Kernel - MMap fixed (non-fixed mappings, bad search), SHM mmap only working

[tpg/acess2.git] / KernelLand / Kernel / drv / shm.c

diff --git a/KernelLand/Kernel/drv/shm.c b/KernelLand/Kernel/drv/shm.c
index f825a0e..da32141 100644 (file)
--- a/KernelLand/Kernel/drv/shm.c
+++ b/KernelLand/Kernel/drv/shm.c
@@ -12,6 +12,8 @@
 #include <memfs_helpers.h> 
 #include <semaphore.h>
 
+#define PAGE_COUNT(v)  (((v)+(PAGE_SIZE-1))/PAGE_SIZE)
+
 // === TYPES ===
 #define PAGES_PER_BLOCK        1024
 typedef struct sSHM_BufferBlock
@@ -23,6 +25,7 @@ typedef struct
 {
        tMemFS_FileHdr  FileHdr;
        tVFS_Node       Node;
+       size_t  nPages;
        tSHM_BufferBlock        FirstBlock;
 } tSHM_Buffer;
 
@@ -30,6 +33,7 @@ typedef struct
  int   SHM_Install(char **Arguments);
  int   SHM_Uninstall(void);
 tSHM_Buffer    *SHM_CreateBuffer(const char *Name);
+bool   SHM_AddPages(tSHM_Buffer *Buffer, size_t num);
 void   SHM_DeleteBuffer(tSHM_Buffer *Buffer);
 // - Root directory
  int   SHM_ReadDir(tVFS_Node *Node, int Id, char Dest[FILENAME_MAX]);
@@ -39,9 +43,10 @@ tVFS_Node    *SHM_MkNod(tVFS_Node *Node, const char *Name, Uint Flags);
 // - Buffers
 void   SHM_Reference(tVFS_Node *Node);
 void   SHM_Close(tVFS_Node *Node);
+off_t  SHM_Truncate(tVFS_Node *Node, off_t NewSize);
 size_t SHM_Read(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags);
 size_t SHM_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffer, Uint Flags);
- int   SHM_MMap(struct sVFS_Node *Node, off_t Offset, int Length, void *Dest);
+ int   SHM_MMap(struct sVFS_Node *Node, off_t Offset, size_t Length, void *Dest);
 
 // === GLOBALS ===
 MODULE_DEFINE(0, 0x0100, SHM, SHM_Install, SHM_Uninstall, NULL);
@@ -61,6 +66,7 @@ tVFS_NodeType gSHM_FileNodeType = {
        .Write = SHM_Write,
        .Close = SHM_Close,
        .MMap  = SHM_MMap,
+       .Truncate = SHM_Truncate,
        .Reference = SHM_Reference,
 };
 tDevFS_Driver  gSHM_DriverInfo = {
@@ -96,6 +102,40 @@ tSHM_Buffer *SHM_CreateBuffer(const char *Name)
        ret->Node.ReferenceCount = 1;
        return ret;
 }
+bool SHM_AddPages(tSHM_Buffer *Buffer, size_t num)
+{
+       tSHM_BufferBlock        *block = &Buffer->FirstBlock;
+       // Search for final block
+       size_t  idx = Buffer->nPages;
+       while( block->Next ) {
+               block = block->Next;
+               idx -= PAGES_PER_BLOCK;
+       }
+       ASSERTC(idx, <=, PAGES_PER_BLOCK);
+       
+       for( size_t i = 0; i < num; i ++ )
+       {
+               if( idx == PAGES_PER_BLOCK )
+               {
+                       block->Next = calloc(1, sizeof(tSHM_BufferBlock));
+                       if(!block->Next) {
+                               Log_Warning("SHM", "Out of memory, allocating new buffer block");
+                               return false;
+                       }
+                       block = block->Next;
+                       idx = 0;
+               }
+               ASSERT(block->Pages[idx] == 0);
+               block->Pages[idx] = MM_AllocPhys();
+               if( !block->Pages[idx] ) {
+                       Log_Warning("SHM", "Out of memory, allocating page");
+                       return false;
+               }
+               Buffer->nPages += 1;
+               idx ++;
+       }
+       return true;
+}
 void SHM_DeleteBuffer(tSHM_Buffer *Buffer)
 {
        ASSERTCR(Buffer->Node.ReferenceCount,==,0,);
@@ -185,6 +225,35 @@ void SHM_Close(tVFS_Node *Node)
                UNIMPLEMENTED();
        }
 }
+off_t SHM_Truncate(tVFS_Node *Node, off_t NewSize)
+{
+       ENTER("pNode XNewSize", Node, NewSize);
+       tSHM_Buffer     *buffer = Node->ImplPtr;
+       LOG("Node->Size = 0x%llx", Node->Size);
+       if( PAGE_COUNT(NewSize) != PAGE_COUNT(Node->Size) )
+       {
+                int    page_difference = PAGE_COUNT(NewSize) - PAGE_COUNT(Node->Size);
+               LOG("page_difference = %i", page_difference);
+               if( page_difference < 0 )
+               {
+                       // Truncate down
+                       // TODO: What if underlying pages are mapped?... should it matter?
+                       UNIMPLEMENTED();
+               }
+               else
+               {
+                       // Truncate up
+                       SHM_AddPages(buffer, page_difference);
+               }
+       }
+       else
+       {
+               LOG("Page count hasn't changed");
+       }
+       Node->Size = NewSize;
+       LEAVE('X', NewSize);
+       return NewSize;
+}
 size_t SHM_Read(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags)
 {
        UNIMPLEMENTED();
@@ -196,9 +265,38 @@ size_t SHM_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffe
        UNIMPLEMENTED();
        return -1;
 }
-int SHM_MMap(struct sVFS_Node *Node, off_t Offset, int Length, void *Dest)
+int SHM_MMap(struct sVFS_Node *Node, off_t Offset, size_t Length, void *Dest)
 {
-       UNIMPLEMENTED();
-       return 1;
+       tSHM_Buffer     *buf = Node->ImplPtr;
+       if( Offset > Node->Size )       return 1;
+       if( Offset + Length > Node->Size )      return 1;
+       
+       const int pagecount = (Length + Offset % PAGE_SIZE) / PAGE_SIZE;
+       int pagenum = Offset / PAGE_SIZE;
+       
+       tSHM_BufferBlock        *block = &buf->FirstBlock;
+       while( pagenum > PAGES_PER_BLOCK ) {
+               block = block->Next;
+               ASSERT(block);
+               pagenum -= PAGES_PER_BLOCK;
+       }
+       
+       tPage *dst = Dest;
+       for( int i = 0; i < pagecount; i ++ )
+       {
+               if( pagenum == PAGES_PER_BLOCK ) {
+                       block = block->Next;
+                       ASSERT(block);
+                       pagenum = 0;
+               }
+               
+               ASSERT(block->Pages[pagenum]);
+               LOG("%p => %i:%P", dst, pagenum, block->Pages[pagenum]);
+               MM_Map(dst, block->Pages[pagenum]);
+               
+               pagenum ++;
+               dst ++;
+       }
+       return 0;
 }