blob: 7b537fa2035dfab2ad99c189f3dafb3c55441351 [file] [log] [blame]
/*
* 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) 1995 Linus Torvalds
* Copyright (C) 1995 Waldorf Electronics
* Copyright (C) 1994, 95, 96, 97, 98, 99, 2000, 01, 02, 03 Ralf Baechle
* Copyright (C) 1996 Stoned Elipot
* Copyright (C) 1999 Silicon Graphics, Inc.
* Copyright (C) 2000, 2001, 2002, 2007 Maciej W. Rozycki
*/
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/export.h>
#include <linux/screen_info.h>
#include <linux/memblock.h>
#include <linux/initrd.h>
#include <linux/root_dev.h>
#include <linux/highmem.h>
#include <linux/console.h>
#include <linux/pfn.h>
#include <linux/debugfs.h>
#include <linux/kexec.h>
#include <linux/sizes.h>
#include <linux/device.h>
#include <linux/dma-contiguous.h>
#include <linux/decompress/generic.h>
#include <linux/of_fdt.h>
#include <linux/of_reserved_mem.h>
#include <linux/dmi.h>
#include <asm/addrspace.h>
#include <asm/bootinfo.h>
#include <asm/bugs.h>
#include <asm/cache.h>
#include <asm/cdmm.h>
#include <asm/cpu.h>
#include <asm/debug.h>
#include <asm/dma-coherence.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/smp-ops.h>
#include <asm/prom.h>
#ifdef CONFIG_MIPS_ELF_APPENDED_DTB
const char __section(.appended_dtb) __appended_dtb[0x100000];
#endif /* CONFIG_MIPS_ELF_APPENDED_DTB */
struct cpuinfo_mips cpu_data[NR_CPUS] __read_mostly;
EXPORT_SYMBOL(cpu_data);
#ifdef CONFIG_VT
struct screen_info screen_info;
#endif
/*
* Setup information
*
* These are initialized so they are in the .data section
*/
unsigned long mips_machtype __read_mostly = MACH_UNKNOWN;
EXPORT_SYMBOL(mips_machtype);
static char __initdata command_line[COMMAND_LINE_SIZE];
char __initdata arcs_cmdline[COMMAND_LINE_SIZE];
#ifdef CONFIG_CMDLINE_BOOL
static const char builtin_cmdline[] __initconst = CONFIG_CMDLINE;
#else
static const char builtin_cmdline[] __initconst = "";
#endif
/*
* mips_io_port_base is the begin of the address space to which x86 style
* I/O ports are mapped.
*/
unsigned long mips_io_port_base = -1;
EXPORT_SYMBOL(mips_io_port_base);
static struct resource code_resource = { .name = "Kernel code", };
static struct resource data_resource = { .name = "Kernel data", };
static struct resource bss_resource = { .name = "Kernel bss", };
static void *detect_magic __initdata = detect_memory_region;
#ifdef CONFIG_MIPS_AUTO_PFN_OFFSET
unsigned long ARCH_PFN_OFFSET;
EXPORT_SYMBOL(ARCH_PFN_OFFSET);
#endif
void __init add_memory_region(phys_addr_t start, phys_addr_t size, long type)
{
/*
* Note: This function only exists for historical reason,
* new code should use memblock_add or memblock_add_node instead.
