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-rw-r--r--arch/s390/boot/physmem_info.c47
-rw-r--r--arch/s390/boot/startup.c7
-rw-r--r--arch/s390/include/asm/physmem_info.h3
3 files changed, 54 insertions, 3 deletions
diff --git a/arch/s390/boot/physmem_info.c b/arch/s390/boot/physmem_info.c
index 1d131a81cb8b..f3ea5dbff10b 100644
--- a/arch/s390/boot/physmem_info.c
+++ b/arch/s390/boot/physmem_info.c
@@ -109,6 +109,42 @@ static int diag260(void)
return 0;
}
+#define DIAG500_SC_STOR_LIMIT 4
+
+static int diag500_storage_limit(unsigned long *max_physmem_end)
+{
+ unsigned long storage_limit;
+ unsigned long reg1, reg2;
+ psw_t old;
+
+ asm volatile(
+ " mvc 0(16,%[psw_old]),0(%[psw_pgm])\n"
+ " epsw %[reg1],%[reg2]\n"
+ " st %[reg1],0(%[psw_pgm])\n"
+ " st %[reg2],4(%[psw_pgm])\n"
+ " larl %[reg1],1f\n"
+ " stg %[reg1],8(%[psw_pgm])\n"
+ " lghi 1,%[subcode]\n"
+ " lghi 2,0\n"
+ " diag 2,4,0x500\n"
+ "1: mvc 0(16,%[psw_pgm]),0(%[psw_old])\n"
+ " lgr %[slimit],2\n"
+ : [reg1] "=&d" (reg1),
+ [reg2] "=&a" (reg2),
+ [slimit] "=d" (storage_limit),
+ "=Q" (get_lowcore()->program_new_psw),
+ "=Q" (old)
+ : [psw_old] "a" (&old),
+ [psw_pgm] "a" (&get_lowcore()->program_new_psw),
+ [subcode] "i" (DIAG500_SC_STOR_LIMIT)
+ : "memory", "1", "2");
+ if (!storage_limit)
+ return -EINVAL;
+ /* Convert inclusive end to exclusive end */
+ *max_physmem_end = storage_limit + 1;
+ return 0;
+}
+
static int tprot(unsigned long addr)
{
unsigned long reg1, reg2;
@@ -157,7 +193,9 @@ unsigned long detect_max_physmem_end(void)
{
unsigned long max_physmem_end = 0;
- if (!sclp_early_get_memsize(&max_physmem_end)) {
+ if (!diag500_storage_limit(&max_physmem_end)) {
+ physmem_info.info_source = MEM_DETECT_DIAG500_STOR_LIMIT;
+ } else if (!sclp_early_get_memsize(&max_physmem_end)) {
physmem_info.info_source = MEM_DETECT_SCLP_READ_INFO;
} else {
max_physmem_end = search_mem_end();
@@ -170,6 +208,13 @@ void detect_physmem_online_ranges(unsigned long max_physmem_end)
{
if (!sclp_early_read_storage_info()) {
physmem_info.info_source = MEM_DETECT_SCLP_STOR_INFO;
+ } else if (physmem_info.info_source == MEM_DETECT_DIAG500_STOR_LIMIT) {
+ unsigned long online_end;
+
+ if (!sclp_early_get_memsize(&online_end)) {
+ physmem_info.info_source = MEM_DETECT_SCLP_READ_INFO;
+ add_physmem_online_range(0, online_end);
+ }
} else if (!diag260()) {
physmem_info.info_source = MEM_DETECT_DIAG260;
} else if (max_physmem_end) {
diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c
index bf145965baf2..abe6e6c0ab98 100644
--- a/arch/s390/boot/startup.c
+++ b/arch/s390/boot/startup.c
@@ -182,12 +182,15 @@ static void kaslr_adjust_got(unsigned long offset)
* Merge information from several sources into a single ident_map_size value.
* "ident_map_size" represents the upper limit of physical memory we may ever
* reach. It might not be all online memory, but also include standby (offline)
- * memory. "ident_map_size" could be lower then actual standby or even online
+ * memory or memory areas reserved for other means (e.g., memory devices such as
+ * virtio-mem).
+ *
+ * "ident_map_size" could be lower then actual standby/reserved or even online
* memory present, due to limiting factors. We should never go above this limit.
* It is the size of our identity mapping.
*
* Consider the following factors:
- * 1. max_physmem_end - end of physical memory online or standby.
+ * 1. max_physmem_end - end of physical memory online, standby or reserved.
* Always >= end of the last online memory range (get_physmem_online_end()).
* 2. CONFIG_MAX_PHYSMEM_BITS - the maximum size of physical memory the
* kernel is able to support.
diff --git a/arch/s390/include/asm/physmem_info.h b/arch/s390/include/asm/physmem_info.h
index f45cfc8bc233..51b68a43e195 100644
--- a/arch/s390/include/asm/physmem_info.h
+++ b/arch/s390/include/asm/physmem_info.h
@@ -9,6 +9,7 @@ enum physmem_info_source {
MEM_DETECT_NONE = 0,
MEM_DETECT_SCLP_STOR_INFO,
MEM_DETECT_DIAG260,
+ MEM_DETECT_DIAG500_STOR_LIMIT,
MEM_DETECT_SCLP_READ_INFO,
MEM_DETECT_BIN_SEARCH
};
@@ -107,6 +108,8 @@ static inline const char *get_physmem_info_source(void)
return "sclp storage info";
case MEM_DETECT_DIAG260:
return "diag260";
+ case MEM_DETECT_DIAG500_STOR_LIMIT:
+ return "diag500 storage limit";
case MEM_DETECT_SCLP_READ_INFO:
return "sclp read info";
case MEM_DETECT_BIN_SEARCH: