| Message ID | 20220104195108.995359-1-sudeep.holla@arm.com (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Delegated to: | Rafael Wysocki |
| Headers | show |
| Series | [v3] ACPI: PCC: Implement OperationRegion handler for the PCC Type 3 subtype | expand |
On Tue, Jan 4, 2022 at 8:51 PM Sudeep Holla <sudeep.holla@arm.com> wrote: > > PCC OpRegion provides a mechanism to communicate with the platform > directly from the AML. PCCT provides the list of PCC channel available > in the platform, a subset or all of them can be used in PCC Opregion. > > This patch registers the PCC OpRegion handler before ACPI tables are > loaded. This relies on the special context data passed to identify and > set up the PCC channel before the OpRegion handler is executed for the > first time. > > Typical PCC Opregion declaration looks like this: > > OperationRegion (PFRM, PCC, 2, 0x74) > Field (PFRM, ByteAcc, NoLock, Preserve) > { > SIGN, 32, > FLGS, 32, > LEN, 32, > CMD, 32, > DATA, 800 > } > > It contains four named double words followed by 100 bytes of buffer > names DATA. > > ASL can fill out the buffer something like: > > /* Create global or local buffer */ > Name (BUFF, Buffer (0x0C){}) > /* Create double word fields over the buffer */ > CreateDWordField (BUFF, 0x0, WD0) > CreateDWordField (BUFF, 0x04, WD1) > CreateDWordField (BUFF, 0x08, WD2) > > /* Fill the named fields */ > WD0 = 0x50434300 > SIGN = BUFF > WD0 = 1 > FLGS = BUFF > WD0 = 0x10 > LEN = BUFF > > /* Fill the payload in the DATA buffer */ > WD0 = 0 > WD1 = 0x08 > WD2 = 0 > DATA = BUFF > > /* Write to CMD field to trigger handler */ > WD0 = 0x4404 > CMD = BUFF > > This buffer is received by acpi_pcc_opregion_space_handler. This > handler will fetch the complete buffer via internal_pcc_buffer. > > The setup handler will receive the special PCC context data which will > contain the PCC channel index which used to set up the channel. The > buffer pointer and length is saved in region context which is then used > in the handler. > > (kernel test robot: Build failure with CONFIG_ACPI_DEBUGGER) > Link: https://lore.kernel.org/r/202201041539.feAV0l27-lkp@intel.com > Reported-by: kernel test robot <lkp@intel.com> > Cc: Rafael J. Wysocki <rafael@kernel.org> > Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Applied as 5.17 material, thanks! > --- > drivers/acpi/Kconfig | 17 ++++++ > drivers/acpi/Makefile | 1 + > drivers/acpi/acpi_pcc.c | 120 ++++++++++++++++++++++++++++++++++++++++ > drivers/acpi/bus.c | 1 + > include/linux/acpi.h | 6 ++ > 5 files changed, 145 insertions(+) > create mode 100644 drivers/acpi/acpi_pcc.c > > v2[2]-v3: > - Fixed build with CONFIG_ACPI_DEBUGGER enabled > Looks like return_ACPI_STATUS is supposed to be used only > in core ACPICA > > v1[0]-v2[2]: > - Addressed all the comments from Rafael[1] > > [0] https://lore.kernel.org/r/20211222190919.137550-1-sudeep.holla@arm.com/ > [1] https://lore.kernel.org/r/CAJZ5v0jWJVSFS3KTavfCTzxWq-Q361nGDCWf+VLXRu-9Z4MJsQ@mail.gmail.com > [2] https://lore.kernel.org/r/20220103155838.616580-1-sudeep.holla@arm.com > > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig > index 91f1da16934d..8cdc7860b6e6 100644 > --- a/drivers/acpi/Kconfig > +++ b/drivers/acpi/Kconfig > @@ -546,6 +546,23 @@ config ACPI_PPTT > bool > endif > > +config