ArmPlatformPkg/PrePi: 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.

This removes the last remaining user of the associated PCD, so drop that
as well.

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

ArmPlatformPkg/ArmPlatformPkg.dec

@@ -61,7 +61,6 @@
   # Stack for CPU Cores in Non Secure Mode
   gArmPlatformTokenSpaceGuid.PcdCPUCoresStackBase|0|UINT64|0x00000009
   gArmPlatformTokenSpaceGuid.PcdCPUCorePrimaryStackSize|0x10000|UINT32|0x00000037
-  gArmPlatformTokenSpaceGuid.PcdCPUCoreSecondaryStackSize|0x1000|UINT32|0x0000000A
 
   # Size of the region used by UEFI in permanent memory (Reserved 128MB by default)
   gArmPlatformTokenSpaceGuid.PcdSystemMemoryUefiRegionSize|0x08000000|UINT32|0x00000015

ArmPlatformPkg/PrePi/AArch64/ModuleEntryPoint.S

@@ -11,11 +11,6 @@ ASM_FUNC(_ModuleEntryPoint)
   // Do early platform specific actions
   bl    ASM_PFX(ArmPlatformPeiBootAction)
 
-  // Get ID of this CPU in multi-core system
-  bl    ASM_PFX(ArmReadMpidr)
-  // Keep a copy of the MpId register value
-  mov   x10, x0
-
 _SetSVCMode:
 // Check if we can install the stack at the top of the System Memory or if we need
 // to install the stacks at the bottom of the Firmware Device (case the FD is located
@@ -71,31 +66,16 @@ _GetBaseUefiMemory:
   sub   x11, x1, x4
 
 _GetStackBase:
-  // r1 = The top of the Mpcore Stacks
+  // r1 = The top of the stack
+  mov   sp, x1
+
   // Stack for the primary core = PrimaryCoreStack
   MOV32 (x2, FixedPcdGet32(PcdCPUCorePrimaryStackSize))
   sub   x12, x1, x2
 
-  // Stack for the secondary core = Number of Cores - 1
-  MOV32 (x1, (FixedPcdGet32(PcdCoreCount) - 1) * FixedPcdGet32(PcdCPUCoreSecondaryStackSize))
-  sub   x12, x12, x1
+  // Get ID of this CPU in multi-core system
+  bl    ASM_PFX(ArmReadMpidr)
 
-  // x12 = The base of the MpCore Stacks (primary stack & secondary stacks)
-  mov   x0, x12
-  mov   x1, x10
-  //ArmPlatformStackSet(StackBase, MpId, PrimaryStackSize, SecondaryStackSize)
-  MOV32 (x2, FixedPcdGet32(PcdCPUCorePrimaryStackSize))
-  MOV32 (x3, FixedPcdGet32(PcdCPUCoreSecondaryStackSize))
-  bl    ASM_PFX(ArmPlatformStackSet)
-
-  // Is it the Primary Core ?
-  mov   x0, x10
-  bl    ASM_PFX(ArmPlatformIsPrimaryCore)
-  cmp   x0, #1
-  bne   _PrepareArguments
-
-_PrepareArguments:
-  mov   x0, x10
   mov   x1, x11
   mov   x2, x12
 

ArmPlatformPkg/PrePi/Arm/ModuleEntryPoint.S

@@ -13,11 +13,6 @@ ASM_FUNC(_ModuleEntryPoint)
   // Do early platform specific actions
   bl    ASM_PFX(ArmPlatformPeiBootAction)
 
-  // Get ID of this CPU in multi-core system
-  bl    ASM_PFX(ArmReadMpidr)
-  // Keep a copy of the MpId register value
-  mov   r8, r0
-
 _SetSVCMode:
   // Enter SVC mode, Disable FIQ and IRQ
   mov     r1, #(CPSR_MODE_SVC | CPSR_IRQ | CPSR_FIQ)
@@ -81,34 +76,18 @@ _GetBaseUefiMemory:
   sub   r9, r1, r4
 
 _GetStackBase:
-  // r1 = The top of the Mpcore Stacks
+  // r1 = The top of the stack
+  mov   sp, r1
+
   // Stack for the primary core = PrimaryCoreStack
   MOV32 (r2, FixedPcdGet32(PcdCPUCorePrimaryStackSize))
   sub   r10, r1, r2
 
-  // Stack for the secondary core = Number of Cores - 1
-  MOV32 (r1, (FixedPcdGet32(PcdCoreCount) - 1) * FixedPcdGet32(PcdCPUCoreSecondaryStackSize))
-  sub   r10, r10, r1
+  // Get ID of this CPU in multi-core system
+  bl    ASM_PFX(ArmReadMpidr)
 
-  // r10 = The base of the MpCore Stacks (primary stack & secondary stacks)
-  mov   r0, r10
-  mov   r1, r8
-  //ArmPlatformStackSet(StackBase, MpId, PrimaryStackSize, SecondaryStackSize)
-  MOV32 (r2, FixedPcdGet32(PcdCPUCorePrimaryStackSize))
-  MOV32 (r3, FixedPcdGet32(PcdCPUCoreSecondaryStackSize))
-  bl    ASM_PFX(ArmPlatformStackSet)
-
-  // Is it the Primary Core ?
-  mov   r0, r8
-  bl    ASM_PFX(ArmPlatformIsPrimaryCore)
-  cmp   r0, #1
-  bne   _PrepareArguments
-
-_PrepareArguments:
-  mov   r0, r8
   mov   r1, r9
   mov   r2, r10
-  mov   r3, sp
 
   // Move sec startup address into a data register
   // Ensure we're jumping to FV version of the code (not boot remapped alias)

ArmPlatformPkg/PrePi/PeiUniCore.inf

@@ -48,7 +48,6 @@
   DebugAgentLib
   PrePiLib
   ArmPlatformLib
-  ArmPlatformStackLib
   MemoryAllocationLib
   HobLib
   PrePiHobListPointerLib
@@ -78,7 +77,6 @@
   gArmTokenSpaceGuid.PcdFvSize
 
   gArmPlatformTokenSpaceGuid.PcdCPUCorePrimaryStackSize
-  gArmPlatformTokenSpaceGuid.PcdCPUCoreSecondaryStackSize
 
   gArmPlatformTokenSpaceGuid.PcdSystemMemoryUefiRegionSize