diff options
Diffstat (limited to 'arch/s390/boot/startup.c')
| -rw-r--r-- | arch/s390/boot/startup.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c index 8826c4f18645..8104e0e3d188 100644 --- a/arch/s390/boot/startup.c +++ b/arch/s390/boot/startup.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 #include <linux/string.h> #include <linux/elf.h> +#include <asm/page-states.h> #include <asm/boot_data.h> #include <asm/sections.h> #include <asm/maccess.h> @@ -57,6 +58,48 @@ static void detect_facilities(void) machine.has_nx = 1; } +static int cmma_test_essa(void) +{ + unsigned long reg1, reg2, tmp = 0; + int rc = 1; + psw_t old; + + /* Test ESSA_GET_STATE */ + 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" + " .insn rrf,0xb9ab0000,%[tmp],%[tmp],%[cmd],0\n" + " la %[rc],0\n" + "1: mvc 0(16,%[psw_pgm]),0(%[psw_old])\n" + : [reg1] "=&d" (reg1), + [reg2] "=&a" (reg2), + [rc] "+&d" (rc), + [tmp] "=&d" (tmp), + "+Q" (S390_lowcore.program_new_psw), + "=Q" (old) + : [psw_old] "a" (&old), + [psw_pgm] "a" (&S390_lowcore.program_new_psw), + [cmd] "i" (ESSA_GET_STATE) + : "cc", "memory"); + return rc; +} + +static void cmma_init(void) +{ + if (!cmma_flag) + return; + if (cmma_test_essa()) { + cmma_flag = 0; + return; + } + if (test_facility(147)) + cmma_flag = 2; +} + static void setup_lpp(void) { S390_lowcore.current_pid = 0; @@ -306,6 +349,7 @@ void startup_kernel(void) setup_boot_command_line(); parse_boot_command_line(); detect_facilities(); + cmma_init(); sanitize_prot_virt_host(); max_physmem_end = detect_max_physmem_end(); setup_ident_map_size(max_physmem_end); |