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minix/kernel/arch/arm/memory.c
Arun Thomas 471a03a362 ARM support for kernel and vm
2012-10-07 21:38:03 -04:00

775 lines
22 KiB
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#include "kernel/kernel.h"
#include "kernel/proc.h"
#include "kernel/vm.h"
#include <machine/vm.h>
#include <minix/type.h>
#include <minix/syslib.h>
#include <minix/cpufeature.h>
#include <string.h>
#include <assert.h>
#include <signal.h>
#include <stdlib.h>
#include <machine/vm.h>
#include "arch_proto.h"
#include "kernel/proto.h"
#include "kernel/debug.h"
phys_bytes device_mem_vaddr = 0;
#define HASPT(procptr) ((procptr)->p_seg.p_ttbr != 0)
static int nfreepdes = 0;
#define MAXFREEPDES 2
static int freepdes[MAXFREEPDES];
static u32_t phys_get32(phys_bytes v);
void mem_clear_mapcache(void)
{
int i;
for(i = 0; i < nfreepdes; i++) {
struct proc *ptproc = get_cpulocal_var(ptproc);
int pde = freepdes[i];
u32_t *ptv;
assert(ptproc);
ptv = ptproc->p_seg.p_ttbr_v;
assert(ptv);
ptv[pde] = 0;
}
}
/* This function sets up a mapping from within the kernel's address
* space to any other area of memory, either straight physical
* memory (pr == NULL) or a process view of memory, in 1MB windows.
* I.e., it maps in 1MB chunks of virtual (or physical) address space
* to 1MB chunks of kernel virtual address space.
*
* It recognizes pr already being in memory as a special case (no
* mapping required).
*
* The target (i.e. in-kernel) mapping area is one of the freepdes[]
* VM has earlier already told the kernel about that is available. It is
* identified as the 'pde' parameter. This value can be chosen freely
* by the caller, as long as it is in range (i.e. 0 or higher and corresonds
* to a known freepde slot). It is up to the caller to keep track of which
* freepde's are in use, and to determine which ones are free to use.
*
* The logical number supplied by the caller is translated into an actual
* pde number to be used, and a pointer to it (linear address) is returned
* for actual use by phys_copy or memset.
*/
static phys_bytes createpde(
const struct proc *pr, /* Requested process, NULL for physical. */
const phys_bytes linaddr,/* Address after segment translation. */
phys_bytes *bytes, /* Size of chunk, function may truncate it. */
int free_pde_idx, /* index of the free slot to use */
int *changed /* If mapping is made, this is set to 1. */
)
{
u32_t pdeval;
phys_bytes offset;
int pde;
assert(free_pde_idx >= 0 && free_pde_idx < nfreepdes);
pde = freepdes[free_pde_idx];
assert(pde >= 0 && pde < 4096);
if(pr && ((pr == get_cpulocal_var(ptproc)) || iskernelp(pr))) {
/* Process memory is requested, and
* it's a process that is already in current page table, or
* the kernel, which is always there.
* Therefore linaddr is valid directly, with the requested
* size.
*/
return linaddr;
}
if(pr) {
/* Requested address is in a process that is not currently
* accessible directly. Grab the PDE entry of that process'
* page table that corresponds to the requested address.
*/
assert(pr->p_seg.p_ttbr_v);
pdeval = pr->p_seg.p_ttbr_v[ARM_VM_PDE(linaddr)];
} else {
/* Requested address is physical. Make up the PDE entry. */
pdeval = (linaddr & ARM_VM_SECTION_MASK) |
ARM_VM_SECTION |
ARM_VM_SECTION_DOMAIN | ARM_VM_SECTION_USER;
}
/* Write the pde value that we need into a pde that the kernel
* can access, into the currently loaded page table so it becomes
* visible.
*/
assert(get_cpulocal_var(ptproc)->p_seg.p_ttbr_v);
if(get_cpulocal_var(ptproc)->p_seg.p_ttbr_v[pde] != pdeval) {
get_cpulocal_var(ptproc)->p_seg.p_ttbr_v[pde] = pdeval;
*changed = 1;
}
/* Memory is now available, but only the 1MB window of virtual
* address space that we have mapped; calculate how much of
* the requested range is visible and return that in *bytes,
* if that is less than the requested range.
