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u-boot/arch/riscv/include/asm/smp.h

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riscv: add infrastructure for calling functions on other harts Harts on RISC-V boot independently, U-Boot is responsible for managing them. Functions are called on other harts with smp_call_function(), which sends inter-processor interrupts (IPIs) to all other available harts. Available harts are those marked as available in the device tree and present in the available_harts mask stored in global data. The available_harts mask is used to register all harts that have entered U-Boot. Functions are specified with their address and two function arguments (argument 2 and 3). The first function argument is always the hart ID of the hart calling the function. On the other harts, the IPI interrupt handler handle_ipi() must be called on software interrupts to handle the request and call the specified function. Functions are stored in the ipi_data data structure. Every hart has its own data structure in global data. While this is not required at the moment (all harts are expected to boot Linux), this does allow future expansion, where other harts may be used for monitoring or other tasks. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com>
2019-03-17 18:28:32 +00:00
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2019 Fraunhofer AISEC,
* Lukas Auer <lukas.auer@aisec.fraunhofer.de>
*/
#ifndef _ASM_RISCV_SMP_H
#define _ASM_RISCV_SMP_H
/**
* struct ipi_data - Inter-processor interrupt (IPI) data structure
*
* IPIs are used for SMP support to communicate to other harts what function to
* call. Functions are in the form
* void (*addr)(ulong hart, ulong arg0, ulong arg1).
*
* The function address and the two arguments, arg0 and arg1, are stored in the
* IPI data structure. The hart ID is inserted by the hart handling the IPI and
* calling the function.
*
riscv: Use a valid bit to ignore already-pending IPIs Some IPIs may already be pending when U-Boot is started. This could be a problem if a secondary hart tries to handle an IPI before the boot hart has initialized the IPI device. To be specific, the Kendryte K210 ROM-based bootloader does not clear IPIs before passing control to U-Boot. Without this patch, the secondary hart jumps to address 0x0 as soon as it enters secondary_hart_loop, and then hangs in its trap handler. This commit introduces a valid bit so secondary harts know when and IPI originates from U-Boot, and it is safe to use the IPI API. The valid bit is initialized to 0 by board_init_f_init_reserve. Before this, secondary harts wait in wait_for_gd_init. Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Bin Meng <bin.meng@windriver.com> Reviewed-by: Rick Chen <rick@andestech.com> Reviewed-by: Leo Liang <ycliang@andestech.com>
2020-09-21 11:51:37 +00:00
* @valid is used to determine whether a sent IPI originated from U-Boot. It is
* initialized to zero by board_init_f_alloc_reserve. When U-Boot sends its
* first IPI, it is set to 1. This prevents already-pending IPIs not sent by
* U-Boot from being taken.
*
riscv: add infrastructure for calling functions on other harts Harts on RISC-V boot independently, U-Boot is responsible for managing them. Functions are called on other harts with smp_call_function(), which sends inter-processor interrupts (IPIs) to all other available harts. Available harts are those marked as available in the device tree and present in the available_harts mask stored in global data. The available_harts mask is used to register all harts that have entered U-Boot. Functions are specified with their address and two function arguments (argument 2 and 3). The first function argument is always the hart ID of the hart calling the function. On the other harts, the IPI interrupt handler handle_ipi() must be called on software interrupts to handle the request and call the specified function. Functions are stored in the ipi_data data structure. Every hart has its own data structure in global data. While this is not required at the moment (all harts are expected to boot Linux), this does allow future expansion, where other harts may be used for monitoring or other tasks. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com>
2019-03-17 18:28:32 +00:00
* @addr: Address of function
* @arg0: First argument of function
* @arg1: Second argument of function
