[SLOF] [PATCH slof v3 5/5] fdt: Pass the resulting device tree to QEMU
Greg Kurz
groug at kaod.org
Tue Oct 3 19:48:10 AEDT 2017
On Tue, 3 Oct 2017 16:15:23 +1100
Alexey Kardashevskiy <aik at ozlabs.ru> wrote:
> This creates flatten device tree and passes it to QEMU via a custom
> hypercall right before jumping to RTAS.
>
> On a machine with 256 CPUs and 256 virtual Intel E1000 devices the blob
> is 360KB (356KB structs and 20KB of strings), building such a tree takes
> ~2s on a POWER8 box. A simple tree with 1 CPU and a couple of devices
> takes 38ms and creates 16KB blob.
>
> This preloads strings with 40 property names from CPU and PCI device nodes
> and the strings lookup only searches within these. Without string reusing
> at all, the strings blob is 200KB and rendering time is 1.7sec; with
> unlimited reusing, the strings blob is 4KB and rendering time is 2.8sec.
>
> While we are here, fix the version handling in fdt-init. It only matters
> a little for the fdt-debug==1 case though.
>
> Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
> ---
>
> Changes:
> v3:
> * fixed stack handling after hcall returned
> * fixed format versions in both rendering and parsing paths
> * rebased on top of removed unused hvcalls
> * renamed used variables to have fdtfl- prefixes as there are already
> some for parsing the initial dt
>
Yeah and this was confusing CAS because ibm,client-architecture-support
uses fdt-struct, but wasn't accessing the right one... it took me some
time to understand what was happening :-\
Maybe we should have word in fdt.fs to avoid using fdt-struct in some
other file ?
> v2:
> * fixed comments from review
> * added strings cache
> * changed last_compat_vers from 0x17 to 0x16 as suggested by dwg
>
> ---
>
> I tested the blob by storing it from QEMU to a file and decompiling it;
> this produces error which I do not really
> understand as the name of the root is an empty string (literaly:
> 00 00 00 01 00 00 00 00) and yet this error:
>
> aik at fstn1-p1:~$ dtc -f -I dtb -O dts -o dbg.dts dbg.dtb
> ERROR (name_properties): "name" property in / is incorrect ("/" instead of base node name)
> Warning: Input tree has errors, output forced
> ---
> lib/libhvcall/libhvcall.h | 3 +-
> board-qemu/slof/fdt.fs | 284 +++++++++++++++++++++++++++++++++++++++++++++-
> board-qemu/slof/rtas.fs | 7 ++
> lib/libhvcall/hvcall.code | 5 +
> lib/libhvcall/hvcall.in | 1 +
> 5 files changed, 297 insertions(+), 3 deletions(-)
>
> diff --git a/lib/libhvcall/libhvcall.h b/lib/libhvcall/libhvcall.h
> index 6356a62..3fa4398 100644
> --- a/lib/libhvcall/libhvcall.h
> +++ b/lib/libhvcall/libhvcall.h
> @@ -24,7 +24,8 @@
> #define KVMPPC_H_LOGICAL_MEMOP (KVMPPC_HCALL_BASE + 0x1)
> /* Client Architecture support */
> #define KVMPPC_H_CAS (KVMPPC_HCALL_BASE + 0x2)
> -#define KVMPPC_HCALL_MAX KVMPPC_H_CAS
> +#define KVMPPC_H_UPDATE_DT (KVMPPC_HCALL_BASE + 0x3)
> +#define KVMPPC_HCALL_MAX KVMPPC_H_UPDATE_DT
>
> #ifndef __ASSEMBLY__
>
> diff --git a/board-qemu/slof/fdt.fs b/board-qemu/slof/fdt.fs
> index 851645e..548cc25 100644
> --- a/board-qemu/slof/fdt.fs
> +++ b/board-qemu/slof/fdt.fs
> @@ -27,7 +27,7 @@ struct
> 4 field >fdth_boot_cpu
> 4 field >fdth_string_size
> 4 field >fdth_struct_size
> -drop
> +constant /fdth
>
> h# d00dfeed constant OF_DT_HEADER
> h# 1 constant OF_DT_BEGIN_NODE
> @@ -69,7 +69,7 @@ fdt-start fdt-init
> dup >fdth_version l@ 3 >= IF
> ." strings size : 0x" dup >fdth_string_size l@ . cr
> THEN
> - dup >fdth_version l@ 17 >= IF
> + dup >fdth_version l@ 11 >= IF
> ." struct size : 0x" dup >fdth_struct_size l@ . cr
> THEN
> THEN
> @@ -439,4 +439,284 @@ r> drop
> fdt-cas-fix?
