Commit 468a3bc2 authored by Heiko Carstens's avatar Heiko Carstens Committed by Vasily Gorbik
Browse files

s390/cmma: move parsing of cmma kernel parameter to early boot code 



The "cmma=" kernel command line parameter needs to be parsed early for
upcoming changes. Therefore move the parsing code.

Note that EX_TABLE handling of cmma_test_essa() needs to be open-coded,
since the early boot code doesn't have infrastructure for handling expected
exceptions.

Reviewed-by: default avatarClaudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 92b519f3

arch/s390/boot/ipl_parm.c

+8 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
#include <linux/init.h>

#include <linux/ctype.h>

#include <linux/pgtable.h>

#include <asm/page-states.h>

#include <asm/ebcdic.h>

#include <asm/sclp.h>

#include <asm/sections.h>
@@ -24,6 +25,7 @@ unsigned int __bootdata_preserved(zlib_dfltcc_support) = ZLIB_DFLTCC_FULL; 
struct ipl_parameter_block __bootdata_preserved(ipl_block);

int __bootdata_preserved(ipl_block_valid);

int __bootdata_preserved(__kaslr_enabled);

int __bootdata_preserved(cmma_flag) = 1;



unsigned long vmalloc_size = VMALLOC_DEFAULT_SIZE;

unsigned long memory_limit;
@@ -295,6 +297,12 @@ void parse_boot_command_line(void) 
		if (!strcmp(param, "nokaslr"))

			__kaslr_enabled = 0;



		if (!strcmp(param, "cmma")) {

			rc = kstrtobool(val, &enabled);

			if (!rc && !enabled)

				cmma_flag = 0;

		}



#if IS_ENABLED(CONFIG_KVM)

		if (!strcmp(param, "prot_virt")) {

			rc = kstrtobool(val, &enabled);

arch/s390/boot/startup.c

+44 −0
Original line number Diff line number Diff line 
// 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);

arch/s390/include/asm/page-states.h

+4 −0
Original line number Diff line number Diff line
@@ -7,6 +7,8 @@ 
#ifndef PAGE_STATES_H

#define PAGE_STATES_H



#include <asm/sections.h>



#define ESSA_GET_STATE			0

#define ESSA_SET_STABLE			1

#define ESSA_SET_UNUSED			2
@@ -18,4 +20,6 @@ 


#define ESSA_MAX	ESSA_SET_STABLE_NODAT



extern int __bootdata_preserved(cmma_flag);



#endif

arch/s390/include/asm/setup.h

+0 −1
Original line number Diff line number Diff line
@@ -125,7 +125,6 @@ static inline void vmcp_cma_reserve(void) { } 


void report_user_fault(struct pt_regs *regs, long signr, int is_mm_fault);



void cmma_init(void);

void cmma_init_nodat(void);



extern void (*_machine_restart)(char *command);

arch/s390/kernel/early.c

+1 −0
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ decompressor_handled_param(vmalloc); 
decompressor_handled_param(dfltcc);

decompressor_handled_param(facilities);

decompressor_handled_param(nokaslr);

decompressor_handled_param(cmma);

#if IS_ENABLED(CONFIG_KVM)

decompressor_handled_param(prot_virt);

#endif