From: Fabien Dessenne <fabien.dessenne@st.com>
To: Ohad Ben-Cohen <ohad@wizery.com>,
Bjorn Andersson <bjorn.andersson@linaro.org>,
Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Maxime Coquelin <mcoquelin.stm32@gmail.com>,
Alexandre Torgue <alexandre.torgue@st.com>,
Jonathan Corbet <corbet@lwn.net>,
<linux-remoteproc@vger.kernel.org>, <devicetree@vger.kernel.org>,
<linux-kernel@vger.kernel.org>,
<linux-stm32@st-md-mailman.stormreply.com>,
<linux-arm-kernel@lists.infradead.org>,
<linux-doc@vger.kernel.org>
Cc: Fabien Dessenne <fabien.dessenne@st.com>,
Benjamin Gaignard <benjamin.gaignard@st.com>
Subject: [PATCH 0/6] hwspinlock: allow sharing of hwspinlocks
Date: Wed, 13 Mar 2019 16:50:31 +0100 [thread overview]
Message-ID: <1552492237-28810-1-git-send-email-fabien.dessenne@st.com> (raw)
The current implementation does not allow two different devices to use
a common hwspinlock. This patch set proposes to have, as an option, some
hwspinlocks shared between several users.
Below is an example that explain the need for this:
exti: interrupt-controller@5000d000 {
compatible = "st,stm32mp1-exti", "syscon";
interrupt-controller;
#interrupt-cells = <2>;
reg = <0x5000d000 0x400>;
hwlocks = <&hsem 1>;
};
The two drivers (stm32mp1-exti and syscon) refer to the same hwlock.
With the current hwspinlock implementation, only the first driver succeeds
in requesting (hwspin_lock_request_specific) the hwlock. The second request
fails.
The proposed approach does not modify the API, but extends the DT 'hwlocks'
property with a second optional parameter (the first one identifies an
hwlock) that specifies whether an hwlock is requested for exclusive usage
(current behavior) or can be shared between several users.
Examples:
hwlocks = <&hsem 8>; Ref to hwlock #8 for exclusive usage
hwlocks = <&hsem 8 0>; Ref to hwlock #8 for exclusive (0) usage
hwlocks = <&hsem 8 1>; Ref to hwlock #8 for shared (1) usage
As a constraint, the #hwlock-cells value must be 1 or 2.
In the current implementation, this can have theorically any value but:
- all of the exisiting drivers use the same value : 1.
- the framework supports only one value : 1 (see implementation of
of_hwspin_lock_simple_xlate())
Hence, it shall not be a problem to restrict this value to 1 or 2 since
it won't break any driver.
Fabien Dessenne (6):
dt-bindings: hwlock: add support of shared locks
hwspinlock: allow sharing of hwspinlocks
dt-bindings: hwlock: update STM32 #hwlock-cells value
ARM: dts: stm32: Add hwspinlock node for stm32mp157 SoC
ARM: dts: stm32: Add hwlock for irqchip on stm32mp157
ARM: dts: stm32: hwlocks for GPIO for stm32mp157
.../devicetree/bindings/hwlock/hwlock.txt | 27 +++++--
.../bindings/hwlock/st,stm32-hwspinlock.txt | 6 +-
Documentation/hwspinlock.txt | 10 ++-
arch/arm/boot/dts/stm32mp157-pinctrl.dtsi | 2 +
arch/arm/boot/dts/stm32mp157c.dtsi | 10 +++
drivers/hwspinlock/hwspinlock_core.c | 82 +++++++++++++++++-----
drivers/hwspinlock/hwspinlock_internal.h | 2 +
7 files changed, 108 insertions(+), 31 deletions(-)
--
2.7.4
next reply other threads:[~2019-03-13 15:51 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-13 15:50 Fabien Dessenne [this message]
2019-03-13 15:50 ` [PATCH 1/6] dt-bindings: hwlock: add support of shared locks Fabien Dessenne
2019-03-28 15:24 ` Rob Herring
2019-03-13 15:50 ` [PATCH 2/6] hwspinlock: allow sharing of hwspinlocks Fabien Dessenne
2019-07-31 9:22 ` Loic PALLARDY
2019-03-13 15:50 ` [PATCH 3/6] dt-bindings: hwlock: update STM32 #hwlock-cells value Fabien Dessenne
2019-03-28 15:26 ` Rob Herring
2019-03-13 15:50 ` [PATCH 4/6] ARM: dts: stm32: Add hwspinlock node for stm32mp157 SoC Fabien Dessenne
2019-03-28 15:26 ` Rob Herring
2019-03-13 15:50 ` [PATCH 5/6] ARM: dts: stm32: Add hwlock for irqchip on stm32mp157 Fabien Dessenne
2019-03-13 15:50 ` [PATCH 6/6] ARM: dts: stm32: hwlocks for GPIO for stm32mp157 Fabien Dessenne
2019-08-01 19:14 ` [PATCH 0/6] hwspinlock: allow sharing of hwspinlocks Bjorn Andersson
2019-08-05 8:48 ` Fabien DESSENNE
2019-08-05 17:46 ` Bjorn Andersson
2019-08-06 7:43 ` Fabien DESSENNE
2019-08-06 17:38 ` Suman Anna
2019-08-06 18:21 ` Bjorn Andersson
2019-08-06 21:30 ` Suman Anna
2019-08-07 8:39 ` Fabien DESSENNE
2019-08-07 16:19 ` Suman Anna
2019-08-08 12:52 ` Fabien DESSENNE
2019-08-08 15:37 ` Bjorn Andersson
2019-08-26 13:30 ` Fabien DESSENNE
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