diff options
Diffstat (limited to 'kernel/old/vm.c')
| -rw-r--r-- | kernel/old/vm.c | 722 |
1 files changed, 201 insertions, 521 deletions
diff --git a/kernel/old/vm.c b/kernel/old/vm.c index 814ff12..749bed3 100644 --- a/kernel/old/vm.c +++ b/kernel/old/vm.c @@ -6,7 +6,7 @@ ** @brief Kernel VM support */ -#define KERNEL_SRC +#define KERNEL_SRC #include <common.h> @@ -37,244 +37,70 @@ pde_t *kpdir; ** @param vector Interrupt vector number ** @param code Error code pushed onto the stack */ -static void vm_isr(int vector, int code) -{ +static void vm_isr( int vector, int code ) { + // get whatever information we can from the fault pfec_t fault; - fault.u = (uint32_t)code; + fault.u = (uint32_t) code; uint32_t addr = r_cr2(); // report what we found - sprint(b256, - "** page fault @ 0x%08x %cP %c %cM %cRSV %c %cPK %cSS %cHLAT %cSGZ", - addr, fault.s.p ? ' ' : '!', fault.s.w ? 'W' : 'R', - fault.s.us ? 'U' : 'S', fault.s.rsvd ? ' ' : '!', - fault.s.id ? 'I' : 'D', fault.s.pk ? ' ' : '!', - fault.s.ss ? ' ' : '!', fault.s.hlat ? ' ' : '!', - fault.s.sgz ? ' ' : '!'); + sprint( b256, + "** page fault @ 0x%08x %cP %c %cM %cRSV %c %cPK %cSS %cHLAT %cSGZ", + addr, + fault.s.p ? ' ' : '!', + fault.s.w ? 'W' : 'R', + fault.s.us ? 'U' : 'S', + fault.s.rsvd ? ' ' : '!', + fault.s.id ? 'I' : 'D', + fault.s.pk ? ' ' : '!', + fault.s.ss ? ' ' : '!', + fault.s.hlat ? ' ' : '!', + fault.s.sgz ? ' ' : '!' + ); // and give up - PANIC(0, b256); + PANIC( 0, b256 ); } /** -** Name: ptcount -** -** Count the number of each type of entry in a page table. -** Returns a 32-bit result containing two 16-bit counts: +** Name: uva2kva ** -** Upper half Lower half -** PDIR: # of 4MB entries # of 'present' entries -** PMT: zero # of 'present' entries -** -** The number of "not present" can be calculated from these. +** Convert a user VA into a kernel address. Works for all addresses - +** if the address is a page address, the PERMS(va) value will be 0; +** otherwise, it is the offset into the page. ** -** @param pt Pointer to the page table -** @param dir Is it a page directory (vs. a page table)? +** @param pdir Pointer to the page directory to examine +** @param va Virtual address to check */ ATTR_UNUSED -static uint32_t ptcount(pte_t *ptr, bool_t dir) -{ - uint16_t n_np = 0, n_p = 0, n_lg = 0; - - for (int i = 0; i < N_PTE; ++i) { - pde_t entry = *ptr++; - if (!IS_PRESENT(entry)) { - ++n_np; - continue; - } - if (dir && IS_LARGE(entry)) { - ++n_lg; - } else { - ++n_p; - } - } - - // n_lg will be 0 for PMTs - return (n_lg << 16) | n_p; -} - -// decode a PDE -static void pde_prt(uint32_t level, uint32_t i, uint32_t entry, bool_t all) -{ - if (!IS_PRESENT(entry) && !all) { - return; - } - - // indent - for (int n = 0; n <= level; ++n) - cio_puts(" "); - - // line header - cio_printf("[%03x] %08x", i, entry); +static void *uva2kva( pde_t *pdir, void *va ) { - // perms - if (IS_LARGE(entry)) { // PS is 1 - if ((entry & PDE_PAT) != 0) - cio_puts(" PAT"); - if ((entry & PDE_G) != 0) - cio_puts(" G"); - cio_puts(" PS"); - if ((entry & PDE_D) != 0) - cio_puts(" D"); + // find the PMT entry for this address + pte_t *pte = vm_getpte( pdir, va, false ); + if( pte == NULL ) { + return NULL; } - if ((entry & PDE_A) != 