x86/platform/uv: Add and decode Arch Type in UVsystab

When the UV BIOS starts the kernel it passes the UVsystab info struct to
the kernel which contains information elements more specific than ACPI,
and generally pertinent only to the MMRs. These are read only fields
so information is passed one way only. A new field starting with UV5 is
the UV architecture type so the ACPI OEM_ID field can be used for other
purposes going forward. The UV Arch Type selects the entirety of the
MMRs available, with their addresses and fields defined in uv_mmrs.h.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Mike Travis <mike.travis@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Reviewed-by: Steve Wahl <steve.wahl@hpe.com>
Link: https://lkml.kernel.org/r/20201005203929.148656-7-mike.travis@hpe.com

1 files changed, 116 insertions, 19 deletions

diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index fca5f94d055e..9b7a334578e6 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -31,7 +31,8 @@ static u64			gru_start_paddr, gru_end_paddr;
 static union uvh_apicid		uvh_apicid;
 static int			uv_node_id;
 
-/* Unpack OEM/TABLE ID's to be NULL terminated strings */
+/* Unpack AT/OEM/TABLE ID's to be NULL terminated strings */
+static u8 uv_archtype[UV_AT_SIZE];
 static u8 oem_id[ACPI_OEM_ID_SIZE + 1];
 static u8 oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1];
 
@@ -284,18 +285,102 @@ static void __init uv_stringify(int len, char *to, char *from)
 	strncpy(to, from, len-1);
 }
 
+/* Find UV arch type entry in UVsystab */
+static unsigned long __init early_find_archtype(struct uv_systab *st)
+{
+	int i;
+
+	for (i = 0; st->entry[i].type != UV_SYSTAB_TYPE_UNUSED; i++) {
+		unsigned long ptr = st->entry[i].offset;
+
+		if (!ptr)
+			continue;
+		ptr += (unsigned long)st;
+		if (st->entry[i].type == UV_SYSTAB_TYPE_ARCH_TYPE)
+			return ptr;
+	}
+	return 0;
+}
+
+/* Validate UV arch type field in UVsystab */
+static int __init decode_arch_type(unsigned long ptr)
+{
+	struct uv_arch_type_entry *uv_ate = (struct uv_arch_type_entry *)ptr;
+	int n = strlen(uv_ate->archtype);
+
+	if (n > 0 && n < sizeof(uv_ate->archtype)) {
+		pr_info("UV: UVarchtype received from BIOS\n");
+		uv_stringify(UV_AT_SIZE, uv_archtype, uv_ate->archtype);
+		return 1;
+	}
+	return 0;
+}
+
+/* Determine if UV arch type entry might exist in UVsystab */
+static int __init early_get_arch_type(void)
+{
+	unsigned long uvst_physaddr, uvst_size, ptr;
+	struct uv_systab *st;
+	u32 rev;
+	int ret;
+
+	uvst_physaddr = get_uv_systab_phys(0);
+	if (!uvst_physaddr)
+		return 0;
+
+	st = early_memremap_ro(uvst_physaddr, sizeof(struct uv_systab));
+	if (!st) {
+		pr_err("UV: Cannot access UVsystab, remap failed\n");
+		return 0;
+	}
+
+	rev = st->revision;
+	if (rev < UV_SYSTAB_VERSION_UV5) {
+		early_memunmap(st, sizeof(struct uv_systab));
+		return 0;
+	}
+
+	uvst_size = st->size;
+	early_memunmap(st, sizeof(struct uv_systab));
+	st = early_memremap_ro(uvst_physaddr, uvst_size);
+	if (!st) {
+		pr_err("UV: Cannot access UVarchtype, remap failed\n");
+		return 0;
+	}
+
+	ptr = early_find_archtype(st);
+	if (!ptr) {
+		early_memunmap(st, uvst_size);
+		return 0;
+	}
+
+	ret = decode_arch_type(ptr);
+	early_memunmap(st, uvst_size);
+	return ret;
+}
+
 static int __init uv_set_system_type(char *_oem_id)
 {
-	/* Save OEM ID */
+	/* Save OEM_ID passed from ACPI MADT */
 	uv_stringify(sizeof(oem_id), oem_id, _oem_id);
 
-	/* Set hubless type if true */
-	if (strncmp(oem_id, "SGI", 3) != 0) {
-		if (strncmp(oem_id, "NSGI", 4) != 0)
+	/* Check if BIOS sent us a UVarchtype */
+	if (!early_get_arch_type())
+
+		/* If not use OEM ID for UVarchtype */
+		uv_stringify(UV_AT_SIZE, uv_archtype, _oem_id);
+
+	/* Check if not hubbed */
+	if (strncmp(uv_archtype, "SGI", 3) != 0) {
+
+		/* (Not hubbed), check if not hubless */
+		if (strncmp(uv_archtype, "NSGI", 4) != 0)
+
+			/* (Not hubless), not a UV */
 			return 0;
 
 		/* UV4 Hubless: CH */
-		if (strncmp(oem_id, "NSGI4", 5) == 0)
+		if (strncmp(uv_archtype, "NSGI4", 5) == 0)
 			uv_hubless_system = 0x11;
 
