linux-stable/drivers/mailbox/pcc.c

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 Based on 3 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 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 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 [author] [kishon] [vijay] [abraham] [i] [kishon]@[ti] [com] 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 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 [author] [graeme] [gregory] [gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i] [kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema] [hk] [hemahk]@[ti] [com] 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1105 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-27 06:55:06 +00:00
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2014 Linaro Ltd.
* Author: Ashwin Chaugule <ashwin.chaugule@linaro.org>
*
* PCC (Platform Communication Channel) is defined in the ACPI 5.0+
* specification. It is a mailbox like mechanism to allow clients
* such as CPPC (Collaborative Processor Performance Control), RAS
* (Reliability, Availability and Serviceability) and MPST (Memory
* Node Power State Table) to talk to the platform (e.g. BMC) through
* shared memory regions as defined in the PCC table entries. The PCC
* specification supports a Doorbell mechanism for the PCC clients
* to notify the platform about new data. This Doorbell information
* is also specified in each PCC table entry.
*
* Typical high level flow of operation is:
*
* PCC Reads:
* * Client tries to acquire a channel lock.
* * After it is acquired it writes READ cmd in communication region cmd
* address.
* * Client issues mbox_send_message() which rings the PCC doorbell
* for its PCC channel.
* * If command completes, then client has control over channel and
* it can proceed with its reads.
* * Client releases lock.
*
* PCC Writes:
* * Client tries to acquire channel lock.
* * Client writes to its communication region after it acquires a
* channel lock.
* * Client writes WRITE cmd in communication region cmd address.
* * Client issues mbox_send_message() which rings the PCC doorbell
* for its PCC channel.
* * If command completes, then writes have succeeded and it can release
* the channel lock.
*
* There is a Nominal latency defined for each channel which indicates
* how long to wait until a command completes. If command is not complete
* the client needs to retry or assume failure.
*
* For more details about PCC, please see the ACPI specification from
* http://www.uefi.org/ACPIv5.1 Section 14.
*
* This file implements PCC as a Mailbox controller and allows for PCC
* clients to be implemented as its Mailbox Client Channels.
*/
#include <linux/acpi.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/log2.h>
#include <linux/platform_device.h>
#include <linux/mailbox_controller.h>
#include <linux/mailbox_client.h>
#include <linux/io-64-nonatomic-lo-hi.h>
mailbox: PCC: Fix lockdep warning when request PCC channel This patch fixes the lockdep warning below DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags)) ------------[ cut here ]------------ WARNING: CPU: 1 PID: 1 at linux-next/kernel/locking/lockdep.c:2876 lockdep_trace_alloc+0xe0/0xf0 Modules linked in: CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.8.0-11756-g86c5152 #46 ... Call trace: Exception stack(0xffff8007da837890 to 0xffff8007da8379c0) 7880: ffff8007da834000 0001000000000000 78a0: ffff8007da837a70 ffff0000081111a0 00000000600000c5 000000000000003d 78c0: 9374bc6a7f3c7832 0000000000381878 ffff000009db7ab8 000000000000002f 78e0: ffff00000811aabc ffff000008be2548 ffff8007da837990 ffff00000811adf8 7900: ffff8007da834000 00000000024080c0 00000000000000c0 ffff000009021000 7920: 0000000000000000 0000000000000000 ffff000008c8f7c8 ffff8007da579810 7940: 000000000000002f ffff8007da858000 0000000000000000 0000000000000001 7960: 0000000000000001 0000000000000000 ffff00000811a468 0000000000000002 7980: 656c62617369645f 0000000000038187 00000000000000ee ffff8007da837850 79a0: ffff000009db50c0 ffff000009db569d 0000000000000006 ffff000089db568f [<ffff0000081111a0>] lockdep_trace_alloc+0xe0/0xf0 [<ffff0000081f4950>] __kmalloc_track_caller+0x50/0x250 [<ffff00000857c088>] devres_alloc_node+0x28/0x60 [<ffff0000081220e0>] devm_request_threaded_irq+0x50/0xe0 [<ffff0000087e6220>] pcc_mbox_request_channel+0x110/0x170 [<ffff0000084b2660>] acpi_cppc_processor_probe+0x264/0x414 [<ffff0000084ae9f4>] __acpi_processor_start+0x28/0xa0 [<ffff0000084aeab0>] acpi_processor_start+0x44/0x54 [<ffff00000857897c>] driver_probe_device+0x1fc/0x2b0 [<ffff000008578ae4>] __driver_attach+0xb4/0xc0 [<ffff00000857683c>] bus_for_each_dev+0x5c/0xa0 [<ffff000008578110>] driver_attach+0x20/0x30 [<ffff000008577c20>] bus_add_driver+0x110/0x230 [<ffff000008579320>] driver_register+0x60/0x100 [<ffff000008d478b8>] acpi_processor_driver_init+0x2c/0xb0 [<ffff000008083168>] do_one_initcall+0x38/0x130 [<ffff000008d20d6c>] kernel_init_freeable+0x210/0x2b4 [<ffff000008945d90>] kernel_init+0x10/0x110 [<ffff000008082e80>] ret_from_fork+0x10/0x50 It's because the spinlock inside pcc_mbox_request_channel() is kept too long. This patch releases spinlock before request_irq() and free_irq() to fix this issue as spinlock is only needed to protect the channel data. Signed-off-by: Hoan Tran <hotran@apm.com> Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-14 19:19:02 +00:00