*/
offset = linaddr & ARM_VM_OFFSET_MASK_1MB; /* Offset in 1MB window. */
*bytes = MIN(*bytes, ARM_BIG_PAGE_SIZE - offset);
/* Return the linear address of the start of the new mapping. */
return ARM_BIG_PAGE_SIZE*pde + offset;
}
/*===========================================================================*
* check_resumed_caller *
*===========================================================================*/
static int check_resumed_caller(struct proc *caller)
{
/* Returns the result from VM if caller was resumed, otherwise OK. */
if (caller && (caller->p_misc_flags & MF_KCALL_RESUME)) {
assert(caller->p_vmrequest.vmresult != VMSUSPEND);
return caller->p_vmrequest.vmresult;
}
return OK;
}
/*===========================================================================*
* lin_lin_copy *
*===========================================================================*/
static int lin_lin_copy(struct proc *srcproc, vir_bytes srclinaddr,
struct proc *dstproc, vir_bytes dstlinaddr, vir_bytes bytes)
{
u32_t addr;
proc_nr_t procslot;
assert(get_cpulocal_var(ptproc));
assert(get_cpulocal_var(proc_ptr));
assert(read_ttbr0() == get_cpulocal_var(ptproc)->p_seg.p_ttbr);
procslot = get_cpulocal_var(ptproc)->p_nr;
assert(procslot >= 0 && procslot < ARM_VM_DIR_ENTRIES);
if(srcproc) assert(!RTS_ISSET(srcproc, RTS_SLOT_FREE));
if(dstproc) assert(!RTS_ISSET(dstproc, RTS_SLOT_FREE));
assert(!RTS_ISSET(get_cpulocal_var(ptproc), RTS_SLOT_FREE));
assert(get_cpulocal_var(ptproc)->p_seg.p_ttbr_v);
if(srcproc) assert(!RTS_ISSET(srcproc, RTS_VMINHIBIT));
if(dstproc) assert(!RTS_ISSET(dstproc, RTS_VMINHIBIT));
while(bytes > 0) {
phys_bytes srcptr, dstptr;
vir_bytes chunk = bytes;
int changed = 0;
#ifdef CONFIG_SMP
unsigned cpu = cpuid;
if (srcproc && GET_BIT(srcproc->p_stale_tlb, cpu)) {
changed = 1;
UNSET_BIT(srcproc->p_stale_tlb, cpu);
}
if (dstproc && GET_BIT(dstproc->p_stale_tlb, cpu)) {
changed = 1;
UNSET_BIT(dstproc->p_stale_tlb, cpu);
}
#endif
/* Set up 1MB ranges. */
srcptr = createpde(srcproc, srclinaddr, &chunk, 0, &changed);
dstptr = createpde(dstproc, dstlinaddr, &chunk, 1, &changed);
if(changed) {
reload_ttbr0();
refresh_tlb();
}
/* Copy pages. */
PHYS_COPY_CATCH(srcptr, dstptr, chunk, addr);
if(addr) {
/* If addr is nonzero, a page fault was caught. */
if(addr >= srcptr && addr < (srcptr + chunk)) {
return EFAULT_SRC;
}
if(addr >= dstptr && addr < (dstptr + chunk)) {
return EFAULT_DST;
}
panic("lin_lin_copy fault out of range");
/* Not reached. */
return EFAULT;
}
/* Update counter and addresses for next iteration, if any. */
bytes -= chunk;
srclinaddr += chunk;
dstlinaddr += chunk;
}
if(srcproc) assert(!RTS_ISSET(srcproc, RTS_SLOT_FREE));
if(dstproc) assert(!RTS_ISSET(dstproc, RTS_SLOT_FREE));
assert(!RTS_ISSET(get_cpulocal_var(ptproc), RTS_SLOT_FREE));
assert(get_cpulocal_var(ptproc)->p_seg.p_ttbr_v);
return OK;
}
static u32_t phys_get32(phys_bytes addr)
{
const u32_t v;
int r;
if((r=lin_lin_copy(NULL, addr,
proc_addr(SYSTEM), (phys_bytes) &v, sizeof(v))) != OK) {
panic("lin_lin_copy for phys_get32 failed: %d", r);
}
return v;
}
/*===========================================================================*
* umap_virtual *
*===========================================================================*/
phys_bytes umap_virtual(rp, seg, vir_addr, bytes)
register struct proc *rp; /* pointer to proc table entry for process */
int seg; /* T, D, or S segment */
vir_bytes vir_addr; /* virtual address in bytes within the seg */
vir_bytes bytes; /* # of bytes to be copied */
{
phys_bytes phys = 0;
if(vm_lookup(rp, vir_addr, &phys, NULL) != OK) {
printf("SYSTEM:umap_virtual: vm_lookup of %s: seg 0x%x: 0x%lx failed\n", rp->p_name, seg, vir_addr);
phys = 0;
} else {
if(phys == 0)
panic("vm_lookup returned phys: %d", phys);
}
if(phys == 0) {
printf("SYSTEM:umap_virtual: lookup failed\n");
return 0;
}
/* Now make sure addresses are contiguous in physical memory
* so that the umap makes sense.
