Commit 1a2c5840 authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

s390/dump: cleanup CPU save area handling 



Introduce save_area_alloc(), save_area_boot_cpu(), save_area_add_regs()
and save_area_add_vxrs to deal with storing the CPU state in case of a
system dump. Remove struct save_area and save_area_ext, and create a new
struct save_area as a local definition to arch/s390/kernel/crash_dump.c.
Copy each individual field from the hardware status area to the save area,
storing the minimum of required data.

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 1a36a39e

arch/s390/include/asm/ipl.h

+5 −6
Original line number Diff line number Diff line
@@ -88,12 +88,11 @@ struct ipl_parameter_block { 
 */

extern u32 ipl_flags;



struct dump_save_areas {

	struct save_area_ext **areas;

	int count;

};



extern struct dump_save_areas dump_save_areas;

struct save_area;

struct save_area * __init save_area_alloc(bool is_boot_cpu);

struct save_area * __init save_area_boot_cpu(void);

void __init save_area_add_regs(struct save_area *, void *regs);

void __init save_area_add_vxrs(struct save_area *, __vector128 *vxrs);



extern void do_reipl(void);

extern void do_halt(void);

arch/s390/include/asm/lowcore.h

+0 −21
Original line number Diff line number Diff line
@@ -16,27 +16,6 @@ 
#define LC_ORDER 1

#define LC_PAGES 2



struct save_area {

	u64	fp_regs[16];

	u64	gp_regs[16];

	u8	psw[16];

	u8	pad1[8];

	u32	pref_reg;

	u32	fp_ctrl_reg;

	u8	pad2[4];

	u32	tod_reg;

	u64	timer;

	u64	clk_cmp;

	u8	pad3[8];

	u32	acc_regs[16];

	u64	ctrl_regs[16];

} __packed;



struct save_area_ext {

	struct save_area	sa;

	__vector128		vx_regs[32];

};



struct _lowcore {

	__u8	pad_0x0000[0x0014-0x0000];	/* 0x0000 */

	__u32	ipl_parmblock_ptr;		/* 0x0014 */

arch/s390/kernel/crash_dump.c

+121 −142
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <linux/slab.h>

#include <linux/bootmem.h>

#include <linux/elf.h>

#include <asm/asm-offsets.h>

#include <linux/memblock.h>

#include <asm/os_info.h>

#include <asm/elf.h>
@@ -32,7 +33,84 @@ static struct memblock_type oldmem_type = { 
	.regions = &oldmem_region,

};



struct dump_save_areas dump_save_areas;

struct save_area {

	struct list_head list;

	u64 psw[2];

	u64 ctrs[16];

	u64 gprs[16];

	u32 acrs[16];

	u64 fprs[16];

	u32 fpc;

	u32 prefix;

	u64 todpreg;

	u64 timer;

	u64 todcmp;

	u64 vxrs_low[16];

	__vector128 vxrs_high[16];

};



static LIST_HEAD(dump_save_areas);



/*

 * Allocate a save area

 */

struct save_area * __init save_area_alloc(bool is_boot_cpu)

{

	struct save_area *sa;



	sa = (void *) memblock_alloc(sizeof(*sa), 8);

	if (!sa)

		return NULL;

	if (is_boot_cpu)

		list_add(&sa->list, &dump_save_areas);

	else

		list_add_tail(&sa->list, &dump_save_areas);

	return sa;

}



/*

 * Return the address of the save area for the boot CPU

 */

struct save_area * __init save_area_boot_cpu(void)

{

	if (list_empty(&dump_save_areas))

		return NULL;

	return list_first_entry(&dump_save_areas, struct save_area, list);

}



/*

 * Copy CPU registers into the save area

 */

void __init save_area_add_regs(struct save_area *sa, void *regs)

