summaryrefslogtreecommitdiffstats
path: root/drivers/thunderbolt/cap.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2026-10-02 12:17:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-10-02 12:17:24 -0700
commit3f1fe48a36b0b6722dc3fd421d93512bac138e9a (patch)
treeb767d7f6e26bc64334d3f14f8422d187239dc45d /drivers/thunderbolt/cap.c
downloadlinux-stable-3f1fe48a36b0b6722dc3fd421d93512bac138e9a.tar.gz
linux-stable-3f1fe48a36b0b6722dc3fd421d93512bac138e9a.zip
Merge tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linuxgrafted
Pull io_uring fixes from Jens Axboe: - Fix a task_work add use-after-free with SQPOLL. The sqpoll thread could pop and complete the last request while io_req_normal_work_add() was still looking at them after the mpscq push. Use the same approach as DEFER_TASKRUN to protect from that, holding an RCU read lock across the add, and have exit wait for an RCU grace period for SQPOLL rings as well. - CQE32 ring fixes: correct the free entry check for 32b CQEs, zero the big_cqe for aux CQEs, and only post the dummy skip CQE on CQE_MIXED rings - Mark the source filter table as COW when cloning bpf filters, so registering another filter on the source doesn't modify the shared table in place - Initialize the task context before running the BPF loop - Requeue zcrx multishot receives stopped by a local resource - End a TX_TIMESTAMP multishot cmd when the CQ is full (lollipopkit) * tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: io_uring: fix task_work add use-after-free with SQPOLL io_uring/cmd_net: end TX_TIMESTAMP multishot when the CQ is full io_uring/zcrx: requeue multishot receives stopped by a local resource io_uring: initialize task context before running the BPF loop io_uring: zero big_cqe for aux CQEs on CQE32 rings io_uring: fix free entry check for 32b CQEs on CQE32 rings io_uring: only post the dummy skip CQE on CQE_MIXED rings io_uring/bpf_filter: mark source as COW when cloning filters
Diffstat (limited to 'drivers/thunderbolt/cap.c')
-rw-r--r--drivers/thunderbolt/cap.c256
1 files changed, 256 insertions, 0 deletions
diff --git a/drivers/thunderbolt/cap.c b/drivers/thunderbolt/cap.c
new file mode 100644
index 000000000..4ab22d529
--- /dev/null
+++ b/drivers/thunderbolt/cap.c
@@ -0,0 +1,256 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Thunderbolt driver - capabilities lookup
+ *
+ * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
+ * Copyright (C) 2018, Intel Corporation
+ */
+
+#include <linux/slab.h>
+#include <linux/errno.h>
+
+#include "tb.h"
+
+#define CAP_OFFSET_MAX 0xff
+#define VSE_CAP_OFFSET_MAX 0xffff
+#define TMU_ACCESS_EN BIT(20)
+
+static int tb_port_enable_tmu(struct tb_port *port, bool enable)
+{
+ struct tb_switch *sw = port->sw;
+ u32 value, offset;
+ int ret;
+
+ /*
+ * Legacy devices need to have TMU access enabled before port
+ * space can be fully accessed.
+ */
+ if (tb_switch_is_light_ridge(sw))
+ offset = 0x26;
+ else if (tb_switch_is_eagle_ridge(sw))
+ offset = 0x2a;
+ else
+ return 0;
+
+ ret = tb_sw_read(sw, &value, TB_CFG_SWITCH, offset, 1);
+ if (ret)
+ return ret;
+
+ if (enable)
+ value |= TMU_ACCESS_EN;
+ else
+ value &= ~TMU_ACCESS_EN;
+
+ return tb_sw_write(sw, &value, TB_CFG_SWITCH, offset, 1);
+}
+
+static void tb_port_dummy_read(struct tb_port *port)
+{
+ /*
+ * When reading from next capability pointer location in port
+ * config space the read data is not cleared on LR. To avoid
+ * reading stale data on next read perform one dummy read after
+ * port capabilities are walked.
+ */
+ if (tb_switch_is_light_ridge(port->sw)) {
+ u32 dummy;
+
+ tb_port_read(port, &dummy, TB_CFG_PORT, 0, 1);
+ }
+}
+
+/**
+ * tb_port_next_cap() - Return next capability in the linked list
+ * @port: Port to find the capability for
+ * @offset: Previous capability offset (%0 for start)
+ *
+ * Finds dword offset of the next capability in port config space
+ * capability list. When passed %0 in @offset parameter, first entry
+ * will be returned, if it exists.
+ *
+ * Return:
+ * * Double word offset of the first or next capability - On success.
+ * * %0 - If no next capability is found.
+ * * Negative errno - Another error occurred.
