[PATCH 09/38] MIPS: SGI-IP27: decode a Bedrock hub's node id and system size
From: Imre Kaloz
Date: Thu Oct 01 2026 - 13:19:50 EST
Bedrock's LB_REV_ID holds the node id in bits 39:32 and the system
size, which sets N mode and the region size, in bits 47:46. Decode
both by hub generation; the assembly form, built only for
MAPPED_KERNEL, keys on the widget ID.
Signed-off-by: Imre Kaloz <kaloz@xxxxxxxxxx>
---
.../include/asm/mach-ip27/kernel-entry-init.h | 8 +++-
arch/mips/include/asm/sn/agent.h | 2 +-
arch/mips/include/asm/sn/sn0/hub.h | 37 +++++++++++++++++--
arch/mips/include/asm/sn/sn0/hubni.h | 3 ++
arch/mips/include/asm/sn/sn1/hub.h | 14 +++++++
arch/mips/include/asm/xtalk/xwidget.h | 2 +-
arch/mips/sgi-ip27/ip27-init.c | 6 ++-
7 files changed, 63 insertions(+), 9 deletions(-)
diff --git a/arch/mips/include/asm/mach-ip27/kernel-entry-init.h b/arch/mips/include/asm/mach-ip27/kernel-entry-init.h
index 3e54f605a70b..cd50e6d3d966 100644
--- a/arch/mips/include/asm/mach-ip27/kernel-entry-init.h
+++ b/arch/mips/include/asm/mach-ip27/kernel-entry-init.h
@@ -65,8 +65,10 @@
* arch/mips/mach-xxx/kernel-entry-init.h when necessary.
*/
.macro kernel_entry_setup
- GET_NASID_ASM t1
+#ifdef CONFIG_MAPPED_KERNEL
+ GET_NASID_ASM t1, t0
move t2, t1 # text and data are here
+#endif
MAPPED_KERNEL_SETUP_TLB
.endm
@@ -74,7 +76,8 @@
* Do SMP slave processor setup necessary before we can safely execute C code.
*/
.macro smp_slave_setup
- GET_NASID_ASM t1
+#ifdef CONFIG_MAPPED_KERNEL
+ GET_NASID_ASM t1, t0
dli t0, KLDIR_OFFSET + (KLI_KERN_VARS * KLDIR_ENT_SIZE) + \
KLDIR_OFF_POINTER + CAC_BASE
dsll t1, NASID_SHFT
@@ -82,6 +85,7 @@
ld t0, 0(t0) # t0 points to kern_vars struct
lh t1, KV_RO_NASID_OFFSET(t0)
lh t2, KV_RW_NASID_OFFSET(t0)
+#endif
MAPPED_KERNEL_SETUP_TLB
/*
diff --git a/arch/mips/include/asm/sn/agent.h b/arch/mips/include/asm/sn/agent.h
index 8873eb34e31b..1d6d0cd5e5fd 100644
--- a/arch/mips/include/asm/sn/agent.h
+++ b/arch/mips/include/asm/sn/agent.h
@@ -15,8 +15,8 @@
#include <asm/sn/arch.h>
#if defined(CONFIG_SGI_IP27)
-#include <asm/sn/sn0/hub.h>
#include <asm/sn/sn1/hub.h>
+#include <asm/sn/sn0/hub.h>
#endif /* CONFIG_SGI_IP27 */
/*
diff --git a/arch/mips/include/asm/sn/sn0/hub.h b/arch/mips/include/asm/sn/sn0/hub.h
index 916394319af5..c5429dbddc7a 100644
--- a/arch/mips/include/asm/sn/sn0/hub.h
+++ b/arch/mips/include/asm/sn/sn0/hub.h
@@ -31,6 +31,8 @@
#include <asm/sn/sn0/hubni.h>
//#include <asm/sn/sn0/hubcore.h>
+#include <asm/xtalk/xwidget.h>
+
/* Translation of uncached attributes */
#define UATTR_HSPEC 0
#define UATTR_IO 1
@@ -39,13 +41,35 @@
#ifdef __ASSEMBLER__
/*
- * Returns the local nasid into res.
+ * Clears tmp on a Bedrock hub. Nothing has read the hub's part number
+ * this early, so take it from the widget ID.
*/
- .macro GET_NASID_ASM res
+ .macro GET_HUB_GEN_ASM tmp
+ dli \tmp, LOCAL_HUB_ADDR(IIO_WID)
+ ld \tmp, (\tmp)
+ dsrl \tmp, WIDGET_PART_NUM_SHFT
+ andi \tmp, (WIDGET_PART_NUM >> WIDGET_PART_NUM_SHFT)
+ xori \tmp, WIDGET_BDRCK_PART_NUM
+ .endm
+
+/*
+ * Returns the local nasid into res, clobbering tmp.
