2019-11-06 16:07:51

by Tiezhu Yang

[permalink] [raw]
Subject: [PATCH] MIPS: Scan the DMI system information

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 <[email protected]>
Signed-off-by: Yinglu Yang <[email protected]>
Signed-off-by: Tiezhu Yang <[email protected]>
---
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
+}
+
+void __init mips_early_memunmap(void *addr, unsigned long size)
+{
+
+}
+
+void *mips_memremap(resource_size_t offset, size_t size, unsigned long flags)
+{
+#if defined(CONFIG_MACH_LOONGSON64)
+ return (void *)TO_CAC(offset);
+#else
+ return NULL;
+#endif
+}
+
+void mips_memunmap(void *addr)
+{
+
+}
+
+#endif /* _ASM_MIPS_DMI_H */
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index c3d4212..da7d312 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -28,6 +28,7 @@
#include <linux/decompress/generic.h>
#include <linux/of_fdt.h>
#include <linux/of_reserved_mem.h>
+#include <linux/dmi.h>

#include <asm/addrspace.h>
#include <asm/bootinfo.h>
@@ -802,6 +803,7 @@ void __init setup_arch(char **cmdline_p)
#endif

arch_mem_init(cmdline_p);
+ dmi_setup();

resource_init();
plat_smp_setup();
--
2.1.0



2019-11-07 01:43:53

by Jiaxun Yang

[permalink] [raw]
Subject: Re: [PATCH] MIPS: Scan the DMI system information



于 2019年11月7日 GMT+08:00 上午12:05:41, Tiezhu Yang <[email protected]> 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 <[email protected]>
>Signed-off-by: Yinglu Yang <[email protected]>
>Signed-off-by: Tiezhu Yang <[email protected]>
>---
> 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.

Btw: Probably we should set DMI default y when MACH_LOONGSON64 is set?

Thanks.

--
Jiaxun Yang

2019-11-07 02:46:05

by Tiezhu Yang

[permalink] [raw]
Subject: Re: [PATCH] MIPS: Scan the DMI system information

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 <[email protected]> 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 <[email protected]>
>> Signed-off-by: Yinglu Yang <[email protected]>
>> Signed-off-by: Tiezhu Yang <[email protected]>
>> ---
>> 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.

>
> 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.

Thanks,

Tiezhu Yang

>
> Thanks.
>

2019-11-07 03:53:10

by Jiaxun Yang

[permalink] [raw]
Subject: Re: [PATCH] MIPS: Scan the DMI system information



于 2019年11月7日 GMT+08:00 上午10:42:23, Tiezhu Yang <[email protected]> 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
><[email protected]> 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 <[email protected]>
>>> Signed-off-by: Yinglu Yang <[email protected]>
>>> Signed-off-by: Tiezhu Yang <[email protected]>
>>> ---
>>> 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.
>
>>
>> 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.

>
>Thanks,
>
>Tiezhu Yang
>
>>
>> Thanks.
>>

--
Jiaxun Yang

2019-11-07 09:30:40

by Tiezhu Yang

[permalink] [raw]
Subject: Re: [PATCH] MIPS: Scan the DMI system information

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<[email protected]> 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
>> <[email protected]> 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<[email protected]>
>>>> Signed-off-by: Yinglu Yang<[email protected]>
>>>> Signed-off-by: Tiezhu Yang<[email protected]>
>>>> ---
>>>> 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.
>>>

2019-11-07 10:45:41

by Jean Delvare

[permalink] [raw]
Subject: Re: [PATCH] MIPS: Scan the DMI system information

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<[email protected]> 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
> >> <[email protected]> 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<[email protected]>
> >>>> Signed-off-by: Yinglu Yang<[email protected]>
> >>>> Signed-off-by: Tiezhu Yang<[email protected]>
> >>>> ---
> >>>> 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?

--
Jean Delvare
SUSE L3 Support

2019-11-07 11:11:30

by Tiezhu Yang

[permalink] [raw]
Subject: Re: [PATCH] MIPS: Scan the DMI system information

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<[email protected]> 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
>>>> <[email protected]> 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<[email protected]>
>>>>>> Signed-off-by: Yinglu Yang<[email protected]>
>>>>>> Signed-off-by: Tiezhu Yang<[email protected]>
>>>>>> ---
>>>>>> 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

>