+ */
+int tb_port_next_cap(struct tb_port *port, unsigned int offset)
+{
+ struct tb_cap_any header;
+ int ret;
+
+ if (!offset)
+ return port->config.first_cap_offset;
+
+ ret = tb_port_read(port, &header, TB_CFG_PORT, offset, 1);
+ if (ret)
+ return ret;
+
+ return header.basic.next;
+}
+
+static int __tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap)
+{
+ int offset = 0;
+
+ do {
+ struct tb_cap_any header;
+ int ret;
+
+ offset = tb_port_next_cap(port, offset);
+ if (offset < 0)
+ return offset;
+
+ ret = tb_port_read(port, &header, TB_CFG_PORT, offset, 1);
+ if (ret)
+ return ret;
+
+ if (header.basic.cap == cap)
+ return offset;
+ } while (offset > 0);
+
+ return -ENOENT;
+}
+
+/**
+ * tb_port_find_cap() - Find port capability
+ * @port: Port to find the capability for
+ * @cap: Capability to look
+ *
+ * Return:
+ * * Offset to the start of capability - On success.
+ * * %-ENOENT - If no such capability was found.
+ * * Negative errno - Another error occurred.
+ */
+int tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap)
+{
+ int ret;
+
+ ret = tb_port_enable_tmu(port, true);
+ if (ret)
+ return ret;
+
+ ret = __tb_port_find_cap(port, cap);
+
+ tb_port_dummy_read(port);
+ tb_port_enable_tmu(port, false);
+
+ return ret;
+}
+
+/**
+ * tb_switch_next_cap() - Return next capability in the linked list
+ * @sw: Switch to find the capability for
+ * @offset: Previous capability offset (%0 for start)
+ *
+ * Finds dword offset of the next capability in port config space
+ * capability list. When passed %0 in @offset parameter, first entry
+ * will be returned, if it exists.
+ *
+ * Return:
+ * * Double word offset of the first or next capability - On success.
+ * * %0 - If no next capability is found.
+ * * Negative errno - Another error occurred.
+ */
+int tb_switch_next_cap(struct tb_switch *sw, unsigned int offset)
+{
+ struct tb_cap_any header;
+ int ret;
+
+ if (!offset)
+ return sw->config.first_cap_offset;
+
+ ret = tb_sw_read(sw, &header, TB_CFG_SWITCH, offset, 2);
+ if (ret)
+ return ret;
+
+ switch (header.basic.cap) {
+ case TB_SWITCH_CAP_TMU:
+ ret = header.basic.next;
+ break;
+
+ case TB_SWITCH_CAP_VSE:
+ if (!header.extended_short.length)
+ ret = header.extended_long.next;
+ else
+ ret = header.extended_short.next;
+ break;
+
+ default:
+ tb_sw_dbg(sw, "unknown capability %#x at %#x\n",
+ header.basic.cap, offset);
+ ret = -EINVAL;
+ break;
+ }
+
+ return ret >= VSE_CAP_OFFSET_MAX ? 0 : ret;
+}
+
+/**
+ * tb_switch_find_cap() - Find switch capability
+ * @sw: Switch to find the capability for
+ * @cap: Capability to look
+ *
+ * Return:
+ * * Offset to the start of capability - On success.
+ * * %-ENOENT - If no such capability was found.
+ * * Negative errno - Another error occurred.
+ */
+int tb_switch_find_cap(struct tb_switch *sw, enum tb_switch_cap cap)
+{
+ int offset = 0;
+
+ do {
+ struct tb_cap_any header;
+ int ret;
+
+ offset = tb_switch_next_cap(sw, offset);
+ if (offset < 0)
+ return offset;
+
+ ret = tb_sw_read(sw, &header, TB_CFG_SWITCH, offset, 1);
+ if (ret)
+ return ret;
+
+ if (header.basic.cap == cap)
+ return offset;
+ } while (offset);
+
+ return -ENOENT;
+}
+
+/**
+ * tb_switch_find_vse_cap() - Find switch vendor specific capability
+ * @sw: Switch to find the capability for
+ * @vsec: Vendor specific capability to look
+ *
+ * This function enumerates vendor specific capabilities (VSEC) of a
+ * switch and returns offset when capability matching @vsec is found.
+ *
+ * Return:
+ * * Offset of capability - On success.
+ * * %-ENOENT - If capability was not found.
+ * * Negative errno - Another error occurred.
+ */
+int tb_switch_find_vse_cap(struct tb_switch *sw, enum tb_switch_vse_cap vsec)
+{
+ int offset = 0;
+
+ do {
+ struct tb_cap_any header;
+ int ret;
+
+ offset = tb_switch_next_cap(sw, offset);
+ if (offset < 0)
+ return offset;
+
+ ret = tb_sw_read(sw, &header, TB_CFG_SWITCH, offset, 1);
+ if (ret)
+ return ret;
+
+ if (header.extended_short.cap == TB_SWITCH_CAP_VSE &&
+ header.extended_short.vsec_id == vsec)
+ return offset;
+ } while (offset);
+
+ return -ENOENT;
+}