#include <acpi/pcc.h>
#include "mailbox.h"
#define MBOX_IRQ_NAME "pcc-mbox"
/**
* struct pcc_chan_reg - PCC register bundle
*
* @vaddr: cached virtual address for this register
* @gas: pointer to the generic address structure for this register
* @preserve_mask: bitmask to preserve when writing to this register
* @set_mask: bitmask to set when writing to this register
* @status_mask: bitmask to determine and/or update the status for this register
*/
struct pcc_chan_reg {
void __iomem *vaddr;
struct acpi_generic_address *gas;
u64 preserve_mask;
u64 set_mask;
u64 status_mask;
};
/**
* struct pcc_chan_info - PCC channel specific information
*
* @chan: PCC channel information with Shared Memory Region info
* @db: PCC register bundle for the doorbell register
* @plat_irq_ack: PCC register bundle for the platform interrupt acknowledge
* register
* @cmd_complete: PCC register bundle for the command complete check register
* @cmd_update: PCC register bundle for the command complete update register
* @error: PCC register bundle for the error status register
* @plat_irq: platform interrupt
*/
struct pcc_chan_info {
struct pcc_mbox_chan chan;
struct pcc_chan_reg db;
struct pcc_chan_reg plat_irq_ack;
struct pcc_chan_reg cmd_complete;
struct pcc_chan_reg cmd_update;
struct pcc_chan_reg error;
int plat_irq;
};
#define to_pcc_chan_info(c) container_of(c, struct pcc_chan_info, chan)
static struct pcc_chan_info *chan_info;
static int pcc_chan_count;
/*
* PCC can be used with perf critical drivers such as CPPC
* So it makes sense to locally cache the virtual address and
* use it to read/write to PCC registers such as doorbell register
*
* The below read_register and write_registers are used to read and
* write from perf critical registers such as PCC doorbell register
*/
static void read_register(void __iomem *vaddr, u64 *val, unsigned int bit_width)
{
switch (bit_width) {
case 8:
*val = readb(vaddr);
break;
case 16:
*val = readw(vaddr);
break;
case 32:
*val = readl(vaddr);
break;
case 64:
*val = readq(vaddr);
break;
}
}
static void write_register(void __iomem *vaddr, u64 val, unsigned int bit_width)
{
switch (bit_width) {
case 8:
writeb(val, vaddr);
break;
case 16:
writew(val, vaddr);
break;
case 32:
writel(val, vaddr);
break;
case 64:
writeq(val, vaddr);
break;
}
}
static int pcc_chan_reg_read(struct pcc_chan_reg *reg, u64 *val)
{
int ret = 0;
if (!reg->gas) {
*val = 0;
return 0;
}
if (reg->vaddr)
read_register(reg->vaddr, val, reg->gas->bit_width);
else
ret = acpi_read(val, reg->gas);
return ret;
}
static int pcc_chan_reg_write(struct pcc_chan_reg *reg, u64 val)
{
int ret = 0;
if (!reg->gas)
return 0;
if (reg->vaddr)
write_register(reg->vaddr, val, reg->gas->bit_width);
else
ret = acpi_write(val, reg->gas);
return ret;
}
static int pcc_chan_reg_read_modify_write(struct pcc_chan_reg *reg)
{
int ret = 0;
u64 val;
ret = pcc_chan_reg_read(reg, &val);
if (ret)
return ret;
val &= reg->preserve_mask;
val |= reg->set_mask;
return pcc_chan_reg_write(reg, val);
}
/**
* pcc_map_interrupt - Map a PCC subspace GSI to a linux IRQ number
* @interrupt: GSI number.
* @flags: interrupt flags
*
* Returns: a valid linux IRQ number on success
* 0 or -EINVAL on failure
*/
static int pcc_map_interrupt(u32 interrupt, u32 flags)
{
int trigger, polarity;
if (!interrupt)
return 0;
trigger = (flags & ACPI_PCCT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE
: ACPI_LEVEL_SENSITIVE;
polarity = (flags & ACPI_PCCT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW
: ACPI_ACTIVE_HIGH;
return acpi_register_gsi(NULL, interrupt, trigger, polarity);
}
/**
* pcc_mbox_irq - PCC mailbox interrupt handler
* @irq: interrupt number
* @p: data/cookie passed from the caller to identify the channel
*
* Returns: IRQ_HANDLED if interrupt is handled or IRQ_NONE if not
*/
static irqreturn_t pcc_mbox_irq(int irq, void *p)
{
struct pcc_chan_info *pchan;
struct mbox_chan *chan = p;
u64 val;
int ret;
pchan = chan->con_priv;
ret = pcc_chan_reg_read(&pchan->cmd_complete, &val);
if (ret)
return IRQ_NONE;
if (val) { /* Ensure GAS exists and value is non-zero */
val &= pchan->cmd_complete.status_mask;
if (!val)
return IRQ_NONE;
}
ret = pcc_chan_reg_read(&pchan->error, &val);
if (ret)
return IRQ_NONE;
val &= pchan->error.status_mask;
if (val) {
val &= ~pchan->error.status_mask;
pcc_chan_reg_write(&pchan->error, val);
return IRQ_NONE;
}
if (pcc_chan_reg_read_modify_write(&pchan->plat_irq_ack))
return IRQ_NONE;
mbox_chan_received_data(chan, NULL);
return IRQ_HANDLED;
}
/**
* pcc_mbox_request_channel - PCC clients call this function to
* request a pointer to their PCC subspace, from which they
* can get the details of communicating with the remote.
* @cl: Pointer to Mailbox client, so we know where to bind the
* Channel.
* @subspace_id: The PCC Subspace index as parsed in the PCC client
* ACPI package. This is used to lookup the array of PCC
* subspaces as parsed by the PCC Mailbox controller.
*
* Return: Pointer to the PCC Mailbox Channel if successful or ERR_PTR.
