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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 /drivers/block/zram/zcomp.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 'drivers/block/zram/zcomp.c')
-rw-r--r--drivers/block/zram/zcomp.c262
1 files changed, 262 insertions, 0 deletions
diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c
new file mode 100644
index 000000000..974c46918
--- /dev/null
+++ b/drivers/block/zram/zcomp.c
@@ -0,0 +1,262 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+#include <linux/cpuhotplug.h>
+#include <linux/vmalloc.h>
+#include <linux/sysfs.h>
+
+#include "zcomp.h"
+
+#include "backend_lzo.h"
+#include "backend_lzorle.h"
+#include "backend_lz4.h"
+#include "backend_lz4hc.h"
+#include "backend_zstd.h"
+#include "backend_deflate.h"
+#include "backend_842.h"
+
+static const struct zcomp_ops *backends[] = {
+#if IS_ENABLED(CONFIG_ZRAM_BACKEND_LZO)
+ &backend_lzorle,
+ &backend_lzo,
+#endif
+#if IS_ENABLED(CONFIG_ZRAM_BACKEND_LZ4)
+ &backend_lz4,
+#endif
+#if IS_ENABLED(CONFIG_ZRAM_BACKEND_LZ4HC)
+ &backend_lz4hc,
+#endif
+#if IS_ENABLED(CONFIG_ZRAM_BACKEND_ZSTD)
+ &backend_zstd,
+#endif
+#if IS_ENABLED(CONFIG_ZRAM_BACKEND_DEFLATE)
+ &backend_deflate,
+#endif
+#if IS_ENABLED(CONFIG_ZRAM_BACKEND_842)
+ &backend_842,
+#endif
+ NULL
+};
+
+static void zcomp_strm_free(struct zcomp *comp, struct zcomp_strm *zstrm)
+{
+ comp->ops->destroy_ctx(&zstrm->ctx);
+ vfree(zstrm->local_copy);
+ vfree(zstrm->buffer);
+ zstrm->buffer = NULL;
+}
+
+static int zcomp_strm_init(struct zcomp *comp, struct zcomp_strm *zstrm)
+{
+ int ret;
+
+ ret = comp->ops->create_ctx(comp->params, &zstrm->ctx);
+ if (ret)
+ return ret;
+
+ zstrm->local_copy = vzalloc(PAGE_SIZE);
+ /*
+ * allocate 2 pages. 1 for compressed data, plus 1 extra for the
+ * case when compressed size is larger than the original one
+ */
+ zstrm->buffer = vzalloc(2 * PAGE_SIZE);
+ if (!zstrm->buffer || !zstrm->local_copy) {
+ zcomp_strm_free(comp, zstrm);
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+static const struct zcomp_ops *lookup_backend_ops(const char *comp)
+{
+ int i = 0;
+
+ while (backends[i]) {
+ if (sysfs_streq(comp, backends[i]->name))
+ break;
+ i++;
+ }
+ return backends[i];
+}
+
+const char *zcomp_lookup_backend_name(const char *comp)
+{
+ const struct zcomp_ops *backend = lookup_backend_ops(comp);
+
+ if (backend)
+ return backend->name;
+
+ return NULL;
+}
+
+/* show available compressors */
+ssize_t zcomp_available_show(const char *comp, char *buf, ssize_t at)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(backends) - 1; i++) {
+ if (!strcmp(comp, backends[i]->name)) {
+ at += sysfs_emit_at(buf, at, "[%s] ",
+ backends[i]->name);
+ } else {
+ at += sysfs_emit_at(buf, at, "%s ", backends[i]->name);
+ }
+ }
+
+ at += sysfs_emit_at(buf, at, "\n");
+ return at;
+}
+
+struct zcomp_strm *zcomp_stream_get(struct zcomp *comp)
+{
+ for (;;) {
+ struct zcomp_strm *zstrm = raw_cpu_ptr(comp->stream);
+
+ /*
+ * Inspired by zswap
+ *
+ * stream is returned with ->mutex locked which prevents
+ * cpu_dead() from releasing this stream under us, however
+ * there is still a race window between raw_cpu_ptr() and
+ * mutex_lock(), during which we could have been migrated
+ * from a CPU that has already destroyed its stream. If
+ * so then unlock and re-try on the current CPU.