{

	struct _lowcore *lc;



	lc = (struct _lowcore *)(regs - __LC_FPREGS_SAVE_AREA);

	memcpy(&sa->psw, &lc->psw_save_area, sizeof(sa->psw));

	memcpy(&sa->ctrs, &lc->cregs_save_area, sizeof(sa->ctrs));

	memcpy(&sa->gprs, &lc->gpregs_save_area, sizeof(sa->gprs));

	memcpy(&sa->acrs, &lc->access_regs_save_area, sizeof(sa->acrs));

	memcpy(&sa->fprs, &lc->floating_pt_save_area, sizeof(sa->fprs));

	memcpy(&sa->fpc, &lc->fpt_creg_save_area, sizeof(sa->fpc));

	memcpy(&sa->prefix, &lc->prefixreg_save_area, sizeof(sa->prefix));

	memcpy(&sa->todpreg, &lc->tod_progreg_save_area, sizeof(sa->todpreg));

	memcpy(&sa->timer, &lc->cpu_timer_save_area, sizeof(sa->timer));

	memcpy(&sa->todcmp, &lc->clock_comp_save_area, sizeof(sa->todcmp));

}



/*

 * Copy vector registers into the save area

 */

void __init save_area_add_vxrs(struct save_area *sa, __vector128 *vxrs)

{

	int i;



	/* Copy lower halves of vector registers 0-15 */

	for (i = 0; i < 16; i++)

		memcpy(&sa->vxrs_low[i], &vxrs[i].u[2], 8);

	/* Copy vector registers 16-31 */

	memcpy(sa->vxrs_high, vxrs + 16, 16 * sizeof(__vector128));

}



/*

 * Return physical address for virtual address
@@ -232,7 +310,7 @@ static void *kzalloc_panic(int len) 
/*

 * Initialize ELF note

 */

static void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len,

static void *nt_init_name(void *buf, Elf64_Word type, void *desc, int d_len,

			  const char *name)

{

	Elf64_Nhdr *note;
@@ -253,137 +331,42 @@ static void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len, 
	return PTR_ADD(buf, len);

}



/*

 * Initialize prstatus note

 */

static void *nt_prstatus(void *ptr, struct save_area *sa)

static inline void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len)

{

	struct elf_prstatus nt_prstatus;

	static int cpu_nr = 1;



	memset(&nt_prstatus, 0, sizeof(nt_prstatus));

	memcpy(&nt_prstatus.pr_reg.gprs, sa->gp_regs, sizeof(sa->gp_regs));

	memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw));

	memcpy(&nt_prstatus.pr_reg.acrs, sa->acc_regs, sizeof(sa->acc_regs));

	nt_prstatus.pr_pid = cpu_nr;

	cpu_nr++;



	return nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus),

			 "CORE");

	return nt_init_name(buf, type, desc, d_len, KEXEC_CORE_NOTE_NAME);

}



/*

 * Initialize fpregset (floating point) note

 * Fill ELF notes for one CPU with save area registers

 */

static void *nt_fpregset(void *ptr, struct save_area *sa)

static void *fill_cpu_elf_notes(void *ptr, int cpu, struct save_area *sa)

{

	struct elf_prstatus nt_prstatus;

	elf_fpregset_t nt_fpregset;



	/* Prepare prstatus note */

	memset(&nt_prstatus, 0, sizeof(nt_prstatus));

	memcpy(&nt_prstatus.pr_reg.gprs, sa->gprs, sizeof(sa->gprs));

	memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw));

	memcpy(&nt_prstatus.pr_reg.acrs, sa->acrs, sizeof(sa->acrs));

	nt_prstatus.pr_pid = cpu;

	/* Prepare fpregset (floating point) note */

	memset(&nt_fpregset, 0, sizeof(nt_fpregset));

	memcpy(&nt_fpregset.fpc, &sa->fp_ctrl_reg, sizeof(sa->fp_ctrl_reg));

	memcpy(&nt_fpregset.fprs, &sa->fp_regs, sizeof(sa->fp_regs));



	return nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset),

		       "CORE");

}



/*

 * Initialize timer note

 */

static void *nt_s390_timer(void *ptr, struct save_area *sa)

{

	return nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer),

			 KEXEC_CORE_NOTE_NAME);

}



/*

 * Initialize TOD clock comparator note

 */

static void *nt_s390_tod_cmp(void *ptr, struct save_area *sa)

