diff options
| author | Lukas Auer <lukas.auer@aisec.fraunhofer.de> | 2019-12-08 23:28:51 +0100 |
|---|---|---|
| committer | Andes <uboot@andestech.com> | 2019-12-10 08:23:10 +0800 |
| commit | 90ae28143700bae4edd23930a7772899ad259058 (patch) | |
| tree | 302fd5ab611f913831da41971eb582270f7295b0 /arch/riscv/lib/smp.c | |
| parent | 8b3e97badf97d6e399014fb4a152031f8a0c94ba (diff) | |
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>
Diffstat (limited to 'arch/riscv/lib/smp.c')
| -rw-r--r-- | arch/riscv/lib/smp.c | 31 |
1 files changed, 22 insertions, 9 deletions
diff --git a/arch/riscv/lib/smp.c b/arch/riscv/lib/smp.c index 188a7e34bd..17adb35730 100644 --- a/arch/riscv/lib/smp.c +++ b/arch/riscv/lib/smp.c @@ -44,11 +44,11 @@ extern int riscv_clear_ipi(int hart); */ extern int riscv_get_ipi(int hart, int *pending); -static int send_ipi_many(struct ipi_data *ipi) +static int send_ipi_many(struct ipi_data *ipi, int wait) { ofnode node, cpus; u32 reg; - int ret; + int ret, pending; cpus = ofnode_path("/cpus"); if (!ofnode_valid(cpus)) { @@ -91,6 +91,15 @@ static int send_ipi_many(struct ipi_data *ipi) pr_err("Cannot send IPI to hart %d\n", reg); return ret; } + + if (wait) { + pending = 1; + while (pending) { + ret = riscv_get_ipi(reg, &pending); + if (ret) + return ret; + } + } } return 0; @@ -104,21 +113,25 @@ void handle_ipi(ulong hart) if (hart >= CONFIG_NR_CPUS) return; + __smp_mb(); + + smp_function = (void (*)(ulong, ulong, ulong))gd->arch.ipi[hart].addr; + invalidate_icache_all(); + + /* + * Clear the IPI to acknowledge the request before jumping to the + * requested function. + */ ret = riscv_clear_ipi(hart); if (ret) { pr_err("Cannot clear IPI of hart %ld\n", hart); return; } - __smp_mb(); - - smp_function = (void (*)(ulong, ulong, ulong))gd->arch.ipi[hart].addr; - invalidate_icache_all(); - smp_function(hart, gd->arch.ipi[hart].arg0, gd->arch.ipi[hart].arg1); } -int smp_call_function(ulong addr, ulong arg0, ulong arg1) +int smp_call_function(ulong addr, ulong arg0, ulong arg1, int wait) { int ret = 0; struct ipi_data ipi; @@ -127,7 +140,7 @@ int smp_call_function(ulong addr, ulong arg0, ulong arg1) ipi.arg0 = arg0; ipi.arg1 = arg1; - ret = send_ipi_many(&ipi); + ret = send_ipi_many(&ipi, wait); return ret; } |