ACPI_PCC > + bool "ACPI PCC Address Space" > + depends on PCC > + default y > + help > + 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. > + > + Enable this feature if you want to set up and install the PCC Address > + Space handler to handle PCC OpRegion in the firmware. > + > source "drivers/acpi/pmic/Kconfig" > > config ACPI_VIOT > diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile > index d3dc79298ce3..f47032769f69 100644 > --- a/drivers/acpi/Makefile > +++ b/drivers/acpi/Makefile > @@ -67,6 +67,7 @@ acpi-$(CONFIG_ACPI_LPIT) += acpi_lpit.o > acpi-$(CONFIG_ACPI_GENERIC_GSI) += irq.o > acpi-$(CONFIG_ACPI_WATCHDOG) += acpi_watchdog.o > acpi-$(CONFIG_ACPI_PRMT) += prmt.o > +acpi-$(CONFIG_ACPI_PCC) += acpi_pcc.o > > # Address translation > acpi-$(CONFIG_ACPI_ADXL) += acpi_adxl.o > diff --git a/drivers/acpi/acpi_pcc.c b/drivers/acpi/acpi_pcc.c > new file mode 100644 > index 000000000000..41e3ebd204ff > --- /dev/null > +++ b/drivers/acpi/acpi_pcc.c > @@ -0,0 +1,120 @@ > +// 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"); > +} > diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c > index dd535b4b9a16..75a61626eddd 100644 > --- a/drivers/acpi/bus.c > +++ b/drivers/acpi/bus.c > @@ -1320,6 +1320,7 @@ static int __init acpi_init(void) > pr_debug("%s: kset create error\n", __func__); > > init_prmt(); > + acpi_init_pcc(); > result = acpi_bus_init(); > if (result) { > kobject_put(acpi_kobj); > diff --git a/include/linux/acpi.h b/include/linux/acpi.h > index 6c0798db6bde..eaeb4b9255bc 100644 > --- a/include/linux/acpi.h > +++ b/include/linux/acpi.h > @@ -1389,6 +1389,12 @@ static inline int find_acpi_cpu_cache_topology(unsigned int cpu, int level) > } > #endif > > +#ifdef CONFIG_ACPI_PCC > +void acpi_init_pcc(void); > +#else > +static inline void acpi_init_pcc(void) { } > +#endif > + > #ifdef CONFIG_ACPI > extern void acpi_device_notify(struct device *dev); > extern void acpi_device_notify_remove(struct device *dev); > > base-commit: 7a716cec17d19211715a34b426aafc3fadb22de6 > -- > 2.25.1 >
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index 91f1da16934d..8cdc7860b6e6 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -546,6 +546,23 @@ config ACPI_PPTT bool endif +config ACPI_PCC + bool "ACPI PCC Address Space" + depends on PCC + default y + help + 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. + + Enable this feature if you want to set up and install the PCC Address + Space handler to handle PCC OpRegion in the firmware. + source "drivers/acpi/pmic/Kconfig" config ACPI_VIOT diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index d3dc79298ce3..f47032769f69 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -67,6 +67,7 @@ acpi-$(CONFIG_ACPI_LPIT) += acpi_lpit.o acpi-$(CONFIG_ACPI_GENERIC_GSI) += irq.o acpi-$(CONFIG_ACPI_WATCHDOG) += acpi_watchdog.o acpi-$(CONFIG_ACPI_PRMT) += prmt.o +acpi-$(CONFIG_ACPI_PCC) += acpi_pcc.o # Address translation acpi-$(CONFIG_ACPI_ADXL) += acpi_adxl.o diff --git a/drivers/acpi/acpi_pcc.c b/drivers/acpi/acpi_pcc.c new file mode 100644 index 000000000000..41e3ebd204ff --- /dev/null +++ b/drivers/acpi/acpi_pcc.c @@ -0,0 +1,120 @@ +// 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"); +} diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c index dd535b4b9a16..75a61626eddd 