{

	return nt_init(ptr, NT_S390_TODCMP, &sa->clk_cmp,

		       sizeof(sa->clk_cmp), KEXEC_CORE_NOTE_NAME);

}



/*

 * Initialize TOD programmable register note

 */

static void *nt_s390_tod_preg(void *ptr, struct save_area *sa)

{

	return nt_init(ptr, NT_S390_TODPREG, &sa->tod_reg,

		       sizeof(sa->tod_reg), KEXEC_CORE_NOTE_NAME);

}



/*

 * Initialize control register note

 */

static void *nt_s390_ctrs(void *ptr, struct save_area *sa)

{

	return nt_init(ptr, NT_S390_CTRS, &sa->ctrl_regs,

		       sizeof(sa->ctrl_regs), KEXEC_CORE_NOTE_NAME);

}



/*

 * Initialize prefix register note

 */

static void *nt_s390_prefix(void *ptr, struct save_area *sa)

{

	return nt_init(ptr, NT_S390_PREFIX, &sa->pref_reg,

			 sizeof(sa->pref_reg), KEXEC_CORE_NOTE_NAME);

}



/*

 * Initialize vxrs high note (full 128 bit VX registers 16-31)

 */

static void *nt_s390_vx_high(void *ptr, __vector128 *vx_regs)

{

	return nt_init(ptr, NT_S390_VXRS_HIGH, &vx_regs[16],

		       16 * sizeof(__vector128), KEXEC_CORE_NOTE_NAME);

}



/*

 * Initialize vxrs low note (lower halves of VX registers 0-15)

 */

static void *nt_s390_vx_low(void *ptr, __vector128 *vx_regs)

{

	Elf64_Nhdr *note;

	u64 len;

	int i;



	note = (Elf64_Nhdr *)ptr;

	note->n_namesz = strlen(KEXEC_CORE_NOTE_NAME) + 1;

	note->n_descsz = 16 * 8;

	note->n_type = NT_S390_VXRS_LOW;

	len = sizeof(Elf64_Nhdr);



	memcpy(ptr + len, KEXEC_CORE_NOTE_NAME, note->n_namesz);

	len = roundup(len + note->n_namesz, 4);



	ptr += len;

	/* Copy lower halves of SIMD registers 0-15 */

	for (i = 0; i < 16; i++) {

		memcpy(ptr, &vx_regs[i].u[2], 8);

		ptr += 8;

	}

	return ptr;

}



/*

 * Fill ELF notes for one CPU with save area registers

 */

static void *fill_cpu_elf_notes(void *ptr, struct save_area *sa,

				__vector128 *vx_regs)

{

	ptr = nt_prstatus(ptr, sa);

	ptr = nt_fpregset(ptr, sa);

	ptr = nt_s390_timer(ptr, sa);

	ptr = nt_s390_tod_cmp(ptr, sa);

	ptr = nt_s390_tod_preg(ptr, sa);

	ptr = nt_s390_ctrs(ptr, sa);

	ptr = nt_s390_prefix(ptr, sa);

	if (MACHINE_HAS_VX && vx_regs) {

		ptr = nt_s390_vx_low(ptr, vx_regs);

		ptr = nt_s390_vx_high(ptr, vx_regs);

	memcpy(&nt_fpregset.fpc, &sa->fpc, sizeof(sa->fpc));

	memcpy(&nt_fpregset.fprs, &sa->fprs, sizeof(sa->fprs));

	/* Create ELF notes for the CPU */

	ptr = nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus));

	ptr = nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset));

	ptr = nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer));

	ptr = nt_init(ptr, NT_S390_TODCMP, &sa->todcmp, sizeof(sa->todcmp));

	ptr = nt_init(ptr, NT_S390_TODPREG, &sa->todpreg, sizeof(sa->todpreg));

	ptr = nt_init(ptr, NT_S390_CTRS, &sa->ctrs, sizeof(sa->ctrs));

	ptr = nt_init(ptr, NT_S390_PREFIX, &sa->prefix, sizeof(sa->prefix));

	if (MACHINE_HAS_VX) {

		ptr = nt_init(ptr, NT_S390_VXRS_HIGH,

			      &sa->vxrs_high, sizeof(sa->vxrs_high));

		ptr = nt_init(ptr, NT_S390_VXRS_LOW,

			      &sa->vxrs_low, sizeof(sa->vxrs_low));

