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s390x: uncouple physical and virtual memory spaces
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Rework VTOP and PTOV macros to reflect the future
uncoupling of physical and virtual address spaces
in kernel. Existing versions are not affected.

Signed-off-by: Alexander Gordeev <[email protected]>
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@k-hagio
Alexander Gordeev authored and k-hagio committed Dec 12, 2023
1 parent 4c78eb4 commit d0164e7
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Showing 2 changed files with 228 additions and 4 deletions.
20 changes: 17 additions & 3 deletions defs.h
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Original file line number Diff line number Diff line change
Expand Up @@ -4564,9 +4564,9 @@ struct efi_memory_desc_t {
#define _64BIT_
#define MACHINE_TYPE "S390X"

#define PTOV(X) ((unsigned long)(X)+(machdep->kvbase))
#define VTOP(X) ((unsigned long)(X)-(machdep->kvbase))
#define IS_VMALLOC_ADDR(X) (vt->vmalloc_start && (ulong)(X) >= vt->vmalloc_start)
#define PTOV(X) s390x_PTOV((ulong)(X))
#define VTOP(X) s390x_VTOP((ulong)(X))
#define IS_VMALLOC_ADDR(X) s390x_IS_VMALLOC_ADDR(X)
#define PTRS_PER_PTE 512
#define PTRS_PER_PMD 1024
#define PTRS_PER_PGD 2048
Expand Down Expand Up @@ -6827,7 +6827,21 @@ void get_s390_panicmsg(char *);
* s390x.c
*/
#ifdef S390X

struct machine_specific
{
ulong (*virt_to_phys)(ulong vaddr);
ulong (*phys_to_virt)(ulong paddr);
int (*is_vmalloc_addr)(ulong vaddr);
ulong __kaslr_offset_phys;
ulong amode31_start;
ulong amode31_end;
};

void s390x_init(int);
ulong s390x_PTOV(ulong);
ulong s390x_VTOP(ulong);
int s390x_IS_VMALLOC_ADDR(ulong);
void s390x_dump_machdep_table(ulong);
#define display_idt_table() \
error(FATAL, "-d option is not applicable to S390X architecture\n")
Expand Down
212 changes: 211 additions & 1 deletion s390x.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -47,6 +47,7 @@
#define S390X_PSW_MASK_PSTATE 0x0001000000000000UL

#define S390X_LC_VMCORE_INFO 0xe0c
#define S390X_LC_OS_INFO 0xe18

/*
* Flags for Region and Segment table entries.
Expand Down Expand Up @@ -168,6 +169,19 @@ static struct line_number_hook s390x_line_number_hooks[];
static int s390x_is_uvaddr(ulong, struct task_context *);
static int s390x_get_kvaddr_ranges(struct vaddr_range *);
static int set_s390x_max_physmem_bits(void);
static ulong s390x_generic_VTOP(ulong vaddr);
static ulong s390x_generic_PTOV(ulong paddr);
static int s390x_generic_IS_VMALLOC_ADDR(ulong vaddr);
static ulong s390x_vr_VTOP(ulong vaddr);
static ulong s390x_vr_PTOV(ulong paddr);
static int s390x_vr_IS_VMALLOC_ADDR(ulong vaddr);
static int s390x_vr_is_kvaddr(ulong);

struct machine_specific s390x_machine_specific = {
.virt_to_phys = s390x_generic_VTOP,
.phys_to_virt = s390x_generic_PTOV,
.is_vmalloc_addr = s390x_generic_IS_VMALLOC_ADDR,
};

/*
* struct lowcore name (old: "_lowcore", new: "lowcore")
Expand Down Expand Up @@ -546,6 +560,191 @@ static void s390x_check_kaslr(void)
free(vmcoreinfo);
}

