Messages in this thread | | | Subject | Re: [PATCH v2 1/3] MIPS: Loongson: Get host bridge information | From | Tiezhu Yang <> | Date | Tue, 24 Mar 2020 20:38:46 +0800 |
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On 03/24/2020 06:02 PM, Jiaxun Yang wrote: > > 于 2020年3月24日 GMT+08:00 下午5:58:33, Tiezhu Yang <yangtiezhu@loongson.cn> 写到: >> On 03/24/2020 03:36 PM, Jiaxun Yang wrote: >>> 于 2020年3月23日 GMT+08:00 上午10:59:13, Tiezhu Yang >> <yangtiezhu@loongson.cn> 写到: >>>> Read the address of HyperTransport Configuration Space to get the >>>> vendor ID >>>> and device ID of bridge chip, and then we can distinguish various >> types >>>> of >>>> bridge chip such as Loongson 7A1000 or AMD RS780E. >>>> >>>> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> >>>> --- >>>> arch/mips/include/asm/mach-loongson64/boot_param.h | 6 ++++++ >>>> arch/mips/loongson64/env.c | 16 >>>> ++++++++++++++++ >>>> 2 files changed, 22 insertions(+) >>>> >>>> diff --git a/arch/mips/include/asm/mach-loongson64/boot_param.h >>>> b/arch/mips/include/asm/mach-loongson64/boot_param.h >>>> index 8c286be..5e8c70d 100644 >>>> --- a/arch/mips/include/asm/mach-loongson64/boot_param.h >>>> +++ b/arch/mips/include/asm/mach-loongson64/boot_param.h >>>> @@ -190,6 +190,11 @@ struct boot_params { >>>> struct efi_reset_system_t reset_system; >>>> }; >>>> >>>> +enum loongson_bridge_type { >>>> + RS780E = 1, >>>> + LS7A1000 = 2 >>>> +}; >>>> + >>>> struct loongson_system_configuration { >>>> u32 nr_cpus; >>>> u32 nr_nodes; >>>> @@ -198,6 +203,7 @@ struct loongson_system_configuration { >>>> u16 boot_cpu_id; >>>> u16 reserved_cpus_mask; >>>> enum loongson_cpu_type cputype; >>>> + enum loongson_bridge_type bridgetype; >>>> u64 ht_control_base; >>>> u64 pci_mem_start_addr; >>>> u64 pci_mem_end_addr; >>>> diff --git a/arch/mips/loongson64/env.c b/arch/mips/loongson64/env.c >>>> index 0daeb7b..42542c7 100644 >>>> --- a/arch/mips/loongson64/env.c >>>> +++ b/arch/mips/loongson64/env.c >>>> @@ -19,6 +19,8 @@ >>>> #include <boot_param.h> >>>> #include <workarounds.h> >>>> >>>> +#define HT1_LO_BUS_CONFIG_BASE 0x90000efdfe000000 >>>> + >>>> u32 cpu_clock_freq; >>>> EXPORT_SYMBOL(cpu_clock_freq); >>>> struct efi_memory_map_loongson *loongson_memmap; >>>> @@ -42,6 +44,8 @@ void __init prom_init_env(void) >>>> struct system_loongson *esys; >>>> struct efi_cpuinfo_loongson *ecpu; >>>> struct irq_source_routing_table *eirq_source; >>>> + u32 id; >>>> + u16 vendor, device; >>>> >>>> /* firmware arguments are initialized in head.S */ >>>> boot_p = (struct boot_params *)fw_arg2; >>>> @@ -155,4 +159,16 @@ void __init prom_init_env(void) >>>> memcpy(loongson_sysconf.sensors, esys->sensors, >>>> sizeof(struct sensor_device) * loongson_sysconf.nr_sensors); >>>> pr_info("CpuClock = %u\n", cpu_clock_freq); >>>> + >>>> + id = readl((u32 *)HT1_LO_BUS_CONFIG_BASE); >>> Is that pointer cast required? >> Yes, otherwise it will compile failed: >> arch/mips/loongson64/env.c:163:13: error: passing argument 1 of ‘readl’ > I don't like it through.... > Can we cast it in macro? > At least it should be void __iomem *.
OK, I will modify the code to make it easy to read.
> > >> makes pointer from integer without a cast [-Werror] >> id = readl(HT1_LO_BUS_CONFIG_BASE); >> ^ >>> And you'd better add a comment here like >>> /* Read HT PCI 00:00:00 Host Bridge's ID to detect bridge model */ >>> Otherwise it's hard for others to understand what you are doing. >> OK, I will do it. >> >>>> + vendor = id & 0xffff; >>>> + device = (id >> 16) & 0xffff; >>>> + >>>> + if (vendor == 0x0014 && device == 0x7a00) { >>> Please confirm with hardware design guys that bridge chip in future >> will have different dev ID. >> >> Yes, it maybe have a new device ID for the new bridge chip. >> >>> Thanks. >>> >>>> + pr_info("The bridge chip is Loongson 7A1000\n"); >>>> + loongson_sysconf.bridgetype = LS7A1000; >>>> + } else { >>>> + pr_info("The bridge chip is AMD RS780E or SR5690\n"); >>>> + loongson_sysconf.bridgetype = RS780E; >>>> + } >>>> }
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