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Differences between /sos/umem_vmm.h (Article 9) and /sos/umem_vmm.h (Article 7.5)


001 /* Copyright (C) 2005 David Decotigny             001 /* Copyright (C) 2005 David Decotigny
002                                                   002 
003    This program is free software; you can redi    003    This program is free software; you can redistribute it and/or
004    modify it under the terms of the GNU Genera    004    modify it under the terms of the GNU General Public License
005    as published by the Free Software Foundatio    005    as published by the Free Software Foundation; either version 2
006    of the License, or (at your option) any lat    006    of the License, or (at your option) any later version.
007                                                   007    
008    This program is distributed in the hope tha    008    This program is distributed in the hope that it will be useful,
009    but WITHOUT ANY WARRANTY; without even the     009    but WITHOUT ANY WARRANTY; without even the implied warranty of
010    MERCHANTABILITY or FITNESS FOR A PARTICULAR    010    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
011    GNU General Public License for more details    011    GNU General Public License for more details.
012                                                   012    
013    You should have received a copy of the GNU     013    You should have received a copy of the GNU General Public License
014    along with this program; if not, write to t    014    along with this program; if not, write to the Free Software
015    Foundation, Inc., 59 Temple Place - Suite 3    015    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
016    USA.                                           016    USA. 
017 */                                                017 */
018 #ifndef _SOS_UMEM_VMM_H_                          018 #ifndef _SOS_UMEM_VMM_H_
019 #define _SOS_UMEM_VMM_H_                          019 #define _SOS_UMEM_VMM_H_
020                                                   020 
021 /**                                               021 /**
022  * @file umem_vmm.h                               022  * @file umem_vmm.h
023  *                                                023  *
024  * Management of the address space of a proces    024  * Management of the address space of a process in SOS. The so-called
025  * "address space" of a process consists in th    025  * "address space" of a process consists in the description of the
026  * virtual addresses that are valid in the use    026  * virtual addresses that are valid in the user space of a process (in
027  * SOS: addresses 1G-4G). The kernel-space of     027  * SOS: addresses 1G-4G). The kernel-space of a process is managed by
028  * the "kmem" subsystem, and is kept identical    028  * the "kmem" subsystem, and is kept identical accross all the
029  * processes in the system.                       029  * processes in the system.
030  *                                                030  *
031  * The umem_vmm subsystem handles the followin    031  * The umem_vmm subsystem handles the following features:
032  *  - demand-mapping of resourcs (files: mmap)    032  *  - demand-mapping of resourcs (files: mmap): mapping in physical RAM
033  *    will be delayed as much as possible, unt    033  *    will be delayed as much as possible, until the process really
034  *    need to access the mapped addresses         034  *    need to access the mapped addresses
035  *  - mprotect/mremap support                     035  *  - mprotect/mremap support
036  *  - private and shared mappings                 036  *  - private and shared mappings
037  *  - Copy-On-Write (COW) of the private mappi    037  *  - Copy-On-Write (COW) of the private mappings upon fork() to favour
038  *    shared physical memory as much as possib    038  *    shared physical memory as much as possible
039  *  - "heap" management (brk/sbrk)                039  *  - "heap" management (brk/sbrk)
040  *                                                040  *
041  * Swap is NOT supported (yet), which means th    041  * Swap is NOT supported (yet), which means that the following is NOT
042  * supported:                                     042  * supported:
043  *  - locked/reserved I/O pages (everything is    043  *  - locked/reserved I/O pages (everything is locked in RAM)
044  *  - "safe" demand-mapping of anonymous pages    044  *  - "safe" demand-mapping of anonymous pages, ie conservative VMM
045  *    allocation (alloc of anonymous pages on     045  *    allocation (alloc of anonymous pages on the swap)
046  * Other unsupported features:                    046  * Other unsupported features:
047  *  - dynamically-resizable regions (Linux's G    047  *  - dynamically-resizable regions (Linux's GROWUP/GROWDOWN vma): the
048  *    user stack is expected to have a suitabl    048  *    user stack is expected to have a suitable virtual size from the
049  *    beginning, or sos_umem_vmm_resize() must    049  *    beginning, or sos_umem_vmm_resize() must be used explicitely to
050  *    resize it                                   050  *    resize it
051  *  - no provision of "stack size" accounting,    051  *  - no provision of "stack size" accounting, since there are
052  *    multiple stacks (ie user threads) in a p    052  *    multiple stacks (ie user threads) in a process: which stack to
053  *    consider ???                                053  *    consider ???
