ArmPlatformPkg/PrePeiCore: Drop secondary stack handling

This SEC driver is single CPU only now, so all of the secondary stack
handling is dead code, and can be removed.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

ArmPlatformPkg/PrePeiCore/AArch64/PrePeiCoreEntryPoint.S

@@ -30,41 +30,23 @@ ASM_FUNC(_ModuleEntryPoint)
   b     ASM_PFX(MainEntryPoint)
 
 ASM_PFX(MainEntryPoint):
-  // Identify CPU ID
-  bl    ASM_PFX(ArmReadMpidr)
-  // Keep a copy of the MpId register value
-  mov   x5, x0
-
-  // Is it the Primary Core ?
-  bl    ASM_PFX(ArmPlatformIsPrimaryCore)
-
   // Get the top of the primary stacks (and the base of the secondary stacks)
   MOV64 (x1, FixedPcdGet64(PcdCPUCoresStackBase) + FixedPcdGet32(PcdCPUCorePrimaryStackSize))
 
-  // x0 is equal to 1 if I am the primary core
-  cmp   x0, #1
-  b.eq   _SetupPrimaryCoreStack
+  // Set up the stack pointer
+  mov   sp, x1
 
-_SetupSecondaryCoreStack:
-  // x1 contains the base of the secondary stacks
+  // Apply the init value to the entire stack
+  MOV64 (x8, FixedPcdGet64 (PcdCPUCoresStackBase))
+  MOV64 (x9, FixedPcdGet32 (PcdInitValueInTempStack) |\
+             FixedPcdGet32 (PcdInitValueInTempStack) << 32)
+0:stp   x9, x9, [x8], #16
+  cmp   x8, x1
+  b.lt  0b
 
-  // Get the Core Position
-  mov   x6, x1      // Save base of the secondary stacks
-  mov   x0, x5
-  bl    ASM_PFX(ArmPlatformGetCorePosition)
-  // The stack starts at the top of the stack region. Add '1' to the Core Position to get the top of the stack
-  add   x0, x0, #1
-
-  // StackOffset = CorePos * StackSize
-  MOV32 (x2, FixedPcdGet32(PcdCPUCoreSecondaryStackSize))
-  mul   x0, x0, x2
-  // SP = StackBase + StackOffset
-  add   sp, x6, x0
-
-_PrepareArguments:
   // The PEI Core Entry Point has been computed by GenFV and stored in the second entry of the Reset Vector
   MOV64 (x2, FixedPcdGet64(PcdFvBaseAddress))
-  ldr   x1, [x2, #8]
+  ldr   x0, [x2, #8]
 
   // Move sec startup address into a data register
   // Ensure we're jumping to FV version of the code (not boot remapped alias)
@@ -74,17 +56,6 @@ _PrepareArguments:
   mov   x29, xzr
 
   // Jump to PrePeiCore C code
-  //    x0 = mp_id
-  //    x1 = pei_core_address
+  //    x0 = pei_core_address
   mov   x0, x5
   blr   x3
-
-_SetupPrimaryCoreStack:
-  mov   sp, x1
-  MOV64 (x8, FixedPcdGet64 (PcdCPUCoresStackBase))
-  MOV64 (x9, FixedPcdGet32 (PcdInitValueInTempStack) |\
-             FixedPcdGet32 (PcdInitValueInTempStack) << 32)
-0:stp   x9, x9, [x8], #16
-  cmp   x8, x1
-  b.lt  0b
-  b     _PrepareArguments

ArmPlatformPkg/PrePeiCore/Arm/PrePeiCoreEntryPoint.S

@@ -11,54 +11,13 @@ ASM_FUNC(_ModuleEntryPoint)
   // Do early platform specific actions
   bl    ASM_PFX(ArmPlatformPeiBootAction)
 
-  // Identify CPU ID
-  bl    ASM_PFX(ArmReadMpidr)
-  // Keep a copy of the MpId register value
-  mov   r5, r0
-
-  // Is it the Primary Core ?
-  bl    ASM_PFX(ArmPlatformIsPrimaryCore)
-
   // Get the top of the primary stacks (and the base of the secondary stacks)
   MOV32 (r1, FixedPcdGet64(PcdCPUCoresStackBase) + FixedPcdGet32(PcdCPUCorePrimaryStackSize))
 
