Hello,
On 10 September 2014 13:20, Ashwin Chaugule <ashwin.chaugule@xxxxxxxxxx> wrote:
> ACPI 5.0+ spec defines a generic mode of communication
> between the OS and a platform such as the BMC. This medium
> (PCC) is typically used by CPPC (ACPI CPU Performance management),
> RAS (ACPI reliability protocol) and MPST (ACPI Memory power
> states).
>
> This patch adds PCC support as a Mailbox Controller.
>
> Signed-off-by: Ashwin Chaugule <ashwin.chaugule@xxxxxxxxxx>
> ---
> drivers/mailbox/Kconfig | 12 ++
> drivers/mailbox/Makefile | 2 +
> drivers/mailbox/mailbox.c | 4 +-
> drivers/mailbox/mailbox.h | 16 +++
> drivers/mailbox/pcc.c | 282 ++++++++++++++++++++++++++++++++++++++++++++++
> 5 files changed, 313 insertions(+), 3 deletions(-)
> create mode 100644 drivers/mailbox/mailbox.h
> create mode 100644 drivers/mailbox/pcc.c
How does this version look? If there are no more changes, please let
me know which tree this can be picked by and I can send a pull request
if that is preferred for this single patch.
Cheers,
Ashwin
>
> diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
> index c8b5c13..e08cc83 100644
> --- a/drivers/mailbox/Kconfig
> +++ b/drivers/mailbox/Kconfig
> @@ -50,4 +50,16 @@ config OMAP_MBOX_KFIFO_SIZE
> Specify the default size of mailbox's kfifo buffers (bytes).
> This can also be changed at runtime (via the mbox_kfifo_size
> module parameter).
> +
> +config PCC
> + bool "Platform Communication Channel Driver"
> + depends on ACPI
> + help
> + ACPI 5.0+ spec defines a generic mode of communication
> + between the OS and a platform such as the BMC. This medium
> + (PCC) is typically used by CPPC (ACPI CPU Performance management),
> + RAS (ACPI reliability protocol) and MPST (ACPI Memory power
> + states). Select this driver if your platform implements the
> + PCC clients mentioned above.
> +
> endif
> diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
> index 2fa343a..0b09d6f 100644
> --- a/drivers/mailbox/Makefile
> +++ b/drivers/mailbox/Makefile
> @@ -9,3 +9,5 @@ obj-$(CONFIG_OMAP1_MBOX) += mailbox_omap1.o
> mailbox_omap1-objs := mailbox-omap1.o
> obj-$(CONFIG_OMAP2PLUS_MBOX) += mailbox_omap2.o
> mailbox_omap2-objs := mailbox-omap2.o
> +
> +obj-$(CONFIG_PCC) += pcc.o
> diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
> index 63ecc17..9d9366a 100644
> --- a/drivers/mailbox/mailbox.c
> +++ b/drivers/mailbox/mailbox.c
> @@ -21,9 +21,7 @@
> #include <linux/mailbox_client.h>
> #include <linux/mailbox_controller.h>
>
> -#define TXDONE_BY_IRQ BIT(0) /* controller has remote RTR irq */
> -#define TXDONE_BY_POLL BIT(1) /* controller can read status of last TX */
> -#define TXDONE_BY_ACK BIT(2) /* S/W ACK recevied by Client ticks the TX */
> +#include "mailbox.h"
>
> static LIST_HEAD(mbox_cons);
> static DEFINE_MUTEX(con_mutex);
> diff --git a/drivers/mailbox/mailbox.h b/drivers/mailbox/mailbox.h
> new file mode 100644
> index 0000000..5a15a25
> --- /dev/null
> +++ b/drivers/mailbox/mailbox.h
> @@ -0,0 +1,16 @@
> +/*
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#ifndef __MAILBOX_H
> +#define __MAILBOX_H
> +
> +#define TXDONE_BY_IRQ BIT(0) /* controller has remote RTR irq */
> +#define TXDONE_BY_POLL BIT(1) /* controller can read status of last TX */
> +#define TXDONE_BY_ACK BIT(2) /* S/W ACK recevied by Client ticks the TX */
> +
> +#endif /* __MAILBOX_H */
> +
> +
> diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
> new file mode 100644
> index 0000000..bb8e8b1
> --- /dev/null
> +++ b/drivers/mailbox/pcc.c
> @@ -0,0 +1,282 @@
> +/*
> + * Copyright (C) 2014 Linaro Ltd.
> + * Author: Ashwin Chaugule <ashwin.chaugule@xxxxxxxxxx>
> + *
> + * 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.
> + *
> + * This program is distributed in the hope that 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.