*/
struct pcc_mbox_chan *
pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id)
{
struct pcc_chan_info *pchan;
struct mbox_chan *chan;
struct device *dev;
unsigned long flags;
if (subspace_id < 0 || subspace_id >= pcc_chan_count)
return ERR_PTR(-ENOENT);
pchan = chan_info + subspace_id;
chan = pchan->chan.mchan;
if (IS_ERR(chan) || chan->cl) {
pr_err("Channel not found for idx: %d\n", subspace_id);
return ERR_PTR(-EBUSY);
}
dev = chan->mbox->dev;
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;
mailbox: PCC: Fix lockdep warning when request PCC channel This patch fixes the lockdep warning below DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags)) ------------[ cut here ]------------ WARNING: CPU: 1 PID: 1 at linux-next/kernel/locking/lockdep.c:2876 lockdep_trace_alloc+0xe0/0xf0 Modules linked in: CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.8.0-11756-g86c5152 #46 ... Call trace: Exception stack(0xffff8007da837890 to 0xffff8007da8379c0) 7880: ffff8007da834000 0001000000000000 78a0: ffff8007da837a70 ffff0000081111a0 00000000600000c5 000000000000003d 78c0: 9374bc6a7f3c7832 0000000000381878 ffff000009db7ab8 000000000000002f 78e0: ffff00000811aabc ffff000008be2548 ffff8007da837990 ffff00000811adf8 7900: ffff8007da834000 00000000024080c0 00000000000000c0 ffff000009021000 7920: 0000000000000000 0000000000000000 ffff000008c8f7c8 ffff8007da579810 7940: 000000000000002f ffff8007da858000 0000000000000000 0000000000000001 7960: 0000000000000001 0000000000000000 ffff00000811a468 0000000000000002 7980: 656c62617369645f 0000000000038187 00000000000000ee ffff8007da837850 79a0: ffff000009db50c0 ffff000009db569d 0000000000000006 ffff000089db568f [<ffff0000081111a0>] lockdep_trace_alloc+0xe0/0xf0 [<ffff0000081f4950>] __kmalloc_track_caller+0x50/0x250 [<ffff00000857c088>] devres_alloc_node+0x28/0x60 [<ffff0000081220e0>] devm_request_threaded_irq+0x50/0xe0 [<ffff0000087e6220>] pcc_mbox_request_channel+0x110/0x170 [<ffff0000084b2660>] acpi_cppc_processor_probe+0x264/0x414 [<ffff0000084ae9f4>] __acpi_processor_start+0x28/0xa0 [<ffff0000084aeab0>] acpi_processor_start+0x44/0x54 [<ffff00000857897c>] driver_probe_device+0x1fc/0x2b0 [<ffff000008578ae4>] __driver_attach+0xb4/0xc0 [<ffff00000857683c>] bus_for_each_dev+0x5c/0xa0 [<ffff000008578110>] driver_attach+0x20/0x30 [<ffff000008577c20>] bus_add_driver+0x110/0x230 [<ffff000008579320>] driver_register+0x60/0x100 [<ffff000008d478b8>] acpi_processor_driver_init+0x2c/0xb0 [<ffff000008083168>] do_one_initcall+0x38/0x130 [<ffff000008d20d6c>] kernel_init_freeable+0x210/0x2b4 [<ffff000008945d90>] kernel_init+0x10/0x110 [<ffff000008082e80>] ret_from_fork+0x10/0x50 It's because the spinlock inside pcc_mbox_request_channel() is kept too long. This patch releases spinlock before request_irq() and free_irq() to fix this issue as spinlock is only needed to protect the channel data. Signed-off-by: Hoan Tran <hotran@apm.com> Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-14 19:19:02 +00:00
spin_unlock_irqrestore(&chan->lock, flags);
if (pchan->plat_irq > 0) {
int rc;
rc = devm_request_irq(dev, pchan->plat_irq, pcc_mbox_irq, 0,
MBOX_IRQ_NAME, chan);
if (unlikely(rc)) {
dev_err(dev, "failed to register PCC interrupt %d\n",
pchan->plat_irq);
pcc_mbox_free_channel(&pchan->chan);
return ERR_PTR(rc);
}
}
return &pchan->chan;
}
EXPORT_SYMBOL_GPL(pcc_mbox_request_channel);
/**
* pcc_mbox_free_channel - Clients call this to free their Channel.
*
* @pchan: Pointer to the PCC mailbox channel as returned by
* pcc_mbox_request_channel()
*/
void pcc_mbox_free_channel(struct pcc_mbox_chan *pchan)
{
struct pcc_chan_info *pchan_info = to_pcc_chan_info(pchan);
struct mbox_chan *chan = pchan->mchan;
unsigned long flags;
if (!chan || !chan->cl)
return;
if (pchan_info->plat_irq > 0)
devm_free_irq(chan->mbox->dev, pchan_info->plat_irq, chan);
mailbox: PCC: Fix lockdep warning when request PCC channel This patch fixes the lockdep warning below DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags)) ------------[ cut here ]------------ WARNING: CPU: 1 PID: 1 at linux-next/kernel/locking/lockdep.c:2876 lockdep_trace_alloc+0xe0/0xf0 Modules linked in: CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.8.0-11756-g86c5152 #46 ... Call trace: Exception stack(0xffff8007da837890 to 0xffff8007da8379c0) 7880: ffff8007da834000 0001000000000000 78a0: ffff8007da837a70 ffff0000081111a0 00000000600000c5 000000000000003d 78c0: 9374bc6a7f3c7832 0000000000381878 ffff000009db7ab8 000000000000002f 78e0: ffff00000811aabc ffff000008be2548 ffff8007da837990 ffff00000811adf8 7900: ffff8007da834000 00000000024080c0 00000000000000c0 ffff000009021000 7920: 0000000000000000 0000000000000000 ffff000008c8f7c8 ffff8007da579810 7940: 000000000000002f ffff8007da858000 0000000000000000 0000000000000001 7960: 0000000000000001 0000000000000000 ffff00000811a468 0000000000000002 7980: 656c62617369645f 0000000000038187 00000000000000ee ffff8007da837850 79a0: ffff000009db50c0 ffff000009db569d 0000000000000006 ffff000089db568f [<ffff0000081111a0>] lockdep_trace_alloc+0xe0/0xf0 [<ffff0000081f4950>] __kmalloc_track_caller+0x50/0x250 [<ffff00000857c088>] devres_alloc_node+0x28/0x60 [<ffff0000081220e0>] devm_request_threaded_irq+0x50/0xe0 [<ffff0000087e6220>] pcc_mbox_request_channel+0x110/0x170 [<ffff0000084b2660>] acpi_cppc_processor_probe+0x264/0x414 [<ffff0000084ae9f4>] __acpi_processor_start+0x28/0xa0 [<ffff0000084aeab0>] acpi_processor_start+0x44/0x54 [<ffff00000857897c>] driver_probe_device+0x1fc/0x2b0 [<ffff000008578ae4>] __driver_attach+0xb4/0xc0 [<ffff00000857683c>] bus_for_each_dev+0x5c/0xa0 [<ffff000008578110>] driver_attach+0x20/0x30 [<ffff000008577c20>] bus_add_driver+0x110/0x230 [<ffff000008579320>] driver_register+0x60/0x100 [<ffff000008d478b8>] acpi_processor_driver_init+0x2c/0xb0 [<ffff000008083168>] do_one_initcall+0x38/0x130 [<ffff000008d20d6c>] kernel_init_freeable+0x210/0x2b4 [<ffff000008945d90>] kernel_init+0x10/0x110 [<ffff000008082e80>] ret_from_fork+0x10/0x50 It's because the spinlock inside pcc_mbox_request_channel() is kept too long. This patch releases spinlock before request_irq() and free_irq() to fix this issue as spinlock is only needed to protect the channel data. Signed-off-by: Hoan Tran <hotran@apm.com> Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-14 19:19:02 +00:00
spin_lock_irqsave(&chan->lock, flags);
chan->cl = NULL;
chan->active_req = NULL;
if (chan->txdone_method == TXDONE_BY_ACK)
chan->txdone_method = TXDONE_BY_POLL;
spin_unlock_irqrestore(&chan->lock, flags);
}
EXPORT_SYMBOL_GPL(pcc_mbox_free_channel);
/**
* pcc_send_data - Called from Mailbox Controller code. Used
* here only to ring the channel doorbell. The PCC client
* specific read/write is done in the client driver in
* order to maintain atomicity over PCC channel once
* OS has control over it. See above for flow of operations.
