121 lines
3.3 KiB
C
121 lines
3.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Author: Sudeep Holla <sudeep.holla@arm.com>
|
|
* Copyright 2021 Arm Limited
|
|
*
|
|
* The PCC Address Space also referred as PCC Operation Region pertains to the
|
|
* region of PCC subspace that succeeds the PCC signature. The PCC Operation
|
|
* Region works in conjunction with the PCC Table(Platform Communications
|
|
* Channel Table). PCC subspaces that are marked for use as PCC Operation
|
|
* Regions must not be used as PCC subspaces for the standard ACPI features
|
|
* such as CPPC, RASF, PDTT and MPST. These standard features must always use
|
|
* the PCC Table instead.
|
|
*
|
|
* This driver sets up the PCC Address Space and installs an handler to enable
|
|
* handling of PCC OpRegion in the firmware.
|
|
*
|
|
*/
|
|
#include <linux/kernel.h>
|
|
#include <linux/acpi.h>
|
|
#include <linux/completion.h>
|
|
#include <linux/idr.h>
|
|
#include <linux/io.h>
|
|
|
|
#include <acpi/pcc.h>
|
|
|
|
struct pcc_data {
|
|
struct pcc_mbox_chan *pcc_chan;
|
|
void __iomem *pcc_comm_addr;
|
|
struct completion done;
|
|
struct mbox_client cl;
|
|
struct acpi_pcc_info ctx;
|
|
};
|
|
|
|
struct acpi_pcc_info pcc_ctx;
|
|
|
|
static void pcc_rx_callback(struct mbox_client *cl, void *m)
|
|
{
|
|
struct pcc_data *data = container_of(cl, struct pcc_data, cl);
|
|
|
|
complete(&data->done);
|
|
}
|
|
|
|
static acpi_status
|
|
acpi_pcc_address_space_setup(acpi_handle region_handle, u32 function,
|
|
void *handler_context, void **region_context)
|
|
{
|
|
struct pcc_data *data;
|
|
struct acpi_pcc_info *ctx = handler_context;
|
|
struct pcc_mbox_chan *pcc_chan;
|
|
|
|
data = kzalloc(sizeof(*data), GFP_KERNEL);
|
|
if (!data)
|
|
return AE_NO_MEMORY;
|
|
|
|
data->cl.rx_callback = pcc_rx_callback;
|
|
data->cl.knows_txdone = true;
|
|
data->ctx.length = ctx->length;
|
|
data->ctx.subspace_id = ctx->subspace_id;
|
|
data->ctx.internal_buffer = ctx->internal_buffer;
|
|
|
|
init_completion(&data->done);
|
|
data->pcc_chan = pcc_mbox_request_channel(&data->cl, ctx->subspace_id);
|
|
if (IS_ERR(data->pcc_chan)) {
|
|
pr_err("Failed to find PCC channel for subspace %d\n",
|
|
ctx->subspace_id);
|
|
return AE_NOT_FOUND;
|
|
}
|
|
|
|
pcc_chan = data->pcc_chan;
|
|
data->pcc_comm_addr = acpi_os_ioremap(pcc_chan->shmem_base_addr,
|
|
pcc_chan->shmem_size);
|
|
if (!data->pcc_comm_addr) {
|
|
pr_err("Failed to ioremap PCC comm region mem for %d\n",
|
|
ctx->subspace_id);
|
|
return AE_NO_MEMORY;
|
|
}
|
|
|
|
*region_context = data;
|
|
return AE_OK;
|
|
}
|
|
|
|
static acpi_status
|
|
acpi_pcc_address_space_handler(u32 function, acpi_physical_address addr,
|
|
u32 bits, acpi_integer *value,
|
|
void *handler_context, void *region_context)
|
|
{
|
|
int ret;
|
|
struct pcc_data *data = region_context;
|
|
|
|
reinit_completion(&data->done);
|
|
|
|
/* Write to Shared Memory */
|
|
memcpy_toio(data->pcc_comm_addr, (void *)value, data->ctx.length);
|
|
|
|
ret = mbox_send_message(data->pcc_chan->mchan, NULL);
|
|
if (ret < 0)
|
|
return AE_ERROR;
|
|
|
|
if (data->pcc_chan->mchan->mbox->txdone_irq)
|
|
wait_for_completion(&data->done);
|
|
|
|
mbox_client_txdone(data->pcc_chan->mchan, ret);
|
|
|
|
memcpy_fromio(value, data->pcc_comm_addr, data->ctx.length);
|
|
|
|
return AE_OK;
|
|
}
|
|
|
|
void __init acpi_init_pcc(void)
|
|
{
|
|
acpi_status status;
|
|
|
|
status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT,
|
|
ACPI_ADR_SPACE_PLATFORM_COMM,
|
|
&acpi_pcc_address_space_handler,
|
|
&acpi_pcc_address_space_setup,
|
|
&pcc_ctx);
|
|
if (ACPI_FAILURE(status))
|
|
pr_alert("OperationRegion handler could not be installed\n");
|
|
}
|