Re: [PATCH v2 07/10] ppc/pnv: Permit ibm, pa-features set per machine variant

[Harsh Prateek Bora <harshpb@linux.ibm.com>]

On 3/12/24 18:44, Nicholas Piggin wrote:
> This allows different pa-features for powernv8/9/10.
> 
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>

> ---
>   hw/ppc/pnv.c | 41 +++++++++++++++++++++++++++++------------
>   1 file changed, 29 insertions(+), 12 deletions(-)
> 
> diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
> index aa9786e970..52d964f77a 100644
> --- a/hw/ppc/pnv.c
> +++ b/hw/ppc/pnv.c
> @@ -133,7 +133,7 @@ static int get_cpus_node(void *fdt)
>    * device tree, used in XSCOM to address cores and in interrupt
>    * servers.
>    */
> -static void pnv_dt_core(PnvChip *chip, PnvCore *pc, void *fdt)
> +static int pnv_dt_core(PnvChip *chip, PnvCore *pc, void *fdt)
>   {
>       PowerPCCPU *cpu = pc->threads[0];
>       CPUState *cs = CPU(cpu);
> @@ -149,11 +149,6 @@ static void pnv_dt_core(PnvChip *chip, PnvCore *pc, void *fdt)
>       uint32_t cpufreq = 1000000000;
>       uint32_t page_sizes_prop[64];
>       size_t page_sizes_prop_size;
> -    const uint8_t pa_features[] = { 24, 0,
> -                                    0xf6, 0x3f, 0xc7, 0xc0, 0x00, 0xf0,
> -                                    0x80, 0x00, 0x00, 0x00, 0x00, 0x00,
> -                                    0x00, 0x00, 0x00, 0x00, 0x80, 0x00,
> -                                    0x80, 0x00, 0x80, 0x00, 0x80, 0x00 };
>       int offset;
>       char *nodename;
>       int cpus_offset = get_cpus_node(fdt);
> @@ -236,15 +231,14 @@ static void pnv_dt_core(PnvChip *chip, PnvCore *pc, void *fdt)
>                              page_sizes_prop, page_sizes_prop_size)));
>       }
>   
> -    _FDT((fdt_setprop(fdt, offset, "ibm,pa-features",
> -                       pa_features, sizeof(pa_features))));
> -
>       /* Build interrupt servers properties */
>       for (i = 0; i < smt_threads; i++) {
>           servers_prop[i] = cpu_to_be32(pc->pir + i);
>       }
>       _FDT((fdt_setprop(fdt, offset, "ibm,ppc-interrupt-server#s",
>                          servers_prop, sizeof(*servers_prop) * smt_threads)));
> +
> +    return offset;
>   }
>   
>   static void pnv_dt_icp(PnvChip *chip, void *fdt, uint32_t pir,
> @@ -299,6 +293,17 @@ PnvChip *pnv_chip_add_phb(PnvChip *chip, PnvPHB *phb)
>       return chip;
>   }
>   
> +/*
> + * Same as spapr pa_features_207 except pnv always enables CI largepages bit.
> + * HTM is always enabled because TCG does implement HTM, it's just a
> + * degenerate implementation.
> + */
> +static const uint8_t pa_features_207[] = { 24, 0,
> +                 0xf6, 0x3f, 0xc7, 0xc0, 0x00, 0xf0,
> +                 0x80, 0x00, 0x00, 0x00, 0x00, 0x00,
> +                 0x00, 0x00, 0x00, 0x00, 0x80, 0x00,
> +                 0x80, 0x00, 0x80, 0x00, 0x80, 0x00 };
> +
>   static void pnv_chip_power8_dt_populate(PnvChip *chip, void *fdt)
>   {
>       static const char compat[] = "ibm,power8-xscom\0ibm,xscom";
> @@ -311,8 +316,12 @@ static void pnv_chip_power8_dt_populate(PnvChip *chip, void *fdt)
>   
>       for (i = 0; i < chip->nr_cores; i++) {
>           PnvCore *pnv_core = chip->cores[i];
> +        int offset;
> +
> +        offset = pnv_dt_core(chip, pnv_core, fdt);
>   
> -        pnv_dt_core(chip, pnv_core, fdt);
> +        _FDT((fdt_setprop(fdt, offset, "ibm,pa-features",
> +                           pa_features_207, sizeof(pa_features_207))));
>   
>           /* Interrupt Control Presenters (ICP). One per core. */
>           pnv_dt_icp(chip, fdt, pnv_core->pir, CPU_CORE(pnv_core)->nr_threads);
> @@ -335,8 +344,12 @@ static void pnv_chip_power9_dt_populate(PnvChip *chip, void *fdt)
>   
>       for (i = 0; i < chip->nr_cores; i++) {
>           PnvCore *pnv_core = chip->cores[i];
> +        int offset;
>   
> -        pnv_dt_core(chip, pnv_core, fdt);
> +        offset = pnv_dt_core(chip, pnv_core, fdt);
> +
> +        _FDT((fdt_setprop(fdt, offset, "ibm,pa-features",
> +                           pa_features_207, sizeof(pa_features_207))));
>       }
>   
>       if (chip->ram_size) {
> @@ -358,8 +371,12 @@ static void pnv_chip_power10_dt_populate(PnvChip *chip, void *fdt)
>   
>       for (i = 0; i < chip->nr_cores; i++) {
>           PnvCore *pnv_core = chip->cores[i];
> +        int offset;
> +
> +        offset = pnv_dt_core(chip, pnv_core, fdt);
>   
> -        pnv_dt_core(chip, pnv_core, fdt);
> +        _FDT((fdt_setprop(fdt, offset, "ibm,pa-features",
> +                           pa_features_207, sizeof(pa_features_207))));
>       }
>   
>       if (chip->ram_size) {