Archived
14
0
Fork 0
This repository has been archived on 2022-02-17. You can view files and clone it, but cannot push or open issues or pull requests.
linux-2.6/arch/ia64/kernel/setup.c

1070 lines
29 KiB
C
Raw Normal View History

/*
* Architecture-specific setup.
*
* Copyright (C) 1998-2001, 2003-2004 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
* Stephane Eranian <eranian@hpl.hp.com>
* Copyright (C) 2000, 2004 Intel Corp
* Rohit Seth <rohit.seth@intel.com>
* Suresh Siddha <suresh.b.siddha@intel.com>
* Gordon Jin <gordon.jin@intel.com>
* Copyright (C) 1999 VA Linux Systems
* Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
*
* 12/26/04 S.Siddha, G.Jin, R.Seth
* Add multi-threading and multi-core detection
* 11/12/01 D.Mosberger Convert get_cpuinfo() to seq_file based show_cpuinfo().
* 04/04/00 D.Mosberger renamed cpu_initialized to cpu_online_map
* 03/31/00 R.Seth cpu_initialized and current->processor fixes
* 02/04/00 D.Mosberger some more get_cpuinfo fixes...
* 02/01/00 R.Seth fixed get_cpuinfo for SMP
* 01/07/99 S.Eranian added the support for command line argument
* 06/24/99 W.Drummond added boot_cpu_data.
* 05/28/05 Z. Menyhart Dynamic stride size for "flush_icache_range()"
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/acpi.h>
#include <linux/bootmem.h>
#include <linux/console.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/reboot.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/string.h>
#include <linux/threads.h>
#include <linux/screen_info.h>
#include <linux/dmi.h>
#include <linux/serial.h>
#include <linux/serial_core.h>
#include <linux/efi.h>
#include <linux/initrd.h>
#include <linux/pm.h>
#include <linux/cpufreq.h>
#include <linux/kexec.h>
#include <linux/crash_dump.h>
#include <asm/machvec.h>
#include <asm/mca.h>
#include <asm/meminit.h>
#include <asm/page.h>
#include <asm/paravirt.h>
#include <asm/paravirt_patch.h>
#include <asm/patch.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/sal.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/smp.h>
#include <asm/tlbflush.h>
#include <asm/unistd.h>
#include <asm/hpsim.h>
#if defined(CONFIG_SMP) && (IA64_CPU_SIZE > PAGE_SIZE)
# error "struct cpuinfo_ia64 too big!"
#endif
#ifdef CONFIG_SMP
unsigned long __per_cpu_offset[NR_CPUS];
EXPORT_SYMBOL(__per_cpu_offset);
#endif
DEFINE_PER_CPU(struct cpuinfo_ia64, ia64_cpu_info);
DEFINE_PER_CPU(unsigned long, local_per_cpu_offset);
unsigned long ia64_cycles_per_usec;
struct ia64_boot_param *ia64_boot_param;
struct screen_info screen_info;
unsigned long vga_console_iobase;
unsigned long vga_console_membase;
static struct resource data_resource = {
.name = "Kernel data",
.flags = IORESOURCE_BUSY | IORESOURCE_MEM
};
static struct resource code_resource = {
.name = "Kernel code",
.flags = IORESOURCE_BUSY | IORESOURCE_MEM
};
static struct resource bss_resource = {
.name = "Kernel bss",
.flags = IORESOURCE_BUSY | IORESOURCE_MEM
};
unsigned long ia64_max_cacheline_size;
unsigned long ia64_iobase; /* virtual address for I/O accesses */
EXPORT_SYMBOL(ia64_iobase);
struct io_space io_space[MAX_IO_SPACES];
EXPORT_SYMBOL(io_space);
unsigned int num_io_spaces;
/*
* "flush_icache_range()" needs to know what processor dependent stride size to use
* when it makes i-cache(s) coherent with d-caches.
*/
#define I_CACHE_STRIDE_SHIFT 5 /* Safest way to go: 32 bytes by 32 bytes */
unsigned long ia64_i_cache_stride_shift = ~0;
/*
* "clflush_cache_range()" needs to know what processor dependent stride size to
* use when it flushes cache lines including both d-cache and i-cache.
*/
/* Safest way to go: 32 bytes by 32 bytes */
#define CACHE_STRIDE_SHIFT 5
unsigned long ia64_cache_stride_shift = ~0;
/*
* The merge_mask variable needs to be set to (max(iommu_page_size(iommu)) - 1). This
* mask specifies a mask of address bits that must be 0 in order for two buffers to be
* mergeable by the I/O MMU (i.e., the end address of the first buffer and the start
* address of the second buffer must be aligned to (merge_mask+1) in order to be
* mergeable). By default, we assume there is no I/O MMU which can merge physically
* discontiguous buffers, so we set the merge_mask to ~0UL, which corresponds to a iommu
* page-size of 2^64.
*/
unsigned long ia64_max_iommu_merge_mask = ~0UL;
EXPORT_SYMBOL(ia64_max_iommu_merge_mask);
/*
* We use a special marker for the end of memory and it uses the extra (+1) slot
*/
struct rsvd_region rsvd_region[IA64_MAX_RSVD_REGIONS + 1] __initdata;
int num_rsvd_regions __initdata;
/*
* Filter incoming memory segments based on the primitive map created from the boot
* parameters. Segments contained in the map are removed from the memory ranges. A
* caller-specified function is called with the memory ranges that remain after filtering.
* This routine does not assume the incoming segments are sorted.
