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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 /lib/zstd/compress/hist.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 'lib/zstd/compress/hist.c')
-rw-r--r--lib/zstd/compress/hist.c176
1 files changed, 176 insertions, 0 deletions
diff --git a/lib/zstd/compress/hist.c b/lib/zstd/compress/hist.c
new file mode 100644
index 000000000..87145a2d9
--- /dev/null
+++ b/lib/zstd/compress/hist.c
@@ -0,0 +1,176 @@
+// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
+/* ******************************************************************
+ * hist : Histogram functions
+ * part of Finite State Entropy project
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * You can contact the author at :
+ * - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy
+ * - Public forum : https://groups.google.com/forum/#!forum/lz4c
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+****************************************************************** */
+
+/* --- dependencies --- */
+#include "../common/mem.h" /* U32, BYTE, etc. */
+#include "../common/debug.h" /* assert, DEBUGLOG */
+#include "../common/error_private.h" /* ERROR */
+#include "hist.h"
+
+
+/* --- Error management --- */
+unsigned HIST_isError(size_t code) { return ERR_isError(code); }
+
+/*-**************************************************************
+ * Histogram functions
+ ****************************************************************/
+void HIST_add(unsigned* count, const void* src, size_t srcSize)
+{
+ const BYTE* ip = (const BYTE*)src;
+ const BYTE* const end = ip + srcSize;
+
+ while (ip<end) {
+ count[*ip++]++;
+ }
+}
+
+unsigned HIST_count_simple(unsigned* count, unsigned* maxSymbolValuePtr,
+ const void* src, size_t srcSize)
+{
+ const BYTE* ip = (const BYTE*)src;
+ const BYTE* const end = ip + srcSize;
+ unsigned maxSymbolValue = *maxSymbolValuePtr;
+ unsigned largestCount=0;
+
+ ZSTD_memset(count, 0, (maxSymbolValue+1) * sizeof(*count));
+ if (srcSize==0) { *maxSymbolValuePtr = 0; return 0; }
+
+ while (ip<end) {
+ assert(*ip <= maxSymbolValue);
+ count[*ip++]++;
+ }
+
+ while (!count[maxSymbolValue]) maxSymbolValue--;
+ *maxSymbolValuePtr = maxSymbolValue;
+
+ { U32 s;
+ for (s=0; s<=maxSymbolValue; s++)
+ if (count[s] > largestCount) largestCount = count[s];
+ }
+
+ return largestCount;
+}
+
+typedef enum { trustInput, checkMaxSymbolValue } HIST_checkInput_e;
+
+/* HIST_count_parallel_wksp() :
+ * store histogram into 4 intermediate tables, recombined at the end.
+ * this design makes better use of OoO cpus,
+ * and is noticeably faster when some values are heavily repeated.
+ * But it needs some additional workspace for intermediate tables.
+ * `workSpace` must be a U32 table of size >= HIST_WKSP_SIZE_U32.