*/
/*
* If the region reaches the top of the physical address space, adjust
* the size slightly so that (start + size) doesn't overflow
*/
if (start + size - 1 == PHYS_ADDR_MAX)
--size;
/* Sanity check */
if (start + size < start) {
pr_warn("Trying to add an invalid memory region, skipped\n");
return;
}
if (start < PHYS_OFFSET)
return;
memblock_add(start, size);
/* Reserve any memory except the ordinary RAM ranges. */
switch (type) {
case BOOT_MEM_RAM:
break;
case BOOT_MEM_NOMAP: /* Discard the range from the system. */
memblock_remove(start, size);
break;
default: /* Reserve the rest of the memory types at boot time */
memblock_reserve(start, size);
break;
}
}
void __init detect_memory_region(phys_addr_t start, phys_addr_t sz_min, phys_addr_t sz_max)
{
void *dm = &detect_magic;
phys_addr_t size;
for (size = sz_min; size < sz_max; size <<= 1) {
if (!memcmp(dm, dm + size, sizeof(detect_magic)))
break;
}
pr_debug("Memory: %lluMB of RAM detected at 0x%llx (min: %lluMB, max: %lluMB)\n",
((unsigned long long) size) / SZ_1M,
(unsigned long long) start,
((unsigned long long) sz_min) / SZ_1M,
((unsigned long long) sz_max) / SZ_1M);
add_memory_region(start, size, BOOT_MEM_RAM);
}
/*
* Manage initrd
*/
#ifdef CONFIG_BLK_DEV_INITRD
static int __init rd_start_early(char *p)
{
unsigned long start = memparse(p, &p);
#ifdef CONFIG_64BIT
/* Guess if the sign extension was forgotten by bootloader */
if (start < XKPHYS)
start = (int)start;
#endif
initrd_start = start;
initrd_end += start;
return 0;
}
early_param("rd_start", rd_start_early);
static int __init rd_size_early(char *p)
{
initrd_end += memparse(p, &p);
return 0;
}
early_param("rd_size", rd_size_early);
/* it returns the next free pfn after initrd */
static unsigned long __init init_initrd(void)
{
unsigned long end;
/*
* Board specific code or command line parser should have
* already set up initrd_start and initrd_end. In these cases
* perfom sanity checks and use them if all looks good.
*/
if (!initrd_start || initrd_end <= initrd_start)
goto disable;
if (initrd_start & ~PAGE_MASK) {
pr_err("initrd start must be page aligned\n");
goto disable;
}
if (initrd_start < PAGE_OFFSET) {
pr_err("initrd start < PAGE_OFFSET\n");
goto disable;
}
/*
* Sanitize initrd addresses. For example firmware
* can't guess if they need to pass them through
* 64-bits values if the kernel has been built in pure
* 32-bit. We need also to switch from KSEG0 to XKPHYS
* addresses now, so the code can now safely use __pa().
*/
end = __pa(initrd_end);
initrd_end = (unsigned long)__va(end);
initrd_start = (unsigned long)__va(__pa(initrd_start));
ROOT_DEV = Root_RAM0;
return PFN_UP(end);
disable:
initrd_start = 0;
initrd_end = 0;
return 0;
}
/* In some conditions (e.g. big endian bootloader with a little endian
kernel), the initrd might appear byte swapped. Try to detect this and
byte swap it if needed. */
static void __init maybe_bswap_initrd(void)
{
#if defined(CONFIG_CPU_CAVIUM_OCTEON)
u64 buf;
/* Check for CPIO signature */
if (!memcmp((void *)initrd_start, "070701", 6))
return;
/* Check for compressed initrd */
if (decompress_method((unsigned char *)initrd_start, 8, NULL))
return;
/* Try again with a byte swapped header */
buf = swab64p((u64 *)initrd_start);
if (!memcmp(&buf, "070701", 6) ||
decompress_method((unsigned char *)(&buf), 8, NULL)) {
unsigned long i;
pr_info("Byteswapped initrd detected\n");
for (i = initrd_start; i < ALIGN(initrd_end, 8); i += 8)
swab64s((u64 *)i);
}
#endif
}
static void __init finalize_initrd(void)
{
unsigned long size = initrd_end - initrd_start;
if (size == 0) {
printk(KERN_INFO "Initrd not found or empty");
goto disable;
}
if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
printk(KERN_ERR "Initrd extends beyond end of memory");
goto disable;
}
maybe_bswap_initrd();
memblock_reserve(__pa(initrd_start), size);
initrd_below_start_ok = 1;
pr_info("Initial ramdisk at: 0x%lx (%lu bytes)\n",
initrd_start, size);
return;
disable:
printk(KERN_CONT " - disabling initrd\n");
initrd_start = 0;
initrd_end = 0;
}
#else /* !CONFIG_BLK_DEV_INITRD */
static unsigned long __init init_initrd(void)
{
return 0;
}
#define finalize_initrd() do {} while (0)
#endif
/*
* Initialize the bootmem allocator. It also setup initrd related data
* if needed.
