diff mbox series

[3/8] ppc/pnv: Add a comment on the "primary-topology-index" property

Message ID 20210901094153.227671-4-clg@kaod.org (mailing list archive)
State New, archived
Headers show
Series ppc: cleanups | expand

Commit Message

Cédric Le Goater Sept. 1, 2021, 9:41 a.m. UTC
On P10, the chip id is calculated from the "Primary topology table
index". See skiboot commits for more information [1].

This information is extracted from the hdata on real systems which
QEMU needs to emulate. Add this property for all machines even if it
is only used on POWER10.

[1] https://github.com/open-power/skiboot/commit/2ce3f083f399
    https://github.com/open-power/skiboot/commit/a2d4d7f9e14a

Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 hw/ppc/pnv_xscom.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

David Gibson Sept. 2, 2021, 1:36 a.m. UTC | #1
On Wed, Sep 01, 2021 at 11:41:48AM +0200, Cédric Le Goater wrote:
> On P10, the chip id is calculated from the "Primary topology table
> index". See skiboot commits for more information [1].
> 
> This information is extracted from the hdata on real systems which
> QEMU needs to emulate. Add this property for all machines even if it
> is only used on POWER10.
> 
> [1] https://github.com/open-power/skiboot/commit/2ce3f083f399
>     https://github.com/open-power/skiboot/commit/a2d4d7f9e14a
> 
> Signed-off-by: Cédric Le Goater <clg@kaod.org>

Applied to ppc-for-6.2, thanks.

> ---
>  hw/ppc/pnv_xscom.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/hw/ppc/pnv_xscom.c b/hw/ppc/pnv_xscom.c
> index faa488e3117a..9ce018dbc279 100644
> --- a/hw/ppc/pnv_xscom.c
> +++ b/hw/ppc/pnv_xscom.c
> @@ -284,6 +284,10 @@ int pnv_dt_xscom(PnvChip *chip, void *fdt, int root_offset,
>      _FDT(xscom_offset);
>      g_free(name);
>      _FDT((fdt_setprop_cell(fdt, xscom_offset, "ibm,chip-id", chip->chip_id)));
> +    /*
> +     * On P10, the xscom bus id has been deprecated and the chip id is
> +     * calculated from the "Primary topology table index". See skiboot.
> +     */
>      _FDT((fdt_setprop_cell(fdt, xscom_offset, "ibm,primary-topology-index",
>                             chip->chip_id)));
>      _FDT((fdt_setprop_cell(fdt, xscom_offset, "#address-cells", 1)));
diff mbox series

Patch

diff --git a/hw/ppc/pnv_xscom.c b/hw/ppc/pnv_xscom.c
index faa488e3117a..9ce018dbc279 100644
--- a/hw/ppc/pnv_xscom.c
+++ b/hw/ppc/pnv_xscom.c
@@ -284,6 +284,10 @@  int pnv_dt_xscom(PnvChip *chip, void *fdt, int root_offset,
     _FDT(xscom_offset);
     g_free(name);
     _FDT((fdt_setprop_cell(fdt, xscom_offset, "ibm,chip-id", chip->chip_id)));
+    /*
+     * On P10, the xscom bus id has been deprecated and the chip id is
+     * calculated from the "Primary topology table index". See skiboot.
+     */
     _FDT((fdt_setprop_cell(fdt, xscom_offset, "ibm,primary-topology-index",
                            chip->chip_id)));
     _FDT((fdt_setprop_cell(fdt, xscom_offset, "#address-cells", 1)));