[xen staging] docs: fusa: Add requirements for generic timer

[patchbot@xxxxxxx]

commit 51ad2c57a2d21b583a5944a0dc21c709af022f3c
Author:     Michal Orzel <michal.orzel@xxxxxxx>
AuthorDate: Thu Aug 29 12:31:20 2024 +0100
Commit:     Stefano Stabellini <stefano.stabellini@xxxxxxx>
CommitDate: Tue Sep 3 19:39:50 2024 -0700

    docs: fusa: Add requirements for generic timer
    
    Add the requirements for the use of generic timer by a domain
    
    Signed-off-by: Michal Orzel <michal.orzel@xxxxxxx>
    Signed-off-by: Ayan Kumar Halder <ayan.kumar.halder@xxxxxxx>
    Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
    Reviewed-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>
---
 docs/fusa/reqs/design-reqs/arm64/generic-timer.rst | 123 +++++++++++++++++++++
 docs/fusa/reqs/index.rst                           |   3 +
 docs/fusa/reqs/intro.rst                           |   3 +-
 docs/fusa/reqs/market-reqs/reqs.rst                |  34 ++++++
 docs/fusa/reqs/product-reqs/arm64/reqs.rst         |  23 ++++
 5 files changed, 185 insertions(+), 1 deletion(-)

diff --git a/docs/fusa/reqs/design-reqs/arm64/generic-timer.rst 
b/docs/fusa/reqs/design-reqs/arm64/generic-timer.rst
new file mode 100644
index 0000000000..f2a0cd7fb8
--- /dev/null
+++ b/docs/fusa/reqs/design-reqs/arm64/generic-timer.rst
@@ -0,0 +1,123 @@
+.. SPDX-License-Identifier: CC-BY-4.0
+
+Generic Timer
+=============
+
+The following are the requirements related to ARM Generic Timer [1] interface
+exposed by Xen to Arm64 domains.
+
+Probe the Generic Timer device tree node from a domain
+------------------------------------------------------
+
+`XenSwdgn~arm64_generic_timer_probe_dt~1`
+
+Description:
+Xen shall generate a device tree node for the Generic Timer (in accordance to
+ARM architected timer device tree binding [2]) in the domain device tree.
+
+Rationale:
+
+Comments:
+Domains can detect the presence of the Generic Timer device tree node.
+
+Covers:
+ - `XenProd~emulated_timer~1`
+
+Read system counter frequency
+-----------------------------
+
+`XenSwdgn~arm64_generic_timer_read_freq~1`
+
+Description:
+Xen shall expose the frequency of the system counter to the domains in
+CNTFRQ_EL0 register and/or domain device tree's "clock-frequency" property.
+
+Rationale:
+
+Comments:
+
+Covers:
+ - `XenProd~emulated_timer~1`
+
+Access CNTKCTL_EL1 system register from a domain
+------------------------------------------------
+
+`XenSwdgn~arm64_generic_timer_access_cntkctlel1~1`
+
+Description:
+Xen shall expose Counter-timer Kernel Control register (CNTKCTL_EL1) to the
+domains.
+
+Rationale:
+
+Comments:
+
+Covers:
+ - `XenProd~emulated_timer~1`
+
+Access virtual timer from a domain
+----------------------------------
+
+`XenSwdgn~arm64_generic_timer_access_virtual_timer~1`
+
+Description:
+Xen shall expose the virtual timer registers (CNTVCT_EL0, CNTV_CTL_EL0,
+CNTV_CVAL_EL0, CNTV_TVAL_EL0) to the domains.
+
+Rationale:
+
+Comments:
+
+Covers:
+ - `XenProd~emulated_timer~1`
+
+Access physical timer from a domain
+-----------------------------------
+
+`XenSwdgn~arm64_generic_timer_access_physical_timer~1`
+
+Description:
+Xen shall expose physical timer registers (CNTPCT_EL0, CNTP_CTL_EL0,
+CNTP_CVAL_EL0, CNTP_TVAL_EL0) to the domains.
+
+Rationale:
+
+Comments:
+
+Covers:
+ - `XenProd~emulated_timer~1`
+
+Trigger the virtual timer interrupt from a domain
+-------------------------------------------------
+
+`XenSwdgn~arm64_generic_timer_trigger_virtual_interrupt~1`
+
+Description:
+Xen shall generate virtual timer interrupts to domains when the virtual timer
+condition is met.
+
+Rationale:
+
+Comments:
+
+Covers:
+ - `XenProd~emulated_timer~1`
+
+Trigger the physical timer interrupt from a domain
+--------------------------------------------------
+
+`XenSwdgn~arm64_generic_timer_trigger_physical_interrupt~1`
+
+Description:
+Xen shall generate physical timer interrupts to domains when the physical timer
+condition is met.
+
+Rationale:
+
+Comments:
+
+Covers:
+ - `XenProd~emulated_timer~1`
+
+[1] Arm Architecture Reference Manual for A-profile architecture, Chapter 11
+[2] 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/timer/arm,arch_timer.yaml
diff --git a/docs/fusa/reqs/index.rst b/docs/fusa/reqs/index.rst
index 78c02b1d9b..183f183b1f 100644
--- a/docs/fusa/reqs/index.rst
+++ b/docs/fusa/reqs/index.rst
@@ -7,3 +7,6 @@ Requirements documentation
    :maxdepth: 2
 
