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authorTiezhu Yang <yangtiezhu@loongson.cn>2020-04-03 17:29:49 +0800
committerThomas Bogendoerfer <tsbogend@alpha.franken.de>2020-04-28 13:26:09 +0200
commit8c88cc53ffa62b4bb05931c878bcf3dd10db66b5 (patch)
tree71d35c56e18ae3cfb15cdf5b7f9e611d411e180b
parent618c35556e5f2156c8bc5cd43664363838e38e45 (diff)
downloadlinux-8c88cc53ffa62b4bb05931c878bcf3dd10db66b5.tar.bz2
MIPS: Loongson: Get host bridge information
Read the address of host bridge configuration space to get the vendor ID and device ID of host bridge, and then we can distinguish various types of host bridge such as LS7A or RS780E. Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
-rw-r--r--arch/mips/include/asm/mach-loongson64/boot_param.h6
-rw-r--r--arch/mips/loongson64/env.c18
2 files changed, 24 insertions, 0 deletions
diff --git a/arch/mips/include/asm/mach-loongson64/boot_param.h b/arch/mips/include/asm/mach-loongson64/boot_param.h
index 2ed483e32d8c..fc9f14bc5777 100644
--- a/arch/mips/include/asm/mach-loongson64/boot_param.h
+++ b/arch/mips/include/asm/mach-loongson64/boot_param.h
@@ -192,6 +192,11 @@ struct boot_params {
struct efi_reset_system_t reset_system;
};
+enum loongson_bridge_type {
+ RS780E = 1,
+ LS7A = 2
+};
+
struct loongson_system_configuration {
u32 nr_cpus;
u32 nr_nodes;
@@ -200,6 +205,7 @@ 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 2554ef11170d..71f4aaf58791 100644
--- a/arch/mips/loongson64/env.c
+++ b/arch/mips/loongson64/env.c
@@ -14,12 +14,15 @@
* Author: Wu Zhangjin, wuzhangjin@gmail.com
*/
#include <linux/export.h>
+#include <linux/pci_ids.h>
#include <asm/bootinfo.h>
#include <loongson.h>
#include <boot_param.h>
#include <builtin_dtbs.h>
#include <workarounds.h>
+#define HOST_BRIDGE_CONFIG_ADDR ((void __iomem *)TO_UNCAC(0x1a000000))
+
u32 cpu_clock_freq;
EXPORT_SYMBOL(cpu_clock_freq);
struct efi_memory_map_loongson *loongson_memmap;
@@ -43,6 +46,8 @@ 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;
@@ -178,4 +183,17 @@ 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);
+
+ /* Read the ID of PCI host bridge to detect bridge type */
+ id = readl(HOST_BRIDGE_CONFIG_ADDR);
+ vendor = id & 0xffff;
+ device = (id >> 16) & 0xffff;
+
+ if (vendor == PCI_VENDOR_ID_LOONGSON && device == 0x7a00) {
+ pr_info("The bridge chip is LS7A\n");
+ loongson_sysconf.bridgetype = LS7A;
+ } else {
+ pr_info("The bridge chip is RS780E or SR5690\n");
+ loongson_sysconf.bridgetype = RS780E;
+ }
}