From ffa7c8b7f8033413d7088edcd9947bf782b9d3fd Mon Sep 17 00:00:00 2001

From: Andreas Krebbel <krebbel@linux.ibm.com>

Date: Mon, 23 Mar 2020 09:04:54 +0100

Subject: [PATCH 1/4] S390x: Add Support for s390x arch

---

 build/Jamfile.v2                   |  13 +++

 build/architecture.jam             |   4 +

 src/asm/jump_s390x_sysv_elf_gas.S  | 145 +++++++++++++++++++++++++++++

 src/asm/make_s390x_sysv_elf_gas.S  |  97 +++++++++++++++++++

 src/asm/ontop_s390x_sysv_elf_gas.S | 143 ++++++++++++++++++++++++++++

 5 files changed, 402 insertions(+)

 create mode 100644 src/asm/jump_s390x_sysv_elf_gas.S

 create mode 100644 src/asm/make_s390x_sysv_elf_gas.S

 create mode 100644 src/asm/ontop_s390x_sysv_elf_gas.S

diff --git a/build/Jamfile.v2 b/build/Jamfile.v2

index 719ca91..08f1675 100644

--- a/libs/context/build/Jamfile.v2

+++ b/libs/context/build/Jamfile.v2

@@ -447,6 +447,19 @@ alias asm_sources

      <binary-format>mach-o

    ;

+# S390X

+# S390X/SYSV/ELF

+alias asm_sources

+   : asm/make_s390x_sysv_elf_gas.S

+     asm/jump_s390x_sysv_elf_gas.S

+     asm/ontop_s390x_sysv_elf_gas.S

+   : <abi>sysv

+     <address-model>64

+     <architecture>s390x

+     <binary-format>elf

+     <toolset>gcc

+   ;

+

 # X86

 # X86/SYSV/ELF

 alias asm_sources

diff --git a/build/architecture.jam b/build/architecture.jam

index 81dcb49..f62806d 100644

--- a/libs/context/build/architecture.jam

+++ b/libs/context/build/architecture.jam

@@ -63,6 +63,10 @@ rule deduce-architecture ( properties * )

         {

             return <architecture>power ;

         }

+        else if [ configure.builds /boost/architecture//s390x : $(properties) : s390x ]

+        {

+            return <architecture>s390x ;

+        }

         else if [ configure.builds /boost/architecture//sparc : $(properties) : sparc ]

         {

             return <architecture>sparc ;

diff --git a/src/asm/jump_s390x_sysv_elf_gas.S b/src/asm/jump_s390x_sysv_elf_gas.S

new file mode 100644

index 0000000..c011d53

--- /dev/null

+++ b/libs/context/src/asm/jump_s390x_sysv_elf_gas.S

@@ -0,0 +1,145 @@

+/*******************************************************

+*                                                     *

+*  -------------------------------------------------  *

+*  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *

+*  -------------------------------------------------  *

+*  |     0     |     8     |    16     |     24    |  *

+*  -------------------------------------------------  *

+*  |    R6     |    R7     |    R8     |    R9     |  *

+*  -------------------------------------------------  *

+*  -------------------------------------------------  *

+*  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *

+*  -------------------------------------------------  *

+*  |     32    |    40     |     48    |     56    |  *

+*  -------------------------------------------------  *

+*  |    R10    |    R11    |     R12   |     R13   |  *

+*  -------------------------------------------------  *

+*  -------------------------------------------------  *

+*  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *

+*  -------------------------------------------------  *

+*  |     64    |    72     |     80    |     88    |  *

+*  -------------------------------------------------  *

+*  |   R14/LR  |    R15    |     F1    |     F3    |  *

+*  -------------------------------------------------  *

+*  -------------------------------------------------  *

+*  |  24 |  25 |  26 |  27 |  28 | 29  |           |  *

+*  -------------------------------------------------  *

+*  |     96    |    104    |    112    |    120    |  *

+*  -------------------------------------------------  *

+*  |    F5     |    F7     |     PC    |           |  *

+*  -------------------------------------------------  *

+* *****************************************************/

+

+.file  "jump_s390x_sysv_elf_gas.S"

+.text

+.align  4 # According to the sample code in the ELF ABI docs

+.global jump_fcontext

+.type   jump_fcontext, @function

+

+jump_fcontext:

+    

+    # Reserved the space for stack to store the data of current context

+    # before we jump to the new context.