-  // r0 is equal to 1 if I am the primary core
-  cmp   r0, #1
-  beq   _SetupPrimaryCoreStack
-
-_SetupSecondaryCoreStack:
-  // r1 contains the base of the secondary stacks
-
-  // Get the Core Position
-  mov   r6, r1      // Save base of the secondary stacks
-  mov   r0, r5
-  bl    ASM_PFX(ArmPlatformGetCorePosition)
-  // The stack starts at the top of the stack region. Add '1' to the Core Position to get the top of the stack
-  add   r0, r0, #1
-
-  // StackOffset = CorePos * StackSize
-  MOV32 (r2, FixedPcdGet32(PcdCPUCoreSecondaryStackSize))
-  mul   r0, r0, r2
-  // SP = StackBase + StackOffset
-  add   sp, r6, r0
-
-_PrepareArguments:
-  // The PEI Core Entry Point has been computed by GenFV and stored in the second entry of the Reset Vector
-  MOV32 (r2, FixedPcdGet32(PcdFvBaseAddress))
-  ldr   r1, [r2, #4]
-
-  // Move sec startup address into a data register
-  // Ensure we're jumping to FV version of the code (not boot remapped alias)
-  ldr   r3, =ASM_PFX(CEntryPoint)
-
-  // Jump to PrePeiCore C code
-  //    r0 = mp_id
-  //    r1 = pei_core_address
-  mov   r0, r5
-  blx   r3
-
-_SetupPrimaryCoreStack:
+  // Set up the stack pointer
   mov   sp, r1
+
+  // Apply the init value to the entire stack
   MOV32 (r8, FixedPcdGet64 (PcdCPUCoresStackBase))
   MOV32 (r9, FixedPcdGet32 (PcdInitValueInTempStack))
   mov   r10, r9
@@ -67,7 +26,15 @@ _SetupPrimaryCoreStack:
 0:stm   r8!, {r9-r12}
   cmp   r8, r1
   blt   0b
-  b     _PrepareArguments
 
-_NeverReturn:
-  b _NeverReturn
+  // The PEI Core Entry Point has been computed by GenFV and stored in the second entry of the Reset Vector
+  MOV32 (r2, FixedPcdGet32(PcdFvBaseAddress))
+  ldr   r0, [r2, #4]
+
+  // Move sec startup address into a data register
+  // Ensure we're jumping to FV version of the code (not boot remapped alias)
+  ldr   r3, =ASM_PFX(CEntryPoint)
+
+  // Jump to PrePeiCore C code
+  //    r0 = pei_core_address
+  blx   r3

ArmPlatformPkg/PrePeiCore/PrePeiCore.c

@@ -81,7 +81,6 @@ PrintFirmwareVersion (
 
 VOID
 CEntryPoint (
-  IN  UINTN                     MpId,
   IN  EFI_PEI_CORE_ENTRY_POINT  PeiCoreEntryPoint
   )
 {
@@ -128,7 +127,7 @@ CEntryPoint (
   SaveAndSetDebugTimerInterrupt (TRUE);
 
   // Initialize the platform specific controllers
-  ArmPlatformInitialize (MpId);
+  ArmPlatformInitialize (ArmReadMpidr ());
 
   // Goto primary Main.
   PrimaryMain (PeiCoreEntryPoint);

ArmPlatformPkg/PrePeiCore/PrePeiCoreUniCore.inf

@@ -62,6 +62,5 @@
 
   gArmPlatformTokenSpaceGuid.PcdCPUCoresStackBase
   gArmPlatformTokenSpaceGuid.PcdCPUCorePrimaryStackSize
-  gArmPlatformTokenSpaceGuid.PcdCPUCoreSecondaryStackSize
 
   gEfiMdeModulePkgTokenSpaceGuid.PcdInitValueInTempStack