Match baremetal "curlwp" with xen

i.e. store thread pointer at the end of the stack.  This is done
merely to minimize diffs for now, and will be fixed with tls.

diff --git a/include/bmk-core/sched.h b/include/bmk-core/sched.h
index edc127c99f8bc6f915e7e9804aff856bd30fd664..4193f759cebba697995c4aff0f6e0a788b6f46a4 100644 (file)
--- a/include/bmk-core/sched.h
+++ b/include/bmk-core/sched.h
@@ -61,7 +61,7 @@ int   bmk_sched_nanosleep_abstime(bmk_time_t);
 void   *bmk_sched_gettls(struct bmk_thread *, unsigned int);
 void   bmk_sched_settls(struct bmk_thread *, unsigned int, void *);
 
-void   bmk_cpu_sched_create(struct bmk_tcb *,
+void   bmk_cpu_sched_create(struct bmk_thread *, struct bmk_tcb *,
                             void (*)(void *), void *,
                             void *, unsigned long);
 void   bmk_cpu_sched_switch(struct bmk_tcb *, struct bmk_tcb *);
@@ -70,6 +70,7 @@ void  bmk_sched_set_hook(void (*)(void *, void *));
 struct bmk_thread *bmk_sched_init_mainlwp(void *);
 
 struct bmk_thread *bmk_sched_current(void);
+struct bmk_thread *bmk_cpu_sched_current(void);
 int *bmk_sched_geterrno(void);
 const char     *bmk_sched_threadname(struct bmk_thread *);
 

diff --git a/platform/baremetal/arch/i386/cpu_sched.c b/platform/baremetal/arch/i386/cpu_sched.c
index 3481531599b81857b4878f5aac77979a93108222..245cca3ebad6a78342b2d3c996802f51a5259a2f 100644 (file)
--- a/platform/baremetal/arch/i386/cpu_sched.c
+++ b/platform/baremetal/arch/i386/cpu_sched.c
@@ -38,8 +38,11 @@
  */
 
 #include <bmk/types.h>
+#include <bmk/kernel.h>
 #include <bmk/sched.h>
 
+#include <bmk-core/core.h>
+
 static void
 stack_push(void **stackp, unsigned long value)
 {
@@ -51,12 +54,17 @@ stack_push(void **stackp, unsigned long value)
 }
 
 void
-bmk_cpu_sched_create(struct bmk_tcb *tcb,
+bmk_cpu_sched_create(struct bmk_thread *thread, struct bmk_tcb *tcb,
        void (*f)(void *), void *arg,
        void *stack_base, unsigned long stack_size)
 {
        void *stack_top = (char *)stack_base + stack_size;
 
+       bmk_assert(stack_size == BMK_THREAD_STACKSIZE);
+
+       /* Save pointer to the thread on the stack, used by current macro */
+       *(unsigned long *)stack_base = (unsigned long)thread;
+
        /* these values are used by bmk_cpu_sched_bouncer() */
        stack_push(&stack_top, (unsigned long)f);
        stack_push(&stack_top, (unsigned long)arg);
@@ -64,3 +72,12 @@ bmk_cpu_sched_create(struct bmk_tcb *tcb,
        tcb->btcb_sp = (unsigned long)stack_top;
        tcb->btcb_ip = (unsigned long)bmk_cpu_sched_bouncer;
 }
+
+struct bmk_thread *
+bmk_cpu_sched_current(void)
+{
+       struct bmk_thread **current;
+
+       current = (void *)((unsigned long)&current & ~(bmk_stacksize-1));
+       return *current;
+};

diff --git a/platform/baremetal/include/bmk/kernel.h b/platform/baremetal/include/bmk/kernel.h
index dd0515fe211ac74fd3bf8a71b61ddc6f6c18ada0..26d9f7aeb3ef134d4bbde17894005d056f405e05 100644 (file)
--- a/platform/baremetal/include/bmk/kernel.h
+++ b/platform/baremetal/include/bmk/kernel.h
@@ -5,7 +5,8 @@
 #include <bmk/types.h>
 
 #define MEMSTART 0x100000
-#define PAGE_SIZE 0x1000
+#define PAGE_SHIFT 12
+#define PAGE_SIZE (1<<PAGE_SHIFT)
 #define STACK_SIZE 0x2000
 