+    lay 15,-120(15)

+

+    # save the registers to the stack

+    stg 6,  0(15)       # save R6     

+    stg 7,  8(15)       # save R7     

+    stg 8,  16(15)      # save R8

+    stg 9,  24(15)      # save R9

+    stg 10, 32(15)      # save R10

+    stg 11, 40(15)      # save R11

+    stg 12, 48(15)      # save R12

+    stg 13, 56(15)      # save R13

+    stg 14, 64(15)      # save R14

+    stg 15, 72(15)      # save R15

+

+    # save the floating point registers

+    # Load the FPR into R0 then save it to the stack

+    # Load F1 into R0

+    lgdr 0,1 

+    stg  0,80(15)       # save F1

+

+    # Load F3 into R0

+    lgdr 0,3

+    stg  0,88(15)       # save F3

+

+    # Load F5 into R0

+    lgdr 0,5

+    stg  0,96(15)       # save F5

+

+    # Load F7 into R0

+    lgdr 0,7

+    stg  0,104(15)      # save F7

+

+    # Save LR as PC

+    stg 14,112(15)

+

+    # Store the SP pointing to the old context-data into R0

+    lgr 0,15

+

+    # Get the SP pointing to the new context-data

+    # Note: Since the return type of the jump_fcontext is struct whose

+    # size is more than 8. The compiler automatically passes the 

+    # address of the transfer_t where the data needs to store into R2.

+

+    # Hence the first param passed to the jump_fcontext which represent

+    # the fctx we want to switch to is present in R3

+    # R2 --> Address of the return transfer_t struct

+    # R3 --> Context we want to switch to

+    # R4 --> Data

+    lgr 15,3

+

+    # Load the registers with the data present in context-data of the

+    # context we are going to switch to

+    lg 6,  0(15)       # restore R6     

+    lg 7,  8(15)       # restore R7     

+    lg 8,  16(15)      # restore R8

+    lg 9,  24(15)      # restore R9

+    lg 10, 32(15)      # restore R10

+    lg 11, 40(15)      # restore R11

+    lg 12, 48(15)      # restore R12

+    lg 13, 56(15)      # restore R13

+    lg 14, 64(15)      # restore R14

+

+    # Restore Floating point registers

+    lg   1,80(15)

+    ldgr 1,1            # restore F1

+

+    lg   1,88(15)

+    ldgr 1,3            # restore F3

+

+    lg   1,96(15)

+    ldgr 1,5            # restore F5

+

+    lg   1,104(15)

+    ldgr 1,7            # restore F7

+

+    # Load PC

+    lg  1,112(15)

+

+    # Adjust the stack

+    lay 15, 120(15)

+

+    # R2 --> Address where the return transfer_t is stored

+    # R0 --> FCTX

+    # R4 --> DATA

+

+    # Store the elements to return transfer_t

+    stg 15, 0(2)

+    stg 4, 8(2)

+

+    # Note: The address in R2 points to the place where the return

+    # transfer_t is stored. Since context_function take transfer_t

+    # as first parameter. And R2 is the register which holds the

+    # first parameter value.

+

+    #jump to context

+    br 1

+

+.size   jump_fcontext,.-jump_fcontext

+# Mark that we don't need executable stack.

+.section .note.GNU-stack,"",%progbits

+

+

+

diff --git a/src/asm/make_s390x_sysv_elf_gas.S b/src/asm/make_s390x_sysv_elf_gas.S