* @chan: Pointer to Mailbox channel over which to send data.
* @data: Client specific data written over channel. Used here
* only for debug after PCC transaction completes.
*
* Return: Err if something failed else 0 for success.
*/
static int pcc_send_data(struct mbox_chan *chan, void *data)
{
int ret;
struct pcc_chan_info *pchan = chan->con_priv;
ret = pcc_chan_reg_read_modify_write(&pchan->cmd_update);
if (ret)
return ret;
return pcc_chan_reg_read_modify_write(&pchan->db);
}
static const struct mbox_chan_ops pcc_chan_ops = {
.send_data = pcc_send_data,
};
/**
* parse_pcc_subspace - Count PCC subspaces defined
* @header: Pointer to the ACPI subtable header under the PCCT.
* @end: End of subtable entry.
*
mailbox: PCC: erroneous error message when parsing ACPI PCCT There have been multiple reports of the following error message: [ 0.068293] Error parsing PCC subspaces from PCCT This error message is not correct. In multiple cases examined, the PCCT (Platform Communications Channel Table) concerned is actually properly constructed; the problem is that acpi_pcc_probe() which reads the PCCT is making the assumption that the only valid PCCT is one that contains subtables of one of two types: ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE or ACPI_PCCT_TYPE_HW_REDUCED_TYPE2. The number of subtables of these types are counted and as long as there is at least one of the desired types, the acpi_pcc_probe() succeeds. When no subtables of these types are found, regardless of whether or not any other subtable types are present, the error mentioned above is reported. In the cases reported to me personally, the PCCT contains exactly one subtable of type ACPI_PCCT_TYPE_GENERIC_SUBSPACE. The function acpi_pcc_probe() does not count it as a valid subtable, so believes there to be no valid subtables, and hence outputs the error message. An example of the PCCT being reported as erroneous yet perfectly fine is the following: Signature : "PCCT" Table Length : 0000006E Revision : 05 Checksum : A9 Oem ID : "XXXXXX" Oem Table ID : "XXXXX " Oem Revision : 00002280 Asl Compiler ID : "XXXX" Asl Compiler Revision : 00000002 Flags (decoded below) : 00000001 Platform : 1 Reserved : 0000000000000000 Subtable Type : 00 [Generic Communications Subspace] Length : 3E Reserved : 000000000000 Base Address : 00000000DCE43018 Address Length : 0000000000001000 Doorbell Register : [Generic Address Structure] Space ID : 01 [SystemIO] Bit Width : 08 Bit Offset : 00 Encoded Access Width : 01 [Byte Access:8] Address : 0000000000001842 Preserve Mask : 00000000000000FD Write Mask : 0000000000000002 Command Latency : 00001388 Maximum Access Rate : 00000000 Minimum Turnaround Time : 0000 To fix this, we count up all of the possible subtable types for the PCCT, and only report an error when there are none (which could mean either no subtables, or no valid subtables), or there are too many. We also change the logic so that if there is a valid subtable, we do try to initialize it per the PCCT subtable contents. This is a change in functionality; previously, the probe would have returned right after the error message and would not have tried to use any other subtable definition. Tested on my personal laptop which showed the error previously; the error message no longer appears and the laptop appears to operate normally. Signed-off-by: Al Stone <ahs3@redhat.com> Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-05-16 22:01:41 +00:00
* Return: If we find a PCC subspace entry of a valid type, return 0.
* Otherwise, return -EINVAL.
*
* This gets called for each entry in the PCC table.
*/
static int parse_pcc_subspace(union acpi_subtable_headers *header,
const unsigned long end)
{
mailbox: PCC: erroneous error message when parsing ACPI PCCT There have been multiple reports of the following error message: [ 0.068293] Error parsing PCC subspaces from PCCT This error message is not correct. In multiple cases examined, the PCCT (Platform Communications Channel Table) concerned is actually properly constructed; the problem is that acpi_pcc_probe() which reads the PCCT is making the assumption that the only valid PCCT is one that contains subtables of one of two types: ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE or ACPI_PCCT_TYPE_HW_REDUCED_TYPE2. The number of subtables of these types are counted and as long as there is at least one of the desired types, the acpi_pcc_probe() succeeds. When no subtables of these types are found, regardless of whether or not any other subtable types are present, the error mentioned above is reported. In the cases reported to me personally, the PCCT contains exactly one subtable of type ACPI_PCCT_TYPE_GENERIC_SUBSPACE. The function acpi_pcc_probe() does not count it as a valid subtable, so believes there to be no valid subtables, and hence outputs the error message. An example of the PCCT being reported as erroneous yet perfectly fine is the following: Signature : "PCCT" Table Length : 0000006E Revision : 05 Checksum : A9 Oem ID : "XXXXXX" Oem Table ID : "XXXXX " Oem Revision : 00002280 Asl Compiler ID : "XXXX" Asl Compiler Revision : 00000002 Flags (decoded below) : 00000001 Platform : 1 Reserved : 0000000000000000 Subtable Type : 00 [Generic Communications Subspace] Length : 3E Reserved : 000000000000 Base Address : 00000000DCE43018 Address Length : 0000000000001000 Doorbell Register : [Generic Address Structure] Space ID : 01 [SystemIO] Bit Width : 08 Bit Offset : 00 Encoded Access Width : 01 [Byte Access:8] Address : 0000000000001842 Preserve Mask : 00000000000000FD Write Mask : 0000000000000002 Command Latency : 00001388 Maximum Access Rate : 00000000 Minimum Turnaround Time : 0000 To fix this, we count up all of the possible subtable types for the PCCT, and only report an error when there are none (which could mean either no subtables, or no valid subtables), or there are too many. We also change the logic so that if there is a valid subtable, we do try to initialize it per the PCCT subtable contents. This is a change in functionality; previously, the probe would have returned right after the error message and would not have tried to use any other subtable definition. Tested on my personal laptop which showed the error previously; the error message no longer appears and the laptop appears to operate normally. Signed-off-by: Al Stone <ahs3@redhat.com> Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-05-16 22:01:41 +00:00