 #define round_page(x) (((x) + (PAGE_SIZE-1)) & ~(PAGE_SIZE-1))

diff --git a/platform/baremetal/kernel.c b/platform/baremetal/kernel.c
index 844434975ad0b59d0a82f137c5aa409712d47214..9459df516ac5b80dc324791d04eba96e24f36768 100644 (file)
--- a/platform/baremetal/kernel.c
+++ b/platform/baremetal/kernel.c
@@ -58,32 +58,62 @@ struct stackcache {
  * as a special case. (nb. even that holds only for native thread stacks,
  * not pthread stacks).
  */
+static size_t currentpg;
+#define MAXPAGEALIGN (1<<BMK_THREAD_STACK_PAGE_ORDER)
 void *
 bmk_allocpg(size_t howmany)
 {
-       struct stackcache *sc;
-       static size_t current = 0;
        unsigned long rv;
 
-       if (howmany == 1<<BMK_THREAD_STACK_PAGE_ORDER &&
+       rv = bmk_membase + PAGE_SIZE*currentpg;
+       currentpg += howmany;
+       if (currentpg*PAGE_SIZE > bmk_memsize)
+               return NULL;
+
+       return (void *)rv;
+}
+
+/*
+ * Allocate a 2^n chunk of pages, aligned at 2^n.  This is currently
+ * for the benefit of thread stack allocation, and should be going
+ * away in some time when the migration to TLS is complete.
+ */
+static void *
+alignedpgalloc(int shift)
+{
+       struct stackcache *sc;
+       int align = 1<<shift;
+       size_t alignedoff;
+       void *rv;
+
+       if (shift == BMK_THREAD_STACK_PAGE_ORDER &&
            (sc = LIST_FIRST(&cacheofstacks)) != NULL) {
                LIST_REMOVE(sc, sc_entries);
                return sc;
        }
 
-       rv = bmk_membase + PAGE_SIZE*current;
-       current += howmany;
-       if (current*PAGE_SIZE > bmk_memsize)
-               return NULL;
+       if (align > MAXPAGEALIGN)
+               align = MAXPAGEALIGN;
 
-       return (void *)rv;
+       /* need to leave this much space until the next aligned alloc */
+       alignedoff = (bmk_membase + currentpg*PAGE_SIZE) % (align*PAGE_SIZE);
+       if (alignedoff)
+               currentpg += align - (alignedoff>>PAGE_SHIFT);
+
+       rv = bmk_allocpg(1<<shift);
+       if (((unsigned long)rv & (align*PAGE_SIZE-1)) != 0) {
+               bmk_printf("wanted %d aligned, got memory at %p\n",
+                   align, rv);
+               bmk_platform_halt("fail");
+       }
+       return rv;
 }
 
 void *
 bmk_platform_allocpg2(int shift)
 {
 
-       return bmk_allocpg(1<<shift);
+       return alignedpgalloc(shift);
 }
 
 void
@@ -151,6 +181,8 @@ parsemem(uint32_t addr, uint32_t len)
        bmk_membase = mbm->addr + ossize;
        bmk_memsize = memsize - ossize;
 
+       bmk_assert((bmk_membase & (PAGE_SIZE-1)) == 0);
+
        return 0;
 }
 

diff --git a/platform/baremetal/sched.c b/platform/baremetal/sched.c
index fd46ed8d0263c206aa03b62ad2756be2178e1577..67159d2aeeeca5728f888b4d877e2201df650b1a 100644 (file)
--- a/platform/baremetal/sched.c
+++ b/platform/baremetal/sched.c
@@ -108,14 +108,6 @@ static TAILQ_HEAD(, bmk_thread) threads = TAILQ_HEAD_INITIALIZER(threads);
 
 static void (*scheduler_hook)(void *, void *);
 
-static struct bmk_thread *current_thread = NULL;
-struct bmk_thread *
-bmk_sched_current(void)
-{
-
-       return current_thread;
-}
-
 static int
 is_runnable(struct bmk_thread *thread)
 {
@@ -166,10 +158,15 @@ sched_switch(struct bmk_thread *prev, struct bmk_thread *next)
 
        if (scheduler_hook)
                scheduler_hook(prev->bt_cookie, next->bt_cookie);
-       current_thread = next;
        bmk_cpu_sched_switch(&prev->bt_tcb, &next->bt_tcb);
 }
 
+struct bmk_thread *
+bmk_sched_current(void)
+{
+
+       return bmk_cpu_sched_current();
+}
 
 void
 bmk_sched_dumpqueue(void)
@@ -313,7 +310,8 @@ bmk_sched_create(const char *name, void *cookie, int joinable,
        if (joinable)
                thread->bt_flags |= THREAD_MUSTJOIN;
 
-       bmk_cpu_sched_create(&thread->bt_tcb, f, data, stack_base, stack_size);
+       bmk_cpu_sched_create(thread, &thread->bt_tcb, f, data,
+           stack_base, stack_size);
 
        thread->bt_cookie = cookie;