*/
if(bytes > 0 && vm_lookup_range(rp, vir_addr, NULL, bytes) != bytes) {
printf("umap_virtual: %s: %lu at 0x%lx (vir 0x%lx) not contiguous\n",
rp->p_name, bytes, vir_addr, vir_addr);
return 0;
}
/* phys must be larger than 0 (or the caller will think the call
* failed), and address must not cross a page boundary.
*/
assert(phys);
return phys;
}
/*===========================================================================*
* vm_lookup *
*===========================================================================*/
int vm_lookup(const struct proc *proc, const vir_bytes virtual,
phys_bytes *physical, u32_t *ptent)
{
u32_t *root, *pt;
int pde, pte;
u32_t pde_v, pte_v;
assert(proc);
assert(physical);
assert(!isemptyp(proc));
assert(HASPT(proc));
/* Retrieve page directory entry. */
root = (u32_t *) proc->p_seg.p_ttbr;
assert(!((u32_t) root % ARM_PAGEDIR_SIZE));
pde = ARM_VM_PDE(virtual);
assert(pde >= 0 && pde < ARM_VM_DIR_ENTRIES);
pde_v = phys_get32((u32_t) (root + pde));
if(!(pde_v & ARM_VM_PDE_PRESENT)) {
return EFAULT;
}
/* We don't expect to ever see this. */
if(pde_v & ARM_VM_BIGPAGE) {
*physical = pde_v & ARM_VM_SECTION_MASK;
if(ptent) *ptent = pde_v;
*physical += virtual & ARM_VM_OFFSET_MASK_1MB;
} else {
/* Retrieve page table entry. */
pt = (u32_t *) (pde_v & ARM_VM_PDE_MASK);
assert(!((u32_t) pt % ARM_PAGETABLE_SIZE));
pte = ARM_VM_PTE(virtual);
assert(pte >= 0 && pte < ARM_VM_PT_ENTRIES);
pte_v = phys_get32((u32_t) (pt + pte));
if(!(pte_v & ARM_VM_PTE_PRESENT)) {
return EFAULT;
}
if(ptent) *ptent = pte_v;
/* Actual address now known; retrieve it and add page offset. */
*physical = pte_v & ARM_VM_PTE_MASK;
*physical += virtual % ARM_PAGE_SIZE;
}
return OK;
}
/*===========================================================================*
* vm_lookup_range *
*===========================================================================*/
size_t vm_lookup_range(const struct proc *proc, vir_bytes vir_addr,
phys_bytes *phys_addr, size_t bytes)
{
/* Look up the physical address corresponding to linear virtual address
* 'vir_addr' for process 'proc'. Return the size of the range covered
* by contiguous physical memory starting from that address; this may
* be anywhere between 0 and 'bytes' inclusive. If the return value is
* nonzero, and 'phys_addr' is non-NULL, 'phys_addr' will be set to the
* base physical address of the range. 'vir_addr' and 'bytes' need not
* be page-aligned, but the caller must have verified that the given
* linear range is valid for the given process at all.