100644 --- a/drivers/acpi/bus.c +++ b/drivers/acpi/bus.c @@ -1320,6 +1320,7 @@ static int __init acpi_init(void) pr_debug("%s: kset create error\n", __func__); init_prmt(); + acpi_init_pcc(); result = acpi_bus_init(); if (result) { kobject_put(acpi_kobj); diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 6c0798db6bde..eaeb4b9255bc 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -1389,6 +1389,12 @@ static inline int find_acpi_cpu_cache_topology(unsigned int cpu, int level) } #endif +#ifdef CONFIG_ACPI_PCC +void acpi_init_pcc(void); +#else +static inline void acpi_init_pcc(void) { } +#endif + #ifdef CONFIG_ACPI extern void acpi_device_notify(struct device *dev); extern void acpi_device_notify_remove(struct device *dev);
PCC OpRegion provides a mechanism to communicate with the platform directly from the AML. PCCT provides the list of PCC channel available in the platform, a subset or all of them can be used in PCC Opregion. This patch registers the PCC OpRegion handler before ACPI tables are loaded. This relies on the special context data passed to identify and set up the PCC channel before the OpRegion handler is executed for the first time. Typical PCC Opregion declaration looks like this: OperationRegion (PFRM, PCC, 2, 0x74) Field (PFRM, ByteAcc, NoLock, Preserve) { SIGN, 32, FLGS, 32, LEN, 32, CMD, 32, DATA, 800 } It contains four named double words followed by 100 bytes of buffer names DATA. ASL can fill out the buffer something like: /* Create global or local buffer */ Name (BUFF, Buffer (0x0C){}) /* Create double word fields over the buffer */ CreateDWordField (BUFF, 0x0, WD0) CreateDWordField (BUFF, 0x04, WD1) CreateDWordField (BUFF, 0x08, WD2) /* Fill the named fields */ WD0 = 0x50434300 SIGN = BUFF WD0 = 1 FLGS = BUFF WD0 = 0x10 LEN = BUFF /* Fill the payload in the DATA buffer */ WD0 = 0 WD1 = 0x08 WD2 = 0 DATA = BUFF /* Write to CMD field to trigger handler */ WD0 = 0x4404 CMD = BUFF This buffer is received by acpi_pcc_opregion_space_handler. This handler will fetch the complete buffer via internal_pcc_buffer. The setup handler will receive the special PCC context data which will contain the PCC channel index which used to set up the channel. The buffer pointer and length is saved in region context which is then used in the handler. (kernel test robot: Build failure with CONFIG_ACPI_DEBUGGER) Link: https://lore.kernel.org/r/202201041539.feAV0l27-lkp@intel.com Reported-by: kernel test robot <lkp@intel.com> Cc: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> --- drivers/acpi/Kconfig | 17 ++++++ drivers/acpi/Makefile | 1 + drivers/acpi/acpi_pcc.c | 120 ++++++++++++++++++++++++++++++++++++++++ drivers/acpi/bus.c | 1 + include/linux/acpi.h | 6 ++ 5 files changed, 145 insertions(+) create mode 100644 drivers/acpi/acpi_pcc.c v2[2]-v3: - Fixed build with CONFIG_ACPI_DEBUGGER enabled Looks like return_ACPI_STATUS is supposed to be used only in core ACPICA v1[0]-v2[2]: - Addressed all the comments from Rafael[1] [0] https://lore.kernel.org/r/20211222190919.137550-1-sudeep.holla@arm.com/ [1] https://lore.kernel.org/r/CAJZ5v0jWJVSFS3KTavfCTzxWq-Q361nGDCWf+VLXRu-9Z4MJsQ@mail.gmail.com [2] https://lore.kernel.org/r/20220103155838.616580-1-sudeep.holla@arm.com base-commit: 7a716cec17d19211715a34b426aafc3fadb22de6