11/10/2023 00:51, David Christensen:
> IBM POWER systems support more than one type of memory management unit
> (MMU). The Power ISA 3.0 specification, which applies to P9 and later
> CPUs, defined a new Radix MMU which, among other things, allows an
> anonymous memory page mapping to be converted into a hugepage mapping
> at a specific address. This is a required feature in DPDK so we need
> to test the MMU type when POWER systems are used and provide a more
> useful error message for the user when running on an unsupported
> system.
>
> Bugzilla ID: 1221
> Suggested-by: Thomas Monjalon <tho...@monjalon.net>
> Signed-off-by: David Christensen <d...@linux.vnet.ibm.com>
> ---
> --- a/lib/eal/linux/eal.c
> +++ b/lib/eal/linux/eal.c
> +/*
> + * IBM POWER systems support more than one type of memory management unit
> (MMU).
> + * The Power ISA 3.0 specification, which applies to P9 and later CPUs,
> defined
> + * a new Radix MMU which, among other things, allows an anonymous memory page
> + * mapping to be converted into a hugepage mapping at a specific address.
> This
> + * is a required feature in DPDK so we need to test the MMU type when POWER
> + * systems are used.
> + */
> +static bool
> +is_mmu_supported(void)
> +{
> +#ifdef RTE_ARCH_PPC_64
> + static const char proc_cpuinfo[] = "/proc/cpuinfo";
> + static const char str_mmu[] = "MMU";
> + static const char str_radix[] = "Radix";
> + char buf[512];
> + char *ret = NULL;
> + FILE *f = fopen(proc_cpuinfo, "r");
> +
> + if (f == NULL) {
> + RTE_LOG(ERR, EAL, "Cannot open %s\n", proc_cpuinfo);
> + return false;
> + }
> +
> + /*
> + * Example "MMU" in /proc/cpuinfo:
> + * ...
> + * model : 8335-GTW
> + * machine : PowerNV 8335-GTW
> + * firmware : OPAL
> + * MMU : Radix
> + * ... or ...
> + * model : IBM,9009-22A
> + * machine : CHRP IBM,9009-22A
> + * MMU : Hash
> + */
> + while (fgets(buf, sizeof(buf), f) != NULL) {
> + ret = strstr(buf, str_mmu);
> + if (ret == NULL)
> + continue;
> + ret += sizeof(str_mmu) - 1;
> + ret = strchr(ret, ':');
> + if (ret == NULL)
> + continue;
> + ret = strstr(ret, str_radix);
> + break;
> + }
> + fclose(f);
> + if (ret == NULL)
> + rte_eal_init_alert("DPDK on PPC64 requires radix-mmu.");
> + return (ret != NULL);
> +#else
> + return true;
> +#endif
> +}
I feel this function should not be implemented in the common EAL.
What about adding a new function in lib/eal/ppc/ ?
And add the "return true" for other architectures?
