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-rw-r--r--mm/early_ioremap.c303
1 files changed, 303 insertions, 0 deletions
diff --git a/mm/early_ioremap.c b/mm/early_ioremap.c
new file mode 100644
index 000000000..a0018ad1a
--- /dev/null
+++ b/mm/early_ioremap.c
@@ -0,0 +1,303 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Provide common bits of early_ioremap() support for architectures needing
+ * temporary mappings during boot before ioremap() is available.
+ *
+ * This is mostly a direct copy of the x86 early_ioremap implementation.
+ *
+ * (C) Copyright 1995 1996, 2014 Linus Torvalds
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <asm/fixmap.h>
+#include <asm/early_ioremap.h>
+
+#ifdef CONFIG_MMU
+static int early_ioremap_debug __initdata;
+
+static int __init early_ioremap_debug_setup(char *str)
+{
+ early_ioremap_debug = 1;
+
+ return 0;
+}
+early_param("early_ioremap_debug", early_ioremap_debug_setup);
+
+static int after_paging_init __initdata;
+
+pgprot_t __init __weak early_memremap_pgprot_adjust(resource_size_t phys_addr,
+ unsigned long size,
+ pgprot_t prot)
+{
+ return prot;
+}
+
+void __init __weak early_ioremap_shutdown(void)
+{
+}
+
+void __init early_ioremap_reset(void)
+{
+ early_ioremap_shutdown();
+ after_paging_init = 1;
+}
+
+/*
+ * Generally, ioremap() is available after paging_init() has been called.
+ * Architectures wanting to allow early_ioremap after paging_init() can
+ * define __late_set_fixmap and __late_clear_fixmap to do the right thing.
+ */
+#ifndef __late_set_fixmap
+static inline void __init __late_set_fixmap(enum fixed_addresses idx,
+ phys_addr_t phys, pgprot_t prot)
+{
+ BUG();
+}
+#endif
+
+#ifndef __late_clear_fixmap
+static inline void __init __late_clear_fixmap(enum fixed_addresses idx)
+{
+ BUG();
+}
+#endif
+
+static void __iomem *prev_map[FIX_BTMAPS_SLOTS] __initdata;
+static unsigned long prev_size[FIX_BTMAPS_SLOTS] __initdata;
+static unsigned long slot_virt[FIX_BTMAPS_SLOTS] __initdata;
+
+void __init early_ioremap_setup(void)
+{
+ int i;
+
+ for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
+ if (WARN_ON(prev_map[i]))
+ break;
+
+ for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
+ slot_virt[i] = __fix_to_virt(FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*i);
+}
+
+static int __init check_early_ioremap_leak(void)
+{
+ int count = 0;
+ int i;
+
+ for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
+ if (prev_map[i])
+ count++;
+
+ if (WARN(count, KERN_WARNING
+ "Debug warning: early ioremap leak of %d areas detected.\n"
+ "please boot with early_ioremap_debug and report the dmesg.\n",
+ count))
+ return 1;
+ return 0;
+}
+late_initcall(check_early_ioremap_leak);
+
+static void __init __iomem *
+__early_ioremap(resource_size_t phys_addr, unsigned long size, pgprot_t prot)
+{
+ unsigned long offset;
+ resource_size_t last_addr;
+ unsigned int nrpages;
+ enum fixed_addresses idx;
+ int i, slot;
+
+ WARN_ON(system_state >= SYSTEM_RUNNING);
+
+ slot = -1;
+ for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
+ if (!prev_map[i]) {
+ slot = i;
+ break;
+ }
+ }
+
+ if (WARN(slot < 0, "%s(%pa, %08lx) not found slot\n",
+ __func__, &phys_addr, size))
+ return NULL;
+
+ /* Don't allow wraparound or zero size */
+ last_addr = phys_addr + size - 1;
+ if (WARN_ON(!size || last_addr < phys_addr))
+ return NULL;
+
+ prev_size[slot] = size;
+ /*
+ * Mappings have to be page-aligned
+ */
+ offset = offset_in_page(phys_addr);
+ phys_addr &= PAGE_MASK;
+ size = PAGE_ALIGN(last_addr + 1) - phys_addr;
+
+ /*
+ * Mappings have to fit in the FIX_BTMAP area.
+ */
+ nrpages = size >> PAGE_SHIFT;
+ if (WARN_ON(nrpages > NR_FIX_BTMAPS))
+ return NULL;
+
+ /*
+ * Ok, go for it..
