Re: [PATCH TIP 01/14] x86/e820: remove conditional early mappingin parse_e820_ext

From: Grant Likely
Date: Thu Feb 03 2011 - 15:57:18 EST


On Mon, Jan 24, 2011 at 09:58:49AM +0530, Sebastian Andrzej Siewior wrote:
> This patch ensures that the memory passed from parse_setup_data() is
> large enough to cover the complete data structure. That means that the
> conditional mapping in parse_e820_ext() can go.
>
> While here, I also attempt not to map two pages if the address is not
> aligned to a page boundary.
>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
> Signed-off-by: Dirk Brandewie <dirk.brandewie@xxxxxxxxx>

I'm going through the dt patches now. If I decide they are ready to
go, should I pick this one up too? hpa, does this look like something
you can ack?

g.

> ---
> arch/x86/include/asm/e820.h | 2 +-
> arch/x86/kernel/e820.c | 8 +-------
> arch/x86/kernel/setup.c | 18 +++++++++++++++---
> 3 files changed, 17 insertions(+), 11 deletions(-)
>
> diff --git a/arch/x86/include/asm/e820.h b/arch/x86/include/asm/e820.h
> index e99d55d..908b969 100644
> --- a/arch/x86/include/asm/e820.h
> +++ b/arch/x86/include/asm/e820.h
> @@ -96,7 +96,7 @@ extern void e820_setup_gap(void);
> extern int e820_search_gap(unsigned long *gapstart, unsigned long *gapsize,
> unsigned long start_addr, unsigned long long end_addr);
> struct setup_data;
> -extern void parse_e820_ext(struct setup_data *data, unsigned long pa_data);
> +extern void parse_e820_ext(struct setup_data *data);
>
> #if defined(CONFIG_X86_64) || \
> (defined(CONFIG_X86_32) && defined(CONFIG_HIBERNATION))
> diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
> index 294f26d..5fad626 100644
> --- a/arch/x86/kernel/e820.c
> +++ b/arch/x86/kernel/e820.c
> @@ -667,21 +667,15 @@ __init void e820_setup_gap(void)
> * boot_params.e820_map, others are passed via SETUP_E820_EXT node of
> * linked list of struct setup_data, which is parsed here.
> */
> -void __init parse_e820_ext(struct setup_data *sdata, unsigned long pa_data)
> +void __init parse_e820_ext(struct setup_data *sdata)
> {
> - u32 map_len;
> int entries;
> struct e820entry *extmap;
>
> entries = sdata->len / sizeof(struct e820entry);
> - map_len = sdata->len + sizeof(struct setup_data);
> - if (map_len > PAGE_SIZE)
> - sdata = early_ioremap(pa_data, map_len);
> extmap = (struct e820entry *)(sdata->data);
> __append_e820_map(extmap, entries);
> sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
> - if (map_len > PAGE_SIZE)
> - early_iounmap(sdata, map_len);
> printk(KERN_INFO "extended physical RAM map:\n");
> e820_print_map("extended");
> }
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index d3cfe26..f8e7152 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -429,16 +429,28 @@ static void __init parse_setup_data(void)
> return;
> pa_data = boot_params.hdr.setup_data;
> while (pa_data) {
> - data = early_memremap(pa_data, PAGE_SIZE);
> + u32 data_len;
> + u32 map_len;
> +
> + map_len = max(PAGE_SIZE - (pa_data & ~PAGE_MASK),
> + (u64)sizeof(struct setup_data));
> + data = early_memremap(pa_data, map_len);
> + data_len = data->len + sizeof(struct setup_data);
> + if (data_len > map_len) {
> + early_iounmap(data, map_len);
> + data = early_memremap(pa_data, data_len);
> + map_len = data_len;
> + }
> +
> switch (data->type) {
> case SETUP_E820_EXT:
> - parse_e820_ext(data, pa_data);
> + parse_e820_ext(data);
> break;
> default:
> break;
> }
> pa_data = data->next;
> - early_iounmap(data, PAGE_SIZE);
> + early_iounmap(data, map_len);
> }
> }
>
> --
> 1.7.3.2
>
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