+ */
+ mutex_lock(&zstrm->lock);
+ if (likely(zstrm->buffer))
+ return zstrm;
+ mutex_unlock(&zstrm->lock);
+ }
+}
+
+void zcomp_stream_put(struct zcomp_strm *zstrm)
+{
+ mutex_unlock(&zstrm->lock);
+}
+
+int zcomp_compress(struct zcomp *comp, struct zcomp_strm *zstrm,
+ const void *src, unsigned int *dst_len)
+{
+ struct zcomp_req req = {
+ .src = src,
+ .dst = zstrm->buffer,
+ .src_len = PAGE_SIZE,
+ .dst_len = 2 * PAGE_SIZE,
+ };
+ int ret;
+
+ might_sleep();
+ ret = comp->ops->compress(comp->params, &zstrm->ctx, &req);
+ if (!ret)
+ *dst_len = req.dst_len;
+ return ret;
+}
+
+int zcomp_decompress(struct zcomp *comp, struct zcomp_strm *zstrm,
+ const void *src, unsigned int src_len, void *dst)
+{
+ struct zcomp_req req = {
+ .src = src,
+ .dst = dst,
+ .src_len = src_len,
+ .dst_len = PAGE_SIZE,
+ };
+
+ might_sleep();
+ return comp->ops->decompress(comp->params, &zstrm->ctx, &req);
+}
+
+int zcomp_cpu_up_prepare(unsigned int cpu, struct hlist_node *node)
+{
+ struct zcomp *comp = hlist_entry(node, struct zcomp, node);
+ struct zcomp_strm *zstrm = per_cpu_ptr(comp->stream, cpu);
+ int ret;
+
+ ret = zcomp_strm_init(comp, zstrm);
+ if (ret)
+ pr_err("Can't allocate a compression stream\n");
+ return ret;
+}
+
+int zcomp_cpu_dead(unsigned int cpu, struct hlist_node *node)
+{
+ struct zcomp *comp = hlist_entry(node, struct zcomp, node);
+ struct zcomp_strm *zstrm = per_cpu_ptr(comp->stream, cpu);
+
+ mutex_lock(&zstrm->lock);
+ zcomp_strm_free(comp, zstrm);
+ mutex_unlock(&zstrm->lock);
+ return 0;
+}
+
+static int zcomp_init(struct zcomp *comp, struct zcomp_params *params)
+{
+ int ret, cpu;
+
+ comp->stream = alloc_percpu(struct zcomp_strm);
+ if (!comp->stream)
+ return -ENOMEM;
+
+ comp->params = params;
+ ret = comp->ops->setup_params(comp->params);
+ if (ret)
+ goto cleanup;
+
+ for_each_possible_cpu(cpu)
+ mutex_init(&per_cpu_ptr(comp->stream, cpu)->lock);
+
+ ret = cpuhp_state_add_instance(CPUHP_ZCOMP_PREPARE, &comp->node);
+ if (ret < 0)
+ goto cleanup;
+
+ return 0;
+
+cleanup:
+ comp->ops->release_params(comp->params);
+ free_percpu(comp->stream);
+ return ret;
+}
+
+void zcomp_destroy(struct zcomp *comp)
+{
+ cpuhp_state_remove_instance(CPUHP_ZCOMP_PREPARE, &comp->node);
+ comp->ops->release_params(comp->params);
+ free_percpu(comp->stream);
+ kfree(comp);
+}
+
+struct zcomp *zcomp_create(const char *alg, struct zcomp_params *params)
+{
+ struct zcomp *comp;
+ int error;
+
+ /*
+ * The backends array has a sentinel NULL value, so the minimum
+ * size is 1. In order to be valid the array, apart from the
+ * sentinel NULL element, should have at least one compression
+ * backend selected.
+ */
+ BUILD_BUG_ON(ARRAY_SIZE(backends) <= 1);
+
+ comp = kzalloc_obj(struct zcomp);
+ if (!comp)
+ return ERR_PTR(-ENOMEM);
+
+ comp->ops = lookup_backend_ops(alg);
+ if (!comp->ops) {
+ kfree(comp);
+ return ERR_PTR(-EINVAL);
+ }
+
+ error = zcomp_init(comp, params);
+ if (error) {
+ kfree(comp);
+ return ERR_PTR(error);
+ }
+ return comp;
+}