On 08/19/2015 06:50 PM, Will Deacon wrote: > On Wed, Aug 19, 2015 at 09:40:25AM +0100, Jens Wiklander wrote: >> Adds helpers to do SMC based on ARM SMC Calling Convention. >> CONFIG_HAVE_SMCCC is enabled for architectures that may support >> the SMC instruction. It's the responsibility of the caller to >> know if the SMC instruction is supported by the platform. > > [...] >> diff --git a/arch/arm64/kernel/smccc-call.S b/arch/arm64/kernel/smccc-call.S >> new file mode 100644 >> index 0000000..3ce7fe8 >> --- /dev/null >> +++ b/arch/arm64/kernel/smccc-call.S >> @@ -0,0 +1,34 @@ >> +/* >> + * Copyright (c) 2015, Linaro Limited >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License Version 2 as >> + * published by the Free Software Foundation. >> + * >> + * 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. >> + * >> + */ >> +#include <linux/linkage.h> >> + >> +#define SMC_PARAM_W0_OFFS 0 >> +#define SMC_PARAM_W2_OFFS 8 >> +#define SMC_PARAM_W4_OFFS 16 >> +#define SMC_PARAM_W6_OFFS 24 >> + >> +/* void smccc_call32(struct smccc_param32 *param) */ >> +ENTRY(smccc_call32) >> + stp x28, x30, [sp, #-16]! > > Why are you saving lr? > >> + mov x28, x0 >> + ldp w0, w1, [x28, #SMC_PARAM_W0_OFFS] >> + ldp w2, w3, [x28, #SMC_PARAM_W2_OFFS] >> + ldp w4, w5, [x28, #SMC_PARAM_W4_OFFS] >> + ldp w6, w7, [x28, #SMC_PARAM_W6_OFFS] >> + smc #0 >> + stp w0, w1, [x28, #SMC_PARAM_W0_OFFS] >> + stp w2, w3, [x28, #SMC_PARAM_W2_OFFS] >> + ldp x28, x30, [sp], #16 >> + ret >> +ENDPROC(smccc_call32) > > Could we deal with this like we do for PSCI instead? (see > __invoke_psci_fn_smc). We could also then rename psci-call.S to fw-call.S > and stick this in there too. I think that make sense to make smc, hvc calling more generic. Remove psci name from __invoke_psci_fn_smc and just use it in other drivers. Thanks, Michal -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