*/
#if defined(CONFIG_SGI_IP27) || (defined(CONFIG_CPU_LOONGSON64) && defined(CONFIG_NUMA))
static void __init bootmem_init(void)
{
init_initrd();
finalize_initrd();
}
#else /* !CONFIG_SGI_IP27 */
static void __init bootmem_init(void)
{
struct memblock_region *mem;
phys_addr_t ramstart, ramend;
ramstart = memblock_start_of_DRAM();
ramend = memblock_end_of_DRAM();
/*
* Sanity check any INITRD first. We don't take it into account
* for bootmem setup initially, rely on the end-of-kernel-code
* as our memory range starting point. Once bootmem is inited we
* will reserve the area used for the initrd.
*/
init_initrd();
/* Reserve memory occupied by kernel. */
memblock_reserve(__pa_symbol(&_text),
__pa_symbol(&_end) - __pa_symbol(&_text));
/* max_low_pfn is not a number of pages but the end pfn of low mem */
#ifdef CONFIG_MIPS_AUTO_PFN_OFFSET
ARCH_PFN_OFFSET = PFN_UP(ramstart);
#else
/*
* Reserve any memory between the start of RAM and PHYS_OFFSET
*/
if (ramstart > PHYS_OFFSET)
memblock_reserve(PHYS_OFFSET, ramstart - PHYS_OFFSET);
if (PFN_UP(ramstart) > ARCH_PFN_OFFSET) {
pr_info("Wasting %lu bytes for tracking %lu unused pages\n",
(unsigned long)((PFN_UP(ramstart) - ARCH_PFN_OFFSET) * sizeof(struct page)),
(unsigned long)(PFN_UP(ramstart) - ARCH_PFN_OFFSET));
}
#endif
min_low_pfn = ARCH_PFN_OFFSET;
max_pfn = PFN_DOWN(ramend);
for_each_memblock(memory, mem) {
unsigned long start = memblock_region_memory_base_pfn(mem);
unsigned long end = memblock_region_memory_end_pfn(mem);
/*
* Skip highmem here so we get an accurate max_low_pfn if low
* memory stops short of high memory.
* If the region overlaps HIGHMEM_START, end is clipped so
* max_pfn excludes the highmem portion.
*/
if (memblock_is_nomap(mem))
continue;
if (start >= PFN_DOWN(HIGHMEM_START))
continue;
if (end > PFN_DOWN(HIGHMEM_START))
end = PFN_DOWN(HIGHMEM_START);
if (end > max_low_pfn)
max_low_pfn = end;
}
if (min_low_pfn >= max_low_pfn)
panic("Incorrect memory mapping !!!");
if (max_pfn > PFN_DOWN(HIGHMEM_START)) {
#ifdef CONFIG_HIGHMEM
highstart_pfn = PFN_DOWN(HIGHMEM_START);
highend_pfn = max_pfn;
#else
max_low_pfn = PFN_DOWN(HIGHMEM_START);
max_pfn = max_low_pfn;
#endif
}
/*
* In any case the added to the memblock memory regions
* (highmem/lowmem, available/reserved, etc) are considered
* as present, so inform sparsemem about them.
*/
memblocks_present();
/*
* Reserve initrd memory if needed.
*/
finalize_initrd();
}
#endif /* CONFIG_SGI_IP27 */
static int usermem __initdata;
static int __init early_parse_mem(char *p)
{
phys_addr_t start, size;
/*
* If a user specifies memory size, we
* blow away any automatically generated
* size.
