Messages in this thread | ![/](/images/icornerl.gif) | | Subject | Re: [PATCH] MIPS: Scan the DMI system information | From | Tiezhu Yang <> | Date | Thu, 7 Nov 2019 17:26:58 +0800 |
| |
Sorry to resend this email because the mail list server was denied due to it is not plain text.
On 11/07/2019 11:42 AM, Jiaxun Yang wrote: > 于 2019年11月7日 GMT+08:00 上午10:42:23, Tiezhu Yang<yangtiezhu@loongson.cn> 写到: >> On 11/07/2019 08:35 AM, Jiaxun Yang wrote: >>> 于 2019年11月7日 GMT+08:00 上午12:05:41, Tiezhu Yang >> <yangtiezhu@loongson.cn> 写到: >>>> Enable DMI scanning on the MIPS architecture, this setups DMI >>>> identifiers >>>> (dmi_system_id) for printing it out on task dumps and prepares DIMM >>>> entry >>>> information (dmi_memdev_info) from the SMBIOS table. With this >> patch, >>>> the >>>> driver can easily match various of mainboards. >>>> >>>> In the SMBIOS reference specification, the table anchor string >> "_SM_" >>>> is >>>> present in the address range 0xF0000 to 0xFFFFF on a 16-byte >> boundary, >>>> but there exists a special case for loongson platform, when call >>>> function >>>> dmi_early_remap, it should specify the start address to 0xFFFE000 >> due >>>> to >>>> it is reserved for SMBIOS and can be normally access in the BIOS. >>>> >>>> Co-developed-by: Yinglu Yang<yangyinglu@loongson.cn> >>>> Signed-off-by: Yinglu Yang<yangyinglu@loongson.cn> >>>> Signed-off-by: Tiezhu Yang<yangtiezhu@loongson.cn> >>>> --- >>>> arch/mips/Kconfig | 12 ++++++++++++ >>>> arch/mips/include/asm/dmi.h | 43 >>>> +++++++++++++++++++++++++++++++++++++++++++ >>>> arch/mips/kernel/setup.c | 2 ++ >>>> 3 files changed, 57 insertions(+) >>>> create mode 100644 arch/mips/include/asm/dmi.h >>>> >>>> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig >>>> index 7cb8947..0a67b18 100644 >>>> --- a/arch/mips/Kconfig >>>> +++ b/arch/mips/Kconfig >>>> @@ -2757,6 +2757,18 @@ config HW_PERF_EVENTS >>>> Enable hardware performance counter support for perf events. If >>>> disabled, perf events will use software events only. >>>> >>>> +# Mark as expert because too many people got it wrong. >>>> +# The code disables itself when not needed. >>>> +config DMI >>>> + default y >>>> + select DMI_SCAN_MACHINE_NON_EFI_FALLBACK >>>> + bool "Enable DMI scanning" if EXPERT >>>> + help >>>> + Enabled scanning of DMI to identify machine quirks. Say Y >>>> + here unless you have verified that your setup is not >>>> + affected by entries in the DMI blacklist. Required by PNP >>>> + BIOS code. >>>> + >>>> config SMP >>>> bool "Multi-Processing support" >>>> depends on SYS_SUPPORTS_SMP >>>> diff --git a/arch/mips/include/asm/dmi.h >> b/arch/mips/include/asm/dmi.h >>>> new file mode 100644 >>>> index 0000000..1f3da37 >>>> --- /dev/null >>>> +++ b/arch/mips/include/asm/dmi.h >>>> @@ -0,0 +1,43 @@ >>>> +/* SPDX-License-Identifier: GPL-2.0 */ >>>> +#ifndef _ASM_MIPS_DMI_H >>>> +#define _ASM_MIPS_DMI_H >>>> + >>>> +#define dmi_early_remap mips_early_memremap >>>> +#define dmi_early_unmap mips_early_memunmap >>>> +#define dmi_remap(_x, _l) mips_memremap(_x, _l, MEMREMAP_WB) >>>> +#define dmi_unmap(_x) mips_memunmap(_x) >>>> + >>>> +#define dmi_alloc(l) memblock_alloc_low(l, PAGE_SIZE) >>>> + >>>> +void __init *mips_early_memremap(resource_size_t phys_addr, >> unsigned >>>> long size) >>>> +{ >>>> +#if defined(CONFIG_MACH_LOONGSON64) >>>> + if (phys_addr == 0xF0000) >>>> + phys_addr = 0xFFFE000; >>>> + >>>> + return (void *)TO_CAC(phys_addr); >>>> +#else >>>> + return NULL; >>>> +#endif >>>> +} >>> Hi Tiezhu, >>> >>> It is really tricky to hijack dmi address here during remap. >>> I think we should set the dmi table address at dmi_scan.c by a marco >> or something else rather than hijack it during remap. >> >> Hi Jiaxun, >> >> Thanks for your review. I agree with you, let me think about it and try >> to >> find a proper way, and then I will send a v2 patch.
Hi Jiaxun,
It seems that there is no absolutely better way to handle this case.
1. use conditional compilation in drivers/firmware/dmi_scan.c:
#if defined(CONFIG_MACH_LOONGSON64)
p = dmi_early_remap(0xFFFE000, 0x10000);
#else
p = dmi_early_remap(0xF0000, 0x10000);
#endif
This will influence the common code.
2. use callback function in arch/mips/include/asm/dmi.h:
struct plat_dmi_ops {
void (*early_memremap)(void);
void (*memremap)(void);
};
extern struct plat_dmi_ops *dmi_ops;
void __init *mips_early_memremap(resource_size_t phys_addr, unsigned long size)
{
dmi_ops->early_memremap();
}
void *mips_memremap(resource_size_t offset, size_t size, unsigned long flags)
{
dmi_ops->memremap();
}
we can implement the callback function in various of MIPS platforms, like this:
struct plat_dmi_ops loongson3_dmi_ops = {
.early_memremap = loongson3_early_memremap,
.memremap = loongson3_memremap,
};
register_dmi_ops(&loongson3_dmi_ops);
#ifdef CONFIG_DMI
void __init *loongson3_early_memremap(resource_size_t phys_addr, unsigned long size)
{
if (phys_addr == 0xF0000)
phys_addr = 0xfffe000;
return (void *)TO_CAC(phys_addr);
}
void *loongson3_memremap(resource_size_t offset, size_t size, unsigned long flags)
{
return (void *)TO_CAC(phys_addr);
}
#else
void __init __iomem *loongson3_early_memremap(u64 phys_addr, unsigned long size)
{
return NULL;
}
void __init __iomem *loongson3_memremap(u64 phys_addr, unsigned long size)
{
return NULL;
}
#endif
This will not influence the common code.
What do you think?
Hi Jean,
Could you give some suggestions?
>>> Btw: Probably we should set DMI default y when MACH_LOONGSON64 is >> set? >> >> CONFIG_DMI is set to y by default, I think there is no need to select >> DMI when >> set CONFIG_MACH_LOONGSON64. > Sorry, I meant only default to y when MACH_LOONGSON64 is set or even depends on MACH_LOONGSON64. As Loongson is the only known MIPS platform that supports DMI. Default y unconditionally may lead to regression on other MIPS platforms.
OK, I prefer to select DMI when set MACH_LOONGSON64 instead of DMI depends on MACH_LOONGSON64, I will modify the Kconfig file.
Thanks,
Tiezhu Yang
>> Thanks, >> >> Tiezhu Yang >> >>> Thanks. >>>
| ![\](/images/icornerr.gif) |