054  *                                                054  *
055  * The address space is divided into "virtual     055  * The address space is divided into "virtual regions" (aka "VR") that
056  * describe a single mapping, aka a segment of    056  * describe a single mapping, aka a segment of contiguous pages in
057  * user-space virtual memory. Each such virtua    057  * user-space virtual memory. Each such virtual region "maps" a
058  * "resource" and is characterised by:            058  * "resource" and is characterised by:
059  *   - its base address and length in user-spa    059  *   - its base address and length in user-space
060  *   - the allowed accesses, aka "protection"     060  *   - the allowed accesses, aka "protection" (read-only or read/write)
061  *   - the resource it maps in virtual memory     061  *   - the resource it maps in virtual memory
062  *                                                062  *
063  * A so-called resource is typically:             063  * A so-called resource is typically:
064  *   - a file                                     064  *   - a file
065  *   - a device                                   065  *   - a device
066  *   - an area initially full of zeros (the VR    066  *   - an area initially full of zeros (the VR mapping this are called
067  *     "anonymous mappings")                      067  *     "anonymous mappings")
068  *                                                068  *
069  * The implementation is very close to that of    069  * The implementation is very close to that of Linux and Kos. This is
070  * a "simple" implementation, not the most ele    070  * a "simple" implementation, not the most elegant one, such as those
071  * based on "shadow objects" hierarchies as fo    071  * based on "shadow objects" hierarchies as found in BSD 4.4 and Mach,
072  * or that of Solaris (based on the "anon" lis    072  * or that of Solaris (based on the "anon" lists). Actually, this
073  * implementation does not use "shadow-objects    073  * implementation does not use "shadow-objects"/anon list when a COW
074  * page of a shared mapping is made anonymous.    074  * page of a shared mapping is made anonymous. This won't hurt the
075  * implementation of the basic demand-mapping     075  * implementation of the basic demand-mapping mechanism; on the
076  * contrary, it will make things simpler. But     076  * contrary, it will make things simpler. But this will largely impact
077  * the implementation of the swap-in/swap-out     077  * the implementation of the swap-in/swap-out strategies, as these
078  * would require a non trivial intrication of     078  * would require a non trivial intrication of low-level and higher
079  * level algorithms.                              079  * level algorithms.
080  */                                               080  */
081                                                   081 
082                                                   082 
083 /**                                               083 /**
084  * Definition of an "address space" in Kos. Th    084  * Definition of an "address space" in Kos. This is an opaque
085  * structure defined in umem_vmm.c. Its main r    085  * structure defined in umem_vmm.c. Its main role is to list virtual
086  * regions. It mainly consists in:                086  * regions. It mainly consists in:
087  *  - a reference to the process owning it        087  *  - a reference to the process owning it
088  *  - maximum allowed protection (ie can it be    088  *  - maximum allowed protection (ie can it be mapped read-only or
089  *    read/write ?)                               089  *    read/write ?)
090  *  - the list of VRs mapping resources           090  *  - the list of VRs mapping resources
091  *  - a mm_context that reflects the configura    091  *  - a mm_context that reflects the configuration of the MMU
092  *  - the location of the heap for this proces    092  *  - the location of the heap for this process
093  *  - statistics                                  093  *  - statistics
094  */                                               094  */
095 struct sos_umem_vmm_as;                           095 struct sos_umem_vmm_as;
096                                                   096 
097                                                   097 
098 /**                                               098 /**
099  * Definition of a "virtual region". Linux wou    099  * Definition of a "virtual region". Linux would call them "vma"
100  * (Virtual Memory Area), and Solaris: "segmen    100  * (Virtual Memory Area), and Solaris: "segments". It mainly consists
101  * in:                                            101  * in:
102  *  - the start/end addresses of the mapping      102  *  - the start/end addresses of the mapping
103  *  - a pointer to the resource that it maps      103  *  - a pointer to the resource that it maps
104  *  - the type of mapping (shared/private)        104  *  - the type of mapping (shared/private)
105  *  - the actual protection flags (@see SOS_VM    105  *  - the actual protection flags (@see SOS_VM_MAP_PROT_* flags in
106  *    hwcore/paging.h)                            106  *    hwcore/paging.h)
107  *  - a set of callbacks (@see sos_umem_vmm_vr    107  *  - a set of callbacks (@see sos_umem_vmm_vr_ops below) automatically
108  *    called by the umem_vmm subsystem each ti    108  *    called by the umem_vmm subsystem each time the VR is modified
109  */                                               109  */
110 struct sos_umem_vmm_vr;                           110 struct sos_umem_vmm_vr;
111                                                   111 
112                                                   112 
113 /** VR flag: region can be shared between a pr    113 /** VR flag: region can be shared between a process and its
114     children */                                   114     children */
115 #define SOS_VR_MAP_SHARED (1 << 0)                115 #define SOS_VR_MAP_SHARED (1 << 0)
116                                                   116 
117                                                   117 
118 #include <sos/types.h>                            118 #include <sos/types.h>
119 #include <sos/process.h>                          119 #include <sos/process.h>
120                                                   120 
121                                                   121 
122 /**                                               122 /**
123  * The callbacks applicable on a virtual regio    123  * The callbacks applicable on a virtual region. Automatically called
124  * by the umem_vmm subsystem.                     124  * by the umem_vmm subsystem.
