diff options
Diffstat (limited to 'sys/arch/i386/include/pmap.h')
| -rw-r--r-- | sys/arch/i386/include/pmap.h | 146 |
1 files changed, 73 insertions, 73 deletions
diff --git a/sys/arch/i386/include/pmap.h b/sys/arch/i386/include/pmap.h index 361c7ac28e1..8e086787f4f 100644 --- a/sys/arch/i386/include/pmap.h +++ b/sys/arch/i386/include/pmap.h @@ -1,4 +1,4 @@ -/* $OpenBSD: pmap.h,v 1.30 2003/04/07 06:14:30 niklas Exp $ */ +/* $OpenBSD: pmap.h,v 1.31 2003/04/09 07:53:57 niklas Exp $ */ /* $NetBSD: pmap.h,v 1.44 2000/04/24 17:18:18 thorpej Exp $ */ /* @@ -47,111 +47,111 @@ #include <uvm/uvm_object.h> /* - * see pte.h for a description of i386 MMU terminology and hardware + * See pte.h for a description of i386 MMU terminology and hardware * interface. * - * a pmap describes a processes' 4GB virtual address space. this + * A pmap describes a process' 4GB virtual address space. This * virtual address space can be broken up into 1024 4MB regions which - * are described by PDEs in the PDP. the PDEs are defined as follows: + * are described by PDEs in the PDP. The PDEs are defined as follows: * - * (ranges are inclusive -> exclusive, just like vm_map_entry start/end) - * (the following assumes that KERNBASE is 0xc0000000) + * Ranges are inclusive -> exclusive, just like vm_map_entry start/end. + * The following assumes that KERNBASE is 0xd0000000. * - * PDE#s VA range usage - * 0->767 0x0 -> 0xbfc00000 user address space, note that the - * max user address is 0xbfbfe000 + * PDE#s VA range Usage + * 0->831 0x0 -> 0xcfc00000 user address space, note that the + * max user address is 0xcfbfe000 * the final two pages in the last 4MB * used to be reserved for the UAREA - * but now are no longer used - * 768 0xbfc00000-> recursive mapping of PDP (used for - * 0xc0000000 linear mapping of PTPs) - * 768->1023 0xc0000000-> kernel address space (constant - * 0xffc00000 across all pmap's/processes) + * but now are no longer used. + * 831 0xcfc00000-> recursive mapping of PDP (used for + * 0xd0000000 linear mapping of PTPs). + * 832->1023 0xd0000000-> kernel address space (constant + * 0xffc00000 across all pmaps/processes). * 1023 0xffc00000-> "alternate" recursive PDP mapping - * <end> (for other pmaps) + * <end> (for other pmaps). * * - * note: a recursive PDP mapping provides a way to map all the PTEs for - * a 4GB address space into a linear chunk of virtual memory. in other + * Note: A recursive PDP mapping provides a way to map all the PTEs for + * a 4GB address space into a linear chunk of virtual memory. In other * words, the PTE for page 0 is the first int mapped into the 4MB recursive - * area. the PTE for page 1 is the second int. the very last int in the + * area. The PTE for page 1 is the second int. The very last int in the * 4MB range is the PTE that maps VA 0xffffe000 (the last page in a 4GB * address). * - * all pmap's PD's must have the same values in slots 768->1023 so that - * the kernel is always mapped in every process. these values are loaded + * All pmaps' PDs must have the same values in slots 832->1023 so that + * the kernel is always mapped in every process. These values are loaded * into the PD at pmap creation time. * - * at any one time only one pmap can be active on a processor. this is - * the pmap whose PDP is pointed to by processor register %cr3. this pmap + * At any one time only one pmap can be active on a processor. This is + * the pmap whose PDP is pointed to by processor register %cr3. This pmap * will have all its PTEs mapped into memory at the recursive mapping - * point (slot #767 as show above). when the pmap code wants to find the + * point (slot #831 as show above). When the pmap code wants to find the * PTE for a virtual address, all it has to do is the following: * - * address of PTE = (767 * 4MB) + (VA / NBPG) * sizeof(pt_entry_t) - * = 0xbfc00000 + (VA / 4096) * 4 + * Address of PTE = (831 * 4MB) + (VA / NBPG) * sizeof(pt_entry_t) + * = 0xcfc00000 + (VA / 4096) * 4 * - * what happens if the pmap layer is asked to perform an operation - * on a pmap that is not the one which is currently active? in that + * What happens if the pmap layer is asked to perform an operation + * on a pmap that is