new file mode 100644

index 0000000..f566533

--- /dev/null

+++ b/libs/context/src/asm/make_s390x_sysv_elf_gas.S

@@ -0,0 +1,97 @@

+/*******************************************************

+*                                                     *

+*  -------------------------------------------------  *

+*  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *

+*  -------------------------------------------------  *

+*  |     0     |     8     |    16     |     24    |  *

+*  -------------------------------------------------  *

+*  |    R6     |    R7     |    R8     |    R9     |  *

+*  -------------------------------------------------  *

+*  -------------------------------------------------  *

+*  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *

+*  -------------------------------------------------  *

+*  |     32    |    40     |     48    |     56    |  *

+*  -------------------------------------------------  *

+*  |    R10    |    R11    |     R12   |     R13   |  *

+*  -------------------------------------------------  *

+*  -------------------------------------------------  *

+*  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *

+*  -------------------------------------------------  *

+*  |     64    |    72     |     80    |     88    |  *

+*  -------------------------------------------------  *

+*  |   R14/LR  |    R15    |     F1    |     F3    |  *

+*  -------------------------------------------------  *

+*  -------------------------------------------------  *

+*  |  24 |  25 |  26 |  27 |  28 | 29  |           |  *

+*  -------------------------------------------------  *

+*  |     96    |    104    |    112    |    120    |  *

+*  -------------------------------------------------  *

+*  |    F5     |    F7     |     PC    |           |  *

+*  -------------------------------------------------  *

+* *****************************************************/

+

+.file  "make_s390x_sysv_elf_gas.S"

+.text

+.align  4 # According to the sample code in the ELF ABI docs

+.global make_fcontext

+.type 	 make_fcontext, @function

+

+make_fcontext:

+

+		# make_fcontext takes in 3 arguments

+		# arg1 --> The address where the context needs to be made

+		# arg2 --> The size of the context

+		# arg3 --> The address of the context function

+

+		# According to the ELF ABI, the register R2 holds the first arg.

+		# R2 also acts as the register which holds return value

+		# Register R3 holds the second, R4 the third so on.

+

+		# Shift the address in R2 to a lower 8 byte boundary

+

+		# This is done because according to the ELF ABI Doc, the stack needs

+		# to be 8 byte aligned.

+		# In order to do so, we need to make sure that the address is divisible

+		# by 8. We can check this, by checking if the the last 3 bits of the

+		# address is zero or not. If not AND it with `-8`. 

+

+		# Here we AND the lower 16 bits of the memory address present in the 

+		# R2 with the bits 1111 1111 1111 1000 which when converted into

+		# decimal is 65528

+		nill    2,65528

+

+		# Reserve space for context-data on context-stack.

+		# This is done by shifting the SP/address by 112 bytes.

+		lay 2,-120(2)

+

+		# third arg of make_fcontext() == address of the context-function

+		# Store the address as a PC to jump in, whenever we call the 

+		# make_fcontext.

+		stg 4,112(2)

+

+		# Save the address of finish as return-address for context-function

+		# This will be entered after context-function return

+		# The address of finish will be saved in Link register, this register

+		# specifies where we need to jump after the function executes

+		# completely.

+		larl 1,finish

+		stg  1,64(2)

+

+		# Return pointer to context data

+		# R14 acts as the link register

+		# R2 holds the address of the context stack. When we return from the

+		# make_fcontext, R2 is passed back.

+		br 14 

+

+	finish:

+

+		# In finish tasks, you load the exit code and exit the make_fcontext

+		# This is called when the context-function is entirely executed

+

+		lghi 2,0

+		brasl 14,_exit

+

+.size   make_fcontext,.-make_fcontext

+# Mark that we don't need executable stack.

+.section .note.GNU-stack,"",%progbits

+

diff --git a/src/asm/ontop_s390x_sysv_elf_gas.S b/src/asm/ontop_s390x_sysv_elf_gas.S

