[Minios-devel] [UNIKRAFT PATCH v2 2/6] plat/common: Implement a few extra registers stub helpers on arm64

[Jia He <justin.he@xxxxxxx>]

On arm64, we don't need the extra registers during context switching so
far. This patch decouple the arch specific structures/functions info arch
related files.

Without this patch, it will report compilation error as follows:
plat/common/include/x86/cpu.h/:: In function 'save_extregs':
plat/common/include/x86/cpu.h:72:3: error: impossible constraint in 'asm'
   asm volatile("xsave (%0)" :: "r"(ctx->extregs),
   ^~~
plat/common/include/x86/cpu.h:76:3: error: impossible constraint in 'asm'
   asm volatile("xsaveopt (%0)" :: "r"(ctx->extregs),

Signed-off-by: Jia He <justin.he@xxxxxxx>
---
 plat/common/include/arm/arm64/cpu.h | 28 ++++++++++++++++++++++++++++
 plat/common/include/x86/cpu.h       | 24 ++++++++++++++++++++++++
 plat/common/sw_ctx.c                | 16 ++++------------
 3 files changed, 56 insertions(+), 12 deletions(-)

diff --git a/plat/common/include/arm/arm64/cpu.h 
b/plat/common/include/arm/arm64/cpu.h
index 1495192..23adf8d 100644
--- a/plat/common/include/arm/arm64/cpu.h
+++ b/plat/common/include/arm/arm64/cpu.h
@@ -33,6 +33,10 @@
  */
 
 #include <inttypes.h>
+#include <uk/essentials.h>
+#include <sw_ctx.h>
+#include <uk/alloc.h>
+#include <uk/assert.h>
 
 /* Define macros to access IO registers */
 #define __IOREG_READ(bits) \
@@ -108,3 +112,27 @@ int32_t smcc_psci_smc_call(uint32_t, uint64_t, uint64_t, 
uint64_t);
 void halt(void);
 void reset(void);
 void system_off(void);
+
+static inline void save_extregs(struct sw_ctx *ctx __unused)
+{
+}
+
+static inline void restore_extregs(struct sw_ctx *ctx __unused)
+{
+}
+
+static inline struct sw_ctx *arch_alloc_sw_ctx(struct uk_alloc *allocator)
+{
+       struct sw_ctx *ctx;
+
+       ctx = uk_malloc(allocator, sizeof(struct sw_ctx));
+       uk_pr_debug("Allocating %lu bytes for sw ctx at %p\n",
+                  sizeof(struct sw_ctx), ctx);
+
+       return ctx;
+}
+
+static inline void arch_init_extregs(struct sw_ctx *ctx)
+{
+       ctx->extregs = (uintptr_t)ctx + sizeof(struct sw_ctx);
+}
diff --git a/plat/common/include/x86/cpu.h b/plat/common/include/x86/cpu.h
index 8acd71e..d2cf53a 100644
--- a/plat/common/include/x86/cpu.h
+++ b/plat/common/include/x86/cpu.h
@@ -34,6 +34,9 @@
 #include <x86/cpu_defs.h>
 #include <sw_ctx.h>
 #include <stdint.h>
+#include <uk/assert.h>
+#include <uk/alloc.h>
+#include <string.h>
 
 void halt(void);
 void system_off(void);
@@ -98,6 +101,27 @@ static inline void restore_extregs(struct sw_ctx *ctx)
        }
 }
 
+static inline struct sw_ctx *arch_alloc_sw_ctx(struct uk_alloc *allocator)
+{
+       struct sw_ctx *ctx;
+       size_t sz;
+
+       sz = ALIGN_UP(sizeof(struct sw_ctx), x86_cpu_features.extregs_align)
+               + x86_cpu_features.extregs_size;
+       ctx = uk_malloc(allocator, sz);
+       uk_pr_debug("Allocating %lu bytes for sw ctx at %p\n", sz, ctx);
+
+       return ctx;
+}
+
+static inline void arch_init_extregs(struct sw_ctx *ctx)
+{
+       ctx->extregs = ALIGN_UP(((uintptr_t)ctx + sizeof(struct sw_ctx)),
+                               x86_cpu_features.extregs_align);
+       // Initialize extregs area: zero out, then save a valid layout to it.
+       memset((void *)ctx->extregs, 0, x86_cpu_features.extregs_size);
+}
+
 static inline void _init_cpufeatures(void)
 {
        __u32 eax, ebx, ecx, edx;
diff --git a/plat/common/sw_ctx.c b/plat/common/sw_ctx.c
index 88a377f..2c78abe 100644
--- a/plat/common/sw_ctx.c
+++ b/plat/common/sw_ctx.c
@@ -34,13 +34,11 @@
 
 #include <stdint.h>
 #include <stdlib.h>
-#include <string.h>
 #include <uk/plat/thread.h>
-#include <uk/alloc.h>
 #include <sw_ctx.h>
 #include <uk/assert.h>
 #include <tls.h>
-#include <x86/cpu.h>
+#include <cpu.h>
 
 static void *sw_ctx_create(struct uk_alloc *allocator, unsigned long sp,
                                unsigned long tlsp);
@@ -57,14 +55,10 @@ static void *sw_ctx_create(struct uk_alloc *allocator, 
unsigned long sp,
                                unsigned long tlsp)
 {
        struct sw_ctx *ctx;
-       size_t sz;
 
        UK_ASSERT(allocator != NULL);
 
-       sz = ALIGN_UP(sizeof(struct sw_ctx), x86_cpu_features.extregs_align)
-               + x86_cpu_features.extregs_size;
-       ctx = uk_malloc(allocator, sz);
-       uk_pr_debug("Allocating %lu bytes for sw ctx at %p\n", sz, ctx);
+       ctx = arch_alloc_sw_ctx(allocator);
        if (ctx == NULL) {
                uk_pr_warn("Error allocating software context.");
                return NULL;
@@ -73,10 +67,8 @@ static void *sw_ctx_create(struct uk_alloc *allocator, 
unsigned long sp,
        ctx->sp = sp;
        ctx->tlsp = tlsp;
        ctx->ip = (unsigned long) asm_thread_starter;
-       ctx->extregs = ALIGN_UP(((uintptr_t)ctx + sizeof(struct sw_ctx)),
-                               x86_cpu_features.extregs_align);
-       // Initialize extregs area: zero out, then save a valid layout to it.
-       memset((void *)ctx->extregs, 0, x86_cpu_features.extregs_size);
+       arch_init_extregs(ctx);
+
        save_extregs(ctx);
 
        return ctx;
-- 
2.17.1


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