Index: /soft/giet_vm/giet_boot/boot.c =================================================================== --- /soft/giet_vm/giet_boot/boot.c (revision 731) +++ /soft/giet_vm/giet_boot/boot.c (revision 732) @@ -31,5 +31,5 @@ // - the various "application.elf" files. // -// 2) The GIET-VM uses the paged virtual memory to provides two services: +// 2) The GIET-VM uses the paged virtual memory to provide two services: // - classical memory protection, when several independant applications compiled // in different virtual spaces are executing on the same hardware platform. @@ -198,4 +198,10 @@ // As each vseg is mapped by a different processor, the PT1 entry cannot // be concurrently accessed, and we don't need to take any lock. +// +// Implementation note: +// This function checks that the PT1 entry is not already mapped, +// to enforce the rule: only one vseg in a given BPP. +// The 4 vsegs used by the boot code being packed in one single BPP, +// this verif is not done for all identity mapping vsegs. ////////////////////////////////////////////////////////////////////////////// void boot_add_pte1( unsigned int vspace_id, @@ -204,13 +210,17 @@ unsigned int vpn, // 20 bits right-justified unsigned int flags, // 10 bits left-justified - unsigned int ppn ) // 28 bits right-justified + unsigned int ppn, // 28 bits right-justified + unsigned int ident ) // identity mapping if non zero { + unsigned int pte1; // PTE1 value + paddr_t paddr; // PTE1 physical address + // compute index in PT1 unsigned int ix1 = vpn >> 9; // 11 bits for ix1 - // get page table physical base address - paddr_t pt1_pbase = _ptabs_paddr[vspace_id][x][y]; - - if ( pt1_pbase == 0 ) + // get PT1 physical base address + paddr_t pt1_base = _ptabs_paddr[vspace_id][x][y]; + + if ( pt1_base == 0 ) { _printf("\n[BOOT ERROR] in boot_add_pte1() : no PTAB in cluster[%d,%d]" @@ -219,11 +229,23 @@ } + // compute pte1 physical address + paddr = pt1_base + 4*ix1; + + // check PTE1 not already mapped + if ( ident == 0 ) + { + if ( _physical_read( paddr ) & PTE_V ) + { + _printf("\n[BOOT ERROR] in boot_add_pte1() : vpn %x already mapped " + "in PTAB[%d,%d] for vspace %d\n", vpn , x , y , vspace_id ); + _exit(); + } + } + // compute pte1 : 2 bits V T / 8 bits flags / 3 bits RSVD / 19 bits bppi - unsigned int pte1 = PTE_V | - (flags & 0x3FC00000) | - ((ppn>>9) & 0x0007FFFF); + pte1 = PTE_V | (flags & 0x3FC00000) | ((ppn>>9) & 0x0007FFFF); // write pte1 in PT1 - _physical_write( pt1_pbase + 4*ix1, pte1 ); + _physical_write( paddr , pte1 ); asm volatile ("sync"); @@ -238,5 +260,5 @@ // allocation), this function checks a possible overflow of the PT2 array. // As a given entry in PT1 can be shared by several vsegs, mapped by -// different processors, we need to take the lock protecting PTAB[v][x]y]. +// different processors, we need to take the lock protecting PTAB[v][x][y]. ////////////////////////////////////////////////////////////////////////////// void boot_add_pte2( unsigned int vspace_id, @@ -245,5 +267,6 @@ unsigned int vpn, // 20 bits right-justified unsigned int flags, // 10 bits left-justified - unsigned int ppn ) // 28 bits right-justified + unsigned int ppn, // 28 bits right-justified + unsigned int ident ) // identity mapping if non zero { unsigned int ix1; @@ -331,10 +354,10 @@ // // A given vseg can be mapped in a Big Physical Pages (BPP: 2 Mbytes) or in a -// Small Physical Pages (SPP: 4 Kbytes), depending on the "big" attribute of vseg, -// with the following rules: -// - SPP : There is only one vseg in a small physical page, but a single vseg -// can cover several contiguous small physical pages. -// - BPP : It can exist several vsegs in a single big physical page, and a single -// vseg can cover several contiguous big physical pages. +// Small Physical Pages (SPP: 4 Kbytes), depending on the "big" attribute of vseg. +// +// All boot vsegs are packed in a single BPP (2 Mbytes). For all other vsegs, +// there is only one vseg in a given page (BPP or SPP), but a single vseg can +// cover several contiguous physical pages. +// Only the vsegs used by the boot code can be identity mapping. // // 1) First step: it computes various vseg attributes and checks @@ -343,15 +366,11 @@ // 2) Second step: it allocates the required number of contiguous physical pages, // computes the physical base address (if the vseg is not identity mapping), -// and register it in the vseg pbase field. -// Only the vsegs used by the boot code and the peripheral vsegs -// can be identity mapping. The first big physical page in cluster[0,0] -// is reserved for the boot vsegs. +// register it in the vseg pbase field, and update the page table(s). // -// 3) Third step (only for vseg that have the VSEG_TYPE_PTAB): the M page tables -// associated to the M vspaces must be packed in the same vseg. +// 3) Third step (only for vseg that have the VSEG_TYPE_PTAB): for a given cluster, +// the M page tables associated to the M vspaces are packed in the same vseg. // We divide this vseg in M sub-segments, and compute the vbase and pbase // addresses for M page tables, and register these addresses in the _ptabs_paddr // and _ptabs_vaddr arrays. -// ///////////////////////////////////////////////////////////////////////////////////// void boot_vseg_map( mapping_vseg_t* vseg, @@ -414,5 +433,5 @@ // compute ppn - if ( vseg->ident ) // identity mapping + if ( vseg->ident ) // identity mapping : no memory allocation required { ppn = vpn; @@ -425,49 +444,11 @@ pmem_alloc_t* palloc = &boot_pmem_alloc[x_dest][y_dest]; - if ( big == 0 ) // SPP : small physical pages + if ( big == 0 ) // allocate contiguous SPPs { - // allocate contiguous small physical pages ppn = _get_small_ppn( palloc, npages ); } - else // BPP : big physical pages + else // allocate contiguous BPPs { - - // one big page can be shared by several vsegs - // we must chek if BPP already allocated - if ( is_ptab ) // It cannot be mapped - { - ppn = _get_big_ppn( palloc, npages ); - } - else // It can be mapped - { - unsigned int ix1 = vpn >> 9; // 11 bits - paddr_t paddr = _ptabs_paddr[vsid][x_dest][y_dest] + (ix1<<2); - unsigned int pte1 = _physical_read( paddr ); - - if ( (pte1 & PTE_V) == 0 ) // BPP not allocated yet - { - // allocate contiguous big physical pages - ppn = _get_big_ppn( palloc, npages ); - } - else // BPP already allocated - { - // test if new vseg has the same mode bits than - // the other vsegs in the same big page - unsigned int pte1_mode = 0; - if (pte1 & PTE_C) pte1_mode |= C_MODE_MASK; - if (pte1 & PTE_X) pte1_mode |= X_MODE_MASK; - if (pte1 & PTE_W) pte1_mode |= W_MODE_MASK; - if (pte1 & PTE_U) pte1_mode |= U_MODE_MASK; - if (vseg->mode != pte1_mode) - { - _printf("\n[BOOT ERROR] in boot_vseg_map() : " - "vseg %s has different flags than another vseg " - "in the same BPP\n", vseg->name ); - _exit(); - } - ppn = ((pte1 << 9) & 0x0FFFFE00); - } - } - ppn = ppn | (vpn & 0x1FF); + ppn = _get_big_ppn( palloc, npages ); } } @@ -478,8 +459,7 @@ } - // update vseg.pbase field and update vsegs chaining + // update vseg.pbase field and register vseg mapped vseg->pbase = ((paddr_t)ppn) << 12; vseg->mapped = 1; - //////////// Third step : (only if the vseg is a page table) @@ -611,5 +591,6 @@ vpn + (p<<9), flags, - ppn + (p<<9) ); + ppn + (p<<9), + vseg->ident ); } else // small pages => PTE2s @@ -620,5 +601,6 @@ vpn + p, flags, - ppn + p ); + ppn + p, + vseg->ident ); } } @@ -638,5 +620,6 @@ vpn + (p<<9), flags, - ppn + (p<<9) ); + ppn + (p<<9), + vseg->ident ); } else // small pages => PTE2s @@ -647,5 +630,6 @@ vpn + p, flags, - ppn + p ); + ppn + p, + vseg->ident ); } } @@ -664,5 +648,6 @@ vpn + (p<<9), flags, - ppn + (p<<9) ); + ppn + (p<<9), + vseg->ident ); } else // small pages = PTE2s @@ -673,5 +658,6 @@ vpn + p, flags, - ppn + p ); + ppn + p, + vseg->ident ); } } @@ -694,5 +680,6 @@ vpn + (p<<9), flags, - ppn + (p<<9) ); + ppn + (p<<9), + vseg->ident ); } else // small pages -> PTE2s @@ -703,5 +690,6 @@ vpn + p, flags, - ppn + p ); + ppn + p, + vseg->ident ); } } @@ -1337,5 +1325,5 @@ psched->context[ltid].slot[CTX_VSID_ID], psched->context[ltid].slot[CTX_NORUN_ID], - psched->context[ltid].slot[CTX_SIG_ID] ); + psched->context[ltid].slot[CTX_SIGS_ID] ); #endif } // end if FIT @@ -1897,5 +1885,5 @@ boot_ptab_extend(); - _printf("\n[BOOT] Physical memory allocators and page tables" + _printf("\n[BOOT] Page tables" " initialized at cycle %d\n", _get_proctime() ); }