#define OS_INFO_VERSION_MAJOR 1
#define OS_INFO_VERSION_MINOR 1

#define OS_INFO_VMCOREINFO 0
#define OS_INFO_REIPL_BLOCK 1
#define OS_INFO_FLAGS_ENTRY 2
#define OS_INFO_RESERVED 3
#define OS_INFO_IDENTITY_BASE 4
#define OS_INFO_KASLR_OFFSET 5
#define OS_INFO_KASLR_OFF_PHYS 6
#define OS_INFO_VMEMMAP 7
#define OS_INFO_AMODE31_START 8
#define OS_INFO_AMODE31_END 9

struct os_info_entry {
union {
__u64 addr;
__u64 val;
};
__u64 size;
__u32 csum;
} __attribute__((packed));

struct os_info {
__u64 magic;
__u32 csum;
__u16 version_major;
__u16 version_minor;
__u64 crashkernel_addr;
__u64 crashkernel_size;
struct os_info_entry entry[10];
__u8 reserved[3864];
} __attribute__((packed));

struct vm_info {
__u64 __identity_base;
__u64 __kaslr_offset;
__u64 __kaslr_offset_phys;
__u64 amode31_start;
__u64 amode31_end;
};

static bool
vmcoreinfo_read_u64(const char *key, __u64 *val)
{
char *string;

string = pc->read_vmcoreinfo(key);
if (string) {
*val = strtoul(string, NULL, 16);
free(string);
return true;
}

return false;
}

static bool vmcoreinfo_read_vm_info(struct vm_info *_vm_info)
{
struct vm_info vm_info;

if (!vmcoreinfo_read_u64("IDENTITYBASE", &vm_info.__identity_base) ||
!vmcoreinfo_read_u64("KERNELOFFSET", &vm_info.__kaslr_offset) ||
!vmcoreinfo_read_u64("KERNELOFFPHYS", &vm_info.__kaslr_offset_phys) ||
!vmcoreinfo_read_u64("SAMODE31", &vm_info.amode31_start) ||
!vmcoreinfo_read_u64("EAMODE31", &vm_info.amode31_end))
return false;

*_vm_info = vm_info;

return true;
}

static bool os_info_read_vm_info(struct vm_info *vm_info)
{
struct os_info os_info;
ulong addr;

if (!readmem(S390X_LC_OS_INFO, PHYSADDR, &addr,
sizeof(addr), "s390x os_info ptr",
QUIET|RETURN_ON_ERROR))
return false;

if (addr == 0)
return true;

if (!readmem(addr, PHYSADDR, &os_info,
offsetof(struct os_info, reserved), "s390x os_info header",
QUIET|RETURN_ON_ERROR))
return false;

vm_info->__identity_base = os_info.entry[OS_INFO_IDENTITY_BASE].val;
vm_info->__kaslr_offset = os_info.entry[OS_INFO_KASLR_OFFSET].val;
vm_info->__kaslr_offset_phys = os_info.entry[OS_INFO_KASLR_OFF_PHYS].val;
vm_info->amode31_start = os_info.entry[OS_INFO_AMODE31_START].val;
vm_info->amode31_end = os_info.entry[OS_INFO_AMODE31_END].val;

return true;
}

static bool vm_info_empty(struct vm_info *vm_info)
{
return !vm_info->__kaslr_offset;
}

static bool s390x_init_vm(void)
{
struct vm_info vm_info;

if (pc->flags & PROC_KCORE) {
if (!vmcoreinfo_read_vm_info(&vm_info))
return true;
} else {
if (!os_info_read_vm_info(&vm_info))
return false;
}
if (vm_info_empty(&vm_info))
return true;

machdep->identity_map_base = vm_info.__identity_base;
machdep->kvbase = vm_info.__kaslr_offset;
machdep->machspec->__kaslr_offset_phys = vm_info.__kaslr_offset_phys;
machdep->machspec->amode31_start = vm_info.amode31_start;
machdep->machspec->amode31_end = vm_info.amode31_end;

machdep->is_kvaddr = s390x_vr_is_kvaddr;
machdep->machspec->virt_to_phys = s390x_vr_VTOP;
machdep->machspec->phys_to_virt = s390x_vr_PTOV;
machdep->machspec->is_vmalloc_addr = s390x_vr_IS_VMALLOC_ADDR;

