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path: root/drivers/i2c/busses/i2c-designware-amdpsp.c
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2023-04-20i2c: designware: Add doorbell support for MendocinoMario Limonciello1-1/+25
Mendocino and later platform don't use the platform feature mailbox for communication for I2C arbitration, they rely upon ringing a doorbell. Detect the platform by the device ID of the root port and choose the appropriate method. Link: https://lore.kernel.org/linux-i2c/20220916131854.687371-3-jsd@semihalf.com/ Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reviewed-by: Mark Hasemeyer <markhas@chromium.org> Tested-by: Mark Hasemeyer <markhas@chromium.org> Acked-by: Wolfram Sang <wsa@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2023-04-20i2c: designware: Use PCI PSP driver for communicationMario Limonciello1-150/+25
Currently the PSP semaphore communication base address is discovered by using an MSR that is not architecturally guaranteed for future platforms. Also the mailbox that is utilized for communication with the PSP may have other consumers in the kernel, so it's better to make all communication go through a single driver. Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> Reviewed-by: Mark Hasemeyer <markhas@chromium.org> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Mark Hasemeyer <markhas@chromium.org> Acked-by: Wolfram Sang <wsa@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2023-03-17crypto: ccp - Move some PSP mailbox bit definitions into common headerMario Limonciello1-11/+5
Some of the bits and fields used for mailboxes communicating with the PSP are common across all mailbox implementations (SEV, TEE, etc). Move these bits into the common `linux/psp.h` so they don't need to be re-defined for each implementation. Acked-by: Rijo Thomas <Rijo-john.Thomas@amd.com> Acked-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2023-03-17crypto: ccp - Add a header for multiple drivers to use `__psp_pa`Mario Limonciello1-1/+1
The TEE subdriver for CCP, the amdtee driver and the i2c-designware-amdpsp drivers all include `psp-sev.h` even though they don't use SEV functionality. Move the definition of `__psp_pa` into a common header to be included by all of these drivers. Reviewed-by: Jan Dabros <jsd@semihalf.com> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> # For the drivers/i2c/busses/i2c-designware-amdpsp.c Acked-by: Sumit Garg <sumit.garg@linaro.org> # For TEE subsystem bits Acked-by: Tom Lendacky <thomas.lendacky@amd.com> Acked-by: Sean Christopherson <seanjc@google.com> # KVM Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2022-08-20i2c: designware: Introduce semaphore reservation timer to AMDPSP driverJan Dabros1-15/+52
In order to optimize performance, limit amount of back and forth transactions between x86 and PSP. This is done by introduction of semaphore reservation period - that is window in which x86 isn't releasing the bus immediately after each I2C transaction. In order to protect PSP from being starved while waiting for arbitration, after a programmed time bus is automatically released by a deferred function. Signed-off-by: Jan Dabros <jsd@semihalf.com> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> [wsa: removed an unneeded empty line] Signed-off-by: Wolfram Sang <wsa@kernel.org>
2022-05-04i2c: designware: Modify timing parameters for amdpsp mailboxJan Dabros1-2/+2
Adjust retry period and timeout values for x86-PSP mailbox based on the typical I2C traffic generated by PSP. In order to limit the possibility of timeouts, x86 should reduce the interval between retries as well as increase overall time after which it gives up. Signed-off-by: Jan Dabros <jsd@semihalf.com> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2022-03-18i2c: designware: Remove code duplicationJan Dabros1-20/+15
Simplify code by moving common part to one function. Signed-off-by: Jan Dabros <jsd@semihalf.com> Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2022-03-01i2c: designware: Fix improper usage of readlJan Dabros1-2/+3
Kernel test robot reported incorrect type in argument 1 of readl(), but more importantly it brought attention that MMIO accessor shouldn't be used in this case, since req->hdr.status is part of a command-response buffer in system memory. Since its value may be altered by PSP outside of the scope of current thread (somehow similar to IRQ handler case), we need to use READ_ONCE() to ensure compiler won't optimize this call. Fix also 'status' variable type to reflect that corresponding field in command-response buffer is platform-independent u32. Fixes: 78d5e9e299e3 ("i2c: designware: Add AMD PSP I2C bus support") Signed-off-by: Jan Dabros <jsd@semihalf.com> Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2022-02-15i2c: designware: remove unneeded semicolonYang Li1-2/+2
Eliminate the following coccicheck warnings: ./drivers/i2c/busses/i2c-designware-amdpsp.c:172:2-3: Unneeded semicolon ./drivers/i2c/busses/i2c-designware-amdpsp.c:245:2-3: Unneeded semicolon Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Yang Li <yang.lee@linux.alibaba.com> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reviewed-by: Jan Dabros <jsd@semihalf.com> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2022-02-11i2c: designware: Add AMD PSP I2C bus supportJan Dabros1-0/+392
Implement an I2C controller sharing mechanism between the host (kernel) and PSP co-processor on some platforms equipped with AMD Cezanne SoC. On these platforms we need to implement "software" i2c arbitration. Default arbitration owner is PSP and kernel asks for acquire as well as inform about release of the i2c bus via mailbox mechanism. +---------+ <- ACQUIRE | | +---------| CPU |\ | | | \ +----------+ SDA | +---------+ \ | |------- MAILBOX +--> | I2C-DW | SCL | +---------+ | |------- | | | +----------+ +---------| PSP | <- ACK | | +---------+ +---------+ <- RELEASE | | +---------| CPU | | | | +----------+ SDA | +---------+ | |------- MAILBOX +--> | I2C-DW | SCL | +---------+ / | |------- | | | / +----------+ +---------| PSP |/ <- ACK | | +---------+ The solution is similar to i2c-designware-baytrail.c implementation, where we are using a generic i2c-designware-* driver with a small "wrapper". In contrary to baytrail semaphore implementation, beside internal acquire_lock() and release_lock() methods we are also applying quirks to lock_bus() and unlock_bus() global adapter methods. With this in place all i2c clients drivers may lock i2c bus for a desired number of i2c transactions (e.g. write-wait-read) without being aware of that such bus is shared with another entity. Modify i2c_dw_probe_lock_support() to select correct semaphore implementation at runtime, since now we have more than one available. Configure new matching ACPI ID "AMDI0019" and register ARBITRATION_SEMAPHORE flag in order to distinguish setup with PSP arbitration. Add myself as a reviewer for I2C DesignWare in order to help with reviewing and testing possible changes touching new i2c-designware-amdpsp.c module. Signed-off-by: Jan Dabros <jsd@semihalf.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> [wsa: removed unneeded blank line and curly braces] Signed-off-by: Wolfram Sang <wsa@kernel.org>