0) - cio_puts(" A"); - if ((entry & PDE_PCD) != 0) - cio_puts(" CD"); - if ((entry & PDE_PWT) != 0) - cio_puts(" WT"); - if ((entry & PDE_US) != 0) - cio_puts(" U"); - if ((entry & PDE_RW) != 0) - cio_puts(" W"); - // frame address - cio_printf(" P --> %s %08x\n", IS_LARGE(entry) ? "Pg" : "PT", - PDE_ADDR(entry)); -} + // get the entry + pte_t entry = *pte; -// decode a PTE -static void pte_prt(uint32_t level, uint32_t i, uint32_t entry, bool_t all) -{ - if (!IS_PRESENT(entry) && !all) { - return; + // is this a valid address for the user? + if( IS_PRESENT(entry) ) { + return NULL; } - // indent - for (int n = 0; n <= level; ++n) - cio_puts(" "); - - // line header - cio_printf("[%03x] %08x", i, entry); - - // perms - if ((entry & PTE_G) != 0) - cio_puts(" G"); - if ((entry & PTE_PAT) != 0) - cio_puts(" PAT"); - if ((entry & PTE_D) != 0) - cio_puts(" D"); - if ((entry & PTE_A) != 0) - cio_puts(" A"); - if ((entry & PTE_PCD) != 0) - cio_puts(" CD"); - if ((entry & PTE_PWT) != 0) - cio_puts(" WT"); - if ((entry & PTE_US) != 0) - cio_puts(" U"); - if ((entry & PTE_RW) != 0) - cio_puts(" W"); - - cio_printf(" P --> Pg %08x\n", PTE_ADDR(entry)); -} - -/** -** Name: ptdump -** -** Recursive helper for table hierarchy dump. -** -** @param level Current hierarchy level -** @param pt Page table to display -** @param dir Is it a page directory (vs. a page table)? -** @param mode How to display the entries -*/ -ATTR_UNUSED -static void ptdump(uint_t level, void *pt, bool_t dir, enum vmmode_e mode) -{ - pte_t *ptr = (pte_t *)pt; - - // indent two spaces per level - for (int n = 0; n < level; ++n) - cio_puts(" "); - - cio_printf("%s at 0x%08x:", dir ? "PDir" : "PTbl", (uint32_t)pt); - uint32_t nums = ptcount(ptr, dir); - if (dir) { - cio_printf(" 4MB=%u", (nums >> 16)); + // is this a system-only page? + if( IS_SYSTEM(entry) ) { + return NULL; } - cio_printf(" P=%u !P=%u\n", nums & 0xffff, - N_PTE - ((nums >> 16) + (nums & 0xffff))); - for (uint32_t i = 0; i < (uint32_t)N_PTE; ++i) { - pte_t entry = *ptr++; + // get the physical address + uint32_t frame = PTE_ADDR(*pte) | PERMS(va); - // only process this entry if it's not empty - if (entry) { - if (dir) { - // this is a PDIR entry; could be either a 4MB - // page, or a PMT pointer - if (mode > Simple) { - pde_prt(level, i, entry, false); - if (!IS_LARGE(entry) && mode > OneLevel) { - ptdump(level + 1, (void *)P2V(PTE_ADDR(entry)), false, - mode); - } - } - } else { - // just a PMT entry - if (mode > Simple) { - pte_prt(level, i, entry, false); - } - } - } - } + return (void *) P2V(frame); } -/** -** Name: pmt_dump -** -** Dump the non-zero entries of a page table or directory -** -** @param pt The page table -** @param dir Is this a page directory? -** @param start First entry to process -** @param num Number of entries to process -*/ -ATTR_UNUSED -static void pmt_dump(pte_t *pt, bool_t dir, uint32_t start, uint32_t num) -{ - cio_printf("\n\nP%c dump", dir ? 