*/
if (usermem == 0) {
usermem = 1;
memblock_remove(memblock_start_of_DRAM(),
memblock_end_of_DRAM() - memblock_start_of_DRAM());
}
start = 0;
size = memparse(p, &p);
if (*p == '@')
start = memparse(p + 1, &p);
add_memory_region(start, size, BOOT_MEM_RAM);
return 0;
}
early_param("mem", early_parse_mem);
static int __init early_parse_memmap(char *p)
{
char *oldp;
u64 start_at, mem_size;
if (!p)
return -EINVAL;
if (!strncmp(p, "exactmap", 8)) {
pr_err("\"memmap=exactmap\" invalid on MIPS\n");
return 0;
}
oldp = p;
mem_size = memparse(p, &p);
if (p == oldp)
return -EINVAL;
if (*p == '@') {
start_at = memparse(p+1, &p);
add_memory_region(start_at, mem_size, BOOT_MEM_RAM);
} else if (*p == '#') {
pr_err("\"memmap=nn#ss\" (force ACPI data) invalid on MIPS\n");
return -EINVAL;
} else if (*p == '$') {
start_at = memparse(p+1, &p);
add_memory_region(start_at, mem_size, BOOT_MEM_RESERVED);
} else {
pr_err("\"memmap\" invalid format!\n");
return -EINVAL;
}
if (*p == '\0') {
usermem = 1;
return 0;
} else
return -EINVAL;
}
early_param("memmap", early_parse_memmap);
#ifdef CONFIG_PROC_VMCORE
unsigned long setup_elfcorehdr, setup_elfcorehdr_size;
static int __init early_parse_elfcorehdr(char *p)
{
struct memblock_region *mem;
setup_elfcorehdr = memparse(p, &p);
for_each_memblock(memory, mem) {
unsigned long start = mem->base;
unsigned long end = start + mem->size;
if (setup_elfcorehdr >= start && setup_elfcorehdr < end) {
/*
* Reserve from the elf core header to the end of
* the memory segment, that should all be kdump
* reserved memory.
*/
setup_elfcorehdr_size = end - setup_elfcorehdr;
break;
}
}
/*
* If we don't find it in the memory map, then we shouldn't
* have to worry about it, as the new kernel won't use it.
*/
return 0;
}
early_param("elfcorehdr", early_parse_elfcorehdr);
#endif
#ifdef CONFIG_KEXEC
static void __init mips_parse_crashkernel(void)
{
unsigned long long total_mem;
unsigned long long crash_size, crash_base;
int ret;
total_mem = memblock_phys_mem_size();
ret = parse_crashkernel(boot_command_line, total_mem,
&crash_size, &crash_base);
if (ret != 0 || crash_size <= 0)
return;
if (!memblock_find_in_range(crash_base, crash_base + crash_size, crash_size, 0)) {
pr_warn("Invalid memory region reserved for crash kernel\n");
return;
}
crashk_res.start = crash_base;
crashk_res.end = crash_base + crash_size - 1;
}
static void __init request_crashkernel(struct resource *res)
{
int ret;
if (crashk_res.start == crashk_res.end)
return;
ret = request_resource(res, &crashk_res);
if (!ret)
pr_info("Reserving %ldMB of memory at %ldMB for crashkernel\n",
(unsigned long)(resource_size(&crashk_res) >> 20),
(unsigned long)(crashk_res.start >> 20));
}
#else /* !defined(CONFIG_KEXEC) */
static void __init mips_parse_crashkernel(void)
{
}
static void __init request_crashkernel(struct resource *res)
{
}
#endif /* !defined(CONFIG_KEXEC) */
static void __init check_kernel_sections_mem(void)
{
phys_addr_t start = PFN_PHYS(PFN_DOWN(__pa_symbol(&_text)));
phys_addr_t size = PFN_PHYS(PFN_UP(__pa_symbol(&_end))) - start;
if (!memblock_is_region_memory(start, size)) {
pr_info("Kernel sections are not in the memory maps\n");
memblock_add(start, size);
}
}
static void __init bootcmdline_append(const char *s, size_t max)
{
if (!s[0] || !max)
return;
if (boot_command_line[0])
strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
strlcat(boot_command_line, s, max);
}
#ifdef CONFIG_OF_EARLY_FLATTREE
static int __init bootcmdline_scan_chosen(unsigned long node, const char *uname,
int depth, void *data)
{
bool *dt_bootargs = data;
const char *p;
int l;
if (depth != 1 || !data ||
(strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
return 0;
p = of_get_flat_dt_prop(node, "bootargs", &l);
if (p != NULL && l > 0) {
bootcmdline_append(p, min(l, COMMAND_LINE_SIZE));
*dt_bootargs = true;
}
return 1;
}
#endif /* CONFIG_OF_EARLY_FLATTREE */
static void __init bootcmdline_init(void)
{
bool dt_bootargs = false;
/*
* If CMDLINE_OVERRIDE is enabled then initializing the command line is
* trivial - we simply use the built-in command line unconditionally &
* unmodified.