> + *
> + */
> +
> +#include <linux/acpi.h>
> +#include <linux/cpufreq.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/init.h>
> +#include <linux/ioctl.h>
> +#include <linux/module.h>
> +#include <linux/uaccess.h>
> +#include <linux/vmalloc.h>
> +#include <linux/platform_device.h>
> +#include <linux/mailbox_controller.h>
> +#include <linux/mailbox_client.h>
> +
> +#include "mailbox.h"
> +
> +#define MAX_PCC_SUBSPACES 256
> +#define PCCS_SS_SIG_MAGIC 0x50434300
> +#define PCC_CMD_COMPLETE 0x1
> +
> +static struct mbox_chan pcc_mbox_chan[MAX_PCC_SUBSPACES];
> +static struct mbox_controller pcc_mbox_ctrl = {};
> +
> +struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl,
> + int index)
> +{
> + struct device *dev = pcc_mbox_ctrl.dev;
> + struct mbox_chan *chan;
> + unsigned long flags;
> +
> + /*
> + * Each PCC Subspace is a Mailbox Channel.
> + * The PCC Clients get their PCC Subspace ID
> + * from their own tables and pass it here.
> + * This returns a pointer to the PCC subspace
> + * for the Client to operate on.
> + */
> + chan = &pcc_mbox_chan[index];
> +
> + if (!chan || chan->cl) {
> + dev_err(dev, "%s: PCC mailbox not free\n", __func__);
> + return ERR_PTR(-EBUSY);
> + }
> +
> + spin_lock_irqsave(&chan->lock, flags);
> + chan->msg_free = 0;
> + chan->msg_count = 0;
> + chan->active_req = NULL;
> + chan->cl = cl;
> + init_completion(&chan->tx_complete);
> +
> + if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone)
> + chan->txdone_method |= TXDONE_BY_ACK;
> +
> + spin_unlock_irqrestore(&chan->lock, flags);
> +
> + return chan;
> +}
> +EXPORT_SYMBOL_GPL(pcc_mbox_request_channel);
> +
> +void pcc_mbox_free_channel(struct mbox_chan *chan)
> +{
> + unsigned long flags;
> +
> + if (!chan || !chan->cl)
> + return;
> +
> + spin_lock_irqsave(&chan->lock, flags);
> + chan->cl = NULL;
> + chan->active_req = NULL;
> + if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK))
> + chan->txdone_method = TXDONE_BY_POLL;
> +
> + spin_unlock_irqrestore(&chan->lock, flags);
> +}
> +EXPORT_SYMBOL_GPL(pcc_mbox_free_channel);
> +
> +static bool pcc_tx_done(struct mbox_chan *chan)
> +{
> + struct acpi_pcct_subspace *pcct_ss = chan->con_priv;
> + struct acpi_pcct_shared_memory *generic_comm_base =
> + (struct acpi_pcct_shared_memory *) pcct_ss->base_address;
> + u16 cmd_delay = pcct_ss->min_turnaround_time;
> +
> + /* Wait for Platform to consume. */
> + while (!(readw_relaxed(&generic_comm_base->status) & PCC_CMD_COMPLETE))
> + udelay(cmd_delay);
> +
> + return true;
> +}
> +
> +static int get_subspace_id(struct mbox_chan *chan)
> +{
> + int id = chan - pcc_mbox_chan;
> +
> + if (id < 0 || id > pcc_mbox_ctrl.num_chans)
> + return -ENOENT;
> +
> + return id;
> +}
> +
> +/* Channel lock is already held by mbox controller code. */
> +static int pcc_send_data(struct mbox_chan *chan, void *data)
> +{
> + struct acpi_pcct_subspace *pcct_ss = chan->con_priv;
> + struct acpi_pcct_shared_memory *generic_comm_base =
> + (struct acpi_pcct_shared_memory *) pcct_ss->base_address;
> + struct acpi_generic_address doorbell;
> + u64 doorbell_preserve;
> + u64 doorbell_val;
> + u64 doorbell_write;
> + u16 cmd = *(u16 *) data;
> + u16 ss_idx = -1;
> + int ret = 0;
> +
> + ss_idx = get_subspace_id(chan);
> +
> + if (ss_idx < 0) {
> + pr_err("Invalid Subspace ID from PCC client\n");
> + ret = -EINVAL;
> + goto out_err;
> + }
> +
> + doorbell = pcct_ss->doorbell_register;
> + doorbell_preserve = pcct_ss->preserve_mask;
> + doorbell_write = pcct_ss->write_mask;
> +
> + /* Write to the shared comm region. */
