Hari Bathini <hbath...@linux.ibm.com> writes:
> diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
> index b8061fb9..a086a09 100644
> --- a/arch/powerpc/kernel/fadump.c
> +++ b/arch/powerpc/kernel/fadump.c
> @@ -283,17 +286,17 @@ static void __init fadump_reserve_crash_area(unsigned
> long base,
>
> int __init fadump_reserve_mem(void)
> {
> + int ret = 1;
> unsigned long base, size, memory_boundary;
Please try to use reverse christmas tree style when possible.
> @@ -363,29 +366,43 @@ int __init fadump_reserve_mem(void)
> * use memblock_find_in_range() here since it doesn't allocate
> * from bottom to top.
> */
> - for (base = fw_dump.boot_memory_size;
> - base <= (memory_boundary - size);
> - base += size) {
> + while (base <= (memory_boundary - size)) {
> if (memblock_is_region_memory(base, size) &&
> !memblock_is_region_reserved(base, size))
> break;
> +
> + base += size;
> }
Some of these changes look like they might not be necessary in this
patch, ie. could be split out into a lead-up patch. eg. the conversion
from for to while. But it's a bit hard to tell.
> diff --git a/arch/powerpc/platforms/powernv/opal-fadump.c
> b/arch/powerpc/platforms/powernv/opal-fadump.c
> index e330877..e5c4700 100644
> --- a/arch/powerpc/platforms/powernv/opal-fadump.c
> +++ b/arch/powerpc/platforms/powernv/opal-fadump.c
> @@ -13,14 +13,86 @@
> #include <linux/seq_file.h>
> #include <linux/of_fdt.h>
> #include <linux/libfdt.h>
> +#include <linux/mm.h>
>
> +#include <asm/page.h>
> #include <asm/opal.h>
>
> #include "../../kernel/fadump-common.h"
> +#include "opal-fadump.h"
> +
> +static struct opal_fadump_mem_struct *opal_fdm;
> +
> +/* Initialize kernel metadata */
> +static void opal_fadump_init_metadata(struct opal_fadump_mem_struct *fdm)
> +{
> + fdm->version = OPAL_FADUMP_VERSION;
> + fdm->region_cnt = 0;
> + fdm->registered_regions = 0;
> + fdm->fadumphdr_addr = 0;
> +}
>
> static ulong opal_fadump_init_mem_struct(struct fw_dump *fadump_conf)
> {
> - return fadump_conf->reserve_dump_area_start;
> + ulong addr = fadump_conf->reserve_dump_area_start;
I just noticed you're using ulong, which I haven't seen much before. KVM
uses it a lot but not much else.
Because this is all 64-bit only code I'd probably rather you just use
u64 explicitly to avoid anyone having to think about it.
> +
> + opal_fdm = __va(fadump_conf->kernel_metadata);
> + opal_fadump_init_metadata(opal_fdm);
> +
> + opal_fdm->region_cnt = 1;
> + opal_fdm->rgn[0].src = RMA_START;
> + opal_fdm->rgn[0].dest = addr;
> + opal_fdm->rgn[0].size = fadump_conf->boot_memory_size;
> + addr += fadump_conf->boot_memory_size;
> +
> + /*
> + * Kernel metadata is passed to f/w and retrieved in capture kerenl.
> + * So, use it to save fadump header address instead of calculating it.
> + */
> + opal_fdm->fadumphdr_addr = (opal_fdm->rgn[0].dest +
> + fadump_conf->boot_memory_size);
> +
> + return addr;
> +}
> +
> +static ulong opal_fadump_get_metadata_size(void)
> +{
> + ulong size = sizeof(struct opal_fadump_mem_struct);
> +
> + size = PAGE_ALIGN(size);
> + return size;
return PAGE_ALIGN(sizeof(struct opal_fadump_mem_struct));
???
> diff --git a/arch/powerpc/platforms/powernv/opal-fadump.h
> b/arch/powerpc/platforms/powernv/opal-fadump.h
> new file mode 100644
> index 0000000..19cac1f
> --- /dev/null
> +++ b/arch/powerpc/platforms/powernv/opal-fadump.h
> @@ -0,0 +1,33 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * Firmware-Assisted Dump support on POWER platform (OPAL).
> + *
> + * Copyright 2019, IBM Corp.
> + * Author: Hari Bathini <hbath...@linux.ibm.com>
> + */
> +
> +#ifndef __PPC64_OPAL_FA_DUMP_H__
> +#define __PPC64_OPAL_FA_DUMP_H__
Usual style is _ASM_POWERPC_OPAL_FADUMP_H.
> +/* OPAL FADump structure format version */
> +#define OPAL_FADUMP_VERSION 0x1
What is the meaning of this version? How/can we change it. What does it
mean if it's a different number? Please provide some comments or doco
describing how it's expected to be used.
We're defining some sort of ABI here and I want to understand/have
better documentation on what the implications of that are.
> diff --git a/arch/powerpc/platforms/pseries/rtas-fadump.c
> b/arch/powerpc/platforms/pseries/rtas-fadump.c
> index 2b94392..4111ee9 100644
> --- a/arch/powerpc/platforms/pseries/rtas-fadump.c
> +++ b/arch/powerpc/platforms/pseries/rtas-fadump.c
> @@ -121,6 +121,21 @@ static ulong rtas_fadump_init_mem_struct(struct fw_dump
> *fadump_conf)
> return addr;
> }
>
> +/*
> + * On this platform, the metadata struture is passed while registering
> + * for FADump and the same is returned by f/w in capture kernel.
> + * No additional provision to setup kernel metadata separately.
> + */
> +static ulong rtas_fadump_get_metadata_size(void)
> +{
> + return 0;
> +}
> +
> +static int rtas_fadump_setup_metadata(struct fw_dump *fadump_conf)
> +{
> + return 0;
> +}
Each of these uses about 16 byes of text as well as space in the symbol
table. I think there's only one call site for each, so allowing the
callback to be NULL and skipping the call when it is would be slightly
more efficient.
> @@ -486,9 +501,10 @@ static void rtas_fadump_trigger(struct
> fadump_crash_info_header *fdh,
> rtas_os_term((char *)msg);
> }
>
> -
> static struct fadump_ops rtas_fadump_ops = {
> .fadump_init_mem_struct = rtas_fadump_init_mem_struct,
> + .fadump_get_metadata_size = rtas_fadump_get_metadata_size,
> + .fadump_setup_metadata = rtas_fadump_setup_metadata,
> .fadump_register = rtas_fadump_register,
> .fadump_unregister = rtas_fadump_unregister,
> .fadump_invalidate = rtas_fadump_invalidate,
cheers
