Subject: Re: [PATCH 14/16] powerpc: add ps3 platform OS params support

From: Michael Ellerman <[email-masked]>
Date: Mon, 13 Nov 2006 12:29:53 +1100

Hi Geoff,

A few comments below ...

On Fri, 2006-11-10 at 12:03 -0800, Geoff Levand wrote:
> Add support to access the parameter data from the ps3pf other OS area of flash
> memory.  The parameter data mainly holds user preferences like static ip
> address, etc.
> 
> Signed-off-by: Geoff Levand <[email-masked]>
> 
> ---
>  arch/powerpc/platforms/ps3pf/Makefile  |    2 
>  arch/powerpc/platforms/ps3pf/os-area.c |  245 +++++++++++++++++++++++++++++++++
>  arch/powerpc/platforms/ps3pf/setup.c   |    1 
>  3 files changed, 247 insertions(+), 1 deletion(-)
> 
> Index: cell--common--6/arch/powerpc/platforms/ps3pf/Makefile
> ===================================================================
> --- cell--common--6.orig/arch/powerpc/platforms/ps3pf/Makefile
> +++ cell--common--6/arch/powerpc/platforms/ps3pf/Makefile
> @@ -1,2 +1,2 @@
>  obj-$(CONFIG_PS3PF) += setup.o mm.o smp.o time.o hvcall.o htab.o repository.o
> -obj-$(CONFIG_PS3PF) += interrupt.o exports.o
> +obj-$(CONFIG_PS3PF) += interrupt.o exports.o os-area.o

You don't need CONFIG_PS3PF in this Makefile, it'll only be built if
CONFIG_PS3PF is already set, just add to obj-y. See the other platform
Makefiles for example.

> Index: cell--common--6/arch/powerpc/platforms/ps3pf/os-area.c
> ===================================================================
> --- /dev/null
> +++ cell--common--6/arch/powerpc/platforms/ps3pf/os-area.c
> @@ -0,0 +1,245 @@
> +/*
> + * os-area.c - PS3 Platform OS data area.
> + *
> + *  Copyright (C) 2006 Sony Computer Entertainment Inc.
> + *  Copyright 2006 Sony Corp.
> + *
> + *  This program is free software; you can redistribute it and/or modify
> + *  it under the terms of the GNU General Public License as published by
> + *  the Free Software Foundation; version 2 of the License.
> + *
> + *  This program is distributed in the hope that it will be useful,
> + *  but WITHOUT ANY WARRANTY; without even the implied warranty of
> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + *  GNU General Public License for more details.
> + *
> + *  You should have received a copy of the GNU General Public License
> + *  along with this program; if not, write to the Free Software
> + *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
> + */
> +
> +#undef DEBUG
> +
> +#include <linux/kernel.h>
> +#include <linux/io.h>
> +
> +#include <asm/lmb.h>
> +#include <asm/ps3pf.h>
> +
> +#include "platform.h"
> +
> +enum {
> +	segment_size = 0x200,
> +	ldr_format_raw = 0,
> +	ldr_format_gzip = 1,
> +	boot_flag_game_os = 0,
> +	boot_flag_other_os = 1,
> +	av_multi_out_ntsc = 0,
> +	av_multi_out_pal_rgb = 1,
> +	av_multi_out_pal_ycbcr = 2,
> +	av_multi_out_secam = 3,
> +	ctrl_button_o_is_yes = 0,
> +	ctrl_button_x_is_yes = 1,
> +};

I know you've got a lot of code to get reviewed and merged, but this
still irks me. These aren't related constants, so I don't think they
belong in an enum together, ctrl_button_o_is_yes == boot_flag_game_os ?

CodingStyle says the labels should be capitalised. 

> +/**
> + * struct header - os area header segment.
> + * @magic_num: Always 'cell_ext_os_area'.
> + * @hdr_version: Header format version number.
> + * @os_region_offset: Segment number of os region.

Doesn't match the name in the struct.

> + * @bootloader_offset: Segment number of bootloader image.

Is it an offset (from something) or a segment number?

> + * @ldr_format: ldr_format flag.
> + * @ldr_size: Size of bootloader image in bytes.

If these three all describe the same thing, the bootloader, it'd be good
if the names were similar, eg: bootloader_offset, bootloader_format,
bootloader_size.

> + */
> +
> +struct header {
> +	s8 magic_num[16];

You compare this later to "cell_ext_os_area", so it's not really a magic
number at all, it's a string?

