arm64: add early_ioremap support
Add support for early IO or memory mappings which are needed before the
normal ioremap() is usable. This also adds fixmap support for permanent
fixed mappings such as that used by the earlyprintk device register
region.
Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Borislav Petkov <borislav.petkov@amd.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit bf4b558eba920a38f91beb5ee62a8ce2628c92f7)
Signed-off-by: Mark Brown <broonie@linaro.org>
Conflicts:
arch/arm64/Kconfig
arch/arm64/mm/ioremap.c
diff --git a/Documentation/arm64/memory.txt b/Documentation/arm64/memory.txt
index 7835a54..c6941f8 100644
--- a/Documentation/arm64/memory.txt
+++ b/Documentation/arm64/memory.txt
@@ -39,7 +39,7 @@
ffffffbffb000000 ffffffbffbbfffff 12MB [guard]
-ffffffbffbc00000 ffffffbffbdfffff 2MB earlyprintk device
+ffffffbffbc00000 ffffffbffbdfffff 2MB fixed mappings
ffffffbffbe00000 ffffffbffbffffff 2MB [guard]
@@ -66,7 +66,7 @@
fffffdfffb000000 fffffdfffbbfffff 12MB [guard]
-fffffdfffbc00000 fffffdfffbdfffff 2MB earlyprintk device
+fffffdfffbc00000 fffffdfffbdfffff 2MB fixed mappings
fffffdfffbe00000 fffffdfffbffffff 2MB [guard]
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 8540eef..1eded47 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -13,6 +13,7 @@
select COMMON_CLK
select DCACHE_WORD_ACCESS
select GENERIC_CLOCKEVENTS
+ select GENERIC_EARLY_IOREMAP
select GENERIC_IOMAP
select GENERIC_IRQ_PROBE
select GENERIC_IRQ_SHOW
diff --git a/arch/arm64/include/asm/Kbuild b/arch/arm64/include/asm/Kbuild
index 53c4a29..bc5da00 100644
--- a/arch/arm64/include/asm/Kbuild
+++ b/arch/arm64/include/asm/Kbuild
@@ -10,6 +10,7 @@
generic-y += div64.h
generic-y += dma.h
generic-y += emergency-restart.h
+generic-y += early_ioremap.h
generic-y += errno.h
generic-y += ftrace.h
generic-y += hw_irq.h
diff --git a/arch/arm64/include/asm/fixmap.h b/arch/arm64/include/asm/fixmap.h
new file mode 100644
index 0000000..5f7bfe6
--- /dev/null
+++ b/arch/arm64/include/asm/fixmap.h
@@ -0,0 +1,67 @@
+/*
+ * fixmap.h: compile-time virtual memory allocation
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1998 Ingo Molnar
+ * Copyright (C) 2013 Mark Salter <msalter@redhat.com>
+ *
+ * Adapted from arch/x86_64 version.
+ *
+ */
+
+#ifndef _ASM_ARM64_FIXMAP_H
+#define _ASM_ARM64_FIXMAP_H
+
+#ifndef __ASSEMBLY__
+#include <linux/kernel.h>
+#include <asm/page.h>
+
+/*
+ * Here we define all the compile-time 'special' virtual
+ * addresses. The point is to have a constant address at
+ * compile time, but to set the physical address only
+ * in the boot process.
+ *
+ * These 'compile-time allocated' memory buffers are
+ * page-sized. Use set_fixmap(idx,phys) to associate
+ * physical memory with fixmap indices.
+ *
+ */
+enum fixed_addresses {
+ FIX_EARLYCON_MEM_BASE,
+ __end_of_permanent_fixed_addresses,
+
+ /*
+ * Temporary boot-time mappings, used by early_ioremap(),
+ * before ioremap() is functional.
+ */
+#ifdef CONFIG_ARM64_64K_PAGES
+#define NR_FIX_BTMAPS 4
+#else
+#define NR_FIX_BTMAPS 64
+#endif
+#define FIX_BTMAPS_SLOTS 7
+#define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
+
+ FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
+ FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
+ __end_of_fixed_addresses
+};
+
+#define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
+#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
+
+#define FIXMAP_PAGE_IO __pgprot(PROT_DEVICE_nGnRE)
+
+extern void __early_set_fixmap(enum fixed_addresses idx,
+ phys_addr_t phys, pgprot_t flags);
+
+#define __set_fixmap __early_set_fixmap
+
+#include <asm-generic/fixmap.h>
+
+#endif /* !__ASSEMBLY__ */
+#endif /* _ASM_ARM64_FIXMAP_H */
diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
index ad80e05..b1ee8f0 100644
--- a/arch/arm64/include/asm/io.h
+++ b/arch/arm64/include/asm/io.h
@@ -26,6 +26,7 @@
#include <asm/byteorder.h>
#include <asm/barrier.h>
#include <asm/pgtable.h>
+#include <asm/early_ioremap.h>
/*
* Generic IO read/write. These perform native-endian accesses.