*/
int __init
filter_rsvd_memory (u64 start, u64 end, void *arg)
{
u64 range_start, range_end, prev_start;
void (*func)(unsigned long, unsigned long, int);
int i;
#if IGNORE_PFN0
if (start == PAGE_OFFSET) {
printk(KERN_WARNING "warning: skipping physical page 0\n");
start += PAGE_SIZE;
if (start >= end) return 0;
}
#endif
/*
* lowest possible address(walker uses virtual)
*/
prev_start = PAGE_OFFSET;
func = arg;
for (i = 0; i < num_rsvd_regions; ++i) {
range_start = max(start, prev_start);
range_end = min(end, rsvd_region[i].start);
if (range_start < range_end)
call_pernode_memory(__pa(range_start), range_end - range_start, func);
/* nothing more available in this segment */
if (range_end == end) return 0;
prev_start = rsvd_region[i].end;
}
/* end of memory marker allows full processing inside loop body */
return 0;
}
/*
* Similar to "filter_rsvd_memory()", but the reserved memory ranges
* are not filtered out.
*/
int __init
filter_memory(u64 start, u64 end, void *arg)
{
void (*func)(unsigned long, unsigned long, int);
#if IGNORE_PFN0
if (start == PAGE_OFFSET) {
printk(KERN_WARNING "warning: skipping physical page 0\n");
start += PAGE_SIZE;
if (start >= end)
return 0;
}
#endif
func = arg;
if (start < end)
call_pernode_memory(__pa(start), end - start, func);
return 0;
}
static void __init
sort_regions (struct rsvd_region *rsvd_region, int max)
{
int j;
/* simple bubble sorting */
while (max--) {
for (j = 0; j < max; ++j) {
if (rsvd_region[j].start > rsvd_region[j+1].start) {
struct rsvd_region tmp;
tmp = rsvd_region[j];
rsvd_region[j] = rsvd_region[j + 1];
rsvd_region[j + 1] = tmp;
}
}
}
}
/* merge overlaps */
static int __init
merge_regions (struct rsvd_region *rsvd_region, int max)
{
int i;
for (i = 1; i < max; ++i) {
if (rsvd_region[i].start >= rsvd_region[i-1].end)
continue;
if (rsvd_region[i].end > rsvd_region[i-1].end)
rsvd_region[i-1].end = rsvd_region[i].end;
--max;
memmove(&rsvd_region[i], &rsvd_region[i+1],
(max - i) * sizeof(struct rsvd_region));
}
return max;
}
/*
* Request address space for all standard resources
*/
static int __init register_memory(void)
{
code_resource.start = ia64_tpa(_text);
code_resource.end = ia64_tpa(_etext) - 1;
data_resource.start = ia64_tpa(_etext);
data_resource.end = ia64_tpa(_edata) - 1;
bss_resource.start = ia64_tpa(__bss_start);
bss_resource.end = ia64_tpa(_end) - 1;
efi_initialize_iomem_resources(&code_resource, &data_resource,
&bss_resource);
return 0;
}
__initcall(register_memory);
#ifdef CONFIG_KEXEC
[IA64] Don't reserve crashkernel memory > 4 GB Some IA64 machines map all cell-local memory above 4 GB (32 bit limit). However, in most cases, the kernel needs some memory below that limit that is DMA-capable. So in this machine configuration, the crashkernel will be reserved above 4 GB. For machines that use SWIOTLB implementation because they lack an I/O MMU the low memory is required by the SWIOTLB implementation. In that case, it doesn't make sense to reserve the crashkernel at all because it's unusable for kdump. A special case is the "hpzx1" machine vector. In theory, it has a I/O MMU, so it can be booted above 4 GB. However, in the kdump case that is not possible because of changeset 51b58e3e26ebfb8cd56825c4b396ed251f51dec9: On HP zx1 machines, the 'machvec=dig' parameter is needed for the kdump kernel to avoid problems with the HP sba iommu. The problem is that during the boot of the kdump kernel, the iommu is re-initialized, so in-flight DMA from improperly shutdown drivers causes an IOTLB miss which leads to an MCA. With kdump, the idea is to get into the kdump kernel with as little code as we can, so shutting down drivers properly is not an option. The workaround is to add 'machvec=dig' to the kdump kernel boot parameters. This makes the kdump kernel avoid using the sba iommu altogether, leaving the IOTLB intact. Any ongoing DMA falls harmlessly outside the kdump kernel. After the kdump kernel reboots, all devices will have been shutdown properly and DMA stopped. This patch pushes that functionality into the sba iommu initialization code, so that users won't have to find the obscure documentation telling them about 'machvec=dig'. This means that also for hpzx1 it's not possible to boot when all memory is above the 4 GB limit. So the only machine vectors that can handle this case are "sn2" and "uv". Signed-off-by: Bernhard Walle <bwalle@suse.de> Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-05-14 22:40:40 +00:00
/*
* This function checks if the reserved crashkernel is allowed on the specific
* IA64 machine flavour. Machines without an IO TLB use swiotlb and require
* some memory below 4 GB (i.e. in 32 bit area), see the implementation of
* lib/swiotlb.c. The hpzx1 architecture has an IO TLB but cannot use that
* in kdump case. See the comment in sba_init() in sba_iommu.c.
*
* So, the only machvec that really supports loading the kdump kernel
* over 4 GB is "sn2".