> +	u32 hdr_version;
> +	u32 os_image_offset;
> +	u32 bootloader_offset;
> +	u32 _reserved_1;
> +	u32 ldr_format;
> +	u32 ldr_size;
> +	u32 _reserved_2[6];
> +} __attribute__ ((packed));
> +
> +/**
> + * struct params - os area params segment.
> + * @boot_flag: User preference of operating system.
> + * @num_params: Number of params in this (params) segment.
> + * @rtc_diff: Difference in seconds between 1970 and the ps3pf rtc value.
> + * @av_multi_out: User preference of AV output.
> + * @ctrl_button: User preference of controller button config.
> + * @static_ip_addr: User preference of static IP address.
> + * @network_mask: User preference of static network mask.
> + * @default_gateway: User preference of static default gateway.
> + * @dns_primary: User preference of static primary dns server.
> + * @dns_secondary: User preference of static secondary dns server.
> + *
> + * User preference of zero for static_ip_addr means use dhcp.
> + */
> +
> +struct params {
> +	u32 boot_flag;
> +	u32 _reserved_1[3];
> +	u32 num_params;
> +	u32 _reserved_2[3];
> +	/* param 0 */
> +	s64 rtc_diff;
> +	u8 av_multi_out;
> +	u8 ctrl_button;
> +	u8 _reserved_3[6];
> +	/* param 1 */
> +	u8 static_ip_addr[4];
> +	u8 network_mask[4];
> +	u8 default_gateway[4];
> +	u8 _reserved_4[4];
> +	/* param 2 */
> +	u8 dns_primary[4];
> +	u8 dns_secondary[4];
> +	u8 _reserved_5[8];
> +} __attribute__ ((packed));
> +
> +/**
> + * struct os_params - Static working copies of data from the os area.
> + *
> + * For the convinience of the guest, the HV makes a copy of the os area in
> + * flash to a high address in the boot memory region and then puts that RAM
> + * address and the byte count into the repository for retreval by the guest.
> + * We copy the data we want into a static variable and allow the memory setup
> + * by the HV to be claimed by the lmb manager.
> + */
> +
> +struct os_params {
> +	/* param 0 */
> +	s64 rtc_diff;
> +	unsigned int av_multi_out;
> +	unsigned int ctrl_button;
> +	/* param 1 */
> +	u8 static_ip_addr[4];
> +	u8 network_mask[4];
> +	u8 default_gateway[4];
> +	/* param 2 */
> +	u8 dns_primary[4];
> +	u8 dns_secondary[4];
> +} static os_params;

Several of these structs could use a better name: header, params etc.

> +
> +#define dump_header(_a) _dump_header(_a, __func__, __LINE__)
> +static void _dump_header(const struct header __iomem *h, const char* func,
> +	int line)
> +{
> +	pr_debug("%s:%d: h.magic_num:         '%s'\n", func, line,
> +		h->magic_num);
> +	pr_debug("%s:%d: h.hdr_version:       %u\n", func, line,
> +		h->hdr_version);
> +	pr_debug("%s:%d: h.os_image_offset:   %u\n", func, line,
> +		h->os_image_offset);
> +	pr_debug("%s:%d: h.bootloader_offset: %u\n", func, line,
> +		h->bootloader_offset);
> +	pr_debug("%s:%d: h.ldr_format:        %u\n", func, line,
> +		h->ldr_format);
> +	pr_debug("%s:%d: h.ldr_size:          %xh\n", func, line,
> +		h->ldr_size);
> +}
> +
> +#define dump_params(_a) _dump_params(_a, __func__, __LINE__)
> +static void _dump_params(const struct params __iomem *p, const char* func,
> +	int line)
> +{
> +	pr_debug("%s:%d: p.boot_flag:       %u\n", func, line, p->boot_flag);
> +	pr_debug("%s:%d: p.num_params:      %u\n", func, line, p->num_params);
> +	pr_debug("%s:%d: p.rtc_diff         %ld\n", func, line, p->rtc_diff);
> +	pr_debug("%s:%d: p.av_multi_out     %u\n", func, line, p->av_multi_out);
> +	pr_debug("%s:%d: p.ctrl_button:     %u\n", func, line, p->ctrl_button);
> +	pr_debug("%s:%d: p.static_ip_addr:  %u.%u.%u.%u\n", func, line,
> +		p->static_ip_addr[0], p->static_ip_addr[1],
> +		p->static_ip_addr[2], p->static_ip_addr[3]);
> +	pr_debug("%s:%d: p.network_mask:    %u.%u.%u.%u\n", func, line,
> +		p->network_mask[0], p->network_mask[1],
> +		p->network_mask[2], p->network_mask[3]);
> +	pr_debug("%s:%d: p.default_gateway: %u.%u.%u.%u\n", func, line,
> +		p->default_gateway[0], p->default_gateway[1],
> +		p->default_gateway[2], p->default_gateway[3]);
> +	pr_debug("%s:%d: p.dns_primary:     %u.%u.%u.%u\n", func, line,
> +		p->dns_primary[0], p->dns_primary[1],
> +		p->dns_primary[2], p->dns_primary[3]);
> +	pr_debug("%s:%d: p.dns_secondary:   %u.%u.%u.%u\n", func, line,
> +		p->dns_secondary[0], p->dns_secondary[1],
> +		p->dns_secondary[2], p->dns_secondary[3]);
> +}
> +
> +static int __init verify_header(const struct header *header)
> +{
> +	if (memcmp(header->magic_num, "cell_ext_os_area", 16)) {
> +		pr_debug("%s:%d magic_num failed\n", __func__, __LINE__);
> +		return -1;
> +	}
> +
> +	if (header->hdr_version != 1) {
> +		pr_debug("%s:%d hdr_version failed\n", __func__, __LINE__);
> +		return -1;
> +	}