	}

	return ptr;

}
@@ -398,8 +381,7 @@ static void *nt_prpsinfo(void *ptr) 
	memset(&prpsinfo, 0, sizeof(prpsinfo));

	prpsinfo.pr_sname = 'R';

	strcpy(prpsinfo.pr_fname, "vmlinux");

	return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo),

		       KEXEC_CORE_NOTE_NAME);

	return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo));

}



/*
@@ -441,7 +423,7 @@ static void *nt_vmcoreinfo(void *ptr) 
		vmcoreinfo = get_vmcoreinfo_old(&size);

	if (!vmcoreinfo)

		return ptr;

	return nt_init(ptr, 0, vmcoreinfo, size, "VMCOREINFO");

	return nt_init_name(ptr, 0, vmcoreinfo, size, "VMCOREINFO");

}



/*
@@ -470,13 +452,12 @@ static void *ehdr_init(Elf64_Ehdr *ehdr, int mem_chunk_cnt) 
 */

static int get_cpu_cnt(void)

{

	int i, cpus = 0;

	struct save_area *sa;

	int cpus = 0;



	for (i = 0; i < dump_save_areas.count; i++) {

		if (dump_save_areas.areas[i]->sa.pref_reg == 0)

			continue;

	list_for_each_entry(sa, &dump_save_areas, list)

		if (sa->prefix != 0)

			cpus++;

	}

	return cpus;

}
@@ -521,18 +502,16 @@ static void loads_init(Elf64_Phdr *phdr, u64 loads_offset) 
 */

static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset)

{

	struct save_area_ext *sa_ext;

	struct save_area *sa;

	void *ptr_start = ptr;

	int i;

	int cpu;



	ptr = nt_prpsinfo(ptr);



	for (i = 0; i < dump_save_areas.count; i++) {

		sa_ext = dump_save_areas.areas[i];

		if (sa_ext->sa.pref_reg == 0)

			continue;

		ptr = fill_cpu_elf_notes(ptr, &sa_ext->sa, sa_ext->vx_regs);

	}

	cpu = 1;

	list_for_each_entry(sa, &dump_save_areas, list)

		if (sa->prefix != 0)

			ptr = fill_cpu_elf_notes(ptr, cpu++, sa);

	ptr = nt_vmcoreinfo(ptr);

	memset(phdr, 0, sizeof(*phdr));

	phdr->p_type = PT_NOTE;

arch/s390/kernel/smp.c

+14 −23
Original line number Diff line number Diff line
@@ -585,7 +585,7 @@ int smp_store_status(int cpu) 
 *    This case does not exist for s390 anymore, setup_arch explicitly

 *    deactivates the elfcorehdr= kernel parameter

 */

static __init void smp_save_cpu_vxrs(struct save_area_ext *sa_ext, u16 addr,

static __init void smp_save_cpu_vxrs(struct save_area *sa, u16 addr,

				     bool is_boot_cpu, unsigned long page)

{

	__vector128 *vxrs = (__vector128 *) page;
@@ -594,10 +594,10 @@ static __init void smp_save_cpu_vxrs(struct save_area_ext *sa_ext, u16 addr, 
		vxrs = boot_cpu_vector_save_area;

	else

		__pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, page);

	memcpy(&sa_ext->vx_regs, vxrs, sizeof(sa_ext->vx_regs));

	save_area_add_vxrs(sa, vxrs);

}



static __init void smp_save_cpu_regs(struct save_area_ext *sa_ext, u16 addr,

static __init void smp_save_cpu_regs(struct save_area *sa, u16 addr,

				     bool is_boot_cpu, unsigned long page)