*/
static int __init check_crashkernel_memory(unsigned long pbase, size_t size)
{
if (ia64_platform_is("sn2") || ia64_platform_is("uv"))
return 1;
else
return pbase < (1UL << 32);
}
static void __init setup_crashkernel(unsigned long total, int *n)
{
unsigned long long base = 0, size = 0;
int ret;
ret = parse_crashkernel(boot_command_line, total,
&size, &base);
if (ret == 0 && size > 0) {
if (!base) {
sort_regions(rsvd_region, *n);
*n = merge_regions(rsvd_region, *n);
base = kdump_find_rsvd_region(size,
rsvd_region, *n);
}
[IA64] Don't reserve crashkernel memory > 4 GB Some IA64 machines map all cell-local memory above 4 GB (32 bit limit). However, in most cases, the kernel needs some memory below that limit that is DMA-capable. So in this machine configuration, the crashkernel will be reserved above 4 GB. For machines that use SWIOTLB implementation because they lack an I/O MMU the low memory is required by the SWIOTLB implementation. In that case, it doesn't make sense to reserve the crashkernel at all because it's unusable for kdump. A special case is the "hpzx1" machine vector. In theory, it has a I/O MMU, so it can be booted above 4 GB. However, in the kdump case that is not possible because of changeset 51b58e3e26ebfb8cd56825c4b396ed251f51dec9: On HP zx1 machines, the 'machvec=dig' parameter is needed for the kdump kernel to avoid problems with the HP sba iommu. The problem is that during the boot of the kdump kernel, the iommu is re-initialized, so in-flight DMA from improperly shutdown drivers causes an IOTLB miss which leads to an MCA. With kdump, the idea is to get into the kdump kernel with as little code as we can, so shutting down drivers properly is not an option. The workaround is to add 'machvec=dig' to the kdump kernel boot parameters. This makes the kdump kernel avoid using the sba iommu altogether, leaving the IOTLB intact. Any ongoing DMA falls harmlessly outside the kdump kernel. After the kdump kernel reboots, all devices will have been shutdown properly and DMA stopped. This patch pushes that functionality into the sba iommu initialization code, so that users won't have to find the obscure documentation telling them about 'machvec=dig'. This means that also for hpzx1 it's not possible to boot when all memory is above the 4 GB limit. So the only machine vectors that can handle this case are "sn2" and "uv". Signed-off-by: Bernhard Walle <bwalle@suse.de> Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-05-14 22:40:40 +00:00
if (!check_crashkernel_memory(base, size)) {
pr_warning("crashkernel: There would be kdump memory "
"at %ld GB but this is unusable because it "
"must\nbe below 4 GB. Change the memory "
"configuration of the machine.\n",
(unsigned long)(base >> 30));
return;
}
if (base != ~0UL) {
printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
"for crashkernel (System RAM: %ldMB)\n",
(unsigned long)(size >> 20),
(unsigned long)(base >> 20),
(unsigned long)(total >> 20));
rsvd_region[*n].start =
(unsigned long)__va(base);
rsvd_region[*n].end =
(unsigned long)__va(base + size);
(*n)++;
crashk_res.start = base;
crashk_res.end = base + size - 1;
}
}
efi_memmap_res.start = ia64_boot_param->efi_memmap;
efi_memmap_res.end = efi_memmap_res.start +
ia64_boot_param->efi_memmap_size;
boot_param_res.start = __pa(ia64_boot_param);
boot_param_res.end = boot_param_res.start +
sizeof(*ia64_boot_param);
}
#else
static inline void __init setup_crashkernel(unsigned long total, int *n)
{}
#endif
/**
* reserve_memory - setup reserved memory areas
*
* Setup the reserved memory areas set aside for the boot parameters,
* initrd, etc. There are currently %IA64_MAX_RSVD_REGIONS defined,
* see arch/ia64/include/asm/meminit.h if you need to define more.
*/
void __init
reserve_memory (void)
{
int n = 0;
unsigned long total_memory;
/*
* none of the entries in this table overlap
*/
rsvd_region[n].start = (unsigned long) ia64_boot_param;
rsvd_region[n].end = rsvd_region[n].start + sizeof(*ia64_boot_param);
n++;
rsvd_region[n].start = (unsigned long) __va(ia64_boot_param->efi_memmap);
rsvd_region[n].end = rsvd_region[n].start + ia64_boot_param->efi_memmap_size;
n++;
rsvd_region[n].start = (unsigned long) __va(ia64_boot_param->command_line);
rsvd_region[n].end = (rsvd_region[n].start
+ strlen(__va(ia64_boot_param->command_line)) + 1);
n++;
rsvd_region[n].start = (unsigned long) ia64_imva((void *)KERNEL_START);
rsvd_region[n].end = (unsigned long) ia64_imva(_end);
n++;
n += paravirt_reserve_memory(&rsvd_region[n]);
#ifdef CONFIG_BLK_DEV_INITRD
if (ia64_boot_param->initrd_start) {
rsvd_region[n].start = (unsigned long)__va(ia64_boot_param->initrd_start);
rsvd_region[n].end = rsvd_region[n].start + ia64_boot_param->initrd_size;
n++;
}
#endif
#ifdef CONFIG_CRASH_DUMP
[IA64] kexec: Use EFI_LOADER_DATA for ELF core header The address where the ELF core header is stored is passed to the secondary kernel as a kernel command line option. The memory area for this header is also marked as a separate EFI memory descriptor on ia64. The separate EFI memory descriptor is at the moment of the type EFI_UNUSABLE_MEMORY. With such a type the secondary kernel skips over the entire memory granule (config option, 16M or 64M) when detecting memory. If we are lucky we will just lose some memory, but if we happen to have data in the same granule (such as an initramfs image), then this data will never get mapped and the kernel bombs out when trying to access it. So this is an attempt to fix this by changing the EFI memory descriptor type into EFI_LOADER_DATA. This type is the same type used for the kernel data and for initramfs. In the secondary kernel we then handle the ELF core header data the same way as we handle the initramfs image. This patch contains the kernel changes to make this happen. Pretty straightforward, we reserve the area in reserve_memory(). The address for the area comes from the kernel command line and the size comes from the specialized EFI parsing function vmcore_find_descriptor_size(). The kexec-tools-testing code for this can be found here: http://lists.osdl.org/pipermail/fastboot/2007-February/005983.html Signed-off-by: Magnus Damm <magnus@valinux.co.jp> Cc: Simon Horman <horms@verge.net.au> Cc: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
2007-03-06 10:34:26 +00:00
if (reserve_elfcorehdr(&rsvd_region[n].start,
&rsvd_region[n].end) == 0)
n++;
#endif
total_memory = efi_memmap_init(&rsvd_region[n].start, &rsvd_region[n].end);
n++;
setup_crashkernel(total_memory, &n);
/* end of memory marker */
rsvd_region[n].start = ~0UL;
rsvd_region[n].end = ~0UL;
n++;
num_rsvd_regions = n;
BUG_ON(IA64_MAX_RSVD_REGIONS + 1 < n);
sort_regions(rsvd_region, num_rsvd_regions);
num_rsvd_regions = merge_regions(rsvd_region, num_rsvd_regions);
}
/**
* find_initrd - get initrd parameters from the boot parameter structure
*
* Grab the initrd start and end from the boot parameter struct given us by
* the boot loader.