> ;
>
> +VARIABLE fdtfl-struct
> +VARIABLE fdtfl-struct-here
> +VARIABLE fdtfl-strings
> +VARIABLE fdtfl-strings-cache
> +VARIABLE fdtfl-strings-here
> +VARIABLE fdtfl-strings-reused \ debug only
> +VARIABLE fdt-ms \ debug only
> +
> +: fdt-skip-string ( cur -- cur )
> + BEGIN
> + dup c@
> + WHILE
> + 1+
> + REPEAT
> + 4 + -4 and
> +;
> +
> +: zstring= ( str len zstr -- flag )
> + 2dup + c@ 0<> IF
> + 3drop false
> + EXIT
> + THEN
> + swap comp 0=
> +;
> +
> +: fdt-find-string ( name namelen -- nameoff true | false )
> + fdtfl-strings @
> + BEGIN
> + dup fdtfl-strings-cache @ <
> + WHILE
> + 3dup zstring= IF
> + fdtfl-strings @ -
> + -rot
> + 2drop
> + true
> + EXIT
> + THEN
> + fdt-skip-string
> + REPEAT
> + 3drop
> + false
> +;
> +
> +: fdt-str-allot ( len -- ) fdtfl-strings-here @ + to fdtfl-strings-here ;
> +: fdt-str-c, ( char -- ) fdtfl-strings-here @ 1 fdt-str-allot c! ;
> +: fdt-str-align ( -- )
> + fdtfl-strings-here @
> + dup dup 4 #aligned swap - ( here bytes-to-erase )
> + dup -rot
> + erase
> + fdt-str-allot
> +;
> +: fdt-str-bytes, ( data len -- ) fdtfl-strings-here @ over fdt-str-allot swap move ;
> +: fdt-str-ztr, ( str len -- ) fdt-str-bytes, 0 fdt-str-c, ;
> +
> +: fdt-add-string ( name namelen -- nameoff )
> + fdtfl-strings-here @ -rot
> + fdt-str-ztr,
> + fdt-str-align
> + fdtfl-strings @ -
> +;
> +
> +: fdt-get-string ( name namelen -- nameoff )
> + 2dup fdt-find-string IF
> + -rot 2drop
> + fdt-debug IF
> + 1 fdtfl-strings-reused +!
> + THEN
> + EXIT
> + THEN
> + fdt-add-string
> +;
> +
> +: fdt-allot ( len -- ) fdtfl-struct-here @ + to fdtfl-struct-here ;
> +: fdt-c, ( char -- ) fdtfl-struct-here @ 1 fdt-allot c! ;
> +: fdt-align ( -- )
> + fdtfl-struct-here @
> + dup dup 4 #aligned swap - ( here bytes-to-erase )
> + dup -rot
> + erase
> + fdt-allot
> +;
> +: fdt-bytes, ( data len -- ) fdtfl-struct-here @ over fdt-allot swap move ;
> +: fdt-ztr, ( str len -- ) fdt-bytes, 0 fdt-c, ;
> +: fdt-l, ( token -- ) fdtfl-struct-here @ l! /l fdt-allot ;
> +
> +: fdt-begin-node ( name namelen -- )
> + OF_DT_BEGIN_NODE fdt-l,
> + 2dup 1 = swap c@ [char] / = and \ is it "/"?
> + IF
> + 2drop s" " \ dtc is still unhappy though
> + THEN
> + fdt-ztr,
> + fdt-align
> +;
> +
> +: fdt-end-node ( -- ) OF_DT_END_NODE fdt-l, ;
> +
> +: fdt-prop ( prop len name namelen -- )
> + OF_DT_PROP fdt-l,
> +
> + \ get string offset
> + fdt-get-string ( prop len nameoff )
> +
> + \ store len and nameoff
> + over fdt-l,
> + fdt-l, ( prop len )
> +
> + \ now store the bytes
> + fdt-bytes,
> + fdt-align
> +;
> +
> +: fdt-end ( -- ) OF_DT_END fdt-l, ;
> +
> +: fdt-properties ( phandle -- )
> + dup encode-int s" phandle" fdt-prop
> + >r
> + s" "
> + BEGIN
> + r@ next-property
> + WHILE
> + 2dup
> + 2dup r@ get-property
> + not IF
> + 2swap fdt-prop
> + THEN
> + REPEAT
> + r>
> + drop
> +;
> +
> +: fdt-flatten-node ( node -- )
> + fdt-debug 1 > IF dup node>path type cr THEN
> + dup node>qname fdt-begin-node
> + dup fdt-properties
> + child
> + BEGIN
> + dup
> + WHILE
> + dup recurse
> + peer
> + REPEAT
> + drop
> + fdt-end-node
> +;
> +
> +: fdtfl-strings-preload ( -- )
> + s" reg" fdt-add-string drop
> + s" status" fdt-add-string drop
> + s" 64-bit" fdt-add-string drop
> + s" phandle" fdt-add-string drop
> + s" ibm,vmx" fdt-add-string drop
> + s" ibm,dfp" fdt-add-string drop
> + s" slb-size" fdt-add-string drop
> + s" ibm,purr" fdt-add-string drop
> + s" vendor-id" fdt-add-string drop
> + s" device-id" fdt-add-string drop
> + s" min-grant" fdt-add-string drop
> + s" class-code" fdt-add-string drop
> + s" compatible" fdt-add-string drop
> + s" interrupts" fdt-add-string drop
> + s" cpu-version" fdt-add-string drop
> + s" #size-cells" fdt-add-string drop
> + s" ibm,req#msi" fdt-add-string drop
> + s" revision-id" fdt-add-string drop
> + s" device_type" fdt-add-string drop
> + s" max-latency" fdt-add-string drop
> + s" ibm,chip-id" fdt-add-string drop
> + s" ibm,pft-size" fdt-add-string drop
> + s" ibm,slb-size" fdt-add-string drop
> + s" devsel-speed" fdt-add-string drop
> + s" ibm,loc-code" fdt-add-string drop
> + s" subsystem-id" fdt-add-string drop
> + s" d-cache-size" fdt-add-string drop
> + s" i-cache-size" fdt-add-string drop
> + s" #address-cells" fdt-add-string drop
> + s" clock-frequency" fdt-add-string drop
> + s" cache-line-size" fdt-add-string drop
> + s" ibm,pa-features" fdt-add-string drop
> + s" ibm,my-drc-index" fdt-add-string drop
> + s" d-cache-line-size" fdt-add-string drop
> + s" i-cache-line-size" fdt-add-string drop
> + s" assigned-addresses" fdt-add-string drop
> + s" d-cache-block-size" fdt-add-string drop
> + s" i-cache-block-size" fdt-add-string drop
> + s" timebase-frequency" fdt-add-string drop
> + s" subsystem-vendor-id" fdt-add-string drop
> + s" ibm,segment-page-sizes" fdt-add-string drop
> + s" ibm,ppc-interrupt-server#s" fdt-add-string drop
> + s" ibm,processor-segment-sizes" fdt-add-string drop
> + s" ibm,ppc-interrupt-gserver#s" fdt-add-string drop
> +;
> +
> +: fdt-append-blob ( bytes cur blob -- cur )
> + 3dup -rot swap move
> + drop +
> +;
> +
> +: fdt-flatten-tree ( root -- tree )
> + 200000 alloc-mem dup fdtfl-struct-here ! fdtfl-struct !
> + 200000 alloc-mem dup fdtfl-strings-here ! fdtfl-strings !
> +
> + fdt-debug IF
> + 0 fdtfl-strings-reused !
> + milliseconds fdt-ms !
> + THEN
> +
> + \ Preload strings cache
> + fdtfl-strings-preload
> + fdtfl-strings-here @ fdtfl-strings-cache !