*/
phys_bytes phys, next_phys;
size_t len;
assert(proc);
assert(bytes > 0);
assert(HASPT(proc));
/* Look up the first page. */
if (vm_lookup(proc, vir_addr, &phys, NULL) != OK)
return 0;
if (phys_addr != NULL)
*phys_addr = phys;
len = ARM_PAGE_SIZE - (vir_addr % ARM_PAGE_SIZE);
vir_addr += len;
next_phys = phys + len;
/* Look up any next pages and test physical contiguity. */
while (len < bytes) {
if (vm_lookup(proc, vir_addr, &phys, NULL) != OK)
break;
if (next_phys != phys)
break;
len += ARM_PAGE_SIZE;
vir_addr += ARM_PAGE_SIZE;
next_phys += ARM_PAGE_SIZE;
}
/* We might now have overshot the requested length somewhat. */
return MIN(bytes, len);
}
/*===========================================================================*
* vm_suspend *
*===========================================================================*/
static void vm_suspend(struct proc *caller, const struct proc *target,
const vir_bytes linaddr, const vir_bytes len, const int type)
{
/* This range is not OK for this process. Set parameters
* of the request and notify VM about the pending request.
*/
assert(!RTS_ISSET(caller, RTS_VMREQUEST));
assert(!RTS_ISSET(target, RTS_VMREQUEST));
RTS_SET(caller, RTS_VMREQUEST);
caller->p_vmrequest.req_type = VMPTYPE_CHECK;
caller->p_vmrequest.target = target->p_endpoint;
caller->p_vmrequest.params.check.start = linaddr;
caller->p_vmrequest.params.check.length = len;
caller->p_vmrequest.params.check.writeflag = 1;
caller->p_vmrequest.type = type;
/* Connect caller on vmrequest wait queue. */
if(!(caller->p_vmrequest.nextrequestor = vmrequest))
if(OK != send_sig(VM_PROC_NR, SIGKMEM))
panic("send_sig failed");
vmrequest = caller;
}
/*===========================================================================*
* vm_check_range *
*===========================================================================*/
int vm_check_range(struct proc *caller, struct proc *target,
vir_bytes vir_addr, size_t bytes)
{
/* Public interface to vm_suspend(), for use by kernel calls. On behalf
* of 'caller', call into VM to check linear virtual address range of
* process 'target', starting at 'vir_addr', for 'bytes' bytes. This
* function assumes that it will called twice if VM returned an error
* the first time (since nothing has changed in that case), and will
* then return the error code resulting from the first call. Upon the
* first call, a non-success error code is returned as well.
*/
int r;
if ((caller->p_misc_flags & MF_KCALL_RESUME) &&
(r = caller->p_vmrequest.vmresult) != OK)
return r;
vm_suspend(caller, target, vir_addr, bytes, VMSTYPE_KERNELCALL);
return VMSUSPEND;
}
/*===========================================================================*
* delivermsg *
*===========================================================================*/
void delivermsg(struct proc *rp)
{
int r = OK;
assert(rp->p_misc_flags & MF_DELIVERMSG);
assert(rp->p_delivermsg.m_source != NONE);
if (copy_msg_to_user(&rp->p_delivermsg,
(message *) rp->p_delivermsg_vir)) {
printf("WARNING wrong user pointer 0x%08lx from "
"process %s / %d\n",
rp->p_delivermsg_vir,
rp->p_name,
rp->p_endpoint);
r = EFAULT;
}
/* Indicate message has been delivered; address is 'used'. */
rp->p_delivermsg.m_source = NONE;
rp->p_misc_flags &= ~MF_DELIVERMSG;
if(!(rp->p_misc_flags & MF_CONTEXT_SET)) {
rp->p_reg.retreg = r;
}
}
/*===========================================================================*
* vmmemset *
*===========================================================================*/
int vm_memset(struct proc* caller, endpoint_t who, phys_bytes ph, int c,
phys_bytes count)
{
u32_t pattern;
struct proc *whoptr = NULL;
phys_bytes cur_ph = ph;
phys_bytes left = count;
phys_bytes ptr, chunk, pfa = 0;
int new_ttbr, r = OK;
if ((r = check_resumed_caller(caller)) != OK)
return r;
/* NONE for physical, otherwise virtual */
if (who != NONE && !(whoptr = endpoint_lookup(who)))
return ESRCH;
c &= 0xFF;
pattern = c | (c << 8) | (c << 16) | (c << 24);
assert(get_cpulocal_var(ptproc)->p_seg.p_ttbr_v);
assert(!catch_pagefaults);
catch_pagefaults = 1;
/* We can memset as many bytes as we have remaining,
* or as many as remain in the 1MB chunk we mapped in.
