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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/thunderbolt/cap.c | |
| download | linux-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/thunderbolt/cap.c')
| -rw-r--r-- | drivers/thunderbolt/cap.c | 256 |
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; +} |