 		/* UV3 Hubless: UV300/MC990X w/o hub */
@@ -314,10 +399,10 @@ static int __init uv_set_system_type(char *_oem_id)
 
 	/* Set hubbed type if true */
 	uv_hub_info->hub_revision =
-		!strncmp(oem_id, "SGI5", 4) ? UV5_HUB_REVISION_BASE :
-		!strncmp(oem_id, "SGI4", 4) ? UV4_HUB_REVISION_BASE :
-		!strncmp(oem_id, "SGI3", 4) ? UV3_HUB_REVISION_BASE :
-		!strcmp(oem_id, "SGI2") ? UV2_HUB_REVISION_BASE : 0;
+		!strncmp(uv_archtype, "SGI5", 4) ? UV5_HUB_REVISION_BASE :
+		!strncmp(uv_archtype, "SGI4", 4) ? UV4_HUB_REVISION_BASE :
+		!strncmp(uv_archtype, "SGI3", 4) ? UV3_HUB_REVISION_BASE :
+		!strcmp(uv_archtype, "SGI2") ? UV2_HUB_REVISION_BASE : 0;
 
 	switch (uv_hub_info->hub_revision) {
 	case UV5_HUB_REVISION_BASE:
@@ -388,8 +473,7 @@ static int __init uv_acpi_madt_oem_check(char *_oem_id, char *_oem_table_id)
 	return 0;
 
 badbios:
-	pr_err("UV: OEM_ID:%s OEM_TABLE_ID:%s\n", oem_id, oem_table_id);
-	pr_err("UV: Current UV Type or BIOS not supported\n");
+	pr_err("UV: UVarchtype:%s not supported\n", uv_archtype);
 	BUG();
 }
 
@@ -1180,6 +1264,7 @@ static void __init decode_gam_rng_tbl(unsigned long ptr)
 	pr_info("UV: GRT: %d entries, sockets(min:%x,max:%x) pnodes(min:%x,max:%x)\n", index, _min_socket, _max_socket, _min_pnode, _max_pnode);
 }
 
+/* Walk through UVsystab decoding the fields */
 static int __init decode_uv_systab(void)
 {
 	struct uv_systab *st;
@@ -1209,7 +1294,8 @@ static int __init decode_uv_systab(void)
 		if (!ptr)
 			continue;
 
-		ptr = ptr + (unsigned long)st;
+		/* point to payload */
+		ptr += (unsigned long)st;
 
 		switch (st->entry[i].type) {
 		case UV_SYSTAB_TYPE_GAM_PARAMS:
@@ -1219,6 +1305,15 @@ static int __init decode_uv_systab(void)
 		case UV_SYSTAB_TYPE_GAM_RNG_TBL:
 			decode_gam_rng_tbl(ptr);
 			break;
+
+		case UV_SYSTAB_TYPE_ARCH_TYPE:
+			/* already processed in early startup */
+			break;
+
+		default:
+			pr_err("UV:%s:Unrecognized UV_SYSTAB_TYPE:%d, skipped\n",
+				__func__, st->entry[i].type);
+			break;
 		}
 	}
 	return 0;
@@ -1259,7 +1354,7 @@ static void __init build_socket_tables(void)
 			pr_info("UV: No UVsystab socket table, ignoring\n");
 			return;
 		}
-		pr_crit("UV: Error: UVsystab address translations not available!\n");
+		pr_err("UV: Error: UVsystab address translations not available!\n");
 		BUG();
 	}
 
@@ -1385,9 +1480,9 @@ static int __maybe_unused proc_hubless_show(struct seq_file *file, void *data)
 	return 0;
 }
 
-static int __maybe_unused proc_oemid_show(struct seq_file *file, void *data)
+static int __maybe_unused proc_archtype_show(struct seq_file *file, void *data)
 {
-	seq_printf(file, "%s/%s\n", oem_id, oem_table_id);
+	seq_printf(file, "%s/%s\n", uv_archtype, oem_table_id);
 	return 0;
 }
 
@@ -1396,7 +1491,7 @@ static __init void uv_setup_proc_files(int hubless)
 	struct proc_dir_entry *pde;
 
 	pde = proc_mkdir(UV_PROC_NODE, NULL);
-	proc_create_single("oemid", 0, pde, proc_oemid_show);
+	proc_create_single("archtype", 0, pde, proc_archtype_show);
 	if (hubless)
 		proc_create_single("hubless", 0, pde, proc_hubless_show);
 	else
@@ -1448,12 +1543,14 @@ static void __init uv_system_init_hub(void)
 
 	map_low_mmrs();
 
-	/* Get uv_systab for decoding: */
+	/* Get uv_systab for decoding, setup UV BIOS calls */
 	uv_bios_init();
 
 	/* If there's an UVsystab problem then abort UV init: */
-	if (decode_uv_systab() < 0)
+	if (decode_uv_systab() < 0) {
+		pr_err("UV: Mangled UVsystab format\n");
 		return;
+	}
 
 	build_socket_tables();
 	build_uv_gr_table();