*/
void __init
find_initrd (void)
{
#ifdef CONFIG_BLK_DEV_INITRD
if (ia64_boot_param->initrd_start) {
initrd_start = (unsigned long)__va(ia64_boot_param->initrd_start);
initrd_end = initrd_start+ia64_boot_param->initrd_size;
printk(KERN_INFO "Initial ramdisk at: 0x%lx (%llu bytes)\n",
initrd_start, ia64_boot_param->initrd_size);
}
#endif
}
static void __init
io_port_init (void)
{
unsigned long phys_iobase;
/*
* Set `iobase' based on the EFI memory map or, failing that, the
* value firmware left in ar.k0.
*
* Note that in ia32 mode, IN/OUT instructions use ar.k0 to compute
* the port's virtual address, so ia32_load_state() loads it with a
* user virtual address. But in ia64 mode, glibc uses the
* *physical* address in ar.k0 to mmap the appropriate area from
* /dev/mem, and the inX()/outX() interfaces use MMIO. In both
* cases, user-mode can only use the legacy 0-64K I/O port space.
*
* ar.k0 is not involved in kernel I/O port accesses, which can use
* any of the I/O port spaces and are done via MMIO using the
* virtual mmio_base from the appropriate io_space[].
*/
phys_iobase = efi_get_iobase();
if (!phys_iobase) {
phys_iobase = ia64_get_kr(IA64_KR_IO_BASE);
printk(KERN_INFO "No I/O port range found in EFI memory map, "
"falling back to AR.KR0 (0x%lx)\n", phys_iobase);
}
ia64_iobase = (unsigned long) ioremap(phys_iobase, 0);
ia64_set_kr(IA64_KR_IO_BASE, __pa(ia64_iobase));
/* setup legacy IO port space */
io_space[0].mmio_base = ia64_iobase;
io_space[0].sparse = 1;
num_io_spaces = 1;
}
/**
* early_console_setup - setup debugging console
*
* Consoles started here require little enough setup that we can start using
* them very early in the boot process, either right after the machine
* vector initialization, or even before if the drivers can detect their hw.
*
* Returns non-zero if a console couldn't be setup.
*/
static inline int __init
early_console_setup (char *cmdline)
{
int earlycons = 0;
#ifdef CONFIG_SERIAL_SGI_L1_CONSOLE
{
extern int sn_serial_console_early_setup(void);
if (!sn_serial_console_early_setup())
earlycons++;
}
#endif
#ifdef CONFIG_EFI_PCDP
if (!efi_setup_pcdp_console(cmdline))
earlycons++;
#endif
if (!simcons_register())
earlycons++;
return (earlycons) ? 0 : -1;
}
static inline void
mark_bsp_online (void)
{
#ifdef CONFIG_SMP
/* If we register an early console, allow CPU 0 to printk */
set_cpu_online(smp_processor_id(), true);
#endif
}
static __initdata int nomca;
static __init int setup_nomca(char *s)
{
nomca = 1;
return 0;
}
early_param("nomca", setup_nomca);
#ifdef CONFIG_CRASH_DUMP
int __init reserve_elfcorehdr(u64 *start, u64 *end)
[IA64] kexec: Use EFI_LOADER_DATA for ELF core header The address where the ELF core header is stored is passed to the secondary kernel as a kernel command line option. The memory area for this header is also marked as a separate EFI memory descriptor on ia64. The separate EFI memory descriptor is at the moment of the type EFI_UNUSABLE_MEMORY. With such a type the secondary kernel skips over the entire memory granule (config option, 16M or 64M) when detecting memory. If we are lucky we will just lose some memory, but if we happen to have data in the same granule (such as an initramfs image), then this data will never get mapped and the kernel bombs out when trying to access it. So this is an attempt to fix this by changing the EFI memory descriptor type into EFI_LOADER_DATA. This type is the same type used for the kernel data and for initramfs. In the secondary kernel we then handle the ELF core header data the same way as we handle the initramfs image. This patch contains the kernel changes to make this happen. Pretty straightforward, we reserve the area in reserve_memory(). The address for the area comes from the kernel command line and the size comes from the specialized EFI parsing function vmcore_find_descriptor_size(). The kexec-tools-testing code for this can be found here: http://lists.osdl.org/pipermail/fastboot/2007-February/005983.html Signed-off-by: Magnus Damm <magnus@valinux.co.jp> Cc: Simon Horman <horms@verge.net.au> Cc: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
2007-03-06 10:34:26 +00:00
{
u64 length;
[IA64] kexec: Use EFI_LOADER_DATA for ELF core header The address where the ELF core header is stored is passed to the secondary kernel as a kernel command line option. The memory area for this header is also marked as a separate EFI memory descriptor on ia64. The separate EFI memory descriptor is at the moment of the type EFI_UNUSABLE_MEMORY. With such a type the secondary kernel skips over the entire memory granule (config option, 16M or 64M) when detecting memory. If we are lucky we will just lose some memory, but if we happen to have data in the same granule (such as an initramfs image), then this data will never get mapped and the kernel bombs out when trying to access it. So this is an attempt to fix this by changing the EFI memory descriptor type into EFI_LOADER_DATA. This type is the same type used for the kernel data and for initramfs. In the secondary kernel we then handle the ELF core header data the same way as we handle the initramfs image. This patch contains the kernel changes to make this happen. Pretty straightforward, we reserve the area in reserve_memory(). The address for the area comes from the kernel command line and the size comes from the specialized EFI parsing function vmcore_find_descriptor_size(). The kexec-tools-testing code for this can be found here: http://lists.osdl.org/pipermail/fastboot/2007-February/005983.html Signed-off-by: Magnus Damm <magnus@valinux.co.jp> Cc: Simon Horman <horms@verge.net.au> Cc: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
2007-03-06 10:34:26 +00:00
/* We get the address using the kernel command line,
* but the size is extracted from the EFI tables.
