local/global clarification (#436)

Fix #432

---------

Signed-off-by: Tariq Kurd <[email protected]>
Co-authored-by: Alexander Richardson <[email protected]>

src/insns/atomic_exceptions.adoc

@@ -8,7 +8,7 @@ If <<c_perm>> is not granted then store the memory tag as zero, and load `cd.tag
 +
 If the authorizing capability does not grant <<lm_perm>>, and the tag of `cd` is 1 and `cd` is not sealed, then an implicit <<ACPERM>> clearing <<w_perm>> and <<lm_perm>> is performed to obtain the intermediate permissions on `cd` (see <<LC>>).
 +
-If the authorizing capability does not grant <<el_perm>>, and the tag of `cd` is 1, then an implicit <<ACPERM>> clearing <<el_perm>> and restricting <<section_cap_level>> to the level of the authorizing capability is performed to obtain the final permissions on `cd` (see <<LC>>).
+If the authorizing capability does not grant <<el_perm>>, and the tag of `cd` is 1, then an implicit <<ACPERM>> clearing <<el_perm>> and restricting the <<section_cap_level>> to the level of the authorizing capability is performed to obtain the final permissions on `cd` (see <<LC>>).
 +
 The stored tag is also set to zero if the authorizing capability does not have <<sl_perm>> set but the stored data has a <<section_cap_level>> of 0 (see <<SC>>).
 endif::[]

src/insns/load_tag_perms.adoc

@@ -4,7 +4,7 @@ The tag value written to `cd` is 0 if the tag of the memory location loaded is
 +
 If the authorizing capability does not grant <<lm_perm>>, and the tag of `cd` is 1 and `cd` is not sealed, then an implicit <<ACPERM>> clearing <<w_perm>> and <<lm_perm>> is performed to obtain the intermediate permissions on `cd`.
 +
-If the authorizing capability does not grant <<el_perm>>, and the tag of `cd` is 1, then an implicit <<ACPERM>> clearing <<el_perm>> and restricting <<section_cap_level>> to the level of the authorizing capability is performed to obtain the final permissions on `cd`.
+If the authorizing capability does not grant <<el_perm>>, and the tag of `cd` is 1, then an implicit <<ACPERM>> clearing <<el_perm>> and restricting the <<section_cap_level>> to the level of the authorizing capability is performed to obtain the final permissions on `cd`.
 
 NOTE: Missing <<lm_perm>> does not affect untagged values since this could result in surprising bit patterns when copying non-capability data.
 Similarly, sealed capabilities are not modified as they are not directly dereferenceable.

src/insns/store_tag_perms.adoc

@@ -2,4 +2,4 @@ Tag of the written capability value::
 
 The capability written to memory has the tag set to 0 if the tag of `cs2` is 0 or if the authorizing capability (<<ddc>> or `cs1`) does not grant <<c_perm>>.
 +
-The stored tag is also set to zero if the authorizing capability does not have <<sl_perm>> set but the stored data has a <<section_cap_level>> of 0.
+The stored tag is also set to zero if the authorizing capability does not have <<sl_perm>> set but the stored data has a <<section_cap_level>> of 0 (_local_).

src/level-ext.adoc

@@ -24,7 +24,7 @@ NOTE: The <<cap_encoding_xlen64,`MXLEN=64` capability encoding>> diagram shows t
 NOTE: {cheri_levels_ext_name} requires that LVLBITS&#8805;1 although LVLBITS>1 is considered an experimental enhancement of this extension.
 See <<section_ext_cheri_multiple_levels>> for the mechanics when LVLBITS>1.
 
-[#section_cap_level,reftext="capability level"]
+[#section_cap_level,reftext="Capability Level (CL)"]
 ==== Capability Level (CL)
 
 The Capability Level (CL) is a new field added to the capability encoding, as shown in xref:section_cap_encoding[xrefstyle=short].
@@ -108,6 +108,8 @@ This avoids the need for a dedicated instruction and allows reducing the level a
 [#section_cap_level_summary]
 === Capability level summary table
 
+NOTE: A capability with <<section_cap_level,CL>>=1 is _global_ and with <<section_cap_level,CL>>=0 is _local_.
+
 .{cheri_levels_ext_name} `LVLBITS=1` summary table for stored capabilities
 [#cap_level_store_summary,width="100%",options=header,halign=center,cols="1,1,1,1,5"]
 |==============================================================================