+ */
+ .macro GET_NASID_ASM res, tmp
+ .set push
+ .set reorder
+ GET_HUB_GEN_ASM \tmp
dli \res, LOCAL_HUB_ADDR(NI_STATUS_REV_ID)
ld \res, (\res)
+ beqz \tmp, 1f
and \res, NSRI_NODEID_MASK
dsrl \res, NSRI_NODEID_SHFT
+ b 2f
+1:
+ dsrl \res, LRI_NODEID_SHFT_IP35
+ andi \res, LRI_NODEID_MASK_IP35
+2:
+ .set pop
.endm
#else
@@ -54,8 +78,13 @@
*/
static inline nasid_t get_nasid(void)
{
- return (nasid_t)((LOCAL_HUB_L(NI_STATUS_REV_ID) & NSRI_NODEID_MASK)
- >> NSRI_NODEID_SHFT);
+ u64 id = LOCAL_HUB_L(NI_STATUS_REV_ID);
+
+ if (system_is_ip35)
+ return (nasid_t)((id >> LRI_NODEID_SHFT_IP35) &
+ LRI_NODEID_MASK_IP35);
+
+ return (nasid_t)((id & NSRI_NODEID_MASK) >> NSRI_NODEID_SHFT);
}
#endif
diff --git a/arch/mips/include/asm/sn/sn0/hubni.h b/arch/mips/include/asm/sn/sn0/hubni.h
index 4830bae723e4..ff7df5e27f66 100644
--- a/arch/mips/include/asm/sn/sn0/hubni.h
+++ b/arch/mips/include/asm/sn/sn0/hubni.h
@@ -252,6 +252,9 @@ typedef union hubni_port_error_u {
static inline int get_region_shift(void)
{
+ if (system_is_ip35)
+ return LRI_SYSTEM_SIZE_IP35(LOCAL_HUB_L(NI_STATUS_REV_ID));
+
if (LOCAL_HUB_L(NI_STATUS_REV_ID) & NSRI_REGIONSIZE_MASK)
return NASID_TO_FINEREG_SHFT;
diff --git a/arch/mips/include/asm/sn/sn1/hub.h b/arch/mips/include/asm/sn/sn1/hub.h
index db41bcb3d34a..71ccd2ba3698 100644
--- a/arch/mips/include/asm/sn/sn1/hub.h
+++ b/arch/mips/include/asm/sn/sn1/hub.h
@@ -12,4 +12,18 @@
#define HUBXBBASE_IP35 0x00700000
#define HUBMDBASE_IP35 0x00780000
+/*
+ * LB_REV_ID, at the base of the LB block and so at Hub's NI_STATUS_REV_ID
+ * offset, holds the node id in bits 39:32.
+ */
+#define LRI_NODEID_SHFT_IP35 32
+#define LRI_NODEID_MASK_IP35 0xff
+
+/*
+ * Bits 47:46 give the system size: 0, 1 or 2 is log2 of the nodes per
+ * region, and 2 is N mode.
+ */
+#define LRI_SYSTEM_SIZE_IP35(id) (((id) >> 46) & 0x3)
+#define LRI_SYSTEM_SIZE_NMODE_IP35 2
+
#endif /* _ASM_SN_SN1_HUB_H */
diff --git a/arch/mips/include/asm/xtalk/xwidget.h b/arch/mips/include/asm/xtalk/xwidget.h
index 6dae5d9628f7..978877e8a090 100644
--- a/arch/mips/include/asm/xtalk/xwidget.h
+++ b/arch/mips/include/asm/xtalk/xwidget.h
@@ -122,7 +122,7 @@ struct widget_ident {
};
/* Known Xtalk Widgets */
-static const struct widget_ident __initconst widget_idents[] = {
+static const struct widget_ident widget_idents[] __initconst __maybe_unused = {
{
WIDGET_XBOW_MFGR_NUM,
WIDGET_XBOW_PART_NUM,
diff --git a/arch/mips/sgi-ip27/ip27-init.c b/arch/mips/sgi-ip27/ip27-init.c
index 6394c2076041..108d90908763 100644
--- a/arch/mips/sgi-ip27/ip27-init.c
+++ b/arch/mips/sgi-ip27/ip27-init.c
@@ -121,7 +121,11 @@ void __init plat_mem_setup(void)
* Try to catch kernel missconfigurations and give user an
* indication what option to select.
*/
- n_mode = LOCAL_HUB_L(NI_STATUS_REV_ID) & NSRI_MORENODES_MASK;
+ if (system_is_ip35)
+ n_mode = LRI_SYSTEM_SIZE_IP35(LOCAL_HUB_L(NI_STATUS_REV_ID)) ==
+ LRI_SYSTEM_SIZE_NMODE_IP35;
+ else
+ n_mode = LOCAL_HUB_L(NI_STATUS_REV_ID) & NSRI_MORENODES_MASK;
printk("Machine is in %c mode.\n", n_mode ? 'N' : 'M');
#ifdef CONFIG_SGI_SN_N_MODE
if (!n_mode)
--
2.47.3