{

	void *regs = (void *) page;
@@ -606,13 +606,13 @@ static __init void smp_save_cpu_regs(struct save_area_ext *sa_ext, u16 addr, 
		copy_oldmem_kernel(regs, (void *) __LC_FPREGS_SAVE_AREA, 512);

	else

		__pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, page);

	memcpy(&sa_ext->sa, regs, sizeof(sa_ext->sa));

	save_area_add_regs(sa, regs);

}



void __init smp_save_dump_cpus(void)

{

	int addr, cpu, boot_cpu_addr, max_cpu_addr;

	struct save_area_ext *sa_ext;

	int addr, boot_cpu_addr, max_cpu_addr;

	struct save_area *sa;

	unsigned long page;

	bool is_boot_cpu;
@@ -625,29 +625,20 @@ void __init smp_save_dump_cpus(void) 
		panic("could not allocate memory for save area\n");

	/* Set multi-threading state to the previous system. */

	pcpu_set_smt(sclp.mtid_prev);

	max_cpu_addr = SCLP_MAX_CORES << sclp.mtid_prev;

	for (cpu = 0, addr = 0; addr <= max_cpu_addr; addr++) {

		if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0) ==

		    SIGP_CC_NOT_OPERATIONAL)

			continue;

		cpu += 1;

	}

	dump_save_areas.areas = (void *)memblock_alloc(sizeof(void *) * cpu, 8);

	dump_save_areas.count = cpu;

	boot_cpu_addr = stap();

	for (cpu = 0, addr = 0; addr <= max_cpu_addr; addr++) {

	max_cpu_addr = SCLP_MAX_CORES << sclp.mtid_prev;

	for (addr = 0; addr <= max_cpu_addr; addr++) {

		if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0) ==

		    SIGP_CC_NOT_OPERATIONAL)

			continue;

		sa_ext = (void *) memblock_alloc(sizeof(*sa_ext), 8);

		dump_save_areas.areas[cpu] = sa_ext;

		if (!sa_ext)

			panic("could not allocate memory for save area\n");

		is_boot_cpu = (addr == boot_cpu_addr);

		cpu += 1;

		/* Allocate save area */

		sa = save_area_alloc(is_boot_cpu);

		if (!sa)

			panic("could not allocate memory for save area\n");

		if (MACHINE_HAS_VX)

			/* Get the vector registers */

			smp_save_cpu_vxrs(sa_ext, addr, is_boot_cpu, page);

			smp_save_cpu_vxrs(sa, addr, is_boot_cpu, page);

		/*

		 * For a zfcp dump OLDMEM_BASE == NULL and the registers

		 * of the boot CPU are stored in the HSA. To retrieve
@@ -656,7 +647,7 @@ void __init smp_save_dump_cpus(void) 
		 */

		if (!is_boot_cpu || OLDMEM_BASE)

			/* Get the CPU registers */

			smp_save_cpu_regs(sa_ext, addr, is_boot_cpu, page);

			smp_save_cpu_regs(sa, addr, is_boot_cpu, page);

	}

	memblock_free(page, PAGE_SIZE);

	diag308_reset();

drivers/s390/char/zcore.c

+5 −6
Original line number Diff line number Diff line
@@ -117,18 +117,17 @@ int memcpy_hsa_kernel(void *dest, unsigned long src, size_t count) 


static int __init init_cpu_info(void)

{

	struct save_area_ext *sa_ext;

	struct save_area *sa;



	/* get info for boot cpu from lowcore, stored in the HSA */



	sa_ext = dump_save_areas.areas[0];

	if (!sa_ext)

	sa = save_area_boot_cpu();

	if (!sa)

		return -ENOMEM;

	if (memcpy_hsa_kernel(&sa_ext->sa, __LC_FPREGS_SAVE_AREA,

			      sizeof(struct save_area)) < 0) {

	if (memcpy_hsa_kernel(hsa_buf, __LC_FPREGS_SAVE_AREA, 512) < 0) {

		TRACE("could not copy from HSA\n");

		return -EIO;

	}

	save_area_add_regs(sa, hsa_buf); /* vx registers are saved in smp.c */

	return 0;

}

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