* Both address and size are required for reservation
* to work properly.
*/
if (!is_vmcore_usable())
[IA64] kexec: Use EFI_LOADER_DATA for ELF core header The address where the ELF core header is stored is passed to the secondary kernel as a kernel command line option. The memory area for this header is also marked as a separate EFI memory descriptor on ia64. The separate EFI memory descriptor is at the moment of the type EFI_UNUSABLE_MEMORY. With such a type the secondary kernel skips over the entire memory granule (config option, 16M or 64M) when detecting memory. If we are lucky we will just lose some memory, but if we happen to have data in the same granule (such as an initramfs image), then this data will never get mapped and the kernel bombs out when trying to access it. So this is an attempt to fix this by changing the EFI memory descriptor type into EFI_LOADER_DATA. This type is the same type used for the kernel data and for initramfs. In the secondary kernel we then handle the ELF core header data the same way as we handle the initramfs image. This patch contains the kernel changes to make this happen. Pretty straightforward, we reserve the area in reserve_memory(). The address for the area comes from the kernel command line and the size comes from the specialized EFI parsing function vmcore_find_descriptor_size(). The kexec-tools-testing code for this can be found here: http://lists.osdl.org/pipermail/fastboot/2007-February/005983.html Signed-off-by: Magnus Damm <magnus@valinux.co.jp> Cc: Simon Horman <horms@verge.net.au> Cc: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
2007-03-06 10:34:26 +00:00
return -EINVAL;
if ((length = vmcore_find_descriptor_size(elfcorehdr_addr)) == 0) {
vmcore_unusable();
[IA64] kexec: Use EFI_LOADER_DATA for ELF core header The address where the ELF core header is stored is passed to the secondary kernel as a kernel command line option. The memory area for this header is also marked as a separate EFI memory descriptor on ia64. The separate EFI memory descriptor is at the moment of the type EFI_UNUSABLE_MEMORY. With such a type the secondary kernel skips over the entire memory granule (config option, 16M or 64M) when detecting memory. If we are lucky we will just lose some memory, but if we happen to have data in the same granule (such as an initramfs image), then this data will never get mapped and the kernel bombs out when trying to access it. So this is an attempt to fix this by changing the EFI memory descriptor type into EFI_LOADER_DATA. This type is the same type used for the kernel data and for initramfs. In the secondary kernel we then handle the ELF core header data the same way as we handle the initramfs image. This patch contains the kernel changes to make this happen. Pretty straightforward, we reserve the area in reserve_memory(). The address for the area comes from the kernel command line and the size comes from the specialized EFI parsing function vmcore_find_descriptor_size(). The kexec-tools-testing code for this can be found here: http://lists.osdl.org/pipermail/fastboot/2007-February/005983.html Signed-off-by: Magnus Damm <magnus@valinux.co.jp> Cc: Simon Horman <horms@verge.net.au> Cc: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
2007-03-06 10:34:26 +00:00
return -EINVAL;
}
*start = (unsigned long)__va(elfcorehdr_addr);
*end = *start + length;
return 0;
}
#endif /* CONFIG_PROC_VMCORE */
void __init
setup_arch (char **cmdline_p)
{
unw_init();
paravirt_arch_setup_early();
ia64_patch_vtop((u64) __start___vtop_patchlist, (u64) __end___vtop_patchlist);
paravirt_patch_apply();
*cmdline_p = __va(ia64_boot_param->command_line);
strlcpy(boot_command_line, *cmdline_p, COMMAND_LINE_SIZE);
efi_init();
io_port_init();
#ifdef CONFIG_IA64_GENERIC
/* machvec needs to be parsed from the command line
* before parse_early_param() is called to ensure
* that ia64_mv is initialised before any command line
* settings may cause console setup to occur
*/
machvec_init_from_cmdline(*cmdline_p);
#endif
parse_early_param();
if (early_console_setup(*cmdline_p) == 0)
mark_bsp_online();
#ifdef CONFIG_ACPI
/* Initialize the ACPI boot-time table parser */
acpi_table_init();
early_acpi_boot_init();
# ifdef CONFIG_ACPI_NUMA
acpi_numa_init();
# ifdef CONFIG_ACPI_HOTPLUG_CPU
prefill_possible_map();
# endif
per_cpu_scan_finalize((cpus_weight(early_cpu_possible_map) == 0 ?