125  *                                                125  *
126  * Calling sequences:                             126  * Calling sequences:
127  * - duplicate_as() (aka fork()):                 127  * - duplicate_as() (aka fork()):
128  *    vr->ops->ref()                              128  *    vr->ops->ref()
129  *    add vr to lists                             129  *    add vr to lists
130  * - delete_as() (aka exit()):                    130  * - delete_as() (aka exit()):
131  *    vr->ops->unmap()                            131  *    vr->ops->unmap()
132  *    remove vr from lists                        132  *    remove vr from lists
133  *    vr->ops->unref()                            133  *    vr->ops->unref()
134  * - mmap():                                      134  * - mmap():
135  *    -> left + new + right VRs can fusion:       135  *    -> left + new + right VRs can fusion:
136  *        remove right_vr from list               136  *        remove right_vr from list
137  *        right_vr->ops->unref()                  137  *        right_vr->ops->unref()
138  *    -> left + new VRs can fusion:               138  *    -> left + new VRs can fusion:
139  *        nothing                                 139  *        nothing
140  *    -> new + right VRs can fusion:              140  *    -> new + right VRs can fusion:
141  *        nothing                                 141  *        nothing
142  *    -> isolated:                                142  *    -> isolated:
143  *        add new_vr to lists                     143  *        add new_vr to lists
144  *        new_vr->map()                           144  *        new_vr->map()
145  *        new_vr->ops->ref()                      145  *        new_vr->ops->ref()
146  * - munmap():                                    146  * - munmap():
147  *    -> VR totally unmapped:                     147  *    -> VR totally unmapped:
148  *        vr->ops->unmap()                        148  *        vr->ops->unmap()
149  *        remove vr from lists                    149  *        remove vr from lists
150  *        vr->ops->unref()                        150  *        vr->ops->unref()
151  *    -> VR unmapped in the middle (split into    151  *    -> VR unmapped in the middle (split into 2):
152  *        add (new) right VR into the lists       152  *        add (new) right VR into the lists
153  *        vr->unmap(middle_unmapped_area)         153  *        vr->unmap(middle_unmapped_area)
154  *        right_vr->ops->ref()                    154  *        right_vr->ops->ref()
155  *    -> VR unmapped on its left:                 155  *    -> VR unmapped on its left:
156  *        vr->ops->unmap(left_unmapped_area)      156  *        vr->ops->unmap(left_unmapped_area)
157  *    -> VR unmapped on its right:                157  *    -> VR unmapped on its right:
158  *        vr->ops->unmap(right_unmapped_area)     158  *        vr->ops->unmap(right_unmapped_area)
159  * - chprot():                                    159  * - chprot():
160  *    -> VR totally chprot:                       160  *    -> VR totally chprot:
161  *        nothing                                 161  *        nothing
162  *    -> VR chprot in the middle (split into 3    162  *    -> VR chprot in the middle (split into 3):
163  *        add (new) middle+right VRs into the     163  *        add (new) middle+right VRs into the lists
164  *        middle_vr->ops->ref()                   164  *        middle_vr->ops->ref()
165  *        right_vr->ops->ref()                    165  *        right_vr->ops->ref()
166  *    -> VR chprot on its left (split into 2):    166  *    -> VR chprot on its left (split into 2):
167  *        add (new) right VR into the lists       167  *        add (new) right VR into the lists
168  *        right_vr->ops->ref()                    168  *        right_vr->ops->ref()
169  *    -> VR chprot on its right (split into 2)    169  *    -> VR chprot on its right (split into 2):
170  *        add (new) right VR into the lists       170  *        add (new) right VR into the lists
171  *        right_vr->ops->ref()                    171  *        right_vr->ops->ref()
172  * - resize():                                    172  * - resize():
173  *    -> if moving the VR: map/unmap              173  *    -> if moving the VR: map/unmap
174  *    -> otherwise: nothing                       174  *    -> otherwise: nothing
175  */                                               175  */
176 struct sos_umem_vmm_vr_ops                        176 struct sos_umem_vmm_vr_ops
177 {                                                 177 {
178   /**                                             178   /**
179    * Called after the virtual region has been     179    * Called after the virtual region has been inserted
180    * inside its address space.                    180    * inside its address space.
181    * @note Optional                               181    * @note Optional
182    */                                             182    */
183   void (*ref)(struct sos_umem_vmm_vr * vr);       183   void (*ref)(struct sos_umem_vmm_vr * vr);
184                                                   184 
185   /**                                             185   /**
186    * Called when the virtual region is removed    186    * Called when the virtual region is removed from its
187    * address space                                187    * address space
188    * @note Optional                               188    * @note Optional
189    */                                             189    */
190   void (*unref)(struct sos_umem_vmm_vr * vr);     190   void (*unref)(struct sos_umem_vmm_vr * vr);
191                                                   191 
192   /**                                             192   /**
193    * Called when part or all a VR is unmapped     193    * Called when part or all a VR is unmapped
194    * @note Optional                               194    * @note Optional
195    */                                             195    */
196   void (*unmap)(struct sos_umem_vmm_vr * vr,      196   void (*unmap)(struct sos_umem_vmm_vr * vr,
197                 sos_uaddr_t uaddr, sos_size_t     197                 sos_uaddr_t uaddr, sos_size_t size);
198                                                   198 
199   /**                                             199   /**
200    * Called by the page fault handler to map d    200    * Called by the page fault handler to map data at the given virtual
201    * address. In the Linux kernel, this callba    201    * address. In the Linux kernel, this callback is named "nopage".