not the one which is currently active? In that * case we take the PA of the PDP of non-active pmap and put it in - * slot 1023 of the active pmap. this causes the non-active pmap's + * slot 1023 of the active pmap. This causes the non-active pmap's * PTEs to get mapped in the final 4MB of the 4GB address space * (e.g. starting at 0xffc00000). * - * the following figure shows the effects of the recursive PDP mapping: + * The following figure shows the effects of the recursive PDP mapping: * * PDP (%cr3) * +----+ * | 0| -> PTP#0 that maps VA 0x0 -> 0x400000 * | | * | | - * | 767| -> points back to PDP (%cr3) mapping VA 0xbfc00000 -> 0xc0000000 - * | 768| -> first kernel PTP (maps 0xc0000000 -> 0xf0400000) + * | 831| -> points back to PDP (%cr3) mapping VA 0xcfc00000 -> 0xd0000000 + * | 832| -> first kernel PTP (maps 0xd0000000 -> 0xe0400000) * | | * |1023| -> points to alternate pmap's PDP (maps 0xffc00000 -> end) * +----+ * - * note that the PDE#767 VA (0xbfc00000) is defined as "PTE_BASE" - * note that the PDE#1023 VA (0xffc00000) is defined as "APTE_BASE" + * Note that the PDE#831 VA (0xcfc00000) is defined as "PTE_BASE". + * Note that the PDE#1023 VA (0xffc00000) is defined as "APTE_BASE". * - * starting at VA 0xbfc00000 the current active PDP (%cr3) acts as a + * Starting at VA 0xdfc00000 the current active PDP (%cr3) acts as a * PTP: * - * PTP#767 == PDP(%cr3) => maps VA 0xbfc00000 -> 0xc0000000 + * PTP#831 == PDP(%cr3) => maps VA 0xcfc00000 -> 0xd0000000 * +----+ - * | 0| -> maps the contents of PTP#0 at VA 0xbfc00000->0xbfc01000 + * | 0| -> maps the contents of PTP#0 at VA 0xcfc00000->0xcfc01000 * | | * | | - * | 767| -> maps contents of PTP#767 (the PDP) at VA 0xbffbf000 - * | 768| -> maps contents of first kernel PTP + * | 831| -> maps the contents of PTP#831 (the PDP) at VA 0xcff3f000 + * | 832| -> maps the contents of first kernel PTP * | | * |1023| * +----+ * - * note that mapping of the PDP at PTP#959's VA (0xeffbf000) is + * Note that mapping of the PDP at PTP#831's VA (0xcff3f000) is * defined as "PDP_BASE".... within that mapping there are two * defines: - * "PDP_PDE" (0xeffbfefc) is the VA of the PDE in the PDP + * "PDP_PDE" (0xcff3fcfc) is the VA of the PDE in the PDP * which points back to itself. - * "APDP_PDE" (0xeffbfffc) is the VA of the PDE in the PDP which + * "APDP_PDE" (0xcff3fffc) is the VA of the PDE in the PDP which * establishes the recursive mapping of the alternate pmap. - * to set the alternate PDP, one just has to put the correct + * To set the alternate PDP, one just has to put the correct * PA info in *APDP_PDE. * - * note that in the APTE_BASE space, the APDP appears at VA + * Note that in the APTE_BASE space, the APDP appears at VA * "APDP_BASE" (0xfffff000). */ /* - * the following defines identify the slots used as described above. + * The following defines identify the slots used as described above. */ -#define PDSLOT_PTE ((KERNBASE/NBPD)-1) /* 767: for recursive PDP map */ -#define PDSLOT_KERN (KERNBASE/NBPD) /* 768: start of kernel space */ +#define PDSLOT_PTE ((KERNBASE/NBPD)-1) /* 831: for recursive PDP map */ +#define PDSLOT_KERN (KERNBASE/NBPD) /* 832: start of kernel space */ #define PDSLOT_APTE ((unsigned)1023) /* 1023: alternative recursive slot */ /* - * the following defines give the virtual addresses of various MMU + * The following defines give the virtual addresses of various MMU * data structures: * PTE_BASE and APTE_BASE: the base VA of the linear PTE mappings * PTD_BASE and APTD_BASE: the base VA of the recursive mapping of the PTD @@ -173,9 +173,9 @@ */ /* - * the follow define determines how many PTPs should be set up for the - * kernel by locore.s at boot time. this should be large enough to - * get the VM system running. once the VM system is running, the + * The following define determines how many PTPs should be set up for the + * kernel by locore.s at boot time. This should be large enough to + * get the VM system running. Once the VM system is running, the * pmap module can add more PTPs to the kernel area on demand. */ @@ -215,11 +215,11 @@ /* * PTP macros: - * a PTP's index is the PD index of the PDE that points to it - * a PTP's offset is the