Initial commit

src/glue/arm/memory.c

@@ -0,0 +1,135 @@
+/*
+ * ARM virtual memory implementation
+ *
+ * Copyright (C) 2007 Bahadir Balban
+ */
+#include <l4/lib/list.h>
+#include <l4/lib/string.h>
+#include <l4/lib/printk.h>
+#include <l4/generic/physmem.h>
+#include <l4/generic/space.h>
+#include <l4/generic/tcb.h>
+#include INC_SUBARCH(mm.h)
+#include INC_GLUE(memlayout.h)
+#include INC_GLUE(memory.h)
+#include INC_PLAT(printascii.h)
+#include INC_PLAT(offsets.h)
+#include INC_ARCH(linker.h)
+
+/*
+ * Conversion from generic protection flags to arch-specific
+ * pte flags.
+ */
+unsigned int space_flags_to_ptflags(unsigned int flags)
+{
+	switch (flags) {
+	case MAP_USR_RW_FLAGS:
+		return __MAP_USR_RW_FLAGS;
+	case MAP_USR_RO_FLAGS:
+		return __MAP_USR_RO_FLAGS;
+	case MAP_SVC_RW_FLAGS:
+		return __MAP_SVC_RW_FLAGS;
+	case MAP_USR_IO_FLAGS:
+		return __MAP_USR_IO_FLAGS;
+	case MAP_SVC_IO_FLAGS:
+		return __MAP_SVC_IO_FLAGS;
+	default:
+		BUG();
+	}
+	BUG(); return 0;
+}
+
+#define NUM_PMD_TABLES				6
+#define NUM_PGD_TABLES				8
+
+/* Initial first level page table to provide startup mappings */
+SECTION(".kspace.pgd") pgd_table_t kspace;
+SECTION(".kspace.pmd") pmd_table_t pmd_tables[NUM_PMD_TABLES];
+
+/* A mini bitmap for boot pmd allocations */
+static int pmd_cnt;
+pmd_table_t *pmd_array;
+
+pmd_table_t *alloc_boot_pmd(void)
+{
+	pmd_table_t *pt;
+
+	if (pmd_cnt == NUM_PMD_TABLES)
+		return 0;
+
+	pt = &pmd_array[pmd_cnt++];
+	BUG_ON((unsigned long)pt & (sizeof(pmd_table_t) - 1));
+
+	return pt;
+}
+
+/*
+ * Initialises pmd allocation cache, this is called before page allocator
+ * initialises. After this call one can add page mappings via add_mapping().
+ * This also sets the alloc_pmd() global function to this boot-time version.
+ */
+void init_pmd_tables(void)
+{
+	pmd_cnt = 0;
+	pmd_array = pmd_tables;
+	memset(pmd_array, 0, NUM_PMD_TABLES * sizeof(pmd_table_t));
+}
+
+/* Clears out all entries in the initial page table */
+void init_clear_ptab(void)
+{
+	memset((void *)virt_to_phys(&kspace), 0, sizeof(pgd_table_t));
+}
+
+/* Sets up struct page array and the physical memory descriptor. */
+void paging_init(void)
+{
+	read_bootdesc();
+	physmem_init();
+	memory_init();
+	copy_bootdesc();
+}
+
+/*
+ * Copies global kernel entries into another pgd. Even for sub-pmd ranges
+ * the associated pmd entries are copied, assuming any pmds copied are
+ * applicable to all tasks in the system.
+ */
+void copy_pgd_kern_by_vrange(pgd_table_t *to, pgd_table_t *from,
+			     unsigned long start, unsigned long end)
+{
+	/* Extend sub-pmd ranges to their respective pmd boundaries */
+	start = align(start, PMD_MAP_SIZE);
+
+	if (end < start)
+		end = 0;
+
+	/* Aligning would overflow if mapping the last virtual pmd */
+	if (end < align(~0, PMD_MAP_SIZE) ||
+	    start > end) /* end may have already overflown as input */
+		end = align_up(end, PMD_MAP_SIZE);
+	else
+		end = 0;
+
+	copy_pgds_by_vrange(to, from, start, end);
+}
+
+/* Copies all standard bits that a user process should have in its pgd */
+void copy_pgd_kern_all(pgd_table_t *to)
+{
+	pgd_table_t *from = current->pgd;
+
+	copy_pgd_kern_by_vrange(to, from, KERNEL_AREA_START, KERNEL_AREA_END);
+	copy_pgd_kern_by_vrange(to, from, IO_AREA_START, IO_AREA_END);
+	copy_pgd_kern_by_vrange(to, from, USER_KIP_PAGE,
+				USER_KIP_PAGE + PAGE_SIZE);
+	copy_pgd_kern_by_vrange(to, from, ARM_HIGH_VECTOR,
+				ARM_HIGH_VECTOR + PAGE_SIZE);
+	copy_pgd_kern_by_vrange(to, from, ARM_SYSCALL_VECTOR,
+				ARM_SYSCALL_VECTOR + PAGE_SIZE);
+
+	/* We temporarily map uart registers to every process */
+	copy_pgd_kern_by_vrange(to, from, USERSPACE_UART_BASE,
+				USERSPACE_UART_BASE + PAGE_SIZE);
+}
+