riscv: Use a valid bit to ignore already-pending IPIs Some IPIs may already be pending when U-Boot is started. This could be a problem if a secondary hart tries to handle an IPI before the boot hart has initialized the IPI device. To be specific, the Kendryte K210 ROM-based bootloader does not clear IPIs before passing control to U-Boot. Without this patch, the secondary hart jumps to address 0x0 as soon as it enters secondary_hart_loop, and then hangs in its trap handler. This commit introduces a valid bit so secondary harts know when and IPI originates from U-Boot, and it is safe to use the IPI API. The valid bit is initialized to 0 by board_init_f_init_reserve. Before this, secondary harts wait in wait_for_gd_init. Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Bin Meng <bin.meng@windriver.com> Reviewed-by: Rick Chen <rick@andestech.com> Reviewed-by: Leo Liang <ycliang@andestech.com>
2020-09-21 11:51:37 +00:00
* @valid: Whether this IPI is valid
riscv: add infrastructure for calling functions on other harts Harts on RISC-V boot independently, U-Boot is responsible for managing them. Functions are called on other harts with smp_call_function(), which sends inter-processor interrupts (IPIs) to all other available harts. Available harts are those marked as available in the device tree and present in the available_harts mask stored in global data. The available_harts mask is used to register all harts that have entered U-Boot. Functions are specified with their address and two function arguments (argument 2 and 3). The first function argument is always the hart ID of the hart calling the function. On the other harts, the IPI interrupt handler handle_ipi() must be called on software interrupts to handle the request and call the specified function. Functions are stored in the ipi_data data structure. Every hart has its own data structure in global data. While this is not required at the moment (all harts are expected to boot Linux), this does allow future expansion, where other harts may be used for monitoring or other tasks. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com>
2019-03-17 18:28:32 +00:00
*/
struct ipi_data {
ulong addr;
ulong arg0;
ulong arg1;
riscv: Use a valid bit to ignore already-pending IPIs Some IPIs may already be pending when U-Boot is started. This could be a problem if a secondary hart tries to handle an IPI before the boot hart has initialized the IPI device. To be specific, the Kendryte K210 ROM-based bootloader does not clear IPIs before passing control to U-Boot. Without this patch, the secondary hart jumps to address 0x0 as soon as it enters secondary_hart_loop, and then hangs in its trap handler. This commit introduces a valid bit so secondary harts know when and IPI originates from U-Boot, and it is safe to use the IPI API. The valid bit is initialized to 0 by board_init_f_init_reserve. Before this, secondary harts wait in wait_for_gd_init. Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Bin Meng <bin.meng@windriver.com> Reviewed-by: Rick Chen <rick@andestech.com> Reviewed-by: Leo Liang <ycliang@andestech.com>
2020-09-21 11:51:37 +00:00
unsigned int valid;
riscv: add infrastructure for calling functions on other harts Harts on RISC-V boot independently, U-Boot is responsible for managing them. Functions are called on other harts with smp_call_function(), which sends inter-processor interrupts (IPIs) to all other available harts. Available harts are those marked as available in the device tree and present in the available_harts mask stored in global data. The available_harts mask is used to register all harts that have entered U-Boot. Functions are specified with their address and two function arguments (argument 2 and 3). The first function argument is always the hart ID of the hart calling the function. On the other harts, the IPI interrupt handler handle_ipi() must be called on software interrupts to handle the request and call the specified function. Functions are stored in the ipi_data data structure. Every hart has its own data structure in global data. While this is not required at the moment (all harts are expected to boot Linux), this does allow future expansion, where other harts may be used for monitoring or other tasks. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com>
2019-03-17 18:28:32 +00:00
};
/**
* handle_ipi() - interrupt handler for software interrupts
*
* The IPI interrupt handler must be called to handle software interrupts. It
* calls the function specified in the hart's IPI data structure.
*
* @hart: Hart ID of the current hart
*/
void handle_ipi(ulong hart);
/**
* smp_call_function() - Call a function on all other harts
*
* Send IPIs with the specified function call to all harts.
