From: Matthias Kruk <m@m10k.eu>
Date: Mon, 4 May 2020 08:26:15 +0000 (+0900)
Subject: kernel/arch: Add pg_dir_memset() function, enhance pg_dir_mmap() function to support... 
X-Git-Url: https://git.corax.cc/?a=commitdiff_plain;h=1a2e9344c06ba4a8b2f84cb0e5109779b4fee2e6;p=corax

kernel/arch: Add pg_dir_memset() function, enhance pg_dir_mmap() function to support mapping of virtual memory for text and data segments
---

diff --git a/kernel/arch/paging.c b/kernel/arch/paging.c
index 8e7d16e..99069e8 100644
--- a/kernel/arch/paging.c
+++ b/kernel/arch/paging.c
@@ -504,6 +504,68 @@ int pg_dir_memcpy(struct pagedir *ddir, void *dvaddr,
 	return(ret_val);
 }
 
+int _pg_dir_memset(struct pagedir *ddir, void *dvaddr, int c, u32_t n)
+{
+	int ret_val;
+	u32_t dpaddr;
+	u32_t wsize;
+
+	ret_val = _pg_dir_vpxlate(ddir, (u32_t)dvaddr, (u32_t*)&dpaddr);
+
+	if(ret_val < 0) {
+		goto gtfo;
+	}
+
+	/*
+	 * Calculate the number of bytes we can set without crossing
+	 * page boundaries, writing into possibly unrelated pages.
+	 */
+	ret_val = _pg_dir_pagesize(ddir, (u32_t)dvaddr, &wsize);
+
+	if(ret_val < 0) {
+		goto gtfo;
+	}
+
+	wsize = ALIGN((u32_t)dvaddr, wsize) - (u32_t)dvaddr;
+
+	memset((void*)dpaddr, c, wsize);
+	ret_val = (int)wsize;
+
+gtfo:
+	return(ret_val);
+}
+
+int pg_dir_memset(struct pagedir *ddir, void *dvaddr,
+		  int c, u32_t n)
+{
+	int ret_val;
+
+	ret_val = 0;
+
+	if(!ddir) {
+		/* kernel pagedir - just call memset() */
+		memset(dvaddr, c, n);
+		return((int)n);
+	}
+
+	while(n > 0) {
+		int set;
+
+		set = _pg_dir_memset(ddir, dvaddr, c, n);
+
+		if(set < 0) {
+			ret_val = set;
+			break;
+		}
+
+		dvaddr += set;
+		n -= set;
+		ret_val += set;
+	}
+
+	return(ret_val);
+}
+
 int _pg_dir_xfer(struct pagedir *ddir, void *dvaddr,
 				 struct pagedir *sdir, void *svaddr, u32_t bytes)
 {
@@ -1440,7 +1502,7 @@ int pg_dir_foreach_region(pg_dir_t *pd, int (*func)(pg_dir_t*, region_t*, void*)
 }
 
 static int _pg_dir_add_region(pg_dir_t *pd, void *base, u32_t size,
-							  u32_t type, u32_t attrs, u32_t flags)
+			      u32_t type, u32_t attrs, u32_t flags)
 {
 	struct region *reg;
 	int ret_val;
@@ -1622,48 +1684,65 @@ void pg_fault_debug(pg_dir_t *pdir, void *addr)
 	return;
 }
 
-int pg_dir_mmap(pg_dir_t *pgdir, void *addr, u32_t size, int prot, int flags, void **dst)
+int pg_dir_mmap(pg_dir_t *pgdir, void *addr, u32_t size,
+		int prot, int flags, void **dst)
 {
 	int ret_val;
 
 	ret_val = -EINVAL;
 
 	if(pgdir && dst) {
+		u32_t attrs;
+		u32_t rflags;
+		void* vaddr;
+	        void* paddr;
+
 		ret_val = -EFAULT;
 
 		/* FIXME: Lock the page directory */
 
-		if(flags & MAP_PHYS) {
-			u32_t attrs;
+		attrs = PAGE_ATTR_PRESENT;
 
-			/* map the physical memory addr:size into the page directory */
-			/* FIXME: Add another flag for identity mappings and otherwise map non-identically */
+		if(!(prot & PROT_EXEC)) {
+			attrs |= PAGE_ATTR_NO_EXEC;
+		}
 
-			attrs = PAGE_ATTR_PRESENT;
+		if(prot & PROT_WRITE) {
+			attrs |= PAGE_ATTR_WRITABLE;
+		}
 
-			if(!(prot & PROT_EXEC)) {
-				attrs |= PAGE_ATTR_NO_EXEC;
-			}
+		if(prot & PROT_READ) {
+			attrs |= PAGE_ATTR_USER;
+		}
 
-			if(prot & PROT_WRITE) {
-				attrs |= PAGE_ATTR_WRITABLE;
-			}
+		rflags = REGION_PRIV;
 
-			if(prot & PROT_READ) {
-				attrs |= PAGE_ATTR_USER;
-			}
+		if(flags & MAP_PHYS) {
+			/*
+			 * Map the physical memory addr:size into
+			 * the page directory
+			 */
 
-			ret_val = pg_dir_map(pgdir, addr, addr, size, attrs);
+			vaddr = addr;
+			paddr = addr;
+			rflags = REGION_SHARED;
+		}
 
-			if(!ret_val) {
-				/* also account for the new region */
-				ret_val = _pg_dir_add_region(pgdir, addr, size,
-											 REGION_MMAP, 0, REGION_SHARED);
+		/*
+		 * FIXME: Add another flag for identity mappings and
+		 * otherwise map non-identically
+		 */
+		ret_val = pg_dir_map(pgdir, paddr, vaddr, size, attrs);
 
-				/* or unmap if it can't be accounted for */
-				if(ret_val < 0) {
-					pg_dir_unmap(pgdir, addr, size);
-				}
+		if(!ret_val) {
+			/* also account for the new region */
+			ret_val = _pg_dir_add_region(pgdir, addr, size,
+						     REGION_MMAP, 0,
+						     rflags);
+
+			/* or unmap if it can't be accounted for */
+			if(ret_val < 0) {
+				pg_dir_unmap(pgdir, addr, size);
 			}
 		}
 
diff --git a/kernel/include/arch.h b/kernel/include/arch.h
index 4741ab2..161fed5 100644
--- a/kernel/include/arch.h
+++ b/kernel/include/arch.h
@@ -237,6 +237,7 @@ void*   pg_dir_get_ustack(pg_dir_t*);
 void*   pg_dir_sbrk(pg_dir_t*, i32_t);
 int     pg_dir_foreach_region(pg_dir_t*, int(*)(pg_dir_t*, struct region*, void*), void*);
 int     pg_dir_memcpy(pg_dir_t*, void*, pg_dir_t*, void*, u32_t);
+int     pg_dir_memset(pg_dir_t*, void*, int, u32_t);
 int     pg_dir_mmap(pg_dir_t*, void*, u32_t, int, int, void**);
 int     pg_dir_munmap(pg_dir_t*, void*, u32_t);