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index 9abb57d..83138d2 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -49,7 +49,7 @@
#define PAGE_OFFSET (UL(0xffffffffffffffff) << (VA_BITS - 1))
#define MODULES_END (PAGE_OFFSET)
#define MODULES_VADDR (MODULES_END - SZ_64M)
-#define EARLYCON_IOBASE (MODULES_VADDR - SZ_4M)
+#define FIXADDR_TOP (MODULES_VADDR - SZ_2M - PAGE_SIZE)
#define TASK_SIZE_64 (UL(1) << VA_BITS)
#ifdef CONFIG_COMPAT
diff --git a/arch/arm64/kernel/early_printk.c b/arch/arm64/kernel/early_printk.c
index fbb6e18..ffbbdde 100644
--- a/arch/arm64/kernel/early_printk.c
+++ b/arch/arm64/kernel/early_printk.c
@@ -26,6 +26,8 @@
#include <linux/amba/serial.h>
#include <linux/serial_reg.h>
+#include <asm/fixmap.h>
+
static void __iomem *early_base;
static void (*printch)(char ch);
@@ -141,8 +143,10 @@
}
/* no options parsing yet */
- if (paddr)
- early_base = early_io_map(paddr, EARLYCON_IOBASE);
+ if (paddr) {
+ set_fixmap_io(FIX_EARLYCON_MEM_BASE, paddr);
+ early_base = (void __iomem *)fix_to_virt(FIX_EARLYCON_MEM_BASE);
+ }
printch = match->printch;
early_console = &early_console_dev;
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 6fc9fc2..1445f78 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -376,7 +376,7 @@
* - identity mapping to enable the MMU (low address, TTBR0)
* - first few MB of the kernel linear mapping to jump to once the MMU has
* been enabled, including the FDT blob (TTBR1)
- * - UART mapping if CONFIG_EARLY_PRINTK is enabled (TTBR1)
+ * - pgd entry for fixed mappings (TTBR1)
*/
__create_page_tables:
pgtbl x25, x26, x24 // idmap_pg_dir and swapper_pg_dir addresses
@@ -433,15 +433,12 @@
sub x6, x6, #1 // inclusive range
create_block_map x0, x7, x3, x5, x6
1:
-#ifdef CONFIG_EARLY_PRINTK
/*
- * Create the pgd entry for the UART mapping. The full mapping is done
- * later based earlyprintk kernel parameter.
+ * Create the pgd entry for the fixed mappings.
*/
- ldr x5, =EARLYCON_IOBASE // UART virtual address
+ ldr x5, =FIXADDR_TOP // Fixed mapping virtual address
add x0, x26, #2 * PAGE_SIZE // section table address
create_pgd_entry x26, x0, x5, x6, x7
-#endif
ret
ENDPROC(__create_page_tables)
.ltorg
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 6c87fe0..5f2e5f2 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -42,6 +42,7 @@
#include <linux/of_fdt.h>
#include <linux/of_platform.h>
+#include <asm/fixmap.h>
#include <asm/cputype.h>
#include <asm/elf.h>
#include <asm/cputable.h>
@@ -269,6 +270,7 @@
*cmdline_p = boot_command_line;
init_mem_pgprot();
+ early_ioremap_init();
parse_early_param();
diff --git a/arch/arm64/mm/ioremap.c b/arch/arm64/mm/ioremap.c
index 1725cd6..00d315a 100644
--- a/arch/arm64/mm/ioremap.c
+++ b/arch/arm64/mm/ioremap.c
@@ -25,6 +25,10 @@
#include <linux/vmalloc.h>
#include <linux/io.h>
+#include <asm/fixmap.h>
+#include <asm/tlbflush.h>
+#include <asm/pgalloc.h>
+
static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size,
pgprot_t prot, void *caller)
{
@@ -82,3 +86,95 @@
vunmap(addr);
}
EXPORT_SYMBOL(__iounmap);
+
+void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size)
+{
+ /* For normal memory we already have a cacheable mapping. */
+ if (pfn_valid(__phys_to_pfn(phys_addr)))
+ return (void __iomem *)__phys_to_virt(phys_addr);
+
+ return __ioremap_caller(phys_addr, size, __pgprot(PROT_NORMAL),
