Changeset 0366d09d in mainline for kernel/arch

Timestamp:

2023-02-07T16:49:43Z (3 years ago)

Author:

Jiří Zárevúcky <zarevucky.jiri@…>

Branches:

master, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

78acbc72

Parents:

1eaead4

git-author:

Jiří Zárevúcky <zarevucky.jiri@…> (2022-08-14 14:08:42)

git-committer:

Jiří Zárevúcky <zarevucky.jiri@…> (2023-02-07 16:49:43)

Message:

Avoid separate allocation for FPU context

With _Alignas, we can encode alignment in the type itself and
include it directly as a member of thread_t, thus removing
the need for a separate allocation.

The alignment requirement is never more than 16 bytes,
so this adds only minimal extra padding to the structure.

Location:

kernel/arch

Files:

• abs32le/include/arch/fpu_context.h (modified) (1 diff)
• arm32/include/arch/fpu_context.h (modified) (1 diff)
• arm64/include/arch/fpu_context.h (modified) (1 diff)
• arm64/include/arch/fpu_context_struct.h (modified) (1 diff)
• ia32/include/arch/fpu_context.h (modified) (1 diff)
• ia64/include/arch/fpu_context.h (modified) (2 diffs)
• mips32/include/arch/fpu_context.h (modified) (1 diff)
• mips32/include/arch/fpu_context_struct.h (modified) (1 diff)
• ppc32/include/arch/fpu_context.h (modified) (1 diff)
• ppc32/include/arch/fpu_context_struct.h (modified) (1 diff)
• sparc64/include/arch/fpu_context.h (modified) (1 diff)

kernel/arch/abs32le/include/arch/fpu_context.h

@@ -36 +36 @@
 #define KERN_abs32le_FPU_CONTEXT_H_
 
-#define FPU_CONTEXT_ALIGN  16
-
 /*
  * On real hardware this stores the FPU registers

kernel/arch/arm32/include/arch/fpu_context.h

@@ -40 +40 @@
 #include <stdint.h>
 
-#define FPU_CONTEXT_ALIGN    8
-
 /*
  * ARM Architecture reference manual, p B-1529.
  */
 typedef struct {
-        uint32_t fpexc;
+        _Alignas(8) uint32_t fpexc;
         uint32_t fpscr;
         uint32_t s[64];

kernel/arch/arm64/include/arch/fpu_context.h

@@ -39 +39 @@
 #include <arch/fpu_context_struct.h>
 
-#define FPU_CONTEXT_ALIGN  16
-
 #endif
 

kernel/arch/arm64/include/arch/fpu_context_struct.h

@@ -42 +42 @@
 /** ARM64 FPU context. */
 typedef struct fpu_context {
-        uint128_t vregs[32];
+        _Alignas(16) uint128_t vregs[32];
         uint32_t fpcr;
         uint32_t fpsr;

kernel/arch/ia32/include/arch/fpu_context.h

@@ -38 +38 @@
 #include <stdint.h>
 
-#define FPU_CONTEXT_ALIGN  16
-
 typedef struct {
-        uint8_t fpu[512];  /* FXSAVE & FXRSTOR storage area */
+        _Alignas(16) uint8_t fpu[512];  /* FXSAVE & FXRSTOR storage area */
 } fpu_context_t;
 

kernel/arch/ia64/include/arch/fpu_context.h

@@ -36 +36 @@
 #define KERN_ia64_FPU_CONTEXT_H_
 
-#define FPU_CONTEXT_ALIGN 16
-
 #include <_bits/int128_t.h>
 
@@ -43 +41 @@
 
 typedef struct {
-        uint128_t fr[FRS];
+        _Alignas(16) uint128_t fr[FRS];
 } fpu_context_t;
 

kernel/arch/mips32/include/arch/fpu_context.h

@@ -39 +39 @@
 #include <arch/fpu_context_struct.h>
 
-#define FPU_CONTEXT_ALIGN    sizeof(sysarg_t)
-
 #endif
 

kernel/arch/mips32/include/arch/fpu_context_struct.h

@@ -42 +42 @@
 
 typedef struct fpu_context {
-        sysarg_t dregs[32];
+        _Alignas(sizeof(sysarg_t)) sysarg_t dregs[32];
         sysarg_t cregs[32];
 } fpu_context_t;

kernel/arch/ppc32/include/arch/fpu_context.h

@@ -36 +36 @@
 #define KERN_ppc32_FPU_CONTEXT_H_
 
-#define FPU_CONTEXT_ALIGN       8
-
 #include <arch/fpu_context_struct.h>
 

kernel/arch/ppc32/include/arch/fpu_context_struct.h

@@ -70 +70 @@
 
 typedef struct fpu_context {
-        uint64_t fr0;
+        _Alignas(8) uint64_t fr0;
         uint64_t fr1;
         uint64_t fr2;

kernel/arch/sparc64/include/arch/fpu_context.h

@@ -38 +38 @@
 #include <stdint.h>
 
-#define FPU_CONTEXT_ALIGN       8
-
 typedef struct {
-        uint64_t        d[32];
-        uint64_t        fsr;
+        _Alignas(8) uint64_t d[32];
+        uint64_t fsr;
 } fpu_context_t;