'D' : 'T'); - cio_printf(" of %08x", (uint32_t)pt); - cio_printf(" [%03x] through [%03x]\n", start, start + num - 1); - - uint_t n = 0; - uint_t z = 0; - - for (uint_t i = 0; i < num; ++i) { - pte_t entry = pt[start + i]; - // four entries per line - if (n && ((n & 0x3) == 0)) { - cio_putchar('\n'); - } - if (IS_PRESENT(entry)) { - cio_printf(" %03x", start + i); - if (IS_LARGE(entry)) { - cio_printf(" 8 %05x", GET_4MFRAME(entry) << 10); - } else { - cio_printf(" 4 %05x", GET_4KFRAME(entry)); - } - ++n; - } else { - ++z; - } - // pause after every four lines of output - if (n && ((n & 0xf) == 0)) { - delay(DELAY_2_SEC); - } - } - - // partial line? - if ((n & 0x3) != 0) { - cio_putchar('\n'); - } - - if (z > 0) { - cio_printf(" %u entries were !P\n", z); - } - - delay(DELAY_2_SEC); -} /* ** PUBLIC FUNCTIONS @@ -285,83 +111,21 @@ static void pmt_dump(pte_t *pt, bool_t dir, uint32_t start, uint32_t num) ** ** Description: Initialize the VM module */ -void vm_init(void) -{ +void vm_init( void ) { + #if TRACING_INIT - cio_puts(" VM"); + cio_puts( " VM" ); #endif // set up the kernel's 4K-page directory kpdir = vm_mkkvm(); - assert(kpdir != NULL); - -#if TRACING_VM - cio_printf("vm_init: kpdir %08x, adding user pages\n", kpdir); -#endif - - // add the entries for the user address space - for (uint32_t addr = 0; addr < NUM_4MB; addr += SZ_PAGE) { - int stat = vm_map(kpdir, (void *)addr, addr, SZ_PAGE, PTE_US | PTE_RW); - if (stat != SUCCESS) { - cio_printf("vm_init, map %08x->%08x failed, status %d\n", addr, - addr, stat); - PANIC(0, "vm_init user range map failed"); - } -#if TRACING_VM - cio_putchar('.'); -#endif - } -#if TRACING_VM - cio_puts(" done\n"); -#endif + assert( kpdir != NULL ); // switch to it vm_set_kvm(); -#if TRACING_VM - cio_puts("vm_init: running on new kpdir\n"); -#endif - // install the page fault handler - install_isr(VEC_PAGE_FAULT, vm_isr); -} - -/** -** Name: vm_uva2kva -** -** Convert a user VA into a kernel address. Works for all addresses - -** if the address is a page address, the low-order nine bits will be -** zeroes; otherwise, they are the offset into the page, which is -** unchanged between the address spaces. -** -** @param pdir Pointer to the page directory to examine -** @param va Virtual address to check -*/ -void *vm_uva2kva(pde_t *pdir, void *va) -{ - // find the PMT entry for this address - pte_t *pte = vm_getpte(pdir, va, false); - if (pte == NULL) { - return NULL; - } - - // get the entry - pte_t entry = *pte; - - // is this a valid address for the user? - if (!IS_PRESENT(entry)) { - return NULL; - } - - // is this a system-only page? - if (IS_SYSTEM(entry)) { - return NULL; - } - - // get the physical address - uint32_t frame = PTE_ADDR(*pte) | PERMS(va); - - return (void *)P2V(frame); + install_isr( VEC_PAGE_FAULT, vm_isr ); } /** @@ -373,11 +137,10 @@ void *vm_uva2kva(pde_t *pdir, void *va) ** ** @return a pointer to the new, duplicate page, or NULL */ -void *vm_pagedup(void *old) -{ - void *new = (void *)km_page_alloc(); - if (new != NULL) { - blkmov(new, old, SZ_PAGE); +void *vm_pagedup( void *old ) { + void *new = (void *) km_page_alloc(); + if( new != NULL ) { + blkmov( new, old, SZ_PAGE ); } return new; } @@ -387,54 +150,58 @@ void *vm_pagedup(void *old) ** ** Duplicate a page directory entry ** -** @param entry The entry to be duplicated +** @param dst Pointer to where the duplicate should go +** @param curr Pointer to the entry to be duplicated ** -** @return the new entry, or -1 on error +** @return true on success, else false */ -pde_t vm_pdedup(pde_t