Is version 2 not going to be backward compatible? Could it be >= 1 ?

> +
> +	if (header->os_image_offset > header->bootloader_offset) {
> +		pr_debug("%s:%d offsets failed\n", __func__, __LINE__);
> +		return -1;
> +	}
> +
> +	return 0;
> +}
> +
> +int __init ps3pf_os_area_init(void)
> +{
> +	int result;
> +	u64 lpar_addr;
> +	unsigned int size;
> +	struct header *header;
> +	struct params *params;
> +
> +	result = ps3pf_repository_read_boot_dat_info(&lpar_addr, &size);
> +
> +	if (result) {
> +		pr_debug("%s:%d ps3pf_repository_read_boot_dat_info failed\n",
> +			__func__, __LINE__);
> +		return result;
> +	}
> +
> +	header = (struct header *)__va(lpar_addr);
> +	params = (struct params *)__va(lpar_addr + segment_size);
> +
> +	result = verify_header(header);
> +
> +	if (result) {
> +		pr_debug("%s:%d verify_header failed\n", __func__, __LINE__);
> +		dump_header(header);
> +		return -EIO;
> +	}
> +
> +	dump_header(header);
> +	dump_params(params);
> +
> +	os_params.rtc_diff = params->rtc_diff;
> +	os_params.av_multi_out = params->av_multi_out;
> +	if (0) { /* currently not used */

Why not?

> +		os_params.ctrl_button = params->ctrl_button;
> +		memcpy(os_params.static_ip_addr, params->static_ip_addr, 4);
> +		memcpy(os_params.network_mask, params->network_mask, 4);
> +		memcpy(os_params.default_gateway, params->default_gateway, 4);
> +		memcpy(os_params.dns_secondary, params->dns_secondary, 4);
> +	}
> +
> +	return result;
> +}
> +
> +/**
> + * ps3pf_os_area_rtc_diff - Returns the ps3pf rtc diff value.
> + *
> + * The ps3pf rtc maintains a value that approximates seconds since
> + * 2000-01-01 00:00:00 UTC.  Returns the exact number of seconds from 1970 to
> + * 2000 when os_params.rtc_diff has not been properly set up.
> + */
> +
> +u64 ps3pf_os_area_rtc_diff(void)
> +{
> +	return os_params.rtc_diff ? os_params.rtc_diff : 946684800UL;
> +}
> Index: cell--common--6/arch/powerpc/platforms/ps3pf/setup.c
> ===================================================================
> --- cell--common--6.orig/arch/powerpc/platforms/ps3pf/setup.c
> +++ cell--common--6/arch/powerpc/platforms/ps3pf/setup.c
> @@ -115,6 +115,7 @@
>  
>  	powerpc_firmware_features |= FW_FEATURE_LPAR;
>  
> +	ps3pf_os_area_init();
>  	ps3pf_mm_init();
>  	ps3pf_mm_vas_create(&htab_size);
>  	ps3pf_hpte_init(htab_size);

cheers

-- 
Michael Ellerman
OzLabs, IBM Australia Development Lab

wwweb: http://michael.ellerman.id.au
phone: +61 2 6212 1183 (tie line 70 21183)

We do not inherit the earth from our ancestors,
we borrow it from our children. - S.M.A.R.T Person