> + \ Render the blobs
> + fdt-flatten-node
> + fdt-end
> +
> + \ Calculate strings and struct sizes
> + fdtfl-struct-here @ fdtfl-struct @ -
> + fdtfl-strings-here @ fdtfl-strings @ - ( struct-len strings-len )
> +
> + 2dup + /fdth +
> + 10 + \ Reserve 16 bytes and an empty reserved block
> +
> + fdt-debug IF
> + 3dup
> + ." FDT flat size=" .d cr
> + ." Strings size=" .d cr
> + ." Struct size=" .d cr
> + ." Reused strings=" fdtfl-strings-reused @ .d cr
> + milliseconds fdt-ms @ -
> + ." Took " .d ." ms" cr
> + THEN
> +
> + \ Allocate flatten DT blob
> + dup alloc-mem ( struct-len strings-len total-len fdt )
> + >r ( struct-len strings-len total-len r: fdt )
> +
> + \ Write header
> + OF_DT_HEADER r@ >fdth_magic l!
> + dup r@ >fdth_tsize l!
> + /fdth 10 + 2 pick + r@ >fdth_struct_off l!
> + /fdth 10 + r@ >fdth_string_off l!
> + /fdth r@ >fdth_rsvmap_off l!
> + 11 r@ >fdth_version l!
> + 10 r@ >fdth_compat_vers l!
> + 0 r@ >fdth_boot_cpu l!
> + over r@ >fdth_string_size l!
> + 2 pick r@ >fdth_struct_size l!
> + ( struct-len strings-len total-len r: fdt )
> +
> + drop ( struct-len strings-len r: fdt )
> + r@ /fdth + ( struct-len strings-len cur r: fdt )
> +
> + \ Write the reserved entry
> + 0 over !
> + cell+
> + 0 over !
> + cell+ ( struct-len strings-len cur r: fdt )
> +
> + \ Write strings and struct blobs
> + fdtfl-strings @ fdt-append-blob
> + fdtfl-struct @ fdt-append-blob
> + drop
> +
> + \ Free temporary blobs
> + fdtfl-struct @ 200000 free-mem
> + fdtfl-strings @ 200000 free-mem
> +
> + \ Return fdt
> + r>
> +;
> +
> +: fdt-flatten-tree-free ( tree )
> + dup >fdth_tsize l@ free-mem
> +;
> +
> +: fdt ( -- )
> + " /" find-node
> + fdt-flatten-tree
> +;
> +
> s" /" find-node fdt-fix-phandles
> diff --git a/board-qemu/slof/rtas.fs b/board-qemu/slof/rtas.fs
> index b17157e..219bcda 100644
> --- a/board-qemu/slof/rtas.fs
> +++ b/board-qemu/slof/rtas.fs
> @@ -98,6 +98,13 @@ find-qemu-rtas
> ;
>
> : rtas-quiesce ( -- )
> + " /" find-node
> + fdt-flatten-tree
> + dup hv-update-dt ?dup IF
> + \ Ignore hcall not implemented error, print error otherwise
> + dup -2 <> IF ." HV-UPDATE-DT error: " . cr ELSE drop THEN
> + THEN
> + fdt-flatten-tree-free
> " quiesce" rtas-get-token rtas-cb rtas>token l!
> 0 rtas-cb rtas>nargs l!
> 0 rtas-cb rtas>nret l!
> diff --git a/lib/libhvcall/hvcall.code b/lib/libhvcall/hvcall.code
> index 744469f..5918c90 100644
> --- a/lib/libhvcall/hvcall.code
> +++ b/lib/libhvcall/hvcall.code
> @@ -123,3 +123,8 @@ PRIM(check_X2d_and_X2d_patch_X2d_sc1)
>
> patch_broken_sc1((void*)start, (void*)end, (void*)patch_ins);
> MIRP
> +
> +PRIM(hv_X2d_update_X2d_dt)
> + unsigned long dt = TOS.u;
> + TOS.u = hv_generic(KVMPPC_H_UPDATE_DT, dt);
> +MIRP
> diff --git a/lib/libhvcall/hvcall.in b/lib/libhvcall/hvcall.in
> index e99d6d1..9193162 100644
> --- a/lib/libhvcall/hvcall.in
> +++ b/lib/libhvcall/hvcall.in
> @@ -30,4 +30,5 @@ cod(RX!)
>
> cod(hv-logical-memop)
> cod(hv-cas)
> +cod(hv-update-dt)
> cod(get-print-version)
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