entry) -{ +bool_t vm_pdedup( pde_t *dst, pde_t *curr ) { + + assert1( curr != NULL ); + assert1( dst != NULL ); + #if TRACING_VM - cio_printf("vm_pdedup curr %08x\n", (uint32_t)entry); + cio_printf( "vm_pdedup dst %08x curr %08x\n", + (uint32_t) dst, (uint32_t) curr ); #endif + pde_t entry = *curr; // simplest case - if (!IS_PRESENT(entry)) { - return 0; - } - - // is this a large page? - if (IS_LARGE(entry)) { - // just copy it - return entry; + if( !IS_PRESENT(entry) ) { + *dst = 0; + return true; } - // OK, we have a 4KB entry; allocate a page table for it - pte_t *tblva = (pte_t *)km_page_alloc(); - if (tblva == NULL) { - return (uint32_t)-1; + // OK, we have an entry; allocate a page table for it + pte_t *newtbl = (pte_t *) km_page_alloc(); + if( newtbl == NULL ) { + return false; } - // make sure the entries are all initially 'not present' - memclr(tblva, SZ_PAGE); + // we could clear the new table, but we'll be assigning to + // each entry anyway, so we'll save the execution time - // VA of the page table for this directory entry - pte_t *old = (pte_t *)P2V(PDE_ADDR(entry)); + // address of the page table for this directory entry + pte_t *old = (pte_t *) PDE_ADDR(entry); - // pointer to the first PTE in the new table (already a VA) - pte_t *new = tblva; + // pointer to the first PTE in the new table + pte_t *new = newtbl; - for (int i = 0; i < N_PTE; ++i) { - // only need to copy 'present' entries - if (IS_PRESENT(*old)) { + for( int i = 0 ; i < N_PTE; ++i ) { + if( !IS_PRESENT(*old) ) { + *new = 0; + } else { *new = *old; } ++old; ++new; } - // replace the page table address - // (PA of page table, lower 12 bits from '*curr') - return (pde_t)(V2P(PTE_ADDR(tblva)) | PERMS(entry)); + // replace the page table address + // upper 22 bits from 'newtbl', lower 12 from '*curr' + *dst = (pde_t) ( PTE_ADDR(newtbl) | PERMS(entry) ); + + return true; } /** @@ -452,37 +219,38 @@ pde_t vm_pdedup(pde_t entry) ** @return A pointer to the page table entry for this VA, or NULL if ** there isn't one and we're not allocating */ -pte_t *vm_getpte(pde_t *pdir, const void *va, bool_t alloc) -{ - pte_t *ptbl; +pte_t *vm_getpte( pde_t *pdir, const void *va, bool_t alloc ) { + pte_t *ptab; // sanity check - assert1(pdir != NULL); + assert1( pdir != NULL ); // get the PDIR entry for this virtual address - pde_t *pde_ptr = &pdir[PDIX(va)]; + pde_t *pde = &pdir[ PDIX(va) ]; // is it already set up? - if (IS_PRESENT(*pde_ptr)) { + if( IS_PRESENT(*pde) ) { + // yes! - ptbl = (pte_t *)P2V(PTE_ADDR(*pde_ptr)); + ptab = (pte_t*)P2V(PTE_ADDR(*pde)); } else { + // no - should we create it? - if (!alloc) { + if( !alloc ) { // nope, so just return return NULL; } // yes - try to allocate a page table - ptbl = (pte_t *)km_page_alloc(); - if (ptbl == NULL) { - WARNING("can't allocate page table"); + ptab = (pte_t *) km_page_alloc(); + if( ptab == NULL ) { + WARNING( "can't allocate page table" ); return NULL; } // who knows what was left in this page.... - memclr(ptbl, SZ_PAGE); + memclr( ptab, SZ_PAGE ); // add this to the page directory // @@ -491,54 +259,46 @@ pte_t *vm_getpte(pde_t *pdir, const void *va, bool_t alloc) // entries, if necessary. // // NOTE: the allocator is serving us virtual page addresses, - // so