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authorDapeng Mi <dapeng1.mi@linux.intel.com>2026-09-17 09:52:33 +0800
committerIngo Molnar <mingo@kernel.org>2026-09-22 11:37:46 +0200
commit0102c8c7fdfc4bd700971daff2b94470f4eafae4 (patch)
tree531306c2299f9a269f0a986e29f17ba972180104 /drivers/acpi/acpica/utlock.c
downloadlinux-stable-0102c8c7fdfc4bd700971daff2b94470f4eafae4.tar.gz
linux-stable-0102c8c7fdfc4bd700971daff2b94470f4eafae4.zip
perf/x86/intel: Rename DMR offcore_rsp attribute to offmodule_rspgrafted
DMR introduces Offmodule Response events in place of the legacy Offcore Response events, but it still exposes the inherited offcore_rsp PMU attribute for programming the corresponding MSR data. Rename the DMR PMU attribute to offmodule_rsp so the sysfs interface matches the underlying event name and avoids user & tooling confusion. Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://patch.msgid.link/20260917015234.981153-12-dapeng1.mi@linux.intel.com
Diffstat (limited to 'drivers/acpi/acpica/utlock.c')
-rw-r--r--drivers/acpi/acpica/utlock.c141
1 files changed, 141 insertions, 0 deletions
diff --git a/drivers/acpi/acpica/utlock.c b/drivers/acpi/acpica/utlock.c
new file mode 100644
index 000000000..cf6b931cd
--- /dev/null
+++ b/drivers/acpi/acpica/utlock.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+/******************************************************************************
+ *
+ * Module Name: utlock - Reader/Writer lock interfaces
+ *
+ * Copyright (C) 2000 - 2026, Intel Corp.
+ *
+ *****************************************************************************/
+
+#include <acpi/acpi.h>
+#include "accommon.h"
+
+#define _COMPONENT ACPI_UTILITIES
+ACPI_MODULE_NAME("utlock")
+
+/*******************************************************************************
+ *
+ * FUNCTION: acpi_ut_create_rw_lock
+ * acpi_ut_delete_rw_lock
+ *
+ * PARAMETERS: lock - Pointer to a valid RW lock
+ *
+ * RETURN: Status
+ *
+ * DESCRIPTION: Reader/writer lock creation and deletion interfaces.
+ *
+ ******************************************************************************/
+acpi_status acpi_ut_create_rw_lock(struct acpi_rw_lock *lock)
+{
+ acpi_status status;
+
+ lock->num_readers = 0;
+ status = acpi_os_create_mutex(&lock->reader_mutex);
+ if (ACPI_FAILURE(status)) {
+ return (status);
+ }
+
+ status = acpi_os_create_mutex(&lock->writer_mutex);
+ return (status);
+}
+
+void acpi_ut_delete_rw_lock(struct acpi_rw_lock *lock)
+{
+
+ acpi_os_delete_mutex(lock->reader_mutex);
+ acpi_os_delete_mutex(lock->writer_mutex);
+
+ lock->num_readers = 0;
+ lock->reader_mutex = NULL;
+ lock->writer_mutex = NULL;
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION: acpi_ut_acquire_read_lock
+ * acpi_ut_release_read_lock
+ *
+ * PARAMETERS: lock - Pointer to a valid RW lock
+ *
+ * RETURN: Status
+ *
+ * DESCRIPTION: Reader interfaces for reader/writer locks. On acquisition,
+ * only the first reader acquires the write mutex. On release,
+ * only the last reader releases the write mutex. Although this
+ * algorithm can in theory starve writers, this should not be a
+ * problem with ACPICA since the subsystem is infrequently used
+ * in comparison to (for example) an I/O system.
+ *
+ ******************************************************************************/
+
+acpi_status acpi_ut_acquire_read_lock(struct acpi_rw_lock *lock)
+{
+ acpi_status status;
+
+ status = acpi_os_acquire_mutex(lock->reader_mutex, ACPI_WAIT_FOREVER);
+ if (ACPI_FAILURE(status)) {
+ return (status);
+ }
+
+ /* Acquire the write lock only for the first reader */
+
+ lock->num_readers++;
+ if (lock->num_readers == 1) {
+ status =
+ acpi_os_acquire_mutex(lock->writer_mutex,
+ ACPI_WAIT_FOREVER);
+ }
+
+ acpi_os_release_mutex(lock->reader_mutex);
+ return (status);
+}
+
+acpi_status acpi_ut_release_read_lock(struct acpi_rw_lock *lock)
+{
+ acpi_status status;
+
+ status = acpi_os_acquire_mutex(lock->reader_mutex, ACPI_WAIT_FOREVER);
+ if (ACPI_FAILURE(status)) {
+ return (status);
+ }
+
+ /* Release the write lock only for the very last reader */
+
+ lock->num_readers--;
+ if (lock->num_readers == 0) {
+ acpi_os_release_mutex(lock->writer_mutex);
+ }
+
+ acpi_os_release_mutex(lock->reader_mutex);
+ return (status);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION: acpi_ut_acquire_write_lock
+ * acpi_ut_release_write_lock
+ *
+ * PARAMETERS: lock - Pointer to a valid RW lock
+ *
+ * RETURN: Status
+ *
+ * DESCRIPTION: Writer interfaces for reader/writer locks. Simply acquire or
+ * release the writer mutex associated with the lock. Acquisition
+ * of the lock is fully exclusive and will block all readers and
+ * writers until it is released.
+ *
+ ******************************************************************************/
+
+acpi_status acpi_ut_acquire_write_lock(struct acpi_rw_lock *lock)
+{
+ acpi_status status;
+
+ status = acpi_os_acquire_mutex(lock->writer_mutex, ACPI_WAIT_FOREVER);
+ return (status);
+}
+
+void acpi_ut_release_write_lock(struct acpi_rw_lock *lock)
+{
+
+ acpi_os_release_mutex(lock->writer_mutex);
+}