struct acpi_pcct_subspace *ss = (struct acpi_pcct_subspace *) header;
mailbox: PCC: erroneous error message when parsing ACPI PCCT There have been multiple reports of the following error message: [ 0.068293] Error parsing PCC subspaces from PCCT This error message is not correct. In multiple cases examined, the PCCT (Platform Communications Channel Table) concerned is actually properly constructed; the problem is that acpi_pcc_probe() which reads the PCCT is making the assumption that the only valid PCCT is one that contains subtables of one of two types: ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE or ACPI_PCCT_TYPE_HW_REDUCED_TYPE2. The number of subtables of these types are counted and as long as there is at least one of the desired types, the acpi_pcc_probe() succeeds. When no subtables of these types are found, regardless of whether or not any other subtable types are present, the error mentioned above is reported. In the cases reported to me personally, the PCCT contains exactly one subtable of type ACPI_PCCT_TYPE_GENERIC_SUBSPACE. The function acpi_pcc_probe() does not count it as a valid subtable, so believes there to be no valid subtables, and hence outputs the error message. An example of the PCCT being reported as erroneous yet perfectly fine is the following: Signature : "PCCT" Table Length : 0000006E Revision : 05 Checksum : A9 Oem ID : "XXXXXX" Oem Table ID : "XXXXX " Oem Revision : 00002280 Asl Compiler ID : "XXXX" Asl Compiler Revision : 00000002 Flags (decoded below) : 00000001 Platform : 1 Reserved : 0000000000000000 Subtable Type : 00 [Generic Communications Subspace] Length : 3E Reserved : 000000000000 Base Address : 00000000DCE43018 Address Length : 0000000000001000 Doorbell Register : [Generic Address Structure] Space ID : 01 [SystemIO] Bit Width : 08 Bit Offset : 00 Encoded Access Width : 01 [Byte Access:8] Address : 0000000000001842 Preserve Mask : 00000000000000FD Write Mask : 0000000000000002 Command Latency : 00001388 Maximum Access Rate : 00000000 Minimum Turnaround Time : 0000 To fix this, we count up all of the possible subtable types for the PCCT, and only report an error when there are none (which could mean either no subtables, or no valid subtables), or there are too many. We also change the logic so that if there is a valid subtable, we do try to initialize it per the PCCT subtable contents. This is a change in functionality; previously, the probe would have returned right after the error message and would not have tried to use any other subtable definition. Tested on my personal laptop which showed the error previously; the error message no longer appears and the laptop appears to operate normally. Signed-off-by: Al Stone <ahs3@redhat.com> Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-05-16 22:01:41 +00:00
if (ss->header.type < ACPI_PCCT_TYPE_RESERVED)
return 0;
mailbox: PCC: erroneous error message when parsing ACPI PCCT There have been multiple reports of the following error message: [ 0.068293] Error parsing PCC subspaces from PCCT This error message is not correct. In multiple cases examined, the PCCT (Platform Communications Channel Table) concerned is actually properly constructed; the problem is that acpi_pcc_probe() which reads the PCCT is making the assumption that the only valid PCCT is one that contains subtables of one of two types: ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE or ACPI_PCCT_TYPE_HW_REDUCED_TYPE2. The number of subtables of these types are counted and as long as there is at least one of the desired types, the acpi_pcc_probe() succeeds. When no subtables of these types are found, regardless of whether or not any other subtable types are present, the error mentioned above is reported. In the cases reported to me personally, the PCCT contains exactly one subtable of type ACPI_PCCT_TYPE_GENERIC_SUBSPACE. The function acpi_pcc_probe() does not count it as a valid subtable, so believes there to be no valid subtables, and hence outputs the error message. An example of the PCCT being reported as erroneous yet perfectly fine is the following: Signature : "PCCT" Table Length : 0000006E Revision : 05 Checksum : A9 Oem ID : "XXXXXX" Oem Table ID : "XXXXX " Oem Revision : 00002280 Asl Compiler ID : "XXXX" Asl Compiler Revision : 00000002 Flags (decoded below) : 00000001 Platform : 1 Reserved : 0000000000000000 Subtable Type : 00 [Generic Communications Subspace] Length : 3E Reserved : 000000000000 Base Address : 00000000DCE43018 Address Length : 0000000000001000 Doorbell Register : [Generic Address Structure] Space ID : 01 [SystemIO] Bit Width : 08 Bit Offset : 00 Encoded Access Width : 01 [Byte Access:8] Address : 0000000000001842 Preserve Mask : 00000000000000FD Write Mask : 0000000000000002 Command Latency : 00001388 Maximum Access Rate : 00000000 Minimum Turnaround Time : 0000 To fix this, we count up all of the possible subtable types for the PCCT, and only report an error when there are none (which could mean either no subtables, or no valid subtables), or there are too many. We also change the logic so that if there is a valid subtable, we do try to initialize it per the PCCT subtable contents. This is a change in functionality; previously, the probe would have returned right after the error message and would not have tried to use any other subtable definition. Tested on my personal laptop which showed the error previously; the error message no longer appears and the laptop appears to operate normally. Signed-off-by: Al Stone <ahs3@redhat.com> Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-05-16 22:01:41 +00:00
return -EINVAL;
}
static int
pcc_chan_reg_init(struct pcc_chan_reg *reg, struct acpi_generic_address *gas,
u64 preserve_mask, u64 set_mask, u64 status_mask, char *name)
{
if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
if (!(gas->bit_width >= 8 && gas->bit_width <= 64 &&
is_power_of_2(gas->bit_width))) {
pr_err("Error: Cannot access register of %u bit width",
gas->bit_width);
return -EFAULT;
}
reg->vaddr = acpi_os_ioremap(gas->address, gas->bit_width / 8);
if (!reg->vaddr) {
pr_err("Failed to ioremap PCC %s register\n", name);
return -ENOMEM;
}
}
reg->gas = gas;
reg->preserve_mask = preserve_mask;
reg->set_mask = set_mask;
reg->status_mask = status_mask;
return 0;
}
/**
* pcc_parse_subspace_irq - Parse the PCC IRQ and PCC ACK register
*
* @pchan: Pointer to the PCC channel info structure.
* @pcct_entry: Pointer to the ACPI subtable header.
*
* Return: 0 for Success, else errno.