we must convert them to physical addresses for the - // table entries - *pde_ptr = V2P(ptbl) | PDE_P | PDE_RW | PDE_US; + // so we must convert them to physical addresses + *pde = ((uint32_t) V2P(ptab)) | PDE_P | PDE_RW; } - // finally, return a pointer to the entry in the page table for this VA - return &ptbl[PTIX(va)]; + // finally, return a pointer to the entry in the + // page table for this VA + return &ptab[ PTIX(va) ]; } // Set up kernel part of a page table. -pde_t *vm_mkkvm(void) +pde_t *vm_mkkvm( void ) { mapping_t *k; // allocate the page directory pde_t *pdir = km_page_alloc(); - if (pdir == NULL) { + if( pdir == NULL ) { return NULL; } -#if 0 && TRACING_VM - cio_puts( "\nEntering vm_mkkvm\n" ); - pmt_dump( pdir, true, 0, N_PDE ); -#endif // clear it out to disable all the entries - memclr(pdir, SZ_PAGE); + memclr( pdir, SZ_PAGE ); - if (P2V(PHYS_TOP) > DEV_BASE) { - cio_printf("PHYS_TOP (%08x -> %08x) > DEV_BASE(%08x)\n", PHYS_TOP, - P2V(PHYS_TOP), DEV_BASE); - PANIC(0, "PHYS_TOP too large"); + if( P2V(PHYS_TOP) > DEV_BASE ) { + cio_printf( "PHYS_TOP (%08x -> %08x) > DEV_BASE(%08x)\n", + PHYS_TOP, P2V(PHYS_TOP), DEV_BASE ); + PANIC( 0, "PHYS_TOP too large" ); } // map in all the page ranges k = kmap; - for (int i = 0; i < n_kmap; ++i, ++k) { - int stat = vm_map(pdir, ((void *)k->va_start), k->pa_start, - k->pa_end - k->pa_start, k->perm); - if (stat != SUCCESS) { - vm_free(pdir); + for( int i = 0; i < n_kmap; ++i, ++k ) { + int stat = vm_map( pdir, ((void *)k->va_start), + k->pa_end - k->pa_start, + k->pa_start, k->perm ); + if( stat != SUCCESS ) { + vm_free( pdir ); return 0; } } -#if 0 && TRACING_VM - cio_puts( "\nvm_mkkvm() final PD:\n" ); - pmt_dump( pdir, true, 0, 16 ); - pmt_dump( pdir, true, 0x200, 16 ); -#endif return pdir; } @@ -549,37 +309,32 @@ pde_t *vm_mkkvm(void) ** ** @return a pointer to the new page directory, or NULL */ -pde_t *vm_mkuvm(void) -{ +pde_t *vm_mkuvm( void ) { + // allocate the directory - pde_t *new = (pde_t *)km_page_alloc(); - if (new == NULL) { + pde_t *new = (pde_t *) km_page_alloc(); + if( new == NULL ) { return NULL; } - // iterate through the 'system' portions of the kernel - // page directory - int i = PDIX(KERN_BASE); - pde_t *curr = &kpdir[i]; - pde_t *dst = &new[i]; - while (i < N_PDE) { - if (*curr != 0) { + // iterate through the kernel page directory + pde_t *curr = kpdir; + pde_t *dst = new; + for( int i = 0; i < N_PDE; ++i ) { + + if( *curr != 0 ) { // found an active one - duplicate it - pde_t entry = vm_pdedup(*curr); - if (entry == (uint32_t)-1) { + if( !vm_pdedup(dst,curr) ) { return NULL; } - *dst = entry; - } else { - *dst = 0; } ++curr; ++dst; - ++i; } return new; + } /** @@ -587,15 +342,8 @@ pde_t *vm_mkuvm(void) ** ** Switch the page table register to the kernel's page directory. */ -void vm_set_kvm(void) -{ -#if TRACING_VM - cio_puts("Entering vm_set_kvm()\n"); -#endif - w_cr3(V2P(kpdir)); // switch to the kernel page table -#if TRACING_VM - cio_puts("Exiting vm_set_kvm()\n"); -#endif +void vm_set_kvm( void ) { + w_cr3( V2P(kpdir) ); // switch to the kernel page table } /** @@ -605,18 +353,11 @@ void vm_set_kvm(void) ** ** @param p PCB of the process we're switching to */ -void vm_set_uvm(pcb_t *p) -{ -#if TRACING_VM - cio_puts("Entering vm_set_uvm()\n"); -#endif - assert(p != NULL); - assert(p->pdir != NULL); +void vm_set_uvm( pcb_t *p ) { + assert( p != NULL ); + assert( p->pdir != NULL ); - w_cr3(V2P(p->pdir)); // switch to process's address space -#if TRACING_VM - cio_puts("Entering vm_set_uvm()\n"); -#endif + w_cr3( V2P(p->pdir) ); // switch to process's address space } /** @@ -635,35 +376,36 @@ void vm_set_uvm(pcb_t *p) ** ** @return status of the allocation attempt */ -int vm_add(pde_t *pdir, bool_t wr, bool_t sys, void *va, uint32_t size, - char *data, uint32_t bytes) -{ +int vm_add( pde_t *pdir, bool_t wr, bool_t sys, + void *va, uint32_t size, char *data, uint32_t bytes ) { + // how many pages do we need? - uint32_t npages = ((size & MOD4K_BITS) ? PGUP(size) : size) >> MOD4K_SHIFT; + uint_t npages = ((size & MOD4K_BITS) ? PGUP(size) : size) >> MOD4K_SHIFT; // permission set for the PTEs - uint32_t entrybase = PTE_P; - if (wr) { + uint_t entrybase = PTE_P; + if( wr ) { entrybase |= PTE_RW; } - if (!sys) { + if( sys ) { entrybase |= PTE_US; } #if TRACING_VM - cio_printf("vm_add: pdir %08x, %s, va %08x size %u (%u pgs)\n", - (uint32_t)pdir, wr ? "W" : "!W", (uint32_t)va, size, npages); - cio_printf(" from %08x, %u bytes, perms %08x\n", (uint32_t)data, - bytes, entrybase); + cio_printf( "vm_add: pdir %08x, %s, va %08x (%u, %u pgs)\n", + (uint32_t) pdir, wr ? "W" : "!W", (uint32_t) va, size ); + cio_printf( " from %08x, %u bytes, perms %08x\n", + (uint32_t) data, bytes, entrybase ); #endif // iterate through the pages - for (int i = 0; i < npages; ++i) { + for( int i = 0; i < npages; ++i ) { + // figure out where this page will go in the hierarchy - pte_t *pte = vm_getpte(pdir, va, true); - if (pte == NULL) { - // if i > 0, this isn't the first frame - is + pte_t *pte = vm_getpte( pdir, va, true ); + if( pte == NULL ) { + // TODO if i > 0, this isn't the first frame - is // there anything to do about other frames? // POSSIBLE MEMORY LEAK? return E_NO_MEMORY; @@ -671,27 +413,27 @@ int vm_add(pde_t *pdir, bool_t wr, bool_t sys, void *va, uint32_t size, // allocate the frame void *page = km_page_alloc(); - if (page == NULL) { - // same question here + if( page == NULL ) { + // TODO same question here return E_NO_MEMORY; } // clear it all out - memclr(page, SZ_PAGE); + memclr( page, SZ_PAGE ); // create the PTE for this frame - uint32_t entry = (uint32_t)(V2P(PTE_ADDR(page)) | entrybase); + uint32_t entry = (uint32_t) (PTE_ADDR(page) | entrybase); *pte = entry; // copy data if we need to - if (data != NULL && bytes > 0) { + if( data != NULL && bytes > 0 ) { // how much to copy - uint32_t num = bytes > SZ_PAGE ? SZ_PAGE : bytes; + uint_t num = bytes > SZ_PAGE ? SZ_PAGE : bytes; // do it! - memmove((void *)page, (void *)data, num); + memcpy( (void *)page, (void *)data, num ); // adjust all the pointers - data += num; // where to continue - bytes -= num; // what's left to copy + data += num; // where to continue + bytes -= num; // what's left to copy } // bump the virtual address @@ -699,6 +441,7 @@ int vm_add(pde_t *pdir, bool_t wr, bool_t sys, void *va, uint32_t size, } return SUCCESS; + } /** @@ -711,43 +454,36 @@ int vm_add(pde_t *pdir, bool_t wr, bool_t sys, void *va, uint32_t size, ** ** @param