*/
while (left > 0) {
new_ttbr = 0;
chunk = left;
ptr = createpde(whoptr, cur_ph, &chunk, 0, &new_ttbr);
if (new_ttbr) {
reload_ttbr0();
refresh_tlb();
}
/* If a page fault happens, pfa is non-null */
if ((pfa = phys_memset(ptr, pattern, chunk))) {
/* If a process pagefaults, VM may help out */
if (whoptr) {
vm_suspend(caller, whoptr, ph, count,
VMSTYPE_KERNELCALL);
assert(catch_pagefaults);
catch_pagefaults = 0;
return VMSUSPEND;
}
/* Pagefault when phys copying ?! */
panic("vm_memset: pf %lx addr=%lx len=%lu\n",
pfa , ptr, chunk);
}
cur_ph += chunk;
left -= chunk;
}
assert(get_cpulocal_var(ptproc)->p_seg.p_ttbr_v);
assert(catch_pagefaults);
catch_pagefaults = 0;
return OK;
}
/*===========================================================================*
* virtual_copy_f *
*===========================================================================*/
int virtual_copy_f(caller, src_addr, dst_addr, bytes, vmcheck)
struct proc * caller;
struct vir_addr *src_addr; /* source virtual address */
struct vir_addr *dst_addr; /* destination virtual address */
vir_bytes bytes; /* # of bytes to copy */
int vmcheck; /* if nonzero, can return VMSUSPEND */
{
/* Copy bytes from virtual address src_addr to virtual address dst_addr. */
struct vir_addr *vir_addr[2]; /* virtual source and destination address */
int i, r;
struct proc *procs[2];
assert((vmcheck && caller) || (!vmcheck && !caller));
/* Check copy count. */
if (bytes <= 0) return(EDOM);
/* Do some more checks and map virtual addresses to physical addresses. */
vir_addr[_SRC_] = src_addr;
vir_addr[_DST_] = dst_addr;
for (i=_SRC_; i<=_DST_; i++) {
endpoint_t proc_e = vir_addr[i]->proc_nr_e;
int proc_nr;
struct proc *p;
if(proc_e == NONE) {
p = NULL;
} else {
if(!isokendpt(proc_e, &proc_nr)) {
printf("virtual_copy: no reasonable endpoint\n");
return ESRCH;
}
p = proc_addr(proc_nr);
}
procs[i] = p;
}
if ((r = check_resumed_caller(caller)) != OK)
return r;
if((r=lin_lin_copy(procs[_SRC_], vir_addr[_SRC_]->offset,
procs[_DST_], vir_addr[_DST_]->offset, bytes)) != OK) {
struct proc *target = NULL;
phys_bytes lin;
if(r != EFAULT_SRC && r != EFAULT_DST)
panic("lin_lin_copy failed: %d", r);
if(!vmcheck || !caller) {
return r;
}
if(r == EFAULT_SRC) {
lin = vir_addr[_SRC_]->offset;
target = procs[_SRC_];
} else if(r == EFAULT_DST) {
lin = vir_addr[_DST_]->offset;
target = procs[_DST_];
} else {
panic("r strange: %d", r);
}
assert(caller);
assert(target);
vm_suspend(caller, target, lin, bytes, VMSTYPE_KERNELCALL);
return VMSUSPEND;
}
return OK;
}
/*===========================================================================*
* data_copy *
*===========================================================================*/
int data_copy(const endpoint_t from_proc, const vir_bytes from_addr,
const endpoint_t to_proc, const vir_bytes to_addr,
size_t bytes)
{
struct vir_addr src, dst;
src.offset = from_addr;
dst.offset = to_addr;
src.proc_nr_e = from_proc;
dst.proc_nr_e = to_proc;
assert(src.proc_nr_e != NONE);
assert(dst.proc_nr_e != NONE);
return virtual_copy(&src, &dst, bytes);
}
/*===========================================================================*
* data_copy_vmcheck *
*===========================================================================*/
int data_copy_vmcheck(struct proc * caller,
const endpoint_t from_proc, const vir_bytes from_addr,