202    *                                              202    *
203    * @note MANDATORY                              203    * @note MANDATORY
204    */                                             204    */
205   sos_ret_t (*page_in)(struct sos_umem_vmm_vr     205   sos_ret_t (*page_in)(struct sos_umem_vmm_vr * vr,
206                        sos_uaddr_t uaddr,         206                        sos_uaddr_t uaddr,
207                        sos_bool_t write_access    207                        sos_bool_t write_access);
208 };                                                208 };
209                                                   209 
210                                                   210 
211 /**                                               211 /**
212  * The definition of a mapped resource. Typica    212  * The definition of a mapped resource. Typically, a mapped resource
213  * is a file or a device: in both cases, only     213  * is a file or a device: in both cases, only part of the resource is
214  * mapped by each VR, this part is given by th    214  * mapped by each VR, this part is given by the offset_in_resource
215  * field of the VR, and the size field of the     215  * field of the VR, and the size field of the VR.
216  */                                               216  */
217 struct sos_umem_vmm_mapped_resource               217 struct sos_umem_vmm_mapped_resource
218 {                                                 218 {
219   /** Represent the maximum authrized SOS_VR_P    219   /** Represent the maximum authrized SOS_VR_PROT_* for the VRs mapping
220       it */                                       220       it */
221   sos_ui32_t  allowed_access_rights;              221   sos_ui32_t  allowed_access_rights;
222                                                   222 
223   /** Some flags associated with the resource.    223   /** Some flags associated with the resource. Currently only
224       SOS_MAPPED_RESOURCE_ANONYMOUS is support    224       SOS_MAPPED_RESOURCE_ANONYMOUS is supported */
225   sos_ui32_t  flags;                              225   sos_ui32_t  flags;
226                                                   226 
227   /** List of VRs mapping this resource */        227   /** List of VRs mapping this resource */
228   struct sos_umem_vmm_vr * list_vr;               228   struct sos_umem_vmm_vr * list_vr;
229                                                   229 
230   /**                                             230   /**
231    * MANDATORY Callback function called when a    231    * MANDATORY Callback function called when a new VR is created,
232    * which maps the resource. This callback is    232    * which maps the resource. This callback is allowed to change the
233    * following fields of the VR:                  233    * following fields of the VR:
234    *   - sos_umem_vmm_set_ops_of_vr()             234    *   - sos_umem_vmm_set_ops_of_vr()
235    */                                             235    */
236   sos_ret_t (*mmap)(struct sos_umem_vmm_vr *);    236   sos_ret_t (*mmap)(struct sos_umem_vmm_vr *);
237                                                   237 
238   /**                                             238   /**
239    * Custom data that the user is free to defi    239    * Custom data that the user is free to define: the umem_vmm
240    * subsystem won't ever look at it or change    240    * subsystem won't ever look at it or change it
241    */                                             241    */
242   void *custom_data;                              242   void *custom_data;
243 };                                                243 };
244                                                   244 
245                                                   245 
246 /** Inidicate that this resource is not backed    246 /** Inidicate that this resource is not backed by any physical
247     storage. This means that the "offset_in_re    247     storage. This means that the "offset_in_resource" field of the
248     VRs will be computed by sos_umem_vmm_map()    248     VRs will be computed by sos_umem_vmm_map() */
249 #define SOS_MAPPED_RESOURCE_ANONYMOUS (1 << 0)    249 #define SOS_MAPPED_RESOURCE_ANONYMOUS (1 << 0)
250                                                   250 
251                                                   251 
252 /**                                               252 /**
253  * Physical address of THE page (full of 0s) u    253  * Physical address of THE page (full of 0s) used for anonymous
254  * mappings. Anybody can map it provided it is    254  * mappings. Anybody can map it provided it is ALWAYS in read-only
255  * mode                                           255  * mode
256  */                                               256  */
257 extern sos_paddr_t sos_zero_physpage;          !! 257 extern sos_paddr_t sos_zero_page;
258                                                << 
259 /**                                            << 
260  * "ZERO" page address mapped in kernel space  << 
261  */                                            << 
262 extern sos_vaddr_t sos_zero_kernelpage;        << 
263                                                   258 
264                                                   259 
265 /**                                               260 /**
266  * Setup the umem_vmm subsystem.                  261  * Setup the umem_vmm subsystem.
267  */                                               262  */
268 sos_ret_t sos_umem_vmm_subsystem_setup();         263 sos_ret_t sos_umem_vmm_subsystem_setup();
269                                                   264 
270                                                   265 
271 /**                                               266 /**
272  * Create a new, empty, address space             267  * Create a new, empty, address space
273  *                                                268  *
274  * @param owner The process that will own the     269  * @param owner The process that will own the new address space
275  *                                                270  *
276  * @note no need to call                          271  * @note no need to call
277  * sos_thread_prepare_user_space_access()/sos_    272  * sos_thread_prepare_user_space_access()/sos_thread_end_user_space_access()
278  */                                               273  */
279 struct sos_umem_vmm_as *                          274 struct sos_umem_vmm_as *
280 sos_umem_vmm_create_empty_as(struct sos_proces    275 sos_umem_vmm_create_empty_as(struct sos_process *owner);
281                                                   276 
282                                                   277 
283 /**                                               278 /**
284  * Create a new address space, copy of the cur    279  * Create a new address space, copy of the current thread's address
285  * space. All the translations belonging to pr    280  * space. All the translations belonging to private mappings are
286  * marked 'read-only' to activate the "copy-on    281  * marked 'read-only' to activate the "copy-on-write" semantics.