*/
if (IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {
strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
return;
}
/*
* If the user specified a built-in command line &
* MIPS_CMDLINE_BUILTIN_EXTEND, then the built-in command line is
* prepended to arguments from the bootloader or DT so we'll copy them
* to the start of boot_command_line here. Otherwise, empty
* boot_command_line to undo anything early_init_dt_scan_chosen() did.
*/
if (IS_ENABLED(CONFIG_MIPS_CMDLINE_BUILTIN_EXTEND))
strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
else
boot_command_line[0] = 0;
#ifdef CONFIG_OF_EARLY_FLATTREE
/*
* If we're configured to take boot arguments from DT, look for those
* now.
*/
if (IS_ENABLED(CONFIG_MIPS_CMDLINE_FROM_DTB) ||
IS_ENABLED(CONFIG_MIPS_CMDLINE_DTB_EXTEND))
of_scan_flat_dt(bootcmdline_scan_chosen, &dt_bootargs);
#endif
/*
* If we didn't get any arguments from DT (regardless of whether that's
* because we weren't configured to look for them, or because we looked
* & found none) then we'll take arguments from the bootloader.
* plat_mem_setup() should have filled arcs_cmdline with arguments from
* the bootloader.
*/
if (IS_ENABLED(CONFIG_MIPS_CMDLINE_DTB_EXTEND) || !dt_bootargs)
bootcmdline_append(arcs_cmdline, COMMAND_LINE_SIZE);
/*
* If the user specified a built-in command line & we didn't already
* prepend it, we append it to boot_command_line here.
*/
if (IS_ENABLED(CONFIG_CMDLINE_BOOL) &&
!IS_ENABLED(CONFIG_MIPS_CMDLINE_BUILTIN_EXTEND))
bootcmdline_append(builtin_cmdline, COMMAND_LINE_SIZE);
}
/*
* arch_mem_init - initialize memory management subsystem
*
* o plat_mem_setup() detects the memory configuration and will record detected
* memory areas using add_memory_region.
*
* At this stage the memory configuration of the system is known to the
* kernel but generic memory management system is still entirely uninitialized.
*
* o bootmem_init()
* o sparse_init()
* o paging_init()
* o dma_contiguous_reserve()
*
* At this stage the bootmem allocator is ready to use.
*
* NOTE: historically plat_mem_setup did the entire platform initialization.
* This was rather impractical because it meant plat_mem_setup had to
* get away without any kind of memory allocator. To keep old code from
* breaking plat_setup was just renamed to plat_mem_setup and a second platform
* initialization hook for anything else was introduced.
*/
static void __init arch_mem_init(char **cmdline_p)
{
/* call board setup routine */
plat_mem_setup();
memblock_set_bottom_up(true);
bootcmdline_init();
strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
*cmdline_p = command_line;
parse_early_param();
if (usermem)
pr_info("User-defined physical RAM map overwrite\n");
check_kernel_sections_mem();
early_init_fdt_reserve_self();
early_init_fdt_scan_reserved_mem();
#ifndef CONFIG_NUMA
memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
#endif
bootmem_init();
/*
* Prevent memblock from allocating high memory.
* This cannot be done before max_low_pfn is detected, so up
* to this point is possible to only reserve physical memory
* with memblock_reserve; memblock_alloc* can be used
* only after this point
*/
memblock_set_current_limit(PFN_PHYS(max_low_pfn));
#ifdef CONFIG_PROC_VMCORE
if (setup_elfcorehdr && setup_elfcorehdr_size) {
printk(KERN_INFO "kdump reserved memory at %lx-%lx\n",
setup_elfcorehdr, setup_elfcorehdr_size);
memblock_reserve(setup_elfcorehdr, setup_elfcorehdr_size);
}
#endif
mips_parse_crashkernel();
#ifdef CONFIG_KEXEC
if (crashk_res.start != crashk_res.end)
memblock_reserve(crashk_res.start, resource_size(&crashk_res));
#endif
device_tree_init();
/*
* In order to reduce the possibility of kernel panic when failed to
* get IO TLB memory under CONFIG_SWIOTLB, it is better to allocate
* low memory as small as possible before plat_swiotlb_setup(), so
* make sparse_init() using top-down allocation.
