kernel/linux.git/drivers/hwspinlock, branch v5.15.7

hwspinlock: add sun6i hardware spinlock support

2021-05-28T03:19:42+00:00

Adds the sun6i_hwspinlock driver for the hardware spinlock unit found in most of the sun6i compatible SoCs. This unit provides at least 32 spinlocks in hardware. The implementation supports 32, 64, 128 or 256 32bit registers. A lock can be taken by reading a register and released by writing a 0 to it. This driver supports all 4 spinlock setups, but for now only the first setup (32 locks) seem to exist in available devices. This spinlock unit is shared between all ARM cores and the embedded companion core. All of them can take/release a lock with a single cycle operation. It can be used to sync access to devices shared by the ARM cores and the companion core. There are two ways to check if a lock is taken. The first way is to read a lock. If a 0 is returned, the lock was free and is taken now. If an 1 is returned, the caller has to try again. Which means the lock is taken. The second way is to read a 32bit wide status register where every bit represents one of the 32 first locks. According to the datasheets this status register supports only the 32 first locks. This is the reason the first way (lock read/write) approach is used to be able to cover all 256 locks in future devices. The driver also reports the amount of supported locks via debugfs. Reviewed-by: Samuel Holland Acked-by: Maxime Ripard Signed-off-by: Wilken Gottwalt Link: https://lore.kernel.org/r/bfd2b97307c2321b15c09683f4bd5e1fcc792f13.1615713499.git.wilken.gottwalt@posteo.net Signed-off-by: Bjorn Andersson

hwspinlock: remove sirf driver

2021-03-18T02:22:06+00:00

The CSR SiRF prima2/atlas platforms are getting removed, so this driver is no longer needed. Cc: Barry Song Link: https://lore.kernel.org/linux-arm-kernel/20210120124812.2800027-1-arnd@kernel.org/T/ Signed-off-by: Arnd Bergmann Link: https://lore.kernel.org/r/20210120132537.2285157-1-arnd@kernel.org Signed-off-by: Bjorn Andersson

hwspinlock: omap: Add support for K3 AM64x SoCs

2021-02-09T17:36:50+00:00

The AM64x SoC contains a HwSpinlock IP instance in the MAIN domain, and is a minor variant of the IP on the current TI K3 SoCs such as AM64x, J721E or J7200 SoCs. The IP is not built with the K3 safety feature in hardware, and has slightly different integration into the overall SoC. Add the support for this IP through a new compatible. Signed-off-by: Suman Anna Link: https://lore.kernel.org/r/20210209172240.2305-3-s-anna@ti.com Signed-off-by: Bjorn Andersson

hwspinlock: sirf: Remove the redundant 'of_match_ptr'

2020-12-10T19:34:40+00:00

Remove the the redundant 'of_match_ptr' macro to fix below warning when the CONFIG_OF is not selected. All warnings: drivers/hwspinlock/sirf_hwspinlock.c:87:34: warning: unused variable 'sirf_hwpinlock_ids' [-Wunused-const-variable] Reported-by: kernel test robot Signed-off-by: Baolin Wang Link: https://lore.kernel.org/r/250d35cb489c3c4c066f7ce256d27f36712a1979.1591618255.git.baolin.wang7@gmail.com Signed-off-by: Bjorn Andersson

hwspinlock: sprd: fixed warning of unused variable 'sprd_hwspinlock_of_match'

2020-11-18T03:42:13+00:00

The macro function of_match_ptr() is NULL if CONFIG_OF is not set, in this case Clang compiler would complain the of_device_id variable is unused. Reviewed-by: Baolin Wang Reported-by: kernel test robot Fixes: d8c8bbbb1aba ("hwspinlock: sprd: Add hardware spinlock driver") Signed-off-by: Chunyan Zhang Link: https://lore.kernel.org/r/20201112070410.14810-1-zhang.lyra@gmail.com Signed-off-by: Bjorn Andersson

hwspinlock: sprd: use module_platform_driver() instead postcore initcall

2020-11-03T00:04:06+00:00

The hardware spinlock devices are defined in the DT, there's no need for init calls order, remove boilerplate code by using module_platform_driver. Reviewed-by: Baolin Wang Signed-off-by: Chunyan Zhang Link: https://lore.kernel.org/r/20201030034654.15775-3-zhang.lyra@gmail.com Signed-off-by: Bjorn Andersson

hwspinlock: sprd: Remove redundant header files

2020-10-26T15:17:54+00:00

Remove redundant header files. Signed-off-by: Baolin Wang Link: https://lore.kernel.org/r/1590991552-93643-1-git-send-email-baolin.wang@linux.alibaba.com Signed-off-by: Bjorn Andersson

hwspinlock: qcom: Allow mmio usage in addition to syscon

2020-07-14T05:29:28+00:00

In modern Qualcomm platforms the mutex region of the TCSR is forked off into its own block, all with a offset of 0 and stride of 4096, and in some of these platforms no other registers in this region is accessed from Linux. So add support for directly memory mapping this register space, to avoid the need to represent this block using a syscon. Reviewed-by: Baolin Wang Reviewed-by: Vinod Koul Signed-off-by: Bjorn Andersson Link: https://lore.kernel.org/r/20200622075956.171058-4-bjorn.andersson@linaro.org Signed-off-by: Bjorn Andersson

hwspinlock: Simplify Kconfig

2020-06-21T07:36:03+00:00

Every hwspinlock driver is expected to depend on the hwspinlock core, so it's possible to simplify the Kconfig, factoring out the HWSPINLOCK dependency. Reviewed-by: Baolin Wang Signed-off-by: Ezequiel Garcia Link: https://lore.kernel.org/r/20200414220943.6203-1-ezequiel@collabora.com Signed-off-by: Bjorn Andersson

hwspinlock: hwspinlock_internal.h: Replace zero-length array with flexible-array member

2020-03-26T05:30:46+00:00

The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Reviewed-by: Baolin Wang Signed-off-by: Gustavo A. R. Silva Link: https://lore.kernel.org/r/20200319213839.GA10669@embeddedor.com Signed-off-by: Bjorn Andersson