byte-offset in the PTE space that this PTP is at - * a PTP's VA is the first VA mapped by that PTP + * A PTP's index is the PD index of the PDE that points to it. + * A PTP's offset is the byte-offset in the PTE space that this PTP is at. + * A PTP's VA is the first VA mapped by that PTP. * - * note that NBPG == number of bytes in a PTP (4096 bytes == 1024 entries) + * Note that NBPG == number of bytes in a PTP (4096 bytes == 1024 entries) * NBPD == number of bytes a PTP can map (4MB) */ @@ -245,15 +245,15 @@ struct pmap; typedef struct pmap *pmap_t; /* - * we maintain a list of all non-kernel pmaps + * We maintain a list of all non-kernel pmaps. */ LIST_HEAD(pmap_head, pmap); /* struct pmap_head: head of a pmap list */ /* - * the pmap structure + * The pmap structure * - * note that the pm_obj contains the simple_lock, the reference count, + * Note that the pm_obj contains the simple_lock, the reference count, * page list, and number of PTPs within the pmap. */ @@ -278,10 +278,10 @@ struct pmap { #define PMF_USER_LDT 0x01 /* pmap has user-set LDT */ /* - * for each managed physical page we maintain a list of <PMAP,VA>'s - * which it is mapped at. the list is headed by a pv_head structure. + * For each managed physical page we maintain a list of <PMAP,VA>s + * which it is mapped at. The list is headed by a pv_head structure. * there is one pv_head per managed phys page (allocated at boot time). - * the pv_head structure points to a list of pv_entry structures (each + * The pv_head structure points to a list of pv_entry structures (each * describes one mapping). */ @@ -302,7 +302,7 @@ struct pv_entry { /* locked by its list's pvh_lock */ /* * pv_entrys are dynamically allocated in chunks from a single page. * we keep track of how many pv_entrys are in use for each page and - * we can free pv_entry pages if needed. there is one lock for the + * we can free pv_entry pages if needed. There is one lock for the * entire allocation system. */ @@ -313,7 +313,7 @@ struct pv_page_info { }; /* - * number of pv_entry's in a pv_page + * number of pv_entries in a pv_page * (note: won't work on systems where NPBG isn't a constant) */ @@ -331,7 +331,7 @@ struct pv_page { /* * pmap_remove_record: a record of VAs that have been unmapped, used to - * flush TLB. if we have more than PMAP_RR_MAX then we stop recording. + * flush TLB. If we have more than PMAP_RR_MAX then we stop recording. */ #define PMAP_RR_MAX 16 /* max of 16 pages (64K) */ @@ -342,7 +342,7 @@ struct pmap_remove_record { }; /* - * global kernel variables + * Global kernel variables */ extern pd_entry_t PTD[]; @@ -355,7 +355,7 @@ extern int nkpde; /* current # of PDEs for kernel */ extern int pmap_pg_g; /* do we support PG_G? */ /* - * macros + * Macros */ #define pmap_kernel() (&kernel_pmap_store) @@ -372,7 +372,7 @@ extern int pmap_pg_g; /* do we support PG_G? */ /* - * prototypes + * Prototypes */ void pmap_bootstrap(vaddr_t); @@ -399,7 +399,7 @@ boolean_t pmap_zero_page_uncached(paddr_t); #define PMAP_PAGEIDLEZERO(pg) pmap_zero_page_uncached(VM_PAGE_TO_PHYS(pg)) /* - * inline functions + * Inline functions */ /* @@ -442,9 +442,9 @@ pmap_update_2pg(va, vb) * pmap_page_protect: change the protection of all recorded mappings * of a managed page * - * => this function is a frontend for pmap_page_remove/pmap_change_attrs - * => we only have to worry about making the page more protected. - * unprotecting a page is done on-demand at fault time. + * => This function is a front end for pmap_page_remove/pmap_change_attrs + * => We only have to worry about making the page more protected. + * Unprotecting a page is done on-demand at fault time. */ __inline static void @@ -464,9 +464,9 @@ pmap_page_protect(pg, prot) /* * pmap_protect: change the protection of pages in a pmap * - * => this function is a frontend for pmap_remove/pmap_write_protect - * => we only have to worry about making the page more protected. - * unprotecting a page is done on-demand at fault time. + * => This function is a front end for pmap_remove/pmap_write_protect. + * => We only have to worry about making the page more protected. + * Unprotecting a page is done on-demand at fault time. */ __inline static void |