return true;
}

static ulong s390x_generic_VTOP(ulong vaddr)
{
return vaddr - machdep->kvbase;
}

static ulong s390x_generic_PTOV(ulong paddr)
{
return paddr + machdep->kvbase;
}

static int s390x_generic_IS_VMALLOC_ADDR(ulong vaddr)
{
return vt->vmalloc_start && vaddr >= vt->vmalloc_start;
}

static ulong s390x_vr_VTOP(ulong vaddr)
{
if (vaddr < LOWCORE_SIZE)
return vaddr;
if ((vaddr < machdep->machspec->amode31_end) &&
(vaddr >= machdep->machspec->amode31_start))
return vaddr;
if (vaddr < machdep->kvbase)
return vaddr - machdep->identity_map_base;
return vaddr - machdep->kvbase + machdep->machspec->__kaslr_offset_phys;
}

static ulong s390x_vr_PTOV(ulong paddr)
{
return paddr + machdep->identity_map_base;
}

static int s390x_vr_IS_VMALLOC_ADDR(ulong vaddr)
{
return (vaddr >= vt->vmalloc_start && vaddr < machdep->kvbase);
}

ulong s390x_VTOP(ulong vaddr)
{
return machdep->machspec->virt_to_phys(vaddr);
}

ulong s390x_PTOV(ulong paddr)
{
return machdep->machspec->phys_to_virt(paddr);
}

int s390x_IS_VMALLOC_ADDR(ulong vaddr)
{
return machdep->machspec->is_vmalloc_addr(vaddr);
}

/*
* Do all necessary machine-specific setup here. This is called several
* times during initialization.
Expand All @@ -560,6 +759,7 @@ s390x_init(int when)
machdep->process_elf_notes = s390x_process_elf_notes;
break;
case PRE_SYMTAB:
machdep->machspec = &s390x_machine_specific;
machdep->verify_symbol = s390x_verify_symbol;
if (pc->flags & KERNEL_DEBUG_QUERY)
return;
Expand Down Expand Up @@ -587,6 +787,8 @@ s390x_init(int when)
machdep->kvbase = 0;
machdep->identity_map_base = 0;
machdep->is_kvaddr = generic_is_kvaddr;
if (!s390x_init_vm())
error(FATAL, "cannot initialize VM parameters.");
machdep->is_uvaddr = s390x_is_uvaddr;
machdep->eframe_search = s390x_eframe_search;
machdep->back_trace = s390x_back_trace_cmd;
Expand Down Expand Up @@ -681,7 +883,9 @@ s390x_dump_machdep_table(ulong arg)
fprintf(fp, " dis_filter: s390x_dis_filter()\n");
fprintf(fp, " cmd_mach: s390x_cmd_mach()\n");
fprintf(fp, " get_smp_cpus: s390x_get_smp_cpus()\n");
fprintf(fp, " is_kvaddr: generic_is_kvaddr()\n");
fprintf(fp, " is_kvaddr: %s()\n", machdep->is_kvaddr == s390x_vr_is_kvaddr ?
"s390x_vr_is_kvaddr" :
"generic_is_kvaddr");
fprintf(fp, " is_uvaddr: s390x_is_uvaddr()\n");
fprintf(fp, " verify_paddr: generic_verify_paddr()\n");
fprintf(fp, " get_kvaddr_ranges: s390x_get_kvaddr_ranges()\n");
Expand All @@ -702,6 +906,12 @@ s390x_dump_machdep_table(ulong arg)
fprintf(fp, " machspec: %lx\n", (ulong)machdep->machspec);
}

static int
s390x_vr_is_kvaddr(ulong vaddr)
{
return (vaddr < LOWCORE_SIZE) || (vaddr >= machdep->identity_map_base);
}

/*
* Check if address is in context's address space
*/
Expand Down

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