new file mode 100644

index 0000000..7ab2cf5

--- /dev/null

+++ b/libs/context/src/asm/ontop_s390x_sysv_elf_gas.S

@@ -0,0 +1,143 @@

+/*******************************************************

+*                                                     *

+*  -------------------------------------------------  *

+*  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  *

+*  -------------------------------------------------  *

+*  |     0     |     8     |    16     |     24    |  *

+*  -------------------------------------------------  *

+*  |    R6     |    R7     |    R8     |    R9     |  *

+*  -------------------------------------------------  *

+*  -------------------------------------------------  *

+*  |  8  |  9  |  10 |  11 |  12 |  13 |  14 |  15 |  *

+*  -------------------------------------------------  *

+*  |     32    |    40     |     48    |     56    |  *

+*  -------------------------------------------------  *

+*  |    R10    |    R11    |     R12   |     R13   |  *

+*  -------------------------------------------------  *

+*  -------------------------------------------------  *

+*  |  16 |  17 |  18 |  19 |  20 |  21 |  22 |  23 |  *

+*  -------------------------------------------------  *

+*  |     64    |    72     |     80    |     88    |  *

+*  -------------------------------------------------  *

+*  |   R14/LR  |    R15    |     F1    |     F3    |  *

+*  -------------------------------------------------  *

+*  -------------------------------------------------  *

+*  |  24 |  25 |  26 |  27 |  28 | 29  |           |  *

+*  -------------------------------------------------  *

+*  |     96    |    104    |    112    |    120    |  *

+*  -------------------------------------------------  *

+*  |    F5     |    F7     |     PC    |           |  *

+*  -------------------------------------------------  *

+* *****************************************************/

+

+.file  "ontop_s390x_sysv_elf_gas.S"

+.text

+.align  4 # According to the sample code in the ELF ABI docs

+.global ontop_fcontext

+.type   ontop_fcontext, @function

+

+ontop_fcontext:

+    

+    # Reserved the space for stack to store the data of current context

+    # before we jump to the new context.

+    lay 15,-120(15)

+

+    # save the registers to the stack

+    stg 6,  0(15)       # save R6     

+    stg 7,  8(15)       # save R7     

+    stg 8,  16(15)      # save R8

+    stg 9,  24(15)      # save R9

+    stg 10, 32(15)      # save R10

+    stg 11, 40(15)      # save R11

+    stg 12, 48(15)      # save R12

+    stg 13, 56(15)      # save R13

+    stg 14, 64(15)      # save R14

+    stg 15, 72(15)      # save R15

+

+    # save the floating point registers

+    # Load the FPR into R0 then save it to the stack

+    # Load F1 into R0

+    lgdr 0,1 

+    stg  0,80(15)       # save F1

+

+    # Load F3 into R0

+    lgdr 0,3

+    stg  0,88(15)       # save F3

+

+    # Load F5 into R0

+    lgdr 0,5

+    stg  0,96(15)       # save F5

+

+    # Load F7 into R0

+    lgdr 0,7

+    stg  0,104(15)      # save F7

+

+    # Save LR as PC

+    stg 14,112(15)

+

+    # Store the SP pointing to the old context-data into R0

+    lgr 0,15

+

+    # Get the SP pointing to the new context-data

+    # Note: Since the return type of the jump_fcontext is struct whose

+    # size is more than 8. The compiler automatically passes the 

+    # address of the transfer_t where the data needs to store into R2.

+

+    # Hence the first param passed to the jump_fcontext which represent

+    # the fctx we want to switch to is present in R3

+    # R2 --> Address of the return transfer_t struct

+    # R3 --> Context we want to switch to

+    # R4 --> Data

+    lgr 15,3

+

+    # Load the registers with the data present in context-data of the

+    # context we are going to switch to

+    lg 6,  0(15)       # restore R6     

+    lg 7,  8(15)       # restore R7     

+    lg 8,  16(15)      # restore R8

+    lg 9,  24(15)      # restore R9

+    lg 10, 32(15)      # restore R10

+    lg 11, 40(15)      # restore R11

+    lg 12, 48(15)      # restore R12

+    lg 13, 56(15)      # restore R13

+    lg 14, 64(15)      # restore R14

+    lg 15, 72(15)      # restore R15

+

+    # Restore Floating point registers

+    lg   1,80(15)

+    ldgr 1,1            # restore F1

+

+    lg   1,88(15)

+    ldgr 1,3            # restore F3

+

+    lg   1,96(15)

+    ldgr 1,5            # restore F5

+

+    lg   1,104(15)

+    ldgr 1,7            # restore F7

+

+    # Skip PC

+

+    # Adjust the stack

+    lay 15, 120(15)

+

+    # R2 --> Address where the return transfer_t is stored

+    # R0 --> FCTX

+    # R4 --> DATA

+    # R5 --> Context function

+

+    # Store the elements to return transfer_t

+    stg 15, 0(2)

+    stg 4, 8(2)

+

+    # Note: The address in R2 points to the place where the return

+    # transfer_t is stored. Since context_function take transfer_t

+    # as first parameter. And R2 is the register which holds the

+    # first parameter value.

+

+    #jump to context function

+    br 5

+

+.size   ontop_fcontext,.-ontop_fcontext

+# Mark that we don't need executable stack.

+.section .note.GNU-stack,"",%progbits

-- 

2.18.1