= len;
+ sg_set_page(tmp, sg_page(*sg), len, (*sg)->offset);
+ if (total <= 0)
+ sg_mark_end(tmp);
+ tmp = sg_next(tmp);
+ }
+
+ *sg = sg_next(*sg);
+ }
+
+ *sg = new_sg;
+
+ return 0;
+}
+
+static int omap_crypto_copy_sgs(int total, int bs, struct scatterlist **sg,
+ struct scatterlist *new_sg, u16 flags)
+{
+ void *buf;
+ int pages;
+ int new_len;
+
+ new_len = ALIGN(total, bs);
+ pages = get_order(new_len);
+
+ buf = (void *)__get_free_pages(GFP_ATOMIC, pages);
+ if (!buf) {
+ pr_err("%s: Couldn't allocate pages for unaligned cases.\n",
+ __func__);
+ return -ENOMEM;
+ }
+
+ if (flags & OMAP_CRYPTO_COPY_DATA) {
+ scatterwalk_map_and_copy(buf, *sg, 0, total, 0);
+ if (flags & OMAP_CRYPTO_ZERO_BUF)
+ memset(buf + total, 0, new_len - total);
+ }
+
+ if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY))
+ sg_init_table(new_sg, 1);
+
+ sg_set_buf(new_sg, buf, new_len);
+
+ *sg = new_sg;
+
+ return 0;
+}
+
+static int omap_crypto_check_sg(struct scatterlist *sg, int total, int bs,
+ u16 flags)
+{
+ int len = 0;
+ int num_sg = 0;
+
+ if (!IS_ALIGNED(total, bs))
+ return OMAP_CRYPTO_NOT_ALIGNED;
+
+ while (sg) {
+ num_sg++;
+
+ if (!IS_ALIGNED(sg->offset, 4))
+ return OMAP_CRYPTO_NOT_ALIGNED;
+ if (!IS_ALIGNED(sg->length, bs))
+ return OMAP_CRYPTO_NOT_ALIGNED;
+
+ len += sg->length;
+ sg = sg_next(sg);
+
+ if (len >= total)
+ break;
+ }
+
+ if ((flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY) && num_sg > 1)
+ return OMAP_CRYPTO_NOT_ALIGNED;
+
+ if (len != total)
+ return OMAP_CRYPTO_BAD_DATA_LENGTH;
+
+ return 0;
+}
+
+int omap_crypto_align_sg(struct scatterlist **sg, int total, int bs,
+ struct scatterlist *new_sg, u16 flags,
+ u8 flags_shift, unsigned long *dd_flags)
+{
+ int ret;
+
+ *dd_flags &= ~(OMAP_CRYPTO_COPY_MASK << flags_shift);
+
+ if (flags & OMAP_CRYPTO_FORCE_COPY)
+ ret = OMAP_CRYPTO_NOT_ALIGNED;
+ else
+ ret = omap_crypto_check_sg(*sg, total, bs, flags);
+
+ if (ret == OMAP_CRYPTO_NOT_ALIGNED) {
+ ret = omap_crypto_copy_sgs(total, bs, sg, new_sg, flags);
+ if (ret)
+ return ret;
+ *dd_flags |= OMAP_CRYPTO_DATA_COPIED << flags_shift;
+ } else if (ret == OMAP_CRYPTO_BAD_DATA_LENGTH) {
+ ret = omap_crypto_copy_sg_lists(total, bs, sg, new_sg, flags);
+ if (ret)
+ return ret;
+ if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY))
+ *dd_flags |= OMAP_CRYPTO_SG_COPIED << flags_shift;
+ } else if (flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY) {
+ sg_set_buf(new_sg, sg_virt(*sg), (*sg)->length);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(omap_crypto_align_sg);
+
+void omap_crypto_cleanup(struct scatterlist *sg, struct scatterlist *orig,
+ int offset, int len, u8 flags_shift,
+ unsigned long flags)
+{
+ void *buf;
+ int pages;
+
+ flags >>= flags_shift;
+ flags &= OMAP_CRYPTO_COPY_MASK;
+
+ if (!flags)
+ return;
+
+ buf = sg_virt(sg);
+ pages = get_order(len);
+
+ if (orig && (flags & OMAP_CRYPTO_COPY_MASK))
+ scatterwalk_map_and_copy(buf, orig, offset, len, 1);
+
+ if (flags & OMAP_CRYPTO_DATA_COPIED)
+ free_pages((unsigned long)buf, pages);
+ else if (flags & OMAP_CRYPTO_SG_COPIED)
+ kfree(sg);
+}
+EXPORT_SYMBOL_GPL(omap_crypto_cleanup);
+
+MODULE_DESCRIPTION("OMAP crypto support library.");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Tero Kristo <t-kristo@ti.com>");