287  *                                                282  *
288  * @param owner The process that will hold the    283  * @param owner The process that will hold the new address space
289  *                                                284  *
290  * @note automatically calls                      285  * @note automatically calls
291  * sos_thread_prepare_user_space_access()/sos_    286  * sos_thread_prepare_user_space_access()/sos_thread_end_user_space_access()
292  */                                               287  */
293 struct sos_umem_vmm_as *                          288 struct sos_umem_vmm_as *
294 sos_umem_vmm_duplicate_current_thread_as(struc    289 sos_umem_vmm_duplicate_current_thread_as(struct sos_process *owner);
295                                                   290 
296                                                   291 
297 /**                                               292 /**
298  * Called at process deletion time, to remove     293  * Called at process deletion time, to remove all mappings present in
299  * the address space. This function not only d    294  * the address space. This function not only delete all the VR data
300  * structures, it also calls the unmap()/unref    295  * structures, it also calls the unmap()/unref() callbacks of these
301  * VRs. However, the physical pages mapped ins    296  * VRs. However, the physical pages mapped inside the address space
302  * won't be unmapped at this stage: they will     297  * won't be unmapped at this stage: they will be unmapped all in one
303  * go when the undelying mm_context will becom    298  * go when the undelying mm_context will become unused.
304  *                                                299  *
305  * @note no need to call                          300  * @note no need to call
306  * sos_thread_prepare_user_space_access()/sos_    301  * sos_thread_prepare_user_space_access()/sos_thread_end_user_space_access()
307  */                                               302  */
308 sos_ret_t                                         303 sos_ret_t
309 sos_umem_vmm_delete_as(struct sos_umem_vmm_as     304 sos_umem_vmm_delete_as(struct sos_umem_vmm_as * as);
310                                                   305 
311                                                   306 
312 /*                                                307 /*
313  * Accessor functions for the address space       308  * Accessor functions for the address space
314  */                                               309  */
315                                                   310 
316 /** Retrieve the pointer (NOT a new reference     311 /** Retrieve the pointer (NOT a new reference !) to the process owning
317     the given address space. */                   312     the given address space. */
318 struct sos_process *                              313 struct sos_process *
319 sos_umem_vmm_get_process(struct sos_umem_vmm_a    314 sos_umem_vmm_get_process(struct sos_umem_vmm_as * as);
320                                                   315 
321 /** Retrieve the pointer (NOT a new reference     316 /** Retrieve the pointer (NOT a new reference !) to the MMU
322     configuration for the given address space     317     configuration for the given address space */
323 struct sos_mm_context *                           318 struct sos_mm_context *
324 sos_umem_vmm_get_mm_context(struct sos_umem_vm    319 sos_umem_vmm_get_mm_context(struct sos_umem_vmm_as * as);
325                                                   320 
326 /** Retrieve a pointer to the VR that covers t    321 /** Retrieve a pointer to the VR that covers the given virtual address
327     in the given address space */                 322     in the given address space */
328 struct sos_umem_vmm_vr *                          323 struct sos_umem_vmm_vr *
329 sos_umem_vmm_get_vr_at_address(struct sos_umem    324 sos_umem_vmm_get_vr_at_address(struct sos_umem_vmm_as * as,
330                                sos_uaddr_t uad    325                                sos_uaddr_t uaddr);
331                                                   326 
332                                                   327 
333 /*                                                328 /*
334  * Accessor functions for the virtual regions     329  * Accessor functions for the virtual regions
335  */                                               330  */
336                                                   331 
337 /** Retrieve the address space owning the give    332 /** Retrieve the address space owning the given VR */
338 struct sos_umem_vmm_as *                          333 struct sos_umem_vmm_as *
339 sos_umem_vmm_get_as_of_vr(struct sos_umem_vmm_    334 sos_umem_vmm_get_as_of_vr(struct sos_umem_vmm_vr * vr);
340                                                   335 
341 /** Retrieve the set of callbacks of the given    336 /** Retrieve the set of callbacks of the given VR */
342 struct sos_umem_vmm_vr_ops *                      337 struct sos_umem_vmm_vr_ops *
343 sos_umem_vmm_get_ops_of_vr(struct sos_umem_vmm    338 sos_umem_vmm_get_ops_of_vr(struct sos_umem_vmm_vr * vr);
344                                                   339 
345 /** Retrieve the current protection of the giv    340 /** Retrieve the current protection of the given VR */
346 sos_ui32_t sos_umem_vmm_get_prot_of_vr(struct     341 sos_ui32_t sos_umem_vmm_get_prot_of_vr(struct sos_umem_vmm_vr * vr);
347                                                   342 
348 /** Retrieve the flags of the given VR. One wi    343 /** Retrieve the flags of the given VR. One will especially be
349     interested in the SOS_VR_MAP_SHARED bit */    344     interested in the SOS_VR_MAP_SHARED bit */