*
* @addr: Address of function
* @arg0: First argument of function
* @arg1: Second argument of function
riscv: add option to wait for ack from secondary harts in smp functions Add a wait option to smp_call_function() to wait for the secondary harts to acknowledge the call-function request. The request is considered to be acknowledged once each secondary hart has cleared the corresponding IPI. As part of the call-function request, the secondary harts invalidate the instruction cache after clearing the IPI. This adds a delay between acknowledgment (clear IPI) and fulfillment (call function) of the request. We want to use the acknowledgment to be able to judge when the request has been completed. Remove the delay by clearing the IPI after cache invalidation and just before calling the function from the request. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Rick Chen <rick@andestech.com> Tested-by: Rick Chen <rick@andestech.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-12-08 22:28:51 +00:00
* @wait: Wait for harts to acknowledge request
riscv: add infrastructure for calling functions on other harts Harts on RISC-V boot independently, U-Boot is responsible for managing them. Functions are called on other harts with smp_call_function(), which sends inter-processor interrupts (IPIs) to all other available harts. Available harts are those marked as available in the device tree and present in the available_harts mask stored in global data. The available_harts mask is used to register all harts that have entered U-Boot. Functions are specified with their address and two function arguments (argument 2 and 3). The first function argument is always the hart ID of the hart calling the function. On the other harts, the IPI interrupt handler handle_ipi() must be called on software interrupts to handle the request and call the specified function. Functions are stored in the ipi_data data structure. Every hart has its own data structure in global data. While this is not required at the moment (all harts are expected to boot Linux), this does allow future expansion, where other harts may be used for monitoring or other tasks. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com>
2019-03-17 18:28:32 +00:00
* @return 0 if OK, -ve on error
*/
riscv: add option to wait for ack from secondary harts in smp functions Add a wait option to smp_call_function() to wait for the secondary harts to acknowledge the call-function request. The request is considered to be acknowledged once each secondary hart has cleared the corresponding IPI. As part of the call-function request, the secondary harts invalidate the instruction cache after clearing the IPI. This adds a delay between acknowledgment (clear IPI) and fulfillment (call function) of the request. We want to use the acknowledgment to be able to judge when the request has been completed. Remove the delay by clearing the IPI after cache invalidation and just before calling the function from the request. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Rick Chen <rick@andestech.com> Tested-by: Rick Chen <rick@andestech.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-12-08 22:28:51 +00:00
int smp_call_function(ulong addr, ulong arg0, ulong arg1, int wait);
riscv: add infrastructure for calling functions on other harts Harts on RISC-V boot independently, U-Boot is responsible for managing them. Functions are called on other harts with smp_call_function(), which sends inter-processor interrupts (IPIs) to all other available harts. Available harts are those marked as available in the device tree and present in the available_harts mask stored in global data. The available_harts mask is used to register all harts that have entered U-Boot. Functions are specified with their address and two function arguments (argument 2 and 3). The first function argument is always the hart ID of the hart calling the function. On the other harts, the IPI interrupt handler handle_ipi() must be called on software interrupts to handle the request and call the specified function. Functions are stored in the ipi_data data structure. Every hart has its own data structure in global data. While this is not required at the moment (all harts are expected to boot Linux), this does allow future expansion, where other harts may be used for monitoring or other tasks. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com>
2019-03-17 18:28:32 +00:00
riscv: Clean up IPI initialization code The previous IPI code initialized the device whenever the first call was made to a riscv_*_ipi function. This made it difficult to determine when the IPI device was initialized. This patch introduces a new function riscv_init_ipi. It is called once during arch_cpu_init_dm. In SPL, it is called in spl_invoke_opensbi. Before this point, no riscv_*_ipi functions should be called. Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Rick Chen <rick@andestech.com>
2020-06-24 10:41:18 +00:00
/**
* riscv_init_ipi() - Initialize inter-process interrupt (IPI) driver
*
* Platform code must provide this function. This function is called once after
* the cpu driver is initialized. No other riscv_*_ipi() calls will be made
* before this function is called.
*
* @return 0 if OK, -ve on error
*/
int riscv_init_ipi(void);
/**
* riscv_send_ipi() - Send inter-processor interrupt (IPI)
*
* Platform code must provide this function.
*
* @hart: Hart ID of receiving hart
* @return 0 if OK, -ve on error
*/
int riscv_send_ipi(int hart);
/**
* riscv_clear_ipi() - Clear inter-processor interrupt (IPI)
*
* Platform code must provide this function.
*
* @hart: Hart ID of hart to be cleared
* @return 0 if OK, -ve on error
*/
int riscv_clear_ipi(int hart);
/**
* riscv_get_ipi() - Get status of inter-processor interrupt (IPI)
*
* Platform code must provide this function.
*
* @hart: Hart ID of hart to be checked
* @pending: Pointer to variable with result of the check,
* 1 if IPI is pending, 0 otherwise
* @return 0 if OK, -ve on error
*/
int riscv_get_ipi(int hart, int *pending);
riscv: add infrastructure for calling functions on other harts Harts on RISC-V boot independently, U-Boot is responsible for managing them. Functions are called on other harts with smp_call_function(), which sends inter-processor interrupts (IPIs) to all other available harts. Available harts are those marked as available in the device tree and present in the available_harts mask stored in global data. The available_harts mask is used to register all harts that have entered U-Boot. Functions are specified with their address and two function arguments (argument 2 and 3). The first function argument is always the hart ID of the hart calling the function. On the other harts, the IPI interrupt handler handle_ipi() must be called on software interrupts to handle the request and call the specified function. Functions are stored in the ipi_data data structure. Every hart has its own data structure in global data. While this is not required at the moment (all harts are expected to boot Linux), this does allow future expansion, where other harts may be used for monitoring or other tasks. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com>
2019-03-17 18:28:32 +00:00
#endif
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