From af0c597e983318e9cfa408eff6810a5c8fb9ca77 Mon Sep 17 00:00:00 2001 From: Achin Gupta Date: Fri, 19 Feb 2021 12:05:55 +0530 Subject: ArmPkg/ArmSvcLib: Return x4-x7 in output parameters The Arm SMC calling convention standard v1.2 allows 8 input and output parameter registers. The FF-A specification relies on this communication. This patch extends the number of output registers returned by ArmCallSvc() to match this convention. Signed-off-by: Achin Gupta Reviewed-by: Sami Mujawar Reviewed-by: Ard Biesheuvel --- ArmPkg/Include/Library/ArmSvcLib.h | 10 ++++++++-- ArmPkg/Library/ArmSvcLib/AArch64/ArmSvc.S | 4 +++- 2 files changed, 11 insertions(+), 3 deletions(-) (limited to 'ArmPkg') diff --git a/ArmPkg/Include/Library/ArmSvcLib.h b/ArmPkg/Include/Library/ArmSvcLib.h index a94ead1965..a4414270f3 100644 --- a/ArmPkg/Include/Library/ArmSvcLib.h +++ b/ArmPkg/Include/Library/ArmSvcLib.h @@ -27,10 +27,16 @@ typedef struct { /** Trigger an SVC call - SVC calls can take up to 7 arguments and return up to 4 return values. - Therefore, the 4 first fields in the ARM_SVC_ARGS structure are used + SVC calls can take up to 8 arguments and return up to 8 return values. + Therefore, the 8 first fields in the ARM_SVC_ARGS structure are used for both input and output values. + @param[in, out] Args Arguments to be passed as part of the SVC call + The return values of the SVC call are also placed + in the same structure + + @retval None + **/ VOID ArmCallSvc ( diff --git a/ArmPkg/Library/ArmSvcLib/AArch64/ArmSvc.S b/ArmPkg/Library/ArmSvcLib/AArch64/ArmSvc.S index ee265f94b9..1a7c10cb79 100644 --- a/ArmPkg/Library/ArmSvcLib/AArch64/ArmSvc.S +++ b/ArmPkg/Library/ArmSvcLib/AArch64/ArmSvc.S @@ -33,9 +33,11 @@ ASM_PFX(ArmCallSvc): ldr x9, [sp, #16] // Store the SVC returned values into the ARM_SVC_ARGS structure. - // A SVC call can return up to 4 values - we do not need to store back x4-x7. + // A SVC call can return up to 8 values stp x0, x1, [x9, #0] stp x2, x3, [x9, #16] + stp x4, x5, [x9, #32] + stp x6, x7, [x9, #48] mov x0, x9 -- cgit v1.2.3