*
* There should be one entry per PCC channel. This gets called for each
* entry in the PCC table. This uses PCCY Type1 structure for all applicable
* types(Type 1-4) to fetch irq
*/
static int pcc_parse_subspace_irq(struct pcc_chan_info *pchan,
struct acpi_subtable_header *pcct_entry)
{
int ret = 0;
struct acpi_pcct_hw_reduced *pcct_ss;
if (pcct_entry->type < ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE ||
pcct_entry->type > ACPI_PCCT_TYPE_EXT_PCC_SLAVE_SUBSPACE)
return 0;
pcct_ss = (struct acpi_pcct_hw_reduced *)pcct_entry;
pchan->plat_irq = pcc_map_interrupt(pcct_ss->platform_interrupt,
(u32)pcct_ss->flags);
if (pchan->plat_irq <= 0) {
pr_err("PCC GSI %d not registered\n",
pcct_ss->platform_interrupt);
return -EINVAL;
}
if (pcct_ss->header.type == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) {
struct acpi_pcct_hw_reduced_type2 *pcct2_ss = (void *)pcct_ss;
ret = pcc_chan_reg_init(&pchan->plat_irq_ack,
&pcct2_ss->platform_ack_register,
pcct2_ss->ack_preserve_mask,
pcct2_ss->ack_write_mask, 0,
"PLAT IRQ ACK");
} else if (pcct_ss->header.type == ACPI_PCCT_TYPE_EXT_PCC_MASTER_SUBSPACE ||
pcct_ss->header.type == ACPI_PCCT_TYPE_EXT_PCC_SLAVE_SUBSPACE) {
struct acpi_pcct_ext_pcc_master *pcct_ext = (void *)pcct_ss;
ret = pcc_chan_reg_init(&pchan->plat_irq_ack,
&pcct_ext->platform_ack_register,
pcct_ext->ack_preserve_mask,
pcct_ext->ack_set_mask, 0,
"PLAT IRQ ACK");
}
return ret;
}
/**
* pcc_parse_subspace_db_reg - Parse the PCC doorbell register
*
* @pchan: Pointer to the PCC channel info structure.
* @pcct_entry: Pointer to the ACPI subtable header.
*
* Return: 0 for Success, else errno.
*/
static int pcc_parse_subspace_db_reg(struct pcc_chan_info *pchan,
struct acpi_subtable_header *pcct_entry)
{
int ret = 0;
if (pcct_entry->type <= ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) {
struct acpi_pcct_subspace *pcct_ss;
pcct_ss = (struct acpi_pcct_subspace *)pcct_entry;
ret = pcc_chan_reg_init(&pchan->db,
&pcct_ss->doorbell_register,
pcct_ss->preserve_mask,
pcct_ss->write_mask, 0, "Doorbell");
} else {
struct acpi_pcct_ext_pcc_master *pcct_ext;
pcct_ext = (struct acpi_pcct_ext_pcc_master *)pcct_entry;
ret = pcc_chan_reg_init(&pchan->db,
&pcct_ext->doorbell_register,
pcct_ext->preserve_mask,
pcct_ext->write_mask, 0, "Doorbell");
if (ret)
return ret;
ret = pcc_chan_reg_init(&pchan->cmd_complete,
&pcct_ext->cmd_complete_register,
0, 0, pcct_ext->cmd_complete_mask,
"Command Complete Check");
if (ret)
return ret;
ret = pcc_chan_reg_init(&pchan->cmd_update,
&pcct_ext->cmd_update_register,
pcct_ext->cmd_update_preserve_mask,
pcct_ext->cmd_update_set_mask, 0,
"Command Complete Update");
if (ret)
return ret;
ret = pcc_chan_reg_init(&pchan->error,
&pcct_ext->error_status_register,
0, 0, pcct_ext->error_status_mask,
"Error Status");
}
return ret;
}
/**
* pcc_parse_subspace_shmem - Parse the PCC Shared Memory Region information
*
* @pchan: Pointer to the PCC channel info structure.
* @pcct_entry: Pointer to the ACPI subtable header.
*
*/
static void pcc_parse_subspace_shmem(struct pcc_chan_info *pchan,
struct acpi_subtable_header *pcct_entry)
{
if (pcct_entry->type <= ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) {
struct acpi_pcct_subspace *pcct_ss =
(struct acpi_pcct_subspace *)pcct_entry;
pchan->chan.shmem_base_addr = pcct_ss->base_address;
pchan->chan.shmem_size = pcct_ss->length;
pchan->chan.latency = pcct_ss->latency;
pchan->chan.max_access_rate = pcct_ss->max_access_rate;
pchan->chan.min_turnaround_time = pcct_ss->min_turnaround_time;
} else {
struct acpi_pcct_ext_pcc_master *pcct_ext =
(struct acpi_pcct_ext_pcc_master *)pcct_entry;
pchan->chan.shmem_base_addr = pcct_ext->base_address;
pchan->chan.shmem_size = pcct_ext->length;
pchan->chan.latency = pcct_ext->latency;
pchan->chan.max_access_rate = pcct_ext->max_access_rate;
pchan->chan.min_turnaround_time = pcct_ext->min_turnaround_time;
}
}
/**
* acpi_pcc_probe - Parse the ACPI tree for the PCCT.
*
* Return: 0 for Success, else errno.
*/
static int __init acpi_pcc_probe(void)
{
int count, i, rc = 0;
acpi_status status;
struct acpi_table_header *pcct_tbl;
mailbox: PCC: erroneous error message when parsing ACPI PCCT There have been multiple reports of the following error message: [ 0.068293] Error parsing PCC subspaces from PCCT This error message is not correct. In multiple cases examined, the PCCT (Platform Communications Channel Table) concerned is actually properly constructed; the problem is that acpi_pcc_probe() which reads the PCCT is making the assumption that the only valid PCCT is one that contains subtables of one of two types: ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE or ACPI_PCCT_TYPE_HW_REDUCED_TYPE2. The number of subtables of these types are counted and as long as there is at least one of the desired types, the acpi_pcc_probe() succeeds. When no subtables of these types are found, regardless of whether or not any other subtable types are present, the error mentioned above is reported. In the cases reported to me personally, the PCCT contains exactly one subtable of type ACPI_PCCT_TYPE_GENERIC_SUBSPACE. The function acpi_pcc_probe() does not count it as a valid subtable, so believes there to be no valid subtables, and hence outputs the error message. An example of the PCCT being reported as erroneous yet perfectly fine is the following: Signature : "PCCT" Table Length : 0000006E Revision : 05 Checksum : A9 Oem ID : "XXXXXX" Oem Table ID : "XXXXX " Oem Revision : 00002280 Asl Compiler ID : "XXXX" Asl Compiler Revision : 00000002 Flags (decoded below) : 00000001 Platform : 1 Reserved : 0000000000000000 Subtable Type : 00 [Generic Communications Subspace] Length : 3E Reserved : 000000000000 Base Address : 00000000DCE43018 Address Length : 0000000000001000 Doorbell Register : [Generic Address Structure] Space ID : 01 [SystemIO] Bit Width : 08 Bit Offset : 00 Encoded Access Width : 01 [Byte Access:8] Address : 0000000000001842 Preserve Mask : 00000000000000FD Write Mask : 0000000000000002 Command Latency : 00001388 Maximum Access Rate : 00000000 Minimum Turnaround Time : 0000 To fix this, we count up all of the possible subtable types for the PCCT, and only report an error when there are none (which could mean either no subtables, or no valid subtables), or there are too many. We also change the logic so that if there is a valid subtable, we do try to initialize it per the PCCT subtable contents. This is a change in functionality; previously, the probe would have returned right after the error message and would not have tried to use any other subtable definition. Tested on my personal laptop which showed the error previously; the error message no longer appears and the laptop appears to operate normally. Signed-off-by: Al Stone <ahs3@redhat.com> Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-05-16 22:01:41 +00:00