350 sos_ui32_t sos_umem_vmm_get_flags_of_vr(struct    345 sos_ui32_t sos_umem_vmm_get_flags_of_vr(struct sos_umem_vmm_vr * vr);
351                                                   346 
352 /** Retrieve the resource mapped by the VR */     347 /** Retrieve the resource mapped by the VR */
353 struct sos_umem_vmm_mapped_resource *             348 struct sos_umem_vmm_mapped_resource *
354 sos_umem_vmm_get_mapped_resource_of_vr(struct     349 sos_umem_vmm_get_mapped_resource_of_vr(struct sos_umem_vmm_vr * vr);
355                                                   350 
356 /** Retrieve the start user address for the gi    351 /** Retrieve the start user address for the given mapping */
357 sos_uaddr_t sos_umem_vmm_get_start_of_vr(struc    352 sos_uaddr_t sos_umem_vmm_get_start_of_vr(struct sos_umem_vmm_vr * vr);
358                                                   353 
359 /** Retrieve the size (in user space) of the g    354 /** Retrieve the size (in user space) of the given mapping */
360 sos_size_t sos_umem_vmm_get_size_of_vr(struct     355 sos_size_t sos_umem_vmm_get_size_of_vr(struct sos_umem_vmm_vr * vr);
361                                                   356 
362 /** Retrieve the offset in the resource of the    357 /** Retrieve the offset in the resource of the mapping */
363 sos_luoffset_t                                    358 sos_luoffset_t
364 sos_umem_vmm_get_offset_in_resource(struct sos    359 sos_umem_vmm_get_offset_in_resource(struct sos_umem_vmm_vr * vr);
365                                                   360 
366                                                   361 
367 /*                                                362 /*
368  * Restricted accessor functions. May only be     363  * Restricted accessor functions. May only be called from inside the
369  * map() callback of a VR                         364  * map() callback of a VR
370  */                                               365  */
371                                                   366 
372 /**                                               367 /**
373  * Function that is not called directly by the    368  * Function that is not called directly by the umem_subsystem: It MUST
374  * always be called by the mmap() callback of     369  * always be called by the mmap() callback of the resource being
375  * mapped (@see sos_umem_vmm_mapped_resource::    370  * mapped (@see sos_umem_vmm_mapped_resource::mmap()). The mmap()
376  * method is called at VR creation time, autom    371  * method is called at VR creation time, automatically by
377  * sos_umem_vmm_map().                            372  * sos_umem_vmm_map().
378  *                                                373  *
379  * @note The VR MUST NOT already have a set of    374  * @note The VR MUST NOT already have a set of operations (fatal error)
380  */                                               375  */
381 sos_ret_t sos_umem_vmm_set_ops_of_vr(struct so    376 sos_ret_t sos_umem_vmm_set_ops_of_vr(struct sos_umem_vmm_vr * vr,
382                                      struct so    377                                      struct sos_umem_vmm_vr_ops * ops);
383                                                   378 
384                                                   379 
385 /*                                                380 /*
386  * mmap API                                       381  * mmap API
387  */                                               382  */
388                                                   383 
389                                                   384 
390 /** sos_umem_vmm_map() flag: the address given    385 /** sos_umem_vmm_map() flag: the address given as parameter to
391     sos_umem_vmm_map() is not only a hint, it     386     sos_umem_vmm_map() is not only a hint, it is where the VR is
392     expected to be mapped */                      387     expected to be mapped */
393 #define SOS_VR_MAP_FIXED  (1 << 31)               388 #define SOS_VR_MAP_FIXED  (1 << 31)
394                                                   389 
395                                                   390 
396 /**                                               391 /**
397  * Add a new VR in the given address space, th    392  * Add a new VR in the given address space, that maps the given
398  * resource. Its semantics follows that of the    393  * resource. Its semantics follows that of the UNIX mmap() call
399  * (including SOS_VR_MAP_FIXED). Real mapping     394  * (including SOS_VR_MAP_FIXED). Real mapping in physical memory will
400  * be delayed as much as possible (demand pagi    395  * be delayed as much as possible (demand paging) and the physical
401  * pages will be shared among processes as muc    396  * pages will be shared among processes as much as possible (COW).
402  *                                                397  *
403  * @param *uaddr must be page-aligned, and can    398  * @param *uaddr must be page-aligned, and can be NULL. It stores the
404  * address of the mapping, when successful        399  * address of the mapping, when successful
405  *                                                400  *
406  * @param size The size of the mapping in user    401  * @param size The size of the mapping in user space
407  *                                                402  *
408  * @param access_rights The allowed accesses t    403  * @param access_rights The allowed accesses to the mapped resource
409  * (@see SOS_VM_MAP_PROT_* flags in hwcore/pag    404  * (@see SOS_VM_MAP_PROT_* flags in hwcore/paging.h)
410  *                                                405  *
411  * @param flags mainly: is it shared mapping (    406  * @param flags mainly: is it shared mapping (SOS_VR_MAP_SHARED) or not ?
