ARM: Add fixed PCI i/o mapping
This adds a fixed virtual mapping for PCI i/o addresses. The mapping is
located at the last 2MB of vmalloc region (0xfee00000-0xff000000). 2MB
is used to align with PMD size, but IO_SPACE_LIMIT is 1MB. The space
is reserved after .map_io and can be mapped at any time later with
pci_ioremap_io. Platforms which need early i/o mapping (e.g. for vga
console) can call pci_map_io_early in their .map_io function.
This has changed completely from the 1st implementation which only
supported creating the static mapping at .map_io.
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Nicolas Pitre <nico@linaro.org>
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index cf4528d..714a7fd 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -31,6 +31,7 @@
#include <asm/mach/arch.h>
#include <asm/mach/map.h>
+#include <asm/mach/pci.h>
#include "mm.h"
@@ -216,7 +217,7 @@
.prot_l1 = PMD_TYPE_TABLE,
.prot_sect = PROT_SECT_DEVICE | PMD_SECT_WB,
.domain = DOMAIN_IO,
- },
+ },
[MT_DEVICE_WC] = { /* ioremap_wc */
.prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_WC,
.prot_l1 = PMD_TYPE_TABLE,
@@ -783,14 +784,27 @@
create_mapping(md);
vm->addr = (void *)(md->virtual & PAGE_MASK);
vm->size = PAGE_ALIGN(md->length + (md->virtual & ~PAGE_MASK));
- vm->phys_addr = __pfn_to_phys(md->pfn);
- vm->flags = VM_IOREMAP | VM_ARM_STATIC_MAPPING;
+ vm->phys_addr = __pfn_to_phys(md->pfn);
+ vm->flags = VM_IOREMAP | VM_ARM_STATIC_MAPPING;
vm->flags |= VM_ARM_MTYPE(md->type);
vm->caller = iotable_init;
vm_area_add_early(vm++);
}
}
+void __init vm_reserve_area_early(unsigned long addr, unsigned long size,
+ void *caller)
+{
+ struct vm_struct *vm;
+
+ vm = early_alloc_aligned(sizeof(*vm), __alignof__(*vm));
+ vm->addr = (void *)addr;
+ vm->size = size;
+ vm->flags = VM_IOREMAP | VM_ARM_STATIC_MAPPING;
+ vm->caller = caller;
+ vm_area_add_early(vm);
+}
+
#ifndef CONFIG_ARM_LPAE
/*
@@ -808,14 +822,7 @@
static void __init pmd_empty_section_gap(unsigned long addr)
{
- struct vm_struct *vm;
-
- vm = early_alloc_aligned(sizeof(*vm), __alignof__(*vm));
- vm->addr = (void *)addr;
- vm->size = SECTION_SIZE;
- vm->flags = VM_IOREMAP | VM_ARM_STATIC_MAPPING;
- vm->caller = pmd_empty_section_gap;
- vm_area_add_early(vm);
+ vm_reserve_area_early(addr, SECTION_SIZE, pmd_empty_section_gap);
}
static void __init fill_pmd_gaps(void)
@@ -864,6 +871,28 @@
#define fill_pmd_gaps() do { } while (0)
#endif
+#if defined(CONFIG_PCI) && !defined(CONFIG_NEED_MACH_IO_H)
+static void __init pci_reserve_io(void)
+{
+ struct vm_struct *vm;
+ unsigned long addr;
+
+ /* we're still single threaded hence no lock needed here */
+ for (vm = vmlist; vm; vm = vm->next) {
+ if (!(vm->flags & VM_ARM_STATIC_MAPPING))
+ continue;
+ addr = (unsigned long)vm->addr;
+ addr &= ~(SZ_2M - 1);
+ if (addr == PCI_IO_VIRT_BASE)
+ return;
+
+ }
+ vm_reserve_area_early(PCI_IO_VIRT_BASE, SZ_2M, pci_reserve_io);
+}
+#else
+#define pci_reserve_io() do { } while (0)
+#endif
+
static void * __initdata vmalloc_min =
(void *)(VMALLOC_END - (240 << 20) - VMALLOC_OFFSET);
@@ -1147,6 +1176,9 @@
mdesc->map_io();
fill_pmd_gaps();
+ /* Reserve fixed i/o space in VMALLOC region */
+ pci_reserve_io();
+
/*
* Finally flush the caches and tlb to ensure that we're in a
* consistent state wrt the writebuffer. This also ensures that