From: Octavian Purdila <tavi.purdila@xxxxxxxxx>
LKL is a non MMU architecture and hence there is not much work left to
do other than initializing the boot allocator and providing the page
and page table definitions.
The backstore memory is allocated via a host operation and the memory
size to be used is specified when the kernel is started, in the
lkl_start_kernel call.
Cc: H.K. Jerry Chu <hkchu@xxxxxxxxxx>
Cc: Levente Kurusa <levex@xxxxxxxxx>
Cc: Yuan Liu <liuyuan@xxxxxxxxxx>
Signed-off-by: Hajime Tazaki <thehajime@xxxxxxxxx>
Signed-off-by: Octavian Purdila <tavi.purdila@xxxxxxxxx>
---
arch/um/lkl/include/asm/page.h | 14 ++++++
arch/um/lkl/include/asm/pgtable.h | 57 +++++++++++++++++++++
arch/um/lkl/include/uapi/asm/host_ops.h | 5 ++
arch/um/lkl/mm/bootmem.c | 66 +++++++++++++++++++++++++
4 files changed, 142 insertions(+)
create mode 100644 arch/um/lkl/include/asm/page.h
create mode 100644 arch/um/lkl/include/asm/pgtable.h
create mode 100644 arch/um/lkl/mm/bootmem.c
diff --git a/arch/um/lkl/include/asm/page.h b/arch/um/lkl/include/asm/page.h
new file mode 100644
index 000000000000..e77f3da22031
--- /dev/null
+++ b/arch/um/lkl/include/asm/page.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_LKL_PAGE_H
+#define _ASM_LKL_PAGE_H
+
+#define CONFIG_KERNEL_RAM_BASE_ADDRESS memory_start
+
+#ifndef __ASSEMBLY__
+void free_mem(void);
+void bootmem_init(unsigned long mem_size);
+#endif
+
+#include <asm-generic/page.h>
+
+#endif /* _ASM_LKL_PAGE_H */
diff --git a/arch/um/lkl/include/asm/pgtable.h b/arch/um/lkl/include/asm/pgtable.h
new file mode 100644
index 000000000000..733beb6d53f6
--- /dev/null
+++ b/arch/um/lkl/include/asm/pgtable.h
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LKL_PGTABLE_H
+#define _LKL_PGTABLE_H
+
+#include <asm-generic/pgtable-nopud.h>
+
+/*
+ * (C) Copyright 2000-2002, Greg Ungerer <gerg@xxxxxxxxxxxx>
+ */
+
+#include <linux/slab.h>
+#include <asm/processor.h>
+#include <asm/io.h>
+
+#define pgd_present(pgd) (1)
+#define pgd_none(pgd) (0)
+#define pgd_bad(pgd) (0)
+#define pgd_clear(pgdp)
+#define kern_addr_valid(addr) (1)
+#define pmd_offset(a, b) ((void *)0)
+
+#define PAGE_NONE __pgprot(0)
+#define PAGE_SHARED __pgprot(0)
+#define PAGE_COPY __pgprot(0)
+#define PAGE_READONLY __pgprot(0)
+#define PAGE_KERNEL __pgprot(0)
+
+void paging_init(void);
+#define swapper_pg_dir ((pgd_t *)0)
+
+#define __swp_type(x) (0)
+#define __swp_offset(x) (0)
+#define __swp_entry(typ, off) ((swp_entry_t) { ((typ) | ((off) << 7)) })
+#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
+#define __swp_entry_to_pte(x) ((pte_t) { (x).val })
+
+/*
+ * ZERO_PAGE is a global shared page that is always zero: used
+ * for zero-mapped memory areas etc..
+ */
+extern void *empty_zero_page;
+#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
+
+/*
+ * All 32bit addresses are effectively valid for vmalloc...
+ * Sort of meaningless for non-VM targets.
+ */
+#define VMALLOC_START 0
+#define VMALLOC_END 0xffffffff
+#define KMAP_START 0
+#define KMAP_END 0xffffffff
+
+#include <asm-generic/pgtable.h>
+
+#define check_pgt_cache() do { } while (0)
+
+#endif
diff --git a/arch/um/lkl/include/uapi/asm/host_ops.h b/arch/um/lkl/include/uapi/asm/host_ops.h
index 7cfb0a93e6a6..6bbc94c120be 100644
--- a/arch/um/lkl/include/uapi/asm/host_ops.h
+++ b/arch/um/lkl/include/uapi/asm/host_ops.h
@@ -17,8 +17,13 @@ struct lkl_jmp_buf {
* These operations must be provided by a host library or by the application
* itself.
*
+ * @mem_alloc - allocate memory
+ * @mem_free - free memory
+ *
*/
struct lkl_host_operations {
+ void *(*mem_alloc)(unsigned long mem);
+ void (*mem_free)(void *mem);
};
void lkl_bug(const char *fmt, ...);
diff --git a/arch/um/lkl/mm/bootmem.c b/arch/um/lkl/mm/bootmem.c
new file mode 100644
index 000000000000..39dd0d22b44e
--- /dev/null
+++ b/arch/um/lkl/mm/bootmem.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/memblock.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+
+unsigned long memory_start, memory_end;
+static unsigned long _memory_start, mem_size;
+
+void *empty_zero_page;
+
+void __init bootmem_init(unsigned long mem_sz)
+{
+ mem_size = mem_sz;
+
+ _memory_start = (unsigned long)lkl_ops->mem_alloc(mem_size);
+ memory_start = _memory_start;
+ WARN_ON(!memory_start);
+ memory_end = memory_start + mem_size;
+
+ if (PAGE_ALIGN(memory_start) != memory_start) {
+ mem_size -= PAGE_ALIGN(memory_start) - memory_start;
+ memory_start = PAGE_ALIGN(memory_start);
+ mem_size = (mem_size / PAGE_SIZE) * PAGE_SIZE;
+ }
+ pr_info("memblock address range: 0x%lx - 0x%lx\n", memory_start,
+ memory_start + mem_size);
+ /*
+ * Give all the memory to the bootmap allocator, tell it to put the
+ * boot mem_map at the start of memory.
+ */
+ max_low_pfn = virt_to_pfn(memory_end);
+ min_low_pfn = virt_to_pfn(memory_start);
+ memblock_add(memory_start, mem_size);
+
+ empty_zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
+ memset((void *)empty_zero_page, 0, PAGE_SIZE);
+
+ {
+ unsigned long zones_size[MAX_NR_ZONES] = {0, };
+
+ zones_size[ZONE_NORMAL] = (mem_size) >> PAGE_SHIFT;
+ free_area_init(zones_size);
+ }
+}
+
+void __init mem_init(void)
+{
+ max_mapnr = (((unsigned long)high_memory) - PAGE_OFFSET) >> PAGE_SHIFT;
+ /* this will put all memory onto the freelists */
+ totalram_pages_add(memblock_free_all());
+ pr_info("Memory available: %luk/%luk RAM\n",
+ (nr_free_pages() << PAGE_SHIFT) >> 10, mem_size >> 10);
+}
+
+/*
+ * In our case __init memory is not part of the page allocator so there is
+ * nothing to free.
+ */
+void free_initmem(void)
+{
+}
+
+void free_mem(void)
+{
+ lkl_ops->mem_free((void *)_memory_start);
+}
--
2.21.0 (Apple Git-122.2)