412  *                                                407  *
413  * @param resource MUST be NON NULL, and its m    408  * @param resource MUST be NON NULL, and its mmap() method must also
414  * be NON NULL                                    409  * be NON NULL
415  *                                                410  *
416  * @param offset_in_resource where inside the     411  * @param offset_in_resource where inside the resource does the
417  * mapping start                                  412  * mapping start
418  *                                                413  *
419  * @return SOS_OK on success (address of the m    414  * @return SOS_OK on success (address of the mapping stored in uaddr)
420  *                                                415  *
421  * @note no need to call                          416  * @note no need to call
422  * sos_thread_prepare_user_space_access()/sos_    417  * sos_thread_prepare_user_space_access()/sos_thread_end_user_space_access()
423  */                                               418  */
424 sos_ret_t                                         419 sos_ret_t
425 sos_umem_vmm_map(struct sos_umem_vmm_as * as,     420 sos_umem_vmm_map(struct sos_umem_vmm_as * as,
426                  sos_uaddr_t *uaddr, sos_size_    421                  sos_uaddr_t *uaddr, sos_size_t size,
427                  sos_ui32_t access_rights,        422                  sos_ui32_t access_rights,
428                  sos_ui32_t flags,                423                  sos_ui32_t flags,
429                  struct sos_umem_vmm_mapped_re    424                  struct sos_umem_vmm_mapped_resource * resource,
430                  sos_luoffset_t offset_in_reso    425                  sos_luoffset_t offset_in_resource);
431                                                   426 
432                                                   427 
433 /**                                               428 /**
434  * Unmap the given address interval. This migh    429  * Unmap the given address interval. This might imply the partial or
435  * complete unmapping of 0, 1 or more VRs. Sam    430  * complete unmapping of 0, 1 or more VRs. Same semantics as unix
436  * munmap()                                       431  * munmap()
437  *                                                432  *
438  * @note automatically calls                      433  * @note automatically calls
439  * sos_thread_prepare_user_space_access()/sos_    434  * sos_thread_prepare_user_space_access()/sos_thread_end_user_space_access()
440  */                                               435  */
441 sos_ret_t                                         436 sos_ret_t
442 sos_umem_vmm_unmap(struct sos_umem_vmm_as * as    437 sos_umem_vmm_unmap(struct sos_umem_vmm_as * as,
443                    sos_uaddr_t uaddr, sos_size    438                    sos_uaddr_t uaddr, sos_size_t size);
444                                                   439 
445                                                   440 
446 /**                                               441 /**
447  * Change the access rights of the given addre    442  * Change the access rights of the given address interval. This might
448  * concern 0, 1 or more VRs, and result in the    443  * concern 0, 1 or more VRs, and result in the splitting in 1 or 2 VRs
449  * if they are partially concerned by the chan    444  * if they are partially concerned by the change in protection.. Same
450  * semantics as unix mprotect()                   445  * semantics as unix mprotect()
451  *                                                446  *
452  * @param new_access_rights @see SOS_VM_MAP_PR    447  * @param new_access_rights @see SOS_VM_MAP_PROT_* flags in hwcore/paging.h
453  *                                                448  *
454  * @note MAKE SURE YOU CALL                       449  * @note MAKE SURE YOU CALL
455  * sos_thread_prepare_user_space_access()/sos_    450  * sos_thread_prepare_user_space_access()/sos_thread_end_user_space_access()
456  */                                               451  */
457 sos_ret_t                                         452 sos_ret_t
458 sos_umem_vmm_chprot(struct sos_umem_vmm_as * a    453 sos_umem_vmm_chprot(struct sos_umem_vmm_as * as,
459                     sos_uaddr_t uaddr, sos_siz    454                     sos_uaddr_t uaddr, sos_size_t size,
460                     sos_ui32_t new_access_righ    455                     sos_ui32_t new_access_rights);
461                                                   456 
462                                                   457 
463                                                   458 
464 /**                                               459 /**
465  * Flag for sos_umem_vmm_resize() to indicate     460  * Flag for sos_umem_vmm_resize() to indicate that the VR being
466  * resized can be moved elsewhere if there is     461  * resized can be moved elsewhere if there is not enough room to
467  * resize it in-place                             462  * resize it in-place
468  */                                               463  */
469 #define SOS_VR_REMAP_MAYMOVE (1 << 30)            464 #define SOS_VR_REMAP_MAYMOVE (1 << 30)
470                                                   465 
471 /**                                               466 /**
472  * Lookup the region covering the old_uaddr/ol    467  * Lookup the region covering the old_uaddr/old_size interval, and
473  * resize it to match the *new_uaddr/new_size     468  * resize it to match the *new_uaddr/new_size requirements. This is a
474  * variant of Unix's mremap() that allow to re    469  * variant of Unix's mremap() that allow to resize the VR by its
475  * low-addresses (mremap only allows to resize    470  * low-addresses (mremap only allows to resize a VR by its
476  * top-address).                                  471  * top-address).
