kernel/linux.git/drivers/reset/core.c, branch v5.2.16

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman

reset: Add acquire/release support for arrays

2019-03-20T10:18:53+00:00

Add implementations that apply acquire and release operations to all reset controls part of a reset control array. Signed-off-by: Thierry Reding Reviewed-by: Philipp Zabel Signed-off-by: Philipp Zabel

reset: Add acquired flag to of_reset_control_array_get()

2019-03-20T10:18:36+00:00

In order to be able to request an array of reset controls in acquired or released mode, add the acquired flag to of_reset_control_array_get() and pass the flag to subsequent calls of __of_reset_control_get(). Signed-off-by: Thierry Reding Acked-by: Felipe Balbi Signed-off-by: Philipp Zabel

reset: add acquired/released state for exclusive reset controls

2019-03-20T10:16:55+00:00

There are cases where a driver needs explicit control over a reset line that is exclusively conneted to its device, but this control has to be temporarily handed over to the power domain controller to handle reset requirements during power transitions. Allow multiple exclusive reset controls to be requested in 'released' state for the same physical reset line, only one of which can be acquired at the same time. Signed-off-by: Philipp Zabel Signed-off-by: Thierry Reding

reset: fix null pointer dereference on dev by dev_name

2019-01-07T15:38:26+00:00

The call to dev_name will dereference dev, however, dev is later being null checked, so there is a possibility of a null pointer dereference on dev by the call to dev_name. Fix this by null checking dev first before the call to dev_name Detected by CoverityScan, CID#1475475 ("Dereference before null check") Fixes: 2a6cb2b1d83b ("reset: Add reset_control_get_count()") Signed-off-by: Colin Ian King Signed-off-by: Philipp Zabel

reset: Add reset_control_get_count()

2019-01-07T15:38:26+00:00

Currently the reset core has internal support for counting the number of resets for a device described in DT. Generalize this to devices using lookup resets, and export it for public use. This will be used by generic drivers that need to be sure a device is controlled by a single, dedicated reset line (e.g. vfio-platform). Signed-off-by: Geert Uytterhoeven [p.zabel@pengutronix.de: fixed a typo in reset_control_get_count comment] Signed-off-by: Philipp Zabel

reset: Fix potential use-after-free in __of_reset_control_get()

2018-10-08T13:25:21+00:00

Calling of_node_put() decreases the reference count of a device tree object, and may free some data. However, the of_phandle_args structure embedding it is passed to reset_controller_dev.of_xlate() after that, so it may still be accessed. Move the call to of_node_put() down to fix this. Signed-off-by: Geert Uytterhoeven [p.zabel@pengutronix.de: moved of_node_put after mutex_unlock] Signed-off-by: Philipp Zabel

treewide: Use struct_size() for kmalloc()-family

2018-06-06T18:15:43+00:00

One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct foo { int stuff; void *entry[]; }; instance = kmalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL); Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL); This patch makes the changes for kmalloc()-family (and kvmalloc()-family) uses. It was done via automatic conversion with manual review for the "CHECKME" non-standard cases noted below, using the following Coccinelle script: // pkey_cache = kmalloc(sizeof *pkey_cache + tprops->pkey_tbl_len * // sizeof *pkey_cache->table, GFP_KERNEL); @@ identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc"; expression GFP; identifier VAR, ELEMENT; expression COUNT; @@ - alloc(sizeof(*VAR) + COUNT * sizeof(*VAR->ELEMENT), GFP) + alloc(struct_size(VAR, ELEMENT, COUNT), GFP) // mr = kzalloc(sizeof(*mr) + m * sizeof(mr->map[0]), GFP_KERNEL); @@ identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc"; expression GFP; identifier VAR, ELEMENT; expression COUNT; @@ - alloc(sizeof(*VAR) + COUNT * sizeof(VAR->ELEMENT[0]), GFP) + alloc(struct_size(VAR, ELEMENT, COUNT), GFP) // Same pattern, but can't trivially locate the trailing element name, // or variable name. @@ identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc"; expression GFP; expression SOMETHING, COUNT, ELEMENT; @@ - alloc(sizeof(SOMETHING) + COUNT * sizeof(ELEMENT), GFP) + alloc(CHECKME_struct_size(&SOMETHING, ELEMENT, COUNT), GFP) Signed-off-by: Kees Cook

reset: modify the way reset lookup works for board files

2018-03-27T08:39:47+00:00

Commit 7af1bb19f1d7 ("reset: add support for non-DT systems") introduced reset control lookup mechanism for boards that still use board files. The routine used to register lookup entries takes the corresponding reset_controlled_dev structure as argument. It's been determined however that for the first user of this new interface - davinci psc driver - it will be easier to register the lookup entries using the reset controller device name. This patch changes the way lookup entries are added. Signed-off-by: Bartosz Golaszewski [p.zabel@pengutronix.de: added missing ERR_PTR] Signed-off-by: Philipp Zabel

reset: add support for non-DT systems

2018-03-27T08:39:47+00:00

The reset framework only supports device-tree. There are some platforms however, which need to use it even in legacy, board-file based mode. An example of such architecture is the DaVinci family of SoCs which supports both device tree and legacy boot modes and we don't want to introduce any regressions. We're currently working on converting the platform from its hand-crafted clock API to using the common clock framework. Part of the overhaul will be representing the chip's power sleep controller's reset lines using the reset framework. This changeset extends the core reset code with a new reset lookup entry structure. It contains data allowing the reset core to associate reset lines with devices by comparing the dev_id and con_id strings. It also provides a function allowing drivers to register lookup entries with the framework. The new lookup function is only called as a fallback in case the of_node field is NULL and doesn't change anything for current users. Tested with a dummy reset driver with several lookup entries. An example lookup table registration from a driver can be found below: static struct reset_control_lookup foobar_reset_lookup[] = { RESET_LOOKUP("foo.0", "foo", 15), RESET_LOOKUP("bar.0", NULL, 5), }; foobar_probe() { ... reset_controller_add_lookup(&rcdev, foobar_reset_lookup, ARRAY_SIZE(foobar_reset_lookup)); ... } Cc: Sekhar Nori Cc: Kevin Hilman Cc: David Lechner Signed-off-by: Bartosz Golaszewski Signed-off-by: Philipp Zabel