linux/drivers/base/platform.c, branch v5.7

driver core: platform: Initialize dma_parms for platform devices

2020-04-28T15:44:33Z

It's currently the platform driver's responsibility to initialize the pointer, dma_parms, for its corresponding struct device. The benefit with this approach allows us to avoid the initialization and to not waste memory for the struct device_dma_parameters, as this can be decided on a case by case basis. However, it has turned out that this approach is not very practical. Not only does it lead to open coding, but also to real errors. In principle callers of dma_set_max_seg_size() doesn't check the error code, but just assumes it succeeds. For these reasons, let's do the initialization from the common platform bus at the device registration point. This also follows the way the PCI devices are being managed, see pci_device_add(). Suggested-by: Christoph Hellwig Cc: Tested-by: Haibo Chen Reviewed-by: Arnd Bergmann Signed-off-by: Ulf Hansson Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20200422100954.31211-1-ulf.hansson@linaro.org Signed-off-by: Greg Kroah-Hartman

driver core: platform: Reimplement devm_platform_ioremap_resource

2020-03-24T11:09:40Z

Reimplement devm_platform_ioremap_resource() by calling devm_platform_ioremap_and_get_resource() with res = NULL to simplify the code. Suggested-by: Geert Uytterhoeven Reviewed-by: Geert Uytterhoeven Signed-off-by: Dejin Zheng Link: https://lore.kernel.org/r/20200323160612.17277-6-zhengdejin5@gmail.com Signed-off-by: Greg Kroah-Hartman

drivers: provide devm_platform_get_and_ioremap_resource()

2020-03-24T11:09:38Z

Since commit "drivers: provide devm_platform_ioremap_resource()", it was wrap platform_get_resource() and devm_ioremap_resource() as single helper devm_platform_ioremap_resource(). but now, many drivers still used platform_get_resource() and devm_ioremap_resource() together in the kernel tree. The reason can not be replaced is they still need use the resource variables obtained by platform_get_resource(). so provide this helper. Suggested-by: Geert Uytterhoeven Suggested-by: Sergei Shtylyov Reviewed-by: Geert Uytterhoeven Signed-off-by: Dejin Zheng Link: https://lore.kernel.org/r/20200323160612.17277-2-zhengdejin5@gmail.com Signed-off-by: Greg Kroah-Hartman

driver code: clarify and fix platform device DMA mask allocation

2020-03-11T16:30:27Z

This does three inter-related things to clarify the usage of the platform device dma_mask field. In the process, fix the bug introduced by cdfee5623290 ("driver core: initialize a default DMA mask for platform device") that caused Artem Tashkinov's laptop to not boot with newer Fedora kernels. This does: - First off, rename the field to "platform_dma_mask" to make it greppable. We have way too many different random fields called "dma_mask" in various data structures, where some of them are actual masks, and some of them are just pointers to the mask. And the structures all have pointers to each other, or embed each other inside themselves, and "pdev" sometimes means "platform device" and sometimes it means "PCI device". So to make it clear in the code when you actually use this new field, give it a unique name (it really should be something even more unique like "platform_device_dma_mask", since it's per platform device, not per platform, but that gets old really fast, and this is unique enough in context). To further clarify when the field gets used, initialize it when we actually start using it with the default value. - Then, use this field instead of the random one-off allocation in platform_device_register_full() that is now unnecessary since we now already have a perfectly fine allocation for it in the platform device structure. - The above then allows us to fix the actual bug, where the error path of platform_device_register_full() would unconditionally free the platform device DMA allocation with 'kfree()'. That kfree() was dont regardless of whether the allocation had been done earlier with the (now removed) kmalloc, or whether setup_pdev_dma_masks() had already been used and the dma_mask pointer pointed to the mask that was part of the platform device. It seems most people never triggered the error path, or only triggered it from a call chain that set an explicit pdevinfo->dma_mask value (and thus caused the unnecessary allocation that was "cleaned up" in the error path) before calling platform_device_register_full(). Robin Murphy points out that in Artem's case the wdat_wdt driver failed in platform_device_add(), and that was the one that had called platform_device_register_full() with pdevinfo.dma_mask = 0, and would have caused that kfree() of pdev.dma_mask corrupting the heap. A later unrelated kmalloc() then oopsed due to the heap corruption. Fixes: cdfee5623290 ("driver core: initialize a default DMA mask for platform device") Reported-bisected-and-tested-by: Artem S. Tashkinov Reviewed-by: Robin Murphy Cc: Greg Kroah-Hartman Signed-off-by: Christoph Hellwig Signed-off-by: Linus Torvalds