32 : cpus_weight(early_cpu_possible_map)),
additional_cpus > 0 ? additional_cpus : 0);
# endif
#endif /* CONFIG_APCI_BOOT */
#ifdef CONFIG_SMP
smp_build_cpu_map();
#endif
find_memory();
/* process SAL system table: */
ia64_sal_init(__va(efi.sal_systab));
[IA64] Workaround for RSE issue Problem: An application violating the architectural rules regarding operation dependencies and having specific Register Stack Engine (RSE) state at the time of the violation, may result in an illegal operation fault and invalid RSE state. Such faults may initiate a cascade of repeated illegal operation faults within OS interruption handlers. The specific behavior is OS dependent. Implication: An application causing an illegal operation fault with specific RSE state may result in a series of illegal operation faults and an eventual OS stack overflow condition. Workaround: OS interruption handlers that switch to kernel backing store implement a check for invalid RSE state to avoid the series of illegal operation faults. The core of the workaround is the RSE_WORKAROUND code sequence inserted into each invocation of the SAVE_MIN_WITH_COVER and SAVE_MIN_WITH_COVER_R19 macros. This sequence includes hard-coded constants that depend on the number of stacked physical registers being 96. The rest of this patch consists of code to disable this workaround should this not be the case (with the presumption that if a future Itanium processor increases the number of registers, it would also remove the need for this patch). Move the start of the RBS up to a mod32 boundary to avoid some corner cases. The dispatch_illegal_op_fault code outgrew the spot it was squatting in when built with this patch and CONFIG_VIRT_CPU_ACCOUNTING=y Move it out to the end of the ivt. Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-05-27 20:23:16 +00:00
#ifdef CONFIG_ITANIUM
ia64_patch_rse((u64) __start___rse_patchlist, (u64) __end___rse_patchlist);
#else
{
unsigned long num_phys_stacked;
[IA64] Workaround for RSE issue Problem: An application violating the architectural rules regarding operation dependencies and having specific Register Stack Engine (RSE) state at the time of the violation, may result in an illegal operation fault and invalid RSE state. Such faults may initiate a cascade of repeated illegal operation faults within OS interruption handlers. The specific behavior is OS dependent. Implication: An application causing an illegal operation fault with specific RSE state may result in a series of illegal operation faults and an eventual OS stack overflow condition. Workaround: OS interruption handlers that switch to kernel backing store implement a check for invalid RSE state to avoid the series of illegal operation faults. The core of the workaround is the RSE_WORKAROUND code sequence inserted into each invocation of the SAVE_MIN_WITH_COVER and SAVE_MIN_WITH_COVER_R19 macros. This sequence includes hard-coded constants that depend on the number of stacked physical registers being 96. The rest of this patch consists of code to disable this workaround should this not be the case (with the presumption that if a future Itanium processor increases the number of registers, it would also remove the need for this patch). Move the start of the RBS up to a mod32 boundary to avoid some corner cases. The dispatch_illegal_op_fault code outgrew the spot it was squatting in when built with this patch and CONFIG_VIRT_CPU_ACCOUNTING=y Move it out to the end of the ivt. Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-05-27 20:23:16 +00:00
if (ia64_pal_rse_info(&num_phys_stacked, 0) == 0 && num_phys_stacked > 96)
ia64_patch_rse((u64) __start___rse_patchlist, (u64) __end___rse_patchlist);
}
#endif
#ifdef CONFIG_SMP
cpu_physical_id(0) = hard_smp_processor_id();
#endif
cpu_init(); /* initialize the bootstrap CPU */
mmu_context_init(); /* initialize context_id bitmap */
paravirt_banner();
paravirt_arch_setup_console(cmdline_p);
#ifdef CONFIG_VT
if (!conswitchp) {
# if defined(CONFIG_DUMMY_CONSOLE)
conswitchp = &dummy_con;
# endif
# if defined(CONFIG_VGA_CONSOLE)
/*
* Non-legacy systems may route legacy VGA MMIO range to system
* memory. vga_con probes the MMIO hole, so memory looks like
* a VGA device to it. The EFI memory map can tell us if it's
* memory so we can avoid this problem.
*/
if (efi_mem_type(0xA0000) != EFI_CONVENTIONAL_MEMORY)
conswitchp = &vga_con;
# endif
}
#endif
/* enable IA-64 Machine Check Abort Handling unless disabled */
if (paravirt_arch_setup_nomca())
nomca = 1;
if (!nomca)
ia64_mca_init();
platform_setup(cmdline_p);
#ifndef CONFIG_IA64_HP_SIM
check_sal_cache_flush();
#endif
paging_init();
}
/*
* Display cpu info for all CPUs.
*/
static int
show_cpuinfo (struct seq_file *m, void *v)
{
#ifdef CONFIG_SMP
# define lpj c->loops_per_jiffy
# define cpunum c->cpu
#else
# define lpj loops_per_jiffy
# define cpunum 0
#endif
static struct {
unsigned long mask;
const char *feature_name;
} feature_bits[] = {
{ 1UL << 0, "branchlong" },
{ 1UL << 1, "spontaneous deferral"},
{ 1UL << 2, "16-byte atomic ops" }
};
char features[128], *cp, *sep;
struct cpuinfo_ia64 *c = v;
unsigned long mask;
unsigned long proc_freq;
int i, size;
mask = c->features;
/* build the feature string: */
memcpy(features, "standard", 9);
cp = features;
size = sizeof(features);
sep = "";
for (i = 0; i < ARRAY_SIZE(feature_bits) && size > 1; ++i) {
if (mask & feature_bits[i].mask) {
cp += snprintf(cp, size, "%s%s", sep,
feature_bits[i].feature_name),
sep = ", ";
mask &= ~feature_bits[i].mask;
size = sizeof(features) - (cp - features);
}
}
if (mask && size > 1) {
/* print unknown features as a hex value */
snprintf(cp, size, "%s0x%lx", sep, mask);
}
proc_freq = cpufreq_quick_get(cpunum);
if (!proc_freq)
