kernel/amd64: Update arch(9)

This commit cleans up arch(9) as a few things were
noticed. First, it would make sense to identify cores (described by
the cpu_info structure) in every arch ported, thus
the lapic_id has been changed to id so it can be shared. Some
annotations have also been added for the sake of clarity. The manpage
for arch(9) has also been cleaned up.

Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 29 insertions, 2 deletions

diff --git a/share/man/man9/arch.9 b/share/man/man9/arch.9
index 6948e81..94ccd6a 100644
--- a/share/man/man9/arch.9
+++ b/share/man/man9/arch.9
@@ -48,16 +48,43 @@ struct which contains CPU specific fields.
 
 Example
 .Ft cpu_info
-structure for x86_64 is shown below:
+structure shown below:
 
 .Bd -literal
 struct cpu_info {
+    /* Per-arch fields */
     void *pmap;                     /* Current pmap */
-    volatile uint32_t lapic_freq;
+    uint32_t id;
+    struct spinlock lock;
+    /* AMD64 */
     ...
 };
 .Ed
 
+There will be some per-architecture fields that, for the sake
+of keeping things tidy, should remain at the top of the struct.
+These fields will be described below.
+
+The
+.Ft pmap
+field points to the current virtual memory context
+which shall be NULL if not used.
+
+The
+.Ft id
+field simply identifies the CPU with a specific "ID".
+
+The
+.Ft lock
+field is a spinlock to prevent race conditions
+while accessing this structure. This must be acquired
+when accessing a
+.Ft cpu_info
+instance.
+
+There are also some common helper macros that shall
+be implemented, these are described below.
+
 The macro
 .Ft this_cpu()
 calls an internal function that fetches the