struct acpi_subtable_proc proc[ACPI_PCCT_TYPE_RESERVED];
status = acpi_get_table(ACPI_SIG_PCCT, 0, &pcct_tbl);
if (ACPI_FAILURE(status) || !pcct_tbl)
return -ENODEV;
mailbox: PCC: erroneous error message when parsing ACPI PCCT There have been multiple reports of the following error message: [ 0.068293] Error parsing PCC subspaces from PCCT This error message is not correct. In multiple cases examined, the PCCT (Platform Communications Channel Table) concerned is actually properly constructed; the problem is that acpi_pcc_probe() which reads the PCCT is making the assumption that the only valid PCCT is one that contains subtables of one of two types: ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE or ACPI_PCCT_TYPE_HW_REDUCED_TYPE2. The number of subtables of these types are counted and as long as there is at least one of the desired types, the acpi_pcc_probe() succeeds. When no subtables of these types are found, regardless of whether or not any other subtable types are present, the error mentioned above is reported. In the cases reported to me personally, the PCCT contains exactly one subtable of type ACPI_PCCT_TYPE_GENERIC_SUBSPACE. The function acpi_pcc_probe() does not count it as a valid subtable, so believes there to be no valid subtables, and hence outputs the error message. An example of the PCCT being reported as erroneous yet perfectly fine is the following: Signature : "PCCT" Table Length : 0000006E Revision : 05 Checksum : A9 Oem ID : "XXXXXX" Oem Table ID : "XXXXX " Oem Revision : 00002280 Asl Compiler ID : "XXXX" Asl Compiler Revision : 00000002 Flags (decoded below) : 00000001 Platform : 1 Reserved : 0000000000000000 Subtable Type : 00 [Generic Communications Subspace] Length : 3E Reserved : 000000000000 Base Address : 00000000DCE43018 Address Length : 0000000000001000 Doorbell Register : [Generic Address Structure] Space ID : 01 [SystemIO] Bit Width : 08 Bit Offset : 00 Encoded Access Width : 01 [Byte Access:8] Address : 0000000000001842 Preserve Mask : 00000000000000FD Write Mask : 0000000000000002 Command Latency : 00001388 Maximum Access Rate : 00000000 Minimum Turnaround Time : 0000 To fix this, we count up all of the possible subtable types for the PCCT, and only report an error when there are none (which could mean either no subtables, or no valid subtables), or there are too many. We also change the logic so that if there is a valid subtable, we do try to initialize it per the PCCT subtable contents. This is a change in functionality; previously, the probe would have returned right after the error message and would not have tried to use any other subtable definition. Tested on my personal laptop which showed the error previously; the error message no longer appears and the laptop appears to operate normally. Signed-off-by: Al Stone <ahs3@redhat.com> Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-05-16 22:01:41 +00:00
/* Set up the subtable handlers */
for (i = ACPI_PCCT_TYPE_GENERIC_SUBSPACE;
i < ACPI_PCCT_TYPE_RESERVED; i++) {
proc[i].id = i;
proc[i].count = 0;
proc[i].handler = parse_pcc_subspace;
}
mailbox: PCC: erroneous error message when parsing ACPI PCCT There have been multiple reports of the following error message: [ 0.068293] Error parsing PCC subspaces from PCCT This error message is not correct. In multiple cases examined, the PCCT (Platform Communications Channel Table) concerned is actually properly constructed; the problem is that acpi_pcc_probe() which reads the PCCT is making the assumption that the only valid PCCT is one that contains subtables of one of two types: ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE or ACPI_PCCT_TYPE_HW_REDUCED_TYPE2. The number of subtables of these types are counted and as long as there is at least one of the desired types, the acpi_pcc_probe() succeeds. When no subtables of these types are found, regardless of whether or not any other subtable types are present, the error mentioned above is reported. In the cases reported to me personally, the PCCT contains exactly one subtable of type ACPI_PCCT_TYPE_GENERIC_SUBSPACE. The function acpi_pcc_probe() does not count it as a valid subtable, so believes there to be no valid subtables, and hence outputs the error message. An example of the PCCT being reported as erroneous yet perfectly fine is the following: Signature : "PCCT" Table Length : 0000006E Revision : 05 Checksum : A9 Oem ID : "XXXXXX" Oem Table ID : "XXXXX " Oem Revision : 00002280 Asl Compiler ID : "XXXX" Asl Compiler Revision : 00000002 Flags (decoded below) : 00000001 Platform : 1 Reserved : 0000000000000000 Subtable Type : 00 [Generic Communications Subspace] Length : 3E Reserved : 000000000000 Base Address : 00000000DCE43018 Address Length : 0000000000001000 Doorbell Register : [Generic Address Structure] Space ID : 01 [SystemIO] Bit Width : 08 Bit Offset : 00 Encoded Access Width : 01 [Byte Access:8] Address : 0000000000001842 Preserve Mask : 00000000000000FD Write Mask : 0000000000000002 Command Latency : 00001388 Maximum Access Rate : 00000000 Minimum Turnaround Time : 0000 To fix this, we count up all of the possible subtable types for the PCCT, and only report an error when there are none (which could mean either no subtables, or no valid subtables), or there are too many. We also change the logic so that if there is a valid subtable, we do try to initialize it per the PCCT subtable contents. This is a change in functionality; previously, the probe would have returned right after the error message and would not have tried to use any other subtable definition. Tested on my personal laptop which showed the error previously; the error message no longer appears and the laptop appears to operate normally. Signed-off-by: Al Stone <ahs3@redhat.com> Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-05-16 22:01:41 +00:00
count = acpi_table_parse_entries_array(ACPI_SIG_PCCT,
sizeof(struct acpi_table_pcct), proc,
ACPI_PCCT_TYPE_RESERVED, MAX_PCC_SUBSPACES);
if (count <= 0 || count > MAX_PCC_SUBSPACES) {
if (count < 0)
pr_warn("Error parsing PCC subspaces from PCCT\n");
else
pr_warn("Invalid PCCT: %d PCC subspaces\n", count);
rc = -EINVAL;
} else {
pcc_chan_count = count;
}
acpi_put_table(pcct_tbl);
return rc;
}
/**
* pcc_mbox_probe - Called when we find a match for the
* PCCT platform device. This is purely used to represent
* the PCCT as a virtual device for registering with the
* generic Mailbox framework.