proc_freq = c->proc_freq / 1000;
seq_printf(m,
"processor : %d\n"
"vendor : %s\n"
"arch : IA-64\n"
"family : %u\n"
"model : %u\n"
"model name : %s\n"
"revision : %u\n"
"archrev : %u\n"
"features : %s\n"
"cpu number : %lu\n"
"cpu regs : %u\n"
"cpu MHz : %lu.%03lu\n"
"itc MHz : %lu.%06lu\n"
"BogoMIPS : %lu.%02lu\n",
cpunum, c->vendor, c->family, c->model,
c->model_name, c->revision, c->archrev,
features, c->ppn, c->number,
proc_freq / 1000, proc_freq % 1000,
c->itc_freq / 1000000, c->itc_freq % 1000000,
lpj*HZ/500000, (lpj*HZ/5000) % 100);
#ifdef CONFIG_SMP
seq_printf(m, "siblings : %u\n", cpus_weight(cpu_core_map[cpunum]));
if (c->socket_id != -1)
seq_printf(m, "physical id: %u\n", c->socket_id);
if (c->threads_per_core > 1 || c->cores_per_socket > 1)
seq_printf(m,
"core id : %u\n"
"thread id : %u\n",
c->core_id, c->thread_id);
#endif
seq_printf(m,"\n");
return 0;
}
static void *
c_start (struct seq_file *m, loff_t *pos)
{
#ifdef CONFIG_SMP
while (*pos < nr_cpu_ids && !cpu_online(*pos))
++*pos;
#endif
return *pos < nr_cpu_ids ? cpu_data(*pos) : NULL;
}
static void *
c_next (struct seq_file *m, void *v, loff_t *pos)
{
++*pos;
return c_start(m, pos);
}
static void
c_stop (struct seq_file *m, void *v)
{
}
const struct seq_operations cpuinfo_op = {
.start = c_start,
.next = c_next,
.stop = c_stop,
.show = show_cpuinfo
};
#define MAX_BRANDS 8
static char brandname[MAX_BRANDS][128];
static char * __cpuinit
get_model_name(__u8 family, __u8 model)
{
static int overflow;
char brand[128];
int i;
memcpy(brand, "Unknown", 8);
if (ia64_pal_get_brand_info(brand)) {
if (family == 0x7)
memcpy(brand, "Merced", 7);
else if (family == 0x1f) switch (model) {
case 0: memcpy(brand, "McKinley", 9); break;
case 1: memcpy(brand, "Madison", 8); break;
case 2: memcpy(brand, "Madison up to 9M cache", 23); break;
}
}
for (i = 0; i < MAX_BRANDS; i++)
if (strcmp(brandname[i], brand) == 0)
return brandname[i];
for (i = 0; i < MAX_BRANDS; i++)
if (brandname[i][0] == '\0')
return strcpy(brandname[i], brand);
if (overflow++ == 0)
printk(KERN_ERR
"%s: Table overflow. Some processor model information will be missing\n",
__func__);
return "Unknown";
}
static void __cpuinit
identify_cpu (struct cpuinfo_ia64 *c)
{
union {
unsigned long bits[5];
struct {
/* id 0 & 1: */
char vendor[16];
/* id 2 */
u64 ppn; /* processor serial number */
/* id 3: */
unsigned number : 8;
unsigned revision : 8;
unsigned model : 8;
unsigned family : 8;
unsigned archrev : 8;
unsigned reserved : 24;
/* id 4: */
u64 features;
} field;
} cpuid;
pal_vm_info_1_u_t vm1;
pal_vm_info_2_u_t vm2;
pal_status_t status;
unsigned long impl_va_msb = 50, phys_addr_size = 44; /* Itanium defaults */
int i;
for (i = 0; i < 5; ++i)
cpuid.bits[i] = ia64_get_cpuid(i);
memcpy(c->vendor, cpuid.field.vendor, 16);
#ifdef CONFIG_SMP
c->cpu = smp_processor_id();
/* below default values will be overwritten by identify_siblings()
* for Multi-Threading/Multi-Core capable CPUs
*/
c->threads_per_core = c->cores_per_socket = c->num_log = 1;
c->socket_id = -1;
identify_siblings(c);
if (c->threads_per_core > smp_num_siblings)
smp_num_siblings = c->threads_per_core;
#endif
c->ppn = cpuid.field.ppn;
c->number = cpuid.field.number;
c->revision = cpuid.field.revision;
c->model = cpuid.field.model;
c->family = cpuid.field.family;
c->archrev = cpuid.field.archrev;
c->features = cpuid.field.features;
c->model_name = get_model_name(c->family, c->model);
status = ia64_pal_vm_summary(&vm1, &vm2);
if (status == PAL_STATUS_SUCCESS) {
impl_va_msb = vm2.pal_vm_info_2_s.impl_va_msb;
phys_addr_size = vm1.pal_vm_info_1_s.phys_add_size;
}
c->unimpl_va_mask = ~((7L<<61) | ((1L << (impl_va_msb + 1)) - 1));
c->unimpl_pa_mask = ~((1L<<63) | ((1L << phys_addr_size) - 1));
}
/*
* Do the following calculations:
*
* 1. the max. cache line size.
* 2. the minimum of the i-cache stride sizes for "flush_icache_range()".
* 3. the minimum of the cache stride sizes for "clflush_cache_range()".
*/
static void __cpuinit
get_cache_info(void)
{
unsigned long line_size, max = 1;
unsigned long l, levels, unique_caches;
pal_cache_config_info_t cci;
long status;
status = ia64_pal_cache_summary(&levels, &unique_caches);
if (status != 0) {
printk(KERN_ERR "%s: ia64_pal_cache_summary() failed (status=%ld)\n",
__func__, status);
max = SMP_CACHE_BYTES;
/* Safest setup for "flush_icache_range()" */
ia64_i_cache_stride_shift = I_CACHE_STRIDE_SHIFT;
/* Safest setup for "clflush_cache_range()" */
ia64_cache_stride_shift = CACHE_STRIDE_SHIFT;
goto out;
}
for (l = 0; l < levels; ++l) {
/* cache_type (data_or_unified)=2 */
status = ia64_pal_cache_config_info(l, 2, &cci);
if (status != 0) {
printk(KERN_ERR "%s: ia64_pal_cache_config_info"
"(l=%lu, 2) failed (status=%ld)\n",
__func__, l, status);
max = SMP_CACHE_BYTES;
/* The safest setup for "flush_icache_range()" */
cci.pcci_stride = I_CACHE_STRIDE_SHIFT;
/* The safest setup for "clflush_cache_range()" */
ia64_cache_stride_shift = CACHE_STRIDE_SHIFT;
cci.pcci_unified = 1;
} else {
if (cci.pcci_stride < ia64_cache_stride_shift)
ia64_cache_stride_shift = cci.pcci_stride;
line_size = 1 << cci.pcci_line_size;
if (line_size > max)
max = line_size;
}
if (!cci.pcci_unified) {
/* cache_type (instruction)=1*/
status = ia64_pal_cache_config_info(l, 1, &cci);
if (status != 0) {
printk(KERN_ERR "%s: ia64_pal_cache_config_info"
"(l=%lu, 1) failed (status=%ld)\n",
__func__, l, status);
/* The safest setup for flush_icache_range() */
cci.pcci_stride = I_CACHE_STRIDE_SHIFT;
}
}
if (cci.pcci_stride < ia64_i_cache_stride_shift)
ia64_i_cache_stride_shift = cci.pcci_stride;
}
out:
if (max > ia64_max_cacheline_size)
ia64_max_cacheline_size = max;
}
/*
* cpu_init() initializes state that is per-CPU. This function acts
* as a 'CPU state barrier', nothing should get across.
