Re: [PATCH 3/4 v11] arm highbank: add support for pl320 IPC

Rafael J. Wysocki
2013-01-28T12:49:01Z

On Friday, January 25, 2013 01:46:44 PM Mark Langsdorf wrote:
> From: Rob Herring <rob.herring@calxeda.com>
>
> The pl320 IPC allows for interprocessor communication between the highbank A9
> and the EnergyCore Management Engine. The pl320 implements a straightforward
> mailbox protocol.
>
> Signed-off-by: Mark Langsdorf <mark.langsdorf@calxeda.com>
> Signed-off-by: Rob Herring <rob.herring@calxeda.com>
> Cc: Omar Ramirez Luna <omar.luna@linaro.org>
> Cc: Arnd Bergmann <arnd@arndb.de>
> ---
> Changes from v10
> Removed deependency on Omar Ramirez Luna's mailbox code. Now the
> patch creates the directory itself.
> Changes from v9
> Used to be the 4th patch in the series.
> Changes from v6, v7, v8
> None.
> Changes from v5
> Renamed ipc_transmit() to pl320_ipc_transmit().
> Properly exported pl320_ipc_{un}register_notifier().
> Changes from v4
> Moved pl320-ipc.c from arch/arm/mach-highbank to drivers/mailbox.
> Moved header information to include/linux/mailbox.h.
> Added Kconfig options to reflect the new code location.
> Change drivers/mailbox/Makefile to build the omap mailboxes only
> when they are configured.
> Removed ipc_call_fast and renamed ipc_call_slow ipc_transmit.
> Changes from v3, v2
> None.
> Changes from v1
> Removed erroneous changes for cpufreq Kconfig.
>
> arch/arm/mach-highbank/Kconfig | 2 +
> drivers/mailbox/Kconfig | 18 ++++
> drivers/mailbox/Makefile | 1 +
> drivers/mailbox/pl320-ipc.c | 199 +++++++++++++++++++++++++++++++++++++++++
> include/linux/mailbox.h | 18 ++++
> 5 files changed, 238 insertions(+)
> create mode 100644 drivers/mailbox/Kconfig
> create mode 100644 drivers/mailbox/Makefile
> create mode 100644 drivers/mailbox/pl320-ipc.c
> create mode 100644 include/linux/mailbox.h
>
> diff --git a/arch/arm/mach-highbank/Kconfig b/arch/arm/mach-highbank/Kconfig
> index 551c97e..2388085 100644
> --- a/arch/arm/mach-highbank/Kconfig
> +++ b/arch/arm/mach-highbank/Kconfig
> @@ -11,5 +11,7 @@ config ARCH_HIGHBANK
> select GENERIC_CLOCKEVENTS
> select HAVE_ARM_SCU
> select HAVE_SMP
> + select MAILBOX
> + select PL320_MBOX
> select SPARSE_IRQ
> select USE_OF
> diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
> new file mode 100644
> index 0000000..9489554
> --- /dev/null
> +++ b/drivers/mailbox/Kconfig
> @@ -0,0 +1,18 @@
> +menuconfig MAILBOX
> + bool "Mailbox Hardware Support"
> + help
> + Mailbox is a framework to control hardware communication between
> + on-chip processors through queued messages and interrupt driven
> + signals. Say Y if your platform supports hardware mailboxes.
> +
> +if MAILBOX
> +config PL320_MBOX
> + bool "ARM PL320 Mailbox"
> + help
> + An implementation of the ARM PL320 Interprocessor Communication
> + Mailbox (IPCM), tailored for the Calxeda Highbank. It is used to
> + send short messages between Highbank's A9 cores and the EnergyCore
> + Management Engine, primarily for cpufreq. Say Y here if you want
> + to use the PL320 IPCM support.
> +
> +endif
> diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
> new file mode 100644
> index 0000000..543ad6a
> --- /dev/null
> +++ b/drivers/mailbox/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_PL320_MBOX) += pl320-ipc.o
> diff --git a/drivers/mailbox/pl320-ipc.c b/drivers/mailbox/pl320-ipc.c
> new file mode 100644
> index 0000000..68c0d50
> --- /dev/null
> +++ b/drivers/mailbox/pl320-ipc.c
> @@ -0,0 +1,199 @@
> +/*
> + * Copyright 2012 Calxeda, Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +#include <linux/types.h>
> +#include <linux/err.h>
> +#include <linux/delay.h>
> +#include <linux/export.h>