*/
memblock_set_bottom_up(false);
sparse_init();
memblock_set_bottom_up(true);
plat_swiotlb_setup();
dma_contiguous_reserve(PFN_PHYS(max_low_pfn));
/* Reserve for hibernation. */
memblock_reserve(__pa_symbol(&__nosave_begin),
__pa_symbol(&__nosave_end) - __pa_symbol(&__nosave_begin));
fdt_init_reserved_mem();
memblock_dump_all();
early_memtest(PFN_PHYS(ARCH_PFN_OFFSET), PFN_PHYS(max_low_pfn));
}
static void __init resource_init(void)
{
struct memblock_region *region;
if (UNCAC_BASE != IO_BASE)
return;
code_resource.start = __pa_symbol(&_text);
code_resource.end = __pa_symbol(&_etext) - 1;
data_resource.start = __pa_symbol(&_etext);
data_resource.end = __pa_symbol(&_edata) - 1;
bss_resource.start = __pa_symbol(&__bss_start);
bss_resource.end = __pa_symbol(&__bss_stop) - 1;
for_each_memblock(memory, region) {
phys_addr_t start = PFN_PHYS(memblock_region_memory_base_pfn(region));
phys_addr_t end = PFN_PHYS(memblock_region_memory_end_pfn(region)) - 1;
struct resource *res;
res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES);
if (!res)
panic("%s: Failed to allocate %zu bytes\n", __func__,
sizeof(struct resource));
res->start = start;
res->end = end;
res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
res->name = "System RAM";
request_resource(&iomem_resource, res);
/*
* We don't know which RAM region contains kernel data,
* so we try it repeatedly and let the resource manager
* test it.
*/
request_resource(res, &code_resource);
request_resource(res, &data_resource);
request_resource(res, &bss_resource);
request_crashkernel(res);
}
}
#ifdef CONFIG_SMP
static void __init prefill_possible_map(void)
{
int i, possible = num_possible_cpus();
if (possible > nr_cpu_ids)
possible = nr_cpu_ids;
for (i = 0; i < possible; i++)
set_cpu_possible(i, true);
for (; i < NR_CPUS; i++)
set_cpu_possible(i, false);
nr_cpu_ids = possible;
}
#else
static inline void prefill_possible_map(void) {}
#endif
void __init setup_arch(char **cmdline_p)
{
cpu_probe();
mips_cm_probe();
prom_init();
setup_early_fdc_console();
#ifdef CONFIG_EARLY_PRINTK
setup_early_printk();
#endif
cpu_report();
check_bugs_early();
#if defined(CONFIG_VT)
#if defined(CONFIG_VGA_CONSOLE)
conswitchp = &vga_con;
#endif
#endif
arch_mem_init(cmdline_p);
dmi_setup();
resource_init();
plat_smp_setup();
prefill_possible_map();
cpu_cache_init();
paging_init();
}
unsigned long kernelsp[NR_CPUS];
unsigned long fw_arg0, fw_arg1, fw_arg2, fw_arg3;
#ifdef CONFIG_USE_OF
unsigned long fw_passed_dtb;
#endif
#ifdef CONFIG_DEBUG_FS
struct dentry *mips_debugfs_dir;
static int __init debugfs_mips(void)
{
mips_debugfs_dir = debugfs_create_dir("mips", NULL);
return 0;
}
arch_initcall(debugfs_mips);
#endif
#ifdef CONFIG_DMA_MAYBE_COHERENT
/* User defined DMA coherency from command line. */
enum coherent_io_user_state coherentio = IO_COHERENCE_DEFAULT;
EXPORT_SYMBOL_GPL(coherentio);
int hw_coherentio; /* Actual hardware supported DMA coherency setting. */
static int __init setcoherentio(char *str)
{
coherentio = IO_COHERENCE_ENABLED;
pr_info("Hardware DMA cache coherency (command line)\n");
return 0;
}
early_param("coherentio", setcoherentio);
static int __init setnocoherentio(char *str)
{
coherentio = IO_COHERENCE_DISABLED;
pr_info("Software DMA cache coherency (command line)\n");
return 0;
}
early_param("nocoherentio", setnocoherentio);
#endif