*
* @pdev: Pointer to platform device returned when a match
* is found.
*
* Return: 0 for Success, else errno.
*/
static int pcc_mbox_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct mbox_controller *pcc_mbox_ctrl;
struct mbox_chan *pcc_mbox_channels;
struct acpi_table_header *pcct_tbl;
struct acpi_subtable_header *pcct_entry;
struct acpi_table_pcct *acpi_pcct_tbl;
acpi_status status = AE_OK;
int i, rc, count = pcc_chan_count;
/* Search for PCCT */
status = acpi_get_table(ACPI_SIG_PCCT, 0, &pcct_tbl);
if (ACPI_FAILURE(status) || !pcct_tbl)
return -ENODEV;
pcc_mbox_channels = devm_kcalloc(dev, count, sizeof(*pcc_mbox_channels),
GFP_KERNEL);
if (!pcc_mbox_channels) {
rc = -ENOMEM;
goto err;
}
chan_info = devm_kcalloc(dev, count, sizeof(*chan_info), GFP_KERNEL);
if (!chan_info) {
rc = -ENOMEM;
goto err;
}
pcc_mbox_ctrl = devm_kmalloc(dev, sizeof(*pcc_mbox_ctrl), GFP_KERNEL);
if (!pcc_mbox_ctrl) {
rc = -ENOMEM;
goto err;
}
/* Point to the first PCC subspace entry */
pcct_entry = (struct acpi_subtable_header *) (
(unsigned long) pcct_tbl + sizeof(struct acpi_table_pcct));
acpi_pcct_tbl = (struct acpi_table_pcct *) pcct_tbl;
if (acpi_pcct_tbl->flags & ACPI_PCCT_DOORBELL)
pcc_mbox_ctrl->txdone_irq = true;
mailbox: PCC: erroneous error message when parsing ACPI PCCT There have been multiple reports of the following error message: [ 0.068293] Error parsing PCC subspaces from PCCT This error message is not correct. In multiple cases examined, the PCCT (Platform Communications Channel Table) concerned is actually properly constructed; the problem is that acpi_pcc_probe() which reads the PCCT is making the assumption that the only valid PCCT is one that contains subtables of one of two types: ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE or ACPI_PCCT_TYPE_HW_REDUCED_TYPE2. The number of subtables of these types are counted and as long as there is at least one of the desired types, the acpi_pcc_probe() succeeds. When no subtables of these types are found, regardless of whether or not any other subtable types are present, the error mentioned above is reported. In the cases reported to me personally, the PCCT contains exactly one subtable of type ACPI_PCCT_TYPE_GENERIC_SUBSPACE. The function acpi_pcc_probe() does not count it as a valid subtable, so believes there to be no valid subtables, and hence outputs the error message. An example of the PCCT being reported as erroneous yet perfectly fine is the following: Signature : "PCCT" Table Length : 0000006E Revision : 05 Checksum : A9 Oem ID : "XXXXXX" Oem Table ID : "XXXXX " Oem Revision : 00002280 Asl Compiler ID : "XXXX" Asl Compiler Revision : 00000002 Flags (decoded below) : 00000001 Platform : 1 Reserved : 0000000000000000 Subtable Type : 00 [Generic Communications Subspace] Length : 3E Reserved : 000000000000 Base Address : 00000000DCE43018 Address Length : 0000000000001000 Doorbell Register : [Generic Address Structure] Space ID : 01 [SystemIO] Bit Width : 08 Bit Offset : 00 Encoded Access Width : 01 [Byte Access:8] Address : 0000000000001842 Preserve Mask : 00000000000000FD Write Mask : 0000000000000002 Command Latency : 00001388 Maximum Access Rate : 00000000 Minimum Turnaround Time : 0000 To fix this, we count up all of the possible subtable types for the PCCT, and only report an error when there are none (which could mean either no subtables, or no valid subtables), or there are too many. We also change the logic so that if there is a valid subtable, we do try to initialize it per the PCCT subtable contents. This is a change in functionality; previously, the probe would have returned right after the error message and would not have tried to use any other subtable definition. Tested on my personal laptop which showed the error previously; the error message no longer appears and the laptop appears to operate normally. Signed-off-by: Al Stone <ahs3@redhat.com> Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-05-16 22:01:41 +00:00
for (i = 0; i < count; i++) {
struct pcc_chan_info *pchan = chan_info + i;
pcc_mbox_channels[i].con_priv = pchan;
pchan->chan.mchan = &pcc_mbox_channels[i];
if (pcct_entry->type == ACPI_PCCT_TYPE_EXT_PCC_SLAVE_SUBSPACE &&
!pcc_mbox_ctrl->txdone_irq) {
pr_err("Plaform Interrupt flag must be set to 1");
rc = -EINVAL;
goto err;
}
if (pcc_mbox_ctrl->txdone_irq) {
rc = pcc_parse_subspace_irq(pchan, pcct_entry);
if (rc < 0)
goto err;
}
rc = pcc_parse_subspace_db_reg(pchan, pcct_entry);
if (rc < 0)
goto err;
pcc_parse_subspace_shmem(pchan, pcct_entry);
pcct_entry = (struct acpi_subtable_header *)
((unsigned long) pcct_entry + pcct_entry->length);
}
pcc_mbox_ctrl->num_chans = count;
pr_info("Detected %d PCC Subspaces\n", pcc_mbox_ctrl->num_chans);
pcc_mbox_ctrl->chans = pcc_mbox_channels;
pcc_mbox_ctrl->ops = &pcc_chan_ops;
pcc_mbox_ctrl->dev = dev;
pr_info("Registering PCC driver as Mailbox controller\n");
rc = mbox_controller_register(pcc_mbox_ctrl);
if (rc)
pr_err("Err registering PCC as Mailbox controller: %d\n", rc);
else
return 0;
err:
acpi_put_table(pcct_tbl);
return rc;
}
static struct platform_driver pcc_mbox_driver = {
.probe = pcc_mbox_probe,
.driver = {
.name = "PCCT",
},
};
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 (IS_ERR(pcc_pdev)) {
pr_debug("Err creating PCC platform bundle\n");
return PTR_ERR(pcc_pdev);
}
return 0;
}
/*
* Make PCC init postcore so that users of this mailbox
* such as the ACPI Processor driver have it available
* at their init.
*/
postcore_initcall(pcc_init);