Re: [PATCH v11 3/5] x86/boot: Add get_acpi_rsdp() to parse RSDP in cmdlien from kexec
From: Chao Fan
Date: Mon Nov 12 2018 - 21:13:21 EST
On Mon, Nov 12, 2018 at 12:43:44PM -0500, Masayoshi Mizuma wrote:
>Hi Chao,
>
>On Mon, Nov 12, 2018 at 05:46:43PM +0800, Chao Fan wrote:
>> Imitate setup_acpi_rsdp() for the early_param of 'acpi_rsdp'.
>> KEXEC writes the RSDP pointer to cmdline for EFI booting.
>> So if 'acpi_rsdp' found in cmdline, use it directely.
>>
>
>> Since function kstrtoull() is needed, include it in
>> arch/x86/boot/string.h. To solve the definition conflict
>> problem, set BOOT_STRING tag to expose only kstrtoull() and
>> functions used by it. Other functions in lib/kstrtox.c will
>> be covered.
>
>How about the following get_acpi_rsdp()...? It doesn't use kstrtoull().
>
>static void get_acpi_rsdp(acpi_physical_address *rsdp_addr)
>{
>#ifdef CONFIG_KEXEC
> unsigned long addr;
> char val[32];
>
> if (cmdline_find_option("acpi_rsdp", val, sizeof(val)) > 0) {
> char *e;
>
> if (!strncmp(val, "0x", 2)) {
> addr = simple_strtoull(val + 2, &e, 16);
> if ((addr == 0) || ((val + 2) == e))
> return;
> *rsdp_addr = (acpi_physical_address)addr;
> }
> }
>#endif
>}
Thanks for the suggestion.
I used this function. In the old version, Boris said simple_strtoull()
is the old function and told me use the new kstrtoull().
Thanks,
Chao Fan
>
>Thanks,
>Masa
>
>>
>> Signed-off-by: Chao Fan <fanc.fnst@xxxxxxxxxxxxxx>
>> ---
>> arch/x86/boot/compressed/acpitb.c | 26 ++++++++++++++++++++++++++
>> arch/x86/boot/string.h | 4 ++++
>> lib/kstrtox.c | 4 ++++
>> 3 files changed, 34 insertions(+)
>>
>> diff --git a/arch/x86/boot/compressed/acpitb.c b/arch/x86/boot/compressed/acpitb.c
>> index 50fa65cf824d..5cfb4efa5a19 100644
>> --- a/arch/x86/boot/compressed/acpitb.c
>> +++ b/arch/x86/boot/compressed/acpitb.c
>> @@ -8,6 +8,12 @@
>> #include <linux/numa.h>
>> #include <linux/acpi.h>
>>
>> +#define STATIC
>> +#include <linux/decompress/mm.h>
>> +
>> +#define BOOT_STRING
>> +#include "../string.h"
>> +
>> /* Search EFI table for RSDP table. */
>> static void efi_get_rsdp_addr(acpi_physical_address *rsdp_addr)
>> {
>> @@ -200,3 +206,23 @@ static void bios_get_rsdp_addr(acpi_physical_address *rsdp_addr)
>> *rsdp_addr = (acpi_physical_address)address;
>> }
>> }
>> +
>> +static void get_acpi_rsdp(acpi_physical_address *rsdp_addr)
>> +{
>> +#ifdef CONFIG_KEXEC
>> + unsigned long long res;
>> + int len = 0;
>> + char *val;
>> +
>> + val = malloc(19);
>> + len = cmdline_find_option("acpi_rsdp", val, 19);
>> +
>> + if (len == -1)
>> + return;
>> +
>> + if (len > 0) {
>> + val[len] = 0;
>> + *rsdp_addr = (acpi_physical_address)kstrtoull(val, 16, &res);
>> + }
>> +#endif
>> +}
>> diff --git a/arch/x86/boot/string.h b/arch/x86/boot/string.h
>> index 3d78e27077f4..0ff3edb888e4 100644
>> --- a/arch/x86/boot/string.h
>> +++ b/arch/x86/boot/string.h
>> @@ -30,3 +30,7 @@ extern unsigned long long simple_strtoull(const char *cp, char **endp,
>> unsigned int base);
>>
>> #endif /* BOOT_STRING_H */
>> +
>> +#ifdef BOOT_STRING
>> +#include "../../../lib/kstrtox.c"
>> +#endif
>> diff --git a/lib/kstrtox.c b/lib/kstrtox.c
>> index 1006bf70bf74..3804db9eed56 100644
>> --- a/lib/kstrtox.c
>> +++ b/lib/kstrtox.c
>> @@ -126,6 +126,8 @@ int kstrtoull(const char *s, unsigned int base, unsigned long long *res)
>> }
>> EXPORT_SYMBOL(kstrtoull);
>>
>> +#ifndef BOOT_STRING
>> +
>> /**
>> * kstrtoll - convert a string to a long long
>> * @s: The start of the string. The string must be null-terminated, and may also
>> @@ -408,3 +410,5 @@ kstrto_from_user(kstrtou16_from_user, kstrtou16, u16);
>> kstrto_from_user(kstrtos16_from_user, kstrtos16, s16);
>> kstrto_from_user(kstrtou8_from_user, kstrtou8, u8);
>> kstrto_from_user(kstrtos8_from_user, kstrtos8, s8);
>> +
>> +#endif
>> --
>> 2.19.1
>>
>>
>>
>
>