+ __builtin_return_address(0));
+}
+EXPORT_SYMBOL(ioremap_cache);
+
+#ifndef CONFIG_ARM64_64K_PAGES
+static pte_t bm_pte[PTRS_PER_PTE] __page_aligned_bss;
+#endif
+
+static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+
+ pgd = pgd_offset_k(addr);
+ BUG_ON(pgd_none(*pgd) || pgd_bad(*pgd));
+
+ pud = pud_offset(pgd, addr);
+ BUG_ON(pud_none(*pud) || pud_bad(*pud));
+
+ return pmd_offset(pud, addr);
+}
+
+static inline pte_t * __init early_ioremap_pte(unsigned long addr)
+{
+ pmd_t *pmd = early_ioremap_pmd(addr);
+
+ BUG_ON(pmd_none(*pmd) || pmd_bad(*pmd));
+
+ return pte_offset_kernel(pmd, addr);
+}
+
+void __init early_ioremap_init(void)
+{
+ pmd_t *pmd;
+
+ pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN));
+#ifndef CONFIG_ARM64_64K_PAGES
+ /* need to populate pmd for 4k pagesize only */
+ pmd_populate_kernel(&init_mm, pmd, bm_pte);
+#endif
+ /*
+ * The boot-ioremap range spans multiple pmds, for which
+ * we are not prepared:
+ */
+ BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
+ != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
+
+ if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) {
+ WARN_ON(1);
+ pr_warn("pmd %p != %p\n",
+ pmd, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END)));
+ pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
+ fix_to_virt(FIX_BTMAP_BEGIN));
+ pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n",
+ fix_to_virt(FIX_BTMAP_END));
+
+ pr_warn("FIX_BTMAP_END: %d\n", FIX_BTMAP_END);
+ pr_warn("FIX_BTMAP_BEGIN: %d\n",
+ FIX_BTMAP_BEGIN);
+ }
+
+ early_ioremap_setup();
+}
+
+void __init __early_set_fixmap(enum fixed_addresses idx,
+ phys_addr_t phys, pgprot_t flags)
+{
+ unsigned long addr = __fix_to_virt(idx);
+ pte_t *pte;
+
+ if (idx >= __end_of_fixed_addresses) {
+ BUG();
+ return;
+ }
+
+ pte = early_ioremap_pte(addr);
+
+ if (pgprot_val(flags))
+ set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
+ else {
+ pte_clear(&init_mm, addr, pte);
+ flush_tlb_kernel_range(addr, addr+PAGE_SIZE);
+ }
+}
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index ba259a0..6b7e895 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -260,47 +260,6 @@
} while (pgd++, addr = next, addr != end);
}
-#ifdef CONFIG_EARLY_PRINTK
-/*
- * Create an early I/O mapping using the pgd/pmd entries already populated
- * in head.S as this function is called too early to allocated any memory. The
- * mapping size is 2MB with 4KB pages or 64KB or 64KB pages.
- */
-void __iomem * __init early_io_map(phys_addr_t phys, unsigned long virt)
-{
- unsigned long size, mask;
- bool page64k = IS_ENABLED(CONFIG_ARM64_64K_PAGES);
- pgd_t *pgd;
- pud_t *pud;
- pmd_t *pmd;
- pte_t *pte;
-
- /*
- * No early pte entries with !ARM64_64K_PAGES configuration, so using
- * sections (pmd).
- */
- size = page64k ? PAGE_SIZE : SECTION_SIZE;
- mask = ~(size - 1);
-
- pgd = pgd_offset_k(virt);
- pud = pud_offset(pgd, virt);
- if (pud_none(*pud))
- return NULL;
- pmd = pmd_offset(pud, virt);
-
- if (page64k) {
- if (pmd_none(*pmd))
- return NULL;
- pte = pte_offset_kernel(pmd, virt);
- set_pte(pte, __pte((phys & mask) | PROT_DEVICE_nGnRE));
- } else {
- set_pmd(pmd, __pmd((phys & mask) | PROT_SECT_DEVICE_nGnRE));
- }
-
- return (void __iomem *)((virt & mask) + (phys & ~mask));
-}
-#endif
-
static void __init map_mem(void)
{
struct memblock_region *reg;