const endpoint_t to_proc, const vir_bytes to_addr,
size_t bytes)
{
struct vir_addr src, dst;
src.offset = from_addr;
dst.offset = to_addr;
src.proc_nr_e = from_proc;
dst.proc_nr_e = to_proc;
assert(src.proc_nr_e != NONE);
assert(dst.proc_nr_e != NONE);
return virtual_copy_vmcheck(caller, &src, &dst, bytes);
}
void memory_init(void)
{
assert(nfreepdes == 0);
freepdes[nfreepdes++] = kinfo.freepde_start++;
freepdes[nfreepdes++] = kinfo.freepde_start++;
assert(kinfo.freepde_start < ARM_VM_DIR_ENTRIES);
assert(nfreepdes == 2);
assert(nfreepdes <= MAXFREEPDES);
}
/*===========================================================================*
* arch_proc_init *
*===========================================================================*/
void arch_proc_init(struct proc *pr, const u32_t ip, const u32_t sp, char *name)
{
arch_proc_reset(pr);
strcpy(pr->p_name, name);
/* set custom state we know */
pr->p_reg.pc = ip;
pr->p_reg.sp = sp;
}
static int device_mem_mapping_index = -1,
usermapped_glo_index = -1,
usermapped_index = -1, first_um_idx = -1;
char *device_mem;
extern char usermapped_start, usermapped_end, usermapped_nonglo_start;
int arch_phys_map(const int index,
phys_bytes *addr,
phys_bytes *len,
int *flags)
{
static int first = 1;
int freeidx = 0;
u32_t glo_len = (u32_t) &usermapped_nonglo_start -
(u32_t) &usermapped_start;
if(first) {
device_mem_mapping_index = freeidx++;
if(glo_len > 0) {
usermapped_glo_index = freeidx++;
}
usermapped_index = freeidx++;
first_um_idx = usermapped_index;
if(usermapped_glo_index != -1)
first_um_idx = usermapped_glo_index;
first = 0;
}
if(index == usermapped_glo_index) {
*addr = vir2phys(&usermapped_start);
*len = glo_len;
*flags = VMMF_USER | VMMF_GLO;
return OK;
}
else if(index == usermapped_index) {
*addr = vir2phys(&usermapped_nonglo_start);
*len = (u32_t) &usermapped_end -
(u32_t) &usermapped_nonglo_start;
*flags = VMMF_USER;
return OK;
}
else if (index == device_mem_mapping_index) {
/* map device memory */
*addr = 0x48000000;
*len = 0x02000000;
*flags = VMMF_UNCACHED | VMMF_WRITE;
return OK;
}
return EINVAL;
}
int arch_phys_map_reply(const int index, const vir_bytes addr)
{
if(index == first_um_idx) {
u32_t usermapped_offset;
assert(addr > (u32_t) &usermapped_start);
usermapped_offset = addr - (u32_t) &usermapped_start;
memset(&minix_kerninfo, 0, sizeof(minix_kerninfo));
#define FIXEDPTR(ptr) (void *) ((u32_t)ptr + usermapped_offset)
#define FIXPTR(ptr) ptr = FIXEDPTR(ptr)
#define ASSIGN(minixstruct) minix_kerninfo.minixstruct = FIXEDPTR(&minixstruct)
ASSIGN(kinfo);
ASSIGN(machine);
ASSIGN(kmessages);
ASSIGN(loadinfo);
/* adjust the pointers of the functions and the struct
* itself to the user-accessible mapping
*/
minix_kerninfo.kerninfo_magic = KERNINFO_MAGIC;
minix_kerninfo.minix_feature_flags = minix_feature_flags;
minix_kerninfo_user = (vir_bytes) FIXEDPTR(&minix_kerninfo);
return OK;
}
if(index == usermapped_index) return OK;
if (index == device_mem_mapping_index) {
device_mem_vaddr = addr;
return OK;
}
return EINVAL;
}
int arch_enable_paging(struct proc * caller)
{
assert(caller->p_seg.p_ttbr);
/* load caller's page table */
switch_address_space(caller);
device_mem = (char *) device_mem_vaddr;
return OK;
}
void release_address_space(struct proc *pr)
{
pr->p_seg.p_ttbr_v = NULL;
refresh_tlb();
}
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