+ * @return : largest histogram frequency,
+ * or an error code (notably when histogram's alphabet is larger than *maxSymbolValuePtr) */
+static size_t HIST_count_parallel_wksp(
+ unsigned* count, unsigned* maxSymbolValuePtr,
+ const void* source, size_t sourceSize,
+ HIST_checkInput_e check,
+ U32* const workSpace)
+{
+ const BYTE* ip = (const BYTE*)source;
+ const BYTE* const iend = ip+sourceSize;
+ size_t const countSize = (*maxSymbolValuePtr + 1) * sizeof(*count);
+ unsigned max=0;
+ U32* const Counting1 = workSpace;
+ U32* const Counting2 = Counting1 + 256;
+ U32* const Counting3 = Counting2 + 256;
+ U32* const Counting4 = Counting3 + 256;
+
+ /* safety checks */
+ assert(*maxSymbolValuePtr <= 255);
+ if (!sourceSize) {
+ ZSTD_memset(count, 0, countSize);
+ *maxSymbolValuePtr = 0;
+ return 0;
+ }
+ ZSTD_memset(workSpace, 0, 4*256*sizeof(unsigned));
+
+ /* by stripes of 16 bytes */
+ { U32 cached = MEM_read32(ip); ip += 4;
+ while (ip < iend-15) {
+ U32 c = cached; cached = MEM_read32(ip); ip += 4;
+ Counting1[(BYTE) c ]++;
+ Counting2[(BYTE)(c>>8) ]++;
+ Counting3[(BYTE)(c>>16)]++;
+ Counting4[ c>>24 ]++;
+ c = cached; cached = MEM_read32(ip); ip += 4;
+ Counting1[(BYTE) c ]++;
+ Counting2[(BYTE)(c>>8) ]++;
+ Counting3[(BYTE)(c>>16)]++;
+ Counting4[ c>>24 ]++;
+ c = cached; cached = MEM_read32(ip); ip += 4;
+ Counting1[(BYTE) c ]++;
+ Counting2[(BYTE)(c>>8) ]++;
+ Counting3[(BYTE)(c>>16)]++;
+ Counting4[ c>>24 ]++;
+ c = cached; cached = MEM_read32(ip); ip += 4;
+ Counting1[(BYTE) c ]++;
+ Counting2[(BYTE)(c>>8) ]++;
+ Counting3[(BYTE)(c>>16)]++;
+ Counting4[ c>>24 ]++;
+ }
+ ip-=4;
+ }
+
+ /* finish last symbols */
+ while (ip<iend) Counting1[*ip++]++;
+
+ { U32 s;
+ for (s=0; s<256; s++) {
+ Counting1[s] += Counting2[s] + Counting3[s] + Counting4[s];
+ if (Counting1[s] > max) max = Counting1[s];
+ } }
+
+ { unsigned maxSymbolValue = 255;
+ while (!Counting1[maxSymbolValue]) maxSymbolValue--;
+ if (check && maxSymbolValue > *maxSymbolValuePtr) return ERROR(maxSymbolValue_tooSmall);
+ *maxSymbolValuePtr = maxSymbolValue;
+ ZSTD_memmove(count, Counting1, countSize); /* in case count & Counting1 are overlapping */
+ }
+ return (size_t)max;
+}
+
+/* HIST_countFast_wksp() :
+ * Same as HIST_countFast(), but using an externally provided scratch buffer.
+ * `workSpace` is a writable buffer which must be 4-bytes aligned,
+ * `workSpaceSize` must be >= HIST_WKSP_SIZE
+ */
+size_t HIST_countFast_wksp(unsigned* count, unsigned* maxSymbolValuePtr,
+ const void* source, size_t sourceSize,
+ void* workSpace, size_t workSpaceSize)
+{
+ if (sourceSize < 1500) /* heuristic threshold */
+ return HIST_count_simple(count, maxSymbolValuePtr, source, sourceSize);
+ if ((size_t)workSpace & 3) return ERROR(GENERIC); /* must be aligned on 4-bytes boundaries */
+ if (workSpaceSize < HIST_WKSP_SIZE) return ERROR(workSpace_tooSmall);
+ return HIST_count_parallel_wksp(count, maxSymbolValuePtr, source, sourceSize, trustInput, (U32*)workSpace);
+}
+
+/* HIST_count_wksp() :
+ * Same as HIST_count(), but using an externally provided scratch buffer.
+ * `workSpace` size must be table of >= HIST_WKSP_SIZE_U32 unsigned */
+size_t HIST_count_wksp(unsigned* count, unsigned* maxSymbolValuePtr,
+ const void* source, size_t sourceSize,
+ void* workSpace, size_t workSpaceSize)
+{
+ if ((size_t)workSpace & 3) return ERROR(GENERIC); /* must be aligned on 4-bytes boundaries */
+ if (workSpaceSize < HIST_WKSP_SIZE) return ERROR(workSpace_tooSmall);
+ if (*maxSymbolValuePtr < 255)
+ return HIST_count_parallel_wksp(count, maxSymbolValuePtr, source, sourceSize, checkMaxSymbolValue, (U32*)workSpace);
+ *maxSymbolValuePtr = 255;
+ return HIST_countFast_wksp(count, maxSymbolValuePtr, source, sourceSize, workSpace, workSpaceSize);
+}
+