Messages in this thread | | | Subject | Re: [PATCH] MIPS: Scan the DMI system information | From | Tiezhu Yang <> | Date | Thu, 7 Nov 2019 19:07:25 +0800 |
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On 11/07/2019 06:42 PM, Jean Delvare wrote: > On Thu, 7 Nov 2019 17:26:58 +0800, Tiezhu Yang wrote: >> 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: > I see no reason to go that route if the decision can be made at build > time. Callback functions are good when the decision is made at run time. > >> 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? > What about: > > #if defined(CONFIG_MACH_LOONGSON64) > #define SMBIOS_ENTRY_POINT_SCAN_START 0xFFFE000 > #else > #define SMBIOS_ENTRY_POINT_SCAN_START 0xF0000 > #endif > > And then just use SMBIOS_ENTRY_POINT_SCAN_START instead of the raw > address everywhere it is needed?
OK, good idea, thank you very much! I will send a v2 patch as soon as possible.
Thanks,
Tiezhu Yang
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