[PATCH 4/4] arm64: add early_ioremap support
From: Mark Salter
Date: Wed Nov 27 2013 - 21:46:03 EST
Signed-off-by: Mark Salter <msalter@xxxxxxxxxx>
CC: Catalin Marinas <catalin.marinas@xxxxxxx>
CC: Will Deacon <will.deacon@xxxxxxx>
CC: Rob Landley <rob@xxxxxxxxxxx>
CC: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
CC: linux-doc@xxxxxxxxxxxxxxx
---
Documentation/arm64/memory.txt | 4 +--
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/Kbuild | 1 +
arch/arm64/include/asm/fixmap.h | 68 +++++++++++++++++++++++++++++++++++
arch/arm64/include/asm/io.h | 1 +
arch/arm64/include/asm/memory.h | 1 +
arch/arm64/kernel/early_printk.c | 8 +++--
arch/arm64/kernel/head.S | 9 ++---
arch/arm64/kernel/setup.c | 2 ++
arch/arm64/mm/ioremap.c | 77 ++++++++++++++++++++++++++++++++++++++++
arch/arm64/mm/mmu.c | 41 ---------------------
11 files changed, 162 insertions(+), 51 deletions(-)
create mode 100644 arch/arm64/include/asm/fixmap.h
diff --git a/Documentation/arm64/memory.txt b/Documentation/arm64/memory.txt
index 5e054bf..953c81e 100644
--- a/Documentation/arm64/memory.txt
+++ b/Documentation/arm64/memory.txt
@@ -35,7 +35,7 @@ ffffffbc00000000 ffffffbdffffffff 8GB vmemmap
ffffffbe00000000 ffffffbffbbfffff ~8GB [guard, future vmmemap]
-ffffffbffbc00000 ffffffbffbdfffff 2MB earlyprintk device
+ffffffbffbc00000 ffffffbffbdfffff 2MB fixed mappings
ffffffbffbe00000 ffffffbffbe0ffff 64KB PCI I/O space
@@ -60,7 +60,7 @@ fffffdfc00000000 fffffdfdffffffff 8GB vmemmap
fffffdfe00000000 fffffdfffbbfffff ~8GB [guard, future vmmemap]
-fffffdfffbc00000 fffffdfffbdfffff 2MB earlyprintk device
+fffffdfffbc00000 fffffdfffbdfffff 2MB fixed mappings
fffffdfffbe00000 fffffdfffbe0ffff 64KB PCI I/O space
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 88c8b6c1..809c1b8 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -12,6 +12,7 @@ config ARM64
select CLONE_BACKWARDS
select COMMON_CLK
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 519f89f..b7f99a3 100644
--- a/arch/arm64/include/asm/Kbuild
+++ b/arch/arm64/include/asm/Kbuild
@@ -10,6 +10,7 @@ generic-y += delay.h
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..a4b193d
--- /dev/null
+++ b/arch/arm64/include/asm/fixmap.h
@@ -0,0 +1,68 @@
+/*
+ * 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@xxxxxxxxxx>
+ *
+ * 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,
+ __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_NORMAL __pgprot(PROT_NORMAL | PTE_PXN | PTE_UXN)
+#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 4cc813e..8fb2152 100644
--- a/arch/arm64/include/asm/io.h
+++ b/arch/arm64/include/asm/io.h
@@ -27,6 +27,7 @@
#include <asm/byteorder.h>
#include <asm/barrier.h>
#include <asm/pgtable.h>
+#include <asm/early_ioremap.h>
#include <xen/xen.h>
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index 3776217..4a6d7ec 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -50,6 +50,7 @@
#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..850d9a4 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 @@ static int __init setup_early_printk(char *buf)
}
/* no options parsing yet */
- if (paddr)
- early_base = early_io_map(paddr, EARLYCON_IOBASE);
+ if (paddr) {
+ set_fixmap_io(FIX_EARLYCON, paddr);
+ early_base = (void __iomem *)fix_to_virt(FIX_EARLYCON);
+ }
printch = match->printch;
early_console = &early_console_dev;
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 7009387..03adf8f 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -411,7 +411,7 @@ ENDPROC(__calc_phys_offset)
* - 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
@@ -464,15 +464,12 @@ __create_page_tables:
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 0bc5e4c..790871a 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>
@@ -216,6 +217,7 @@ void __init setup_arch(char **cmdline_p)
*cmdline_p = boot_command_line;
+ early_ioremap_init();
parse_early_param();
arm64_memblock_init();
diff --git a/arch/arm64/mm/ioremap.c b/arch/arm64/mm/ioremap.c
index 2bb1d58..fb338ab 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)
{
@@ -98,3 +102,76 @@ void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size)
__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 = pgd_offset_k(addr);
+ pud_t *pud = pud_offset(pgd, addr);
+ pmd_t *pmd = pmd_offset(pud, addr);
+
+ return pmd;
+}
+
+static inline pte_t * __init early_ioremap_pte(unsigned long addr)
+{
+ pmd_t *pmd = early_ioremap_pmd(addr);
+ 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 f557ebb..9849f7f 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -252,47 +252,6 @@ static void __init create_mapping(phys_addr_t phys, unsigned long virt,
} 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;
--
1.8.3.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/