driver core: platform: fix u32 greater or equal to zero comparison

2020-01-22T14:27:11Z

Currently the check that a u32 variable i is >= 0 is always true because the unsigned variable will never be negative, causing the loop to run forever. Fix this by changing the pre-decrement check to a zero check on i followed by a decrement of i. Addresses-Coverity: ("Unsigned compared against 0") Fixes: 39cc539f90d0 ("driver core: platform: Prevent resouce overflow from causing infinite loops") Signed-off-by: Colin Ian King Reviewed-by: Rafael J. Wysocki Link: https://lore.kernel.org/r/20200116175758.88396-1-colin.king@canonical.com Signed-off-by: Greg Kroah-Hartman

driver core: platform: Prevent resouce overflow from causing infinite loops

2020-01-14T15:14:47Z

num_resources in the platform_device struct is declared as a u32. The for loops that iterate over num_resources use an int as the counter, which can cause infinite loops on architectures with smaller ints. Change the loop counters to u32. Signed-off-by: Simon Schwartz Link: https://lore.kernel.org/r/2201ce63a2a171ffd2ed14e867875316efcf71db.camel@theschwartz.xyz Signed-off-by: Greg Kroah-Hartman

drivers: Fix boot problem on SuperH

2019-12-10T14:51:20Z

SuperH images crash too eearly to display any console output. Bisect points to commit 507fd01d5333 ("drivers: move the early platform device support to arch/sh"). An analysis of that patch suggests that early_platform_cleanup() is now called at the wrong time. Restoring its call point fixes the problem. Cc: Bartosz Golaszewski Fixes: 507fd01d5333 ("drivers: move the early platform device support to arch/sh") Tested-by: Geert Uytterhoeven Signed-off-by: Guenter Roeck Acked-by: Rob Landley Link: https://lore.kernel.org/r/20191203205852.15659-1-linux@roeck-us.net Signed-off-by: Greg Kroah-Hartman

driver core: platform: Declare ret variable only once

2019-11-14T04:33:55Z

We may define ret variable only once and avoid adding it each time platform_get_irq_optional() get extended. For the sake of consistency do the same in __platform_get_irq_byname(). Signed-off-by: Andy Shevchenko Reviewed-by: Rafael J. Wysocki Link: https://lore.kernel.org/r/20191023122505.64684-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

driver core: platform: use the correct callback type for bus_find_device

2019-11-14T03:30:56Z

platform_find_device_by_driver calls bus_find_device and passes platform_match as the callback function. Casting the function to a mismatching type trips indirect call Control-Flow Integrity (CFI) checking. This change adds a callback function with the correct type and instead of casting the function, explicitly casts the second parameter to struct device_driver* as expected by platform_match. Fixes: 36f3313d6bff9 ("platform: Add platform_find_device_by_driver() helper") Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook Cc: stable Link: https://lore.kernel.org/r/20191112214156.3430-1-samitolvanen@google.com Signed-off-by: Greg Kroah-Hartman

drivers: provide devm_platform_ioremap_resource_byname()

2019-11-05T17:33:13Z

Provide a variant of devm_platform_ioremap_resource() that allows to lookup resources from platform devices by name rather than by index. Signed-off-by: Bartosz Golaszewski Reviewed-by: Arnd Bergmann Link: https://lore.kernel.org/r/20191022084318.22256-7-brgl@bgdev.pl Signed-off-by: Greg Kroah-Hartman