+ */
+ idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
+ while (nrpages > 0) {
+ if (after_paging_init)
+ __late_set_fixmap(idx, phys_addr, prot);
+ else
+ __early_set_fixmap(idx, phys_addr, prot);
+ phys_addr += PAGE_SIZE;
+ --idx;
+ --nrpages;
+ }
+ WARN(early_ioremap_debug, "%s(%pa, %08lx) [%d] => %08lx + %08lx\n",
+ __func__, &phys_addr, size, slot, offset, slot_virt[slot]);
+
+ prev_map[slot] = (void __iomem *)(offset + slot_virt[slot]);
+ return prev_map[slot];
+}
+
+void __init early_iounmap(void __iomem *addr, unsigned long size)
+{
+ unsigned long virt_addr;
+ unsigned long offset;
+ unsigned int nrpages;
+ enum fixed_addresses idx;
+ int i, slot;
+
+ slot = -1;
+ for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
+ if (prev_map[i] == addr) {
+ slot = i;
+ break;
+ }
+ }
+
+ if (WARN(slot < 0, "early_iounmap(%p, %08lx) not found slot\n",
+ addr, size))
+ return;
+
+ if (WARN(prev_size[slot] != size,
+ "early_iounmap(%p, %08lx) [%d] size not consistent %08lx\n",
+ addr, size, slot, prev_size[slot]))
+ return;
+
+ WARN(early_ioremap_debug, "early_iounmap(%p, %08lx) [%d]\n",
+ addr, size, slot);
+
+ virt_addr = (unsigned long)addr;
+ if (WARN_ON(virt_addr < fix_to_virt(FIX_BTMAP_BEGIN)))
+ return;
+
+ offset = offset_in_page(virt_addr);
+ nrpages = PAGE_ALIGN(offset + size) >> PAGE_SHIFT;
+
+ idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
+ while (nrpages > 0) {
+ if (after_paging_init)
+ __late_clear_fixmap(idx);
+ else
+ __early_set_fixmap(idx, 0, FIXMAP_PAGE_CLEAR);
+ --idx;
+ --nrpages;
+ }
+ prev_map[slot] = NULL;
+}
+
+/* Remap an IO device */
+void __init __iomem *
+early_ioremap(resource_size_t phys_addr, unsigned long size)
+{
+ return __early_ioremap(phys_addr, size, FIXMAP_PAGE_IO);
+}
+
+/* Remap memory */
+void __init *
+early_memremap(resource_size_t phys_addr, unsigned long size)
+{
+ pgprot_t prot = early_memremap_pgprot_adjust(phys_addr, size,
+ FIXMAP_PAGE_NORMAL);
+
+ return (__force void *)__early_ioremap(phys_addr, size, prot);
+}
+#ifdef FIXMAP_PAGE_RO
+void __init *
+early_memremap_ro(resource_size_t phys_addr, unsigned long size)
+{
+ pgprot_t prot = early_memremap_pgprot_adjust(phys_addr, size,
+ FIXMAP_PAGE_RO);
+
+ return (__force void *)__early_ioremap(phys_addr, size, prot);
+}
+#endif
+
+#ifdef CONFIG_ARCH_USE_MEMREMAP_PROT
+void __init *
+early_memremap_prot(resource_size_t phys_addr, unsigned long size,
+ unsigned long prot_val)
+{
+ return (__force void *)__early_ioremap(phys_addr, size,
+ __pgprot(prot_val));
+}
+#endif
+
+#define MAX_MAP_CHUNK (NR_FIX_BTMAPS << PAGE_SHIFT)
+
+void __init copy_from_early_mem(void *dest, phys_addr_t src, unsigned long size)
+{
+ unsigned long slop, clen;
+ char *p;
+
+ while (size) {
+ slop = offset_in_page(src);
+ clen = size;
+ if (clen > MAX_MAP_CHUNK - slop)
+ clen = MAX_MAP_CHUNK - slop;
+ p = early_memremap(src & PAGE_MASK, clen + slop);
+ memcpy(dest, p + slop, clen);
+ early_memunmap(p, clen + slop);
+ dest += clen;
+ src += clen;
+ size -= clen;
+ }
+}
+
+#else /* CONFIG_MMU */
+
+void __init __iomem *
+early_ioremap(resource_size_t phys_addr, unsigned long size)
+{
+ return (__force void __iomem *)phys_addr;
+}
+
+/* Remap memory */
+void __init *
+early_memremap(resource_size_t phys_addr, unsigned long size)
+{
+ return (void *)phys_addr;
+}
+void __init *
+early_memremap_ro(resource_size_t phys_addr, unsigned long size)
+{
+ return (void *)phys_addr;
+}
+
+void __init early_iounmap(void __iomem *addr, unsigned long size)
+{
+}
+
+#endif /* CONFIG_MMU */
+
+
+void __init early_memunmap(void *addr, unsigned long size)
+{
+ early_iounmap((__force void __iomem *)addr, size);
+}