477  *                                                472  *
478  * @param old_uaddr Low address of the interva    473  * @param old_uaddr Low address of the interval covered by the VR to resize
479  *                                                474  *
480  * @param old_size Size of the interval covere    475  * @param old_size Size of the interval covered by the VR to resize
481  *                                                476  *
482  * @param new_uaddr MUST BE page-aligned ! Ini    477  * @param new_uaddr MUST BE page-aligned ! Initially: the new start
483  * address of the VR, allowing to change the l    478  * address of the VR, allowing to change the low-address. Once the
484  * function returns: the actual start address     479  * function returns: the actual start address of the VR (which might
485  * be different, due to SOS_VR_REMAP_MAYMOVE f    480  * be different, due to SOS_VR_REMAP_MAYMOVE flag, when set)
486  *                                                481  *
487  * @param new_size The size requested for the     482  * @param new_size The size requested for the VR. Might be
488  * smaller/larger than the original VR size       483  * smaller/larger than the original VR size
489  *                                                484  *
490  * @param flags Essentially: 0 or SOS_VR_REMAP    485  * @param flags Essentially: 0 or SOS_VR_REMAP_MAYMOVE
491  *                                                486  *
492  * @note MAKE SURE YOU CALL                       487  * @note MAKE SURE YOU CALL
493  * sos_thread_prepare_user_space_access()/sos_    488  * sos_thread_prepare_user_space_access()/sos_thread_end_user_space_access()
494  */                                               489  */
495 sos_ret_t                                         490 sos_ret_t
496 sos_umem_vmm_resize(struct sos_umem_vmm_as * a    491 sos_umem_vmm_resize(struct sos_umem_vmm_as * as,
497                     sos_uaddr_t old_uaddr, sos    492                     sos_uaddr_t old_uaddr, sos_size_t old_size,
498                     sos_uaddr_t /* in/out */*n    493                     sos_uaddr_t /* in/out */*new_uaddr, sos_size_t new_size,
499                     sos_ui32_t flags);            494                     sos_ui32_t flags);
500                                                   495 
501                                                   496 
502 /*                                                497 /*
503  * Heap management API (ie libc's malloc suppo    498  * Heap management API (ie libc's malloc support)
504  */                                               499  */
505                                                   500 
506 /**                                               501 /**
507  * Change the top address of the heap.            502  * Change the top address of the heap.
508  *                                                503  *
509  * @param new_top_uaddr When NULL don't change    504  * @param new_top_uaddr When NULL don't change anything. Otherwise:
510  * change the top address of the heap             505  * change the top address of the heap
511  *                                                506  *
512  * @return The top address of the heap after h    507  * @return The top address of the heap after having been updated (if
513  * ever)                                          508  * ever)
514  */                                               509  */
515 sos_uaddr_t                                       510 sos_uaddr_t
516 sos_umem_vmm_brk(struct sos_umem_vmm_as * as,     511 sos_umem_vmm_brk(struct sos_umem_vmm_as * as,
517                  sos_uaddr_t new_top_uaddr);      512                  sos_uaddr_t new_top_uaddr);
518                                                   513 
519                                                   514 
520 /*                                                515 /*
521  * Reserved functions                             516  * Reserved functions
522  */                                               517  */
523                                                   518 
524 /**                                               519 /**
525  * Called by the main page fault handler when     520  * Called by the main page fault handler when a physical page is not
526  * mapped for the given address of the current    521  * mapped for the given address of the current address space. This
527  * function is called only if:                    522  * function is called only if:
528  *  - The access (read / write) is allowed on     523  *  - The access (read / write) is allowed on this VR
529  *  - no physical page is mapped yet              524  *  - no physical page is mapped yet
530  * This function first calls the sos_paging_tr    525  * This function first calls the sos_paging_try_resolve_COW() to
531  * resolve the COW if a COW access pattern is     526  * resolve the COW if a COW access pattern is detected, and, if
532  * unsuccessful, the sos_umem_vmm_vr_ops::page    527  * unsuccessful, the sos_umem_vmm_vr_ops::page_in() method of the VR.
533  *                                                528  *
534  * @param uaddr The address that was accessed,    529  * @param uaddr The address that was accessed, causing the fault.
535  *                                                530  *
536  * @param write_access Was it write access ?      531  * @param write_access Was it write access ?
537  *                                                532  *
538  * @param user_access Was it a user access ? O    533  * @param user_access Was it a user access ? Or a kernel access (by
539  * uaccess.h functions) ?                         534  * uaccess.h functions) ?
540  *                                                535  *
541  * @return SOS_OK when the fault could be solv    536  * @return SOS_OK when the fault could be solved, ie a page could be
542  * mapped for the given address. -SOS_EFAULT o    537  * mapped for the given address. -SOS_EFAULT otherwise, meaning the
543  * faulting thread should be terminated or sig    538  * faulting thread should be terminated or signalled (SIGSEGV)
544  *                                                539  *
545  * @note: The current mm_context MUST be that     540  * @note: The current mm_context MUST be that of the current thread
546  * (which caused the exception) !                 541  * (which caused the exception) !
547  */                                               542  */
548 sos_ret_t sos_umem_vmm_try_resolve_page_fault(    543 sos_ret_t sos_umem_vmm_try_resolve_page_fault(sos_uaddr_t uaddr,
549                                                   544                                               sos_bool_t write_access,
550                                                   545                                               sos_bool_t user_access);
551                                                   546 
552                                                   547 
553                                                   548 
554 /**                                               549 /**
555  * Initialize the initial heap once the progra    550  * Initialize the initial heap once the program code/data is mapped
556  * Called by the ELF32 program loader.            551  * Called by the ELF32 program loader.
557  */                                               552  */
558 sos_ret_t                                         553 sos_ret_t
559 sos_umem_vmm_init_heap(struct sos_umem_vmm_as     554 sos_umem_vmm_init_heap(struct sos_umem_vmm_as * as,
560                        sos_uaddr_t heap_start)    555                        sos_uaddr_t heap_start);
561                                                   556 
562 #endif /* _SOS_UMEM_VMM_H_ */                     557 #endif /* _SOS_UMEM_VMM_H_ */
                                                      

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