> +#include <linux/io.h>
> +#include <linux/interrupt.h>
> +#include <linux/completion.h>
> +#include <linux/mutex.h>
> +#include <linux/notifier.h>
> +#include <linux/spinlock.h>
> +#include <linux/device.h>
> +#include <linux/amba/bus.h>
> +
> +#include <linux/mailbox.h>
> +
> +#define IPCMxSOURCE(m) ((m) * 0x40)
> +#define IPCMxDSET(m) (((m) * 0x40) + 0x004)
> +#define IPCMxDCLEAR(m) (((m) * 0x40) + 0x008)
> +#define IPCMxDSTATUS(m) (((m) * 0x40) + 0x00C)
> +#define IPCMxMODE(m) (((m) * 0x40) + 0x010)
> +#define IPCMxMSET(m) (((m) * 0x40) + 0x014)
> +#define IPCMxMCLEAR(m) (((m) * 0x40) + 0x018)
> +#define IPCMxMSTATUS(m) (((m) * 0x40) + 0x01C)
> +#define IPCMxSEND(m) (((m) * 0x40) + 0x020)
> +#define IPCMxDR(m, dr) (((m) * 0x40) + ((dr) * 4) + 0x024)
> +
> +#define IPCMMIS(irq) (((irq) * 8) + 0x800)
> +#define IPCMRIS(irq) (((irq) * 8) + 0x804)
> +
> +#define MBOX_MASK(n) (1 << (n))
> +#define IPC_TX_MBOX 1
> +#define IPC_RX_MBOX 2
> +
> +#define CHAN_MASK(n) (1 << (n))
> +#define A9_SOURCE 1
> +#define M3_SOURCE 0
> +
> +static void __iomem *ipc_base;
> +static int ipc_irq;
> +static DEFINE_MUTEX(ipc_m1_lock);
> +static DECLARE_COMPLETION(ipc_completion);
> +static ATOMIC_NOTIFIER_HEAD(ipc_notifier);
> +
> +static inline void set_destination(int source, int mbox)
> +{
> + __raw_writel(CHAN_MASK(source), ipc_base + IPCMxDSET(mbox));
> + __raw_writel(CHAN_MASK(source), ipc_base + IPCMxMSET(mbox));
> +}
> +
> +static inline void clear_destination(int source, int mbox)
> +{
> + __raw_writel(CHAN_MASK(source), ipc_base + IPCMxDCLEAR(mbox));
> + __raw_writel(CHAN_MASK(source), ipc_base + IPCMxMCLEAR(mbox));
> +}
> +
> +static void __ipc_send(int mbox, u32 *data)
> +{
> + int i;
> + for (i = 0; i < 7; i++)
> + __raw_writel(data[i], ipc_base + IPCMxDR(mbox, i));
> + __raw_writel(0x1, ipc_base + IPCMxSEND(mbox));
> +}
> +
> +static u32 __ipc_rcv(int mbox, u32 *data)
> +{
> + int i;
> + for (i = 0; i < 7; i++)
> + data[i] = __raw_readl(ipc_base + IPCMxDR(mbox, i));
> + return data[1];
> +}
> +
> +/* blocking implmentation from the A9 side, not usuable in interrupts! */
> +int pl320_ipc_transmit(u32 *data)
> +{
> + int ret;
> +
> + mutex_lock(&ipc_m1_lock);
> +
> + init_completion(&ipc_completion);
> + __ipc_send(IPC_TX_MBOX, data);
> + ret = wait_for_completion_timeout(&ipc_completion,
> + msecs_to_jiffies(1000));
> + if (ret == 0) {
> + ret = -ETIMEDOUT;
> + goto out;
> + }
> +
> + ret = __ipc_rcv(IPC_TX_MBOX, data);
> +out:
> + mutex_unlock(&ipc_m1_lock);
> + return ret;
> +}
> +EXPORT_SYMBOL(pl320_ipc_transmit);
> +
> +irqreturn_t ipc_handler(int irq, void *dev)
> +{
> + u32 irq_stat;
> + u32 data[7];
> +
> + irq_stat = __raw_readl(ipc_base + IPCMMIS(1));
> + if (irq_stat & MBOX_MASK(IPC_TX_MBOX)) {
> + __raw_writel(0, ipc_base + IPCMxSEND(IPC_TX_MBOX));
> + complete(&ipc_completion);
> + }
> + if (irq_stat & MBOX_MASK(IPC_RX_MBOX)) {
> + __ipc_rcv(IPC_RX_MBOX, data);
> + atomic_notifier_call_chain(&ipc_notifier, data[0], data + 1);
> + __raw_writel(2, ipc_base + IPCMxSEND(IPC_RX_MBOX));
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> +int pl320_ipc_register_notifier(struct notifier_block *nb)
> +{
> + return atomic_notifier_chain_register(&ipc_notifier, nb);
> +}
> +EXPORT_SYMBOL(pl320_ipc_register_notifier);
> +
> +int pl320_ipc_unregister_notifier(struct notifier_block *nb)
> +{
> + return atomic_notifier_chain_unregister(&ipc_notifier, nb);
> +}
> +EXPORT_SYMBOL(pl320_ipc_unregister_notifier);

I need all of your symbols to be exported with EXPORT_SYMBOL_GPL().

Is it OK to make that change when applying the patch or do you want to send
a new one?

Rafael

--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.