> + writew(cmd, &generic_comm_base->command);
> +
> + /* Write Subspace MAGIC value so platform can identify destination. */
> + writel((PCCS_SS_SIG_MAGIC | ss_idx), &generic_comm_base->signature);
> +
> + /* Flip CMD COMPLETE bit */
> + writew(0, &generic_comm_base->status);
> +
> + /* Sync notification from OSPM to Platform. */
> + acpi_read(&doorbell_val, &doorbell);
> + acpi_write((doorbell_val & doorbell_preserve) | doorbell_write,
> + &doorbell);
> +
> +out_err:
> + return ret;
> +}
> +
> +static struct mbox_chan_ops pcc_chan_ops = {
> + .send_data = pcc_send_data,
> + .last_tx_done = pcc_tx_done,
> +};
> +
> +static int parse_pcc_subspace(struct acpi_subtable_header *header,
> + const unsigned long end)
> +{
> + struct acpi_pcct_subspace *pcct_ss;
> +
> + if (pcc_mbox_ctrl.num_chans <= MAX_PCC_SUBSPACES) {
> + pcct_ss = (struct acpi_pcct_subspace *) header;
> +
> + if (pcct_ss->header.type != ACPI_PCCT_TYPE_GENERIC_SUBSPACE) {
> + pr_err("Incorrect PCC Subspace type detected\n");
> + return -EINVAL;
> + }
> +
> + /* New mbox channel entry for each PCC subspace detected. */
> + pcc_mbox_chan[pcc_mbox_ctrl.num_chans].con_priv = pcct_ss;
> + pcc_mbox_ctrl.num_chans++;
> +
> + } else {
> + pr_err("No more space for PCC subspaces.\n");
> + return -ENOSPC;
> + }
> +
> + return 0;
> +}
> +
> +static int __init acpi_pcc_probe(void)
> +{
> + acpi_status status = AE_OK;
> + acpi_size pcct_tbl_header_size;
> + struct acpi_table_pcct *pcct_tbl;
> +
> + /* Search for PCCT */
> + status = acpi_get_table_with_size(ACPI_SIG_PCCT, 0,
> + (struct acpi_table_header **)&pcct_tbl,
> + &pcct_tbl_header_size);
> +
> + if (ACPI_SUCCESS(status) && !pcct_tbl) {
> + pr_warn("PCCT header not found.\n");
> + status = AE_NOT_FOUND;
> + goto out_err;
> + }
> +
> + status = acpi_table_parse_entries(ACPI_SIG_PCCT,
> + sizeof(struct acpi_table_pcct),
> + ACPI_PCCT_TYPE_GENERIC_SUBSPACE,
> + parse_pcc_subspace, MAX_PCC_SUBSPACES);
> +
> + if (ACPI_SUCCESS(status)) {
> + pr_err("Error parsing PCC subspaces from PCCT\n");
> + status = AE_ERROR;
> + goto out_err;
> + }
> +
> + pr_info("Detected %d PCC Subspaces\n", pcc_mbox_ctrl.num_chans);
> +
> + pcc_mbox_ctrl.chans = pcc_mbox_chan;
> + pcc_mbox_ctrl.ops = &pcc_chan_ops;
> + pcc_mbox_ctrl.txdone_poll = true;
> + pcc_mbox_ctrl.txpoll_period = 1;
> +
> +out_err:
> + return ACPI_SUCCESS(status) ? -EINVAL : 0;
> +}
> +
> +static int pcc_mbox_probe(struct platform_device *pdev)
> +{
> + int ret = 0;
> +
> + pcc_mbox_ctrl.dev = &pdev->dev;
> +
> + pr_info("Registering PCC driver as Mailbox controller\n");
> + ret = mbox_controller_register(&pcc_mbox_ctrl);
> +
> + if (ret) {
> + pr_err("Err registering PCC as Mailbox controller: %d\n", ret);
> + ret = -ENODEV;
> + }
> +
> + return ret;
> +}
> +
> +struct platform_driver pcc_mbox_driver = {
> + .probe = pcc_mbox_probe,
> + .driver = {
> + .name = "PCCT",
> + .owner = THIS_MODULE,
> + },
> +};
> +
> +static int __init pcc_init(void)
> +{
> + int ret;
> + struct platform_device *pcc_pdev;
> +
> + if (acpi_disabled)
> + return -ENODEV;
> +
> + /* Check if PCC support is available. */
> + ret = acpi_pcc_probe();
> +
> + if (ret) {
> + pr_debug("ACPI PCC probe failed.\n");
> + return -ENODEV;
> + }
> +
> + pcc_pdev = platform_create_bundle(&pcc_mbox_driver,
> + pcc_mbox_probe, NULL, 0, NULL, 0);
> +
> + if (!pcc_pdev) {
> + pr_err("Err creating PCC platform bundle\n");
> + return -ENODEV;
> + }
> +
> + return 0;
> +}
> +
> +device_initcall(pcc_init);
> --
> 1.9.1
>
--
To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