pdir Pointer to the page directory */ -void vm_free(pde_t *pdir) -{ -#if TRACING_VM - cio_printf("vm_free(%08x)\n", (uint32_t)pdir); -#endif +void vm_free( pde_t *pdir ) { // do we have anything to do? - if (pdir == NULL) { + if( pdir == NULL ) { return; } // iterate through the page directory entries, freeing the // PMTS and the frames they point to pde_t *curr = pdir; - int nf = 0; - int nt = 0; + for( int i = 0; i < N_PDE; ++i ) { - for (int i = 0; i < N_PDE; ++i) { // the entry itself pde_t entry = *curr; // does this entry point to anything useful? - if (IS_PRESENT(entry)) { + if( IS_PRESENT(entry) ) { + // yes - large pages make us unhappy - assert(!IS_LARGE(entry)); + assert( !IS_LARGE(entry) ); // get the PMT pointer - pte_t *pmt = (pte_t *)P2V(PTE_ADDR(entry)); + pte_t *pmt = (pte_t *) PTE_ADDR(entry); // walk the PMT - for (int j = 0; j < N_PTE; ++j) { - pte_t tmp = *pmt; + for( int j = 0; j < N_PTE; ++j ) { // does this entry point to a frame? - if (IS_PRESENT(tmp)) { + if( IS_PRESENT(*pmt) ) { // yes - free the frame - km_page_free((void *)P2V(PTE_ADDR(tmp))); - ++nf; + km_page_free( (void *) PTE_ADDR(*pmt) ); // mark it so we don't get surprised *pmt = 0; } @@ -755,8 +491,7 @@ void vm_free(pde_t *pdir) ++pmt; } // now, free the PMT itself - km_page_free((void *)P2V(PDE_ADDR(entry))); - ++nt; + km_page_free( (void *) PDE_ADDR(entry) ); *curr = 0; } @@ -765,12 +500,7 @@ void vm_free(pde_t *pdir) } // finally, free the PDIR itself - km_page_free((void *)pdir); - ++nt; - -#if TRACING_VM - cio_printf("vm_free: %d pages, %d tables\n", nf, nt); -#endif + km_page_free( (void *) pdir ); } /* @@ -782,74 +512,47 @@ void vm_free(pde_t *pdir) ** ** @param pdir Page directory for this address space ** @param va The starting virtual address -** @param pa The starting physical address ** @param size Length of the range to be mapped +** @param pa The starting physical address ** @param perm Permission bits for the PTEs ** ** @return the status of the mapping attempt */ -int vm_map(pde_t *pdir, void *va, uint32_t pa, uint32_t size, int perm) -{ +int vm_map( pde_t *pdir, void *va, uint_t size, uint_t pa, int perm ) { + // round the VA down to its page boundary - char *addr = (char *)PGDOWN((uint32_t)va); + char *addr = (char*)PGDOWN((uint_t)va); // round the end of the range down to its page boundary - char *last = (char *)PGDOWN(((uint32_t)va) + size - 1); + char *last = (char*)PGDOWN(((uint_t)va) + size - 1); -#if TRACING_VM - cio_printf("vm_map pdir %08x va %08x pa %08x size %08x perm %03x\n", - (uint32_t)pdir, (uint32_t)va, pa, size, perm); -#endif + while( addr < last ) { - while (addr <= last) { // get a pointer to the PTE for the current VA - pte_t *pte = vm_getpte(pdir, addr, true); - if (pte == NULL) { + pte_t *pte = vm_getpte( pdir, addr, true ); + if( pte == NULL ) { // couldn't find it return E_NO_PTE; } -#if 0 && TRACING_VM - cio_printf( " addr %08x pa %08x last %08x pte %08x *pte %08x\n", - (uint32_t) addr, pa, (uint32_t) last, (uint32_t) pte, *pte - ); -#endif - - // create the new entry for the page table - pde_t newpte = pa | perm | PTE_P; // if this entry has already been mapped, we're in trouble - if (IS_PRESENT(*pte)) { - if (*pte != newpte) { -#if TRACING_VM - cio_printf( - "vm_map: va %08x pa %08x pte %08x *pte %08x entry %08x\n", - (uint32_t)va, pa, (uint32_t)pte, (uint32_t)*pte, newpte); - cio_printf(" addr %08x PDIX 0x%x PTIX 0x%x\n", (uint32_t)addr, - PDIX(addr), PTIX(addr)); - - // dump the directory - pmt_dump(pdir, true, PDIX(addr), 4); + if( IS_PRESENT(*pte) ) { + cio_printf( "vm_map(%08x,%08x,%u,%08x,%03x)\n", + (uint32_t) pdir, (uint32_t) va, size, pa, perm ); + cio_printf( " addr %08x last %08x pte %08x *pte %08x\n", + (uint32_t) addr, (uint32_t) last, + (uint32_t) pte, *pte ); - // find the relevant PDE entry - uint32_t ix = PDIX(va); - pde_t entry = pdir[ix]; - if (!IS_LARGE(entry)) { - // round the PMT index down - uint32_t ix2 = PTIX(va) & MOD4_MASK; - // dump the PMT for the relevant directory entry - pmt_dump((void *)P2V(PDE_ADDR(entry)), false, ix2, 4); - } -#endif - PANIC(0, "mapping an already-mapped address"); - } + PANIC( 0, "mapping an already-mapped address" ); } // ok, set the PTE as requested - *pte = newpte; + *pte = pa | perm | PTE_P; // nope - move to the next page addr += SZ_PAGE; pa += SZ_PAGE; + } return SUCCESS; } @@ -866,48 +569,48 @@ int vm_map(pde_t *pdir, void *va, uint32_t pa, uint32_t size, int perm) ** now have two sets of page tables that refer to the same physical ** frames in memory. ** -** @param new New page directory ** @param old Existing page directory +** @param new New page directory ** ** @return status of the duplication attempt */ -int vm_uvmdup(pde_t *new, pde_t *old) -{ - if (old == NULL || new == NULL) { +int vm_uvmdup( pde_t *old, pde_t *new ) { + + if( old == NULL || new == NULL ) { return E_BAD_PARAM; } -#if TRACING_VM - cio_printf("vmdup: old %08x new %08x\n", (uint32_t)old, (uint32_t)new); -#endif - // we only want to deal with the "user" half of the address space - for (int i = 0; i < (N_PDE >> 1); ++i) { + for( int i = 0; i < (N_PDE >> 1); ++i ) { + // the entry to copy pde_t entry = *old; // is this entry in use? - if (IS_PRESENT(entry)) { + if( IS_PRESENT(entry) ) { + // yes. if it points to a 4MB page, we just copy it; // otherwise, we must duplicate the next level PMT - if (!IS_LARGE(entry)) { + if( !IS_LARGE(entry) ) { + // it's a 4KB page, so we need to duplicate the PMT - pte_t *newpt = - (pte_t *)vm_pagedup((void *)P2V(PTE_ADDR(entry))); - if (newpt == NULL) { + pte_t *newpt = (pte_t *) vm_pagedup( (void *)PTE_ADDR(entry) ); + if( newpt == NULL ) { return E_NO_MEMORY; } uint32_t perms = PERMS(entry); // create the new PDE entry by replacing the frame # - entry = ((uint32_t)V2P(PTE_ADDR(newpt))) | perms; + entry = ((uint32_t) newpt) | perms; } } else { + // not present, so create an empty entry entry = 0; + } // send it on its way @@ -920,26 +623,3 @@ int vm_uvmdup(pde_t *new, pde_t *old) return SUCCESS; } - -/** -** Name: vm_print -** -** Print out a paging hierarchy. -** -** @param pt Page table to display -** @param dir Is it a page directory (vs. a page table)? -** @param mode How to display the entries -*/ -void vm_print(void *pt, bool_t dir, enum vmmode_e mode) -{ - cio_puts("\nVM hierarchy"); - if (pt == NULL) { - cio_puts(" (NULL pointer)\n"); - return; - } - - cio_printf(", starting at 0x%08x (%s):\n", (uint32_t)pt, - dir ? "PDIR" : "PMT"); - - ptdump(1, pt, dir, mode); -} |