    intro
+   market-reqs
+   product-reqs
+   design-reqs/arm64
diff --git a/docs/fusa/reqs/intro.rst b/docs/fusa/reqs/intro.rst
index d67b18dd9f..245a219ff2 100644
--- a/docs/fusa/reqs/intro.rst
+++ b/docs/fusa/reqs/intro.rst
@@ -55,7 +55,8 @@ Title of the requirement
   be 'XenMkt', 'XenProd' or 'XenSwdgn' to denote market, product or design
   requirement.
   name - This denotes name of the requirement. In case of architecture specific
-  requirements, this starts with the architecture type (ie x86_64, arm64).
+  requirements, this starts with the architecture type (eg x86_64, arm64)
+  followed by component name (eg generic_timer) and action (eg read_xxx).
   revision number - This gets incremented each time the requirement is 
modified.
 
 
diff --git a/docs/fusa/reqs/market-reqs/reqs.rst 
b/docs/fusa/reqs/market-reqs/reqs.rst
new file mode 100644
index 0000000000..9c98c84a9a
--- /dev/null
+++ b/docs/fusa/reqs/market-reqs/reqs.rst
@@ -0,0 +1,34 @@
+.. SPDX-License-Identifier: CC-BY-4.0
+
+Functional Requirements
+=======================
+
+Run Arm64 VMs
+-------------
+
+`XenMkt~run_arm64_vms~1`
+
+Description:
+Xen shall run Arm64 VMs.
+
+Rationale:
+
+Comments:
+
+Needs:
+ - XenProd
+
+Provide timer to the VMs
+------------------------
+
+`XenMkt~provide_timer_vms~1`
+
+Description:
+Xen shall provide a timer to a VM.
+
+Rationale:
+
+Comments:
+
+Needs:
+ - XenProd
diff --git a/docs/fusa/reqs/product-reqs/arm64/reqs.rst 
b/docs/fusa/reqs/product-reqs/arm64/reqs.rst
new file mode 100644
index 0000000000..7aa3eeab6a
--- /dev/null
+++ b/docs/fusa/reqs/product-reqs/arm64/reqs.rst
@@ -0,0 +1,23 @@
+.. SPDX-License-Identifier: CC-BY-4.0
+
+Domain Creation And Runtime
+===========================
+
+Emulated Timer
+--------------
+
+`XenProd~emulated_timer~1`
+
+Description:
+Xen shall grant access to "Arm Generic Timer" for the domains.
+
+Rationale:
+
+Comments:
+
+Covers:
+ - `XenMkt~run_arm64_vms~1`
+ - `XenMkt~provide_timer_vms~1`
+
+Needs:
+ - XenSwdgn
--
generated by git-patchbot for /home/xen/git/xen.git#staging