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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /crypto/scatterwalk.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'crypto/scatterwalk.c')
-rw-r--r--crypto/scatterwalk.c204
1 files changed, 204 insertions, 0 deletions
diff --git a/crypto/scatterwalk.c b/crypto/scatterwalk.c
new file mode 100644
index 000000000..be0e24843
--- /dev/null
+++ b/crypto/scatterwalk.c
@@ -0,0 +1,204 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Cryptographic API.
+ *
+ * Cipher operations.
+ *
+ * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
+ * 2002 Adam J. Richter <adam@yggdrasil.com>
+ * 2004 Jean-Luc Cooke <jlcooke@certainkey.com>
+ */
+
+#include <crypto/scatterwalk.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/scatterlist.h>
+
+void scatterwalk_skip(struct scatter_walk *walk, unsigned int nbytes)
+{
+ struct scatterlist *sg = walk->sg;
+
+ nbytes += walk->offset - sg->offset;
+
+ while (nbytes > sg->length) {
+ nbytes -= sg->length;
+ sg = sg_next(sg);
+ }
+ walk->sg = sg;
+ walk->offset = sg->offset + nbytes;
+}
+EXPORT_SYMBOL_GPL(scatterwalk_skip);
+
+inline void memcpy_from_scatterwalk(void *buf, struct scatter_walk *walk,
+ unsigned int nbytes)
+{
+ do {
+ unsigned int to_copy;
+
+ to_copy = scatterwalk_next(walk, nbytes);
+ memcpy(buf, walk->addr, to_copy);
+ scatterwalk_done_src(walk, to_copy);
+ buf += to_copy;
+ nbytes -= to_copy;
+ } while (nbytes);
+}
+EXPORT_SYMBOL_GPL(memcpy_from_scatterwalk);
+
+inline void memcpy_to_scatterwalk(struct scatter_walk *walk, const void *buf,
+ unsigned int nbytes)
+{
+ do {
+ unsigned int to_copy;
+
+ to_copy = scatterwalk_next(walk, nbytes);
+ memcpy(walk->addr, buf, to_copy);
+ scatterwalk_done_dst(walk, to_copy);
+ buf += to_copy;
+ nbytes -= to_copy;
+ } while (nbytes);
+}
+EXPORT_SYMBOL_GPL(memcpy_to_scatterwalk);
+
+void memcpy_from_sglist(void *buf, struct scatterlist *sg,
+ unsigned int start, unsigned int nbytes)
+{
+ struct scatter_walk walk;
+
+ if (unlikely(nbytes == 0)) /* in case sg == NULL */
+ return;
+
+ scatterwalk_start_at_pos(&walk, sg, start);
+ memcpy_from_scatterwalk(buf, &walk, nbytes);
+}
+EXPORT_SYMBOL_GPL(memcpy_from_sglist);
+
+void memcpy_to_sglist(struct scatterlist *sg, unsigned int start,
+ const void *buf, unsigned int nbytes)
+{
+ struct scatter_walk walk;
+
+ if (unlikely(nbytes == 0)) /* in case sg == NULL */
+ return;
+
+ scatterwalk_start_at_pos(&walk, sg, start);
+ memcpy_to_scatterwalk(&walk, buf, nbytes);
+}
+EXPORT_SYMBOL_GPL(memcpy_to_sglist);
+
+/**
+ * memcpy_sglist() - Copy data from one scatterlist to another
+ * @dst: The destination scatterlist. Can be NULL if @nbytes == 0.
+ * @src: The source scatterlist. Can be NULL if @nbytes == 0.
+ * @nbytes: Number of bytes to copy
+ *
+ * The scatterlists can describe exactly the same memory, in which case this
+ * function is a no-op. No other overlaps are supported.
+ *
+ * Context: Any context
+ */
+void memcpy_sglist(struct scatterlist *dst, struct scatterlist *src,
+ unsigned int nbytes)
+{
+ unsigned int src_offset, dst_offset;
+
+ if (unlikely(nbytes == 0)) /* in case src and/or dst is NULL */
+ return;
+
+ src_offset = src->offset;
+ dst_offset = dst->offset;
+ for (;;) {
+ /* Compute the length to copy this step. */
+ unsigned int len = min3(src->offset + src->length - src_offset,
+ dst->offset + dst->length - dst_offset,
+ nbytes);
+ struct page *src_page = sg_page(src);
+ struct page *dst_page = sg_page(dst);
+ const void *src_virt;
+ void *dst_virt;
+
+ if (IS_ENABLED(CONFIG_HIGHMEM)) {
+ /* HIGHMEM: we may have to actually map the pages. */
+ const unsigned int src_oip = offset_in_page(src_offset);
+ const unsigned int dst_oip = offset_in_page(dst_offset);
+ const unsigned int limit = PAGE_SIZE;
+
+ /* Further limit len to not cross a page boundary. */
+ len = min3(len, limit - src_oip, limit - dst_oip);
+
+ /* Compute the source and destination pages. */
+ src_page += src_offset / PAGE_SIZE;
+ dst_page += dst_offset / PAGE_SIZE;
+
+ if (src_page != dst_page) {
+ /* Copy between different pages. */
+ memcpy_page(dst_page, dst_oip,
+ src_page, src_oip, len);
+ flush_dcache_page(dst_page);
+ } else if (src_oip != dst_oip) {
+ /* Copy between different parts of same page. */
+ dst_virt = kmap_local_page(dst_page);
+ memcpy(dst_virt + dst_oip, dst_virt + src_oip,
+ len);
+ kunmap_local(dst_virt);
+ flush_dcache_page(dst_page);
+ } /* Else, it's the same memory. No action needed. */
+ } else {
+ /*
+ * !HIGHMEM: no mapping needed. Just work in the linear
+ * buffer of each sg entry. Note that we can cross page
+ * boundaries, as they are not significant in this case.
+ */
+ src_virt = page_address(src_page) + src_offset;
+ dst_virt = page_address(dst_page) + dst_offset;
+ if (src_virt != dst_virt) {
+ memcpy(dst_virt, src_virt, len);
+ if (ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE)
+ __scatterwalk_flush_dcache_pages(
+ dst_page, dst_offset, len);
+ } /* Else, it's the same memory. No action needed. */
+ }
+ nbytes -= len;
+ if (nbytes == 0) /* No more to copy? */
+ break;
+
+ /*
+ * There's more to copy. Advance the offsets by the length
+ * copied this step, and advance the sg entries as needed.
+ */
+ src_offset += len;
+ if (src_offset >= src->offset + src->length) {
+ src = sg_next(src);
+ src_offset = src->offset;
+ }
+ dst_offset += len;
+ if (dst_offset >= dst->offset + dst->length) {
+ dst = sg_next(dst);
+ dst_offset = dst->offset;
+ }
+ }
+}
+EXPORT_SYMBOL_GPL(memcpy_sglist);
+
+struct scatterlist *scatterwalk_ffwd(struct scatterlist dst[2],
+ struct scatterlist *src,
+ unsigned int len)
+{
+ for (;;) {
+ if (!len)
+ return src;
+
+ if (src->length > len)
+ break;
+
+ len -= src->length;
+ src = sg_next(src);
+ }
+
+ sg_init_table(dst, 2);
+ sg_set_page(dst, sg_page(src), src->length - len, src->offset + len);
+ scatterwalk_crypto_chain(dst, sg_next(src), 2);
+
+ return dst;
+}
+EXPORT_SYMBOL_GPL(scatterwalk_ffwd);