*/
void __cpuinit
cpu_init (void)
{
extern void __cpuinit ia64_mmu_init (void *);
[IA64] remove per-cpu ia64_phys_stacked_size_p8 It's not efficient to use a per-cpu variable just to store how many physical stack register a cpu has. Ever since the incarnation of ia64 up till upcoming Montecito processor, that variable has "glued" to 96. Having a variable in memory means that the kernel is burning an extra cacheline access on every syscall and kernel exit path. Such "static" value is better served with the instruction patching utility exists today. Convert ia64_phys_stacked_size_p8 into dynamic insn patching. This also has a pleasant side effect of eliminating access to per-cpu area while psr.ic=0 in the kernel exit path. (fixable for per-cpu DTC work, but why bother?) There are some concerns with the default value that the instruc- tion encoded in the kernel image. It shouldn't be concerned. The reasons are: (1) cpu_init() is called at CPU initialization. In there, we find out physical stack register size from PAL and patch two instructions in kernel exit code. The code in question can not be executed before the patching is done. (2) current implementation stores zero in ia64_phys_stacked_size_p8, and that's what the current kernel exit path loads the value with. With the new code, it is equivalent that we store reg size 96 in ia64_phys_stacked_size_p8, thus creating a better safety net. Given (1) above can never fail, having (2) is just a bonus. All in all, this patch allow one less memory reference in the kernel exit path, thus reducing syscall and interrupt return latency; and avoid polluting potential useful data in the CPU cache. Signed-off-by: Ken Chen <kenneth.w.chen@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2006-10-13 17:05:45 +00:00
static unsigned long max_num_phys_stacked = IA64_NUM_PHYS_STACK_REG;
unsigned long num_phys_stacked;
pal_vm_info_2_u_t vmi;
unsigned int max_ctx;
struct cpuinfo_ia64 *cpu_info;
void *cpu_data;
cpu_data = per_cpu_init();
#ifdef CONFIG_SMP
/*
* insert boot cpu into sibling and core mapes
* (must be done after per_cpu area is setup)
*/
if (smp_processor_id() == 0) {
cpu_set(0, per_cpu(cpu_sibling_map, 0));
cpu_set(0, cpu_core_map[0]);
} else {
/*
* Set ar.k3 so that assembly code in MCA handler can compute
* physical addresses of per cpu variables with a simple:
* phys = ar.k3 + &per_cpu_var
* and the alt-dtlb-miss handler can set per-cpu mapping into
* the TLB when needed. head.S already did this for cpu0.
*/
ia64_set_kr(IA64_KR_PER_CPU_DATA,
ia64_tpa(cpu_data) - (long) __per_cpu_start);
}
#endif
get_cache_info();
/*
* We can't pass "local_cpu_data" to identify_cpu() because we haven't called
* ia64_mmu_init() yet. And we can't call ia64_mmu_init() first because it
* depends on the data returned by identify_cpu(). We break the dependency by
* accessing cpu_data() through the canonical per-CPU address.
*/
cpu_info = cpu_data + ((char *) &__ia64_per_cpu_var(ia64_cpu_info) - __per_cpu_start);
identify_cpu(cpu_info);
#ifdef CONFIG_MCKINLEY
{
# define FEATURE_SET 16
struct ia64_pal_retval iprv;
if (cpu_info->family == 0x1f) {
PAL_CALL_PHYS(iprv, PAL_PROC_GET_FEATURES, 0, FEATURE_SET, 0);
if ((iprv.status == 0) && (iprv.v0 & 0x80) && (iprv.v2 & 0x80))
PAL_CALL_PHYS(iprv, PAL_PROC_SET_FEATURES,
(iprv.v1 | 0x80), FEATURE_SET, 0);
}
}
#endif
/* Clear the stack memory reserved for pt_regs: */
memset(task_pt_regs(current), 0, sizeof(struct pt_regs));
ia64_set_kr(IA64_KR_FPU_OWNER, 0);
/*
* Initialize the page-table base register to a global
* directory with all zeroes. This ensure that we can handle
* TLB-misses to user address-space even before we created the
* first user address-space. This may happen, e.g., due to
* aggressive use of lfetch.fault.
*/
ia64_set_kr(IA64_KR_PT_BASE, __pa(ia64_imva(empty_zero_page)));
/*
* Initialize default control register to defer speculative faults except
* for those arising from TLB misses, which are not deferred. The
* kernel MUST NOT depend on a particular setting of these bits (in other words,
* the kernel must have recovery code for all speculative accesses). Turn on
* dcr.lc as per recommendation by the architecture team. Most IA-32 apps
* shouldn't be affected by this (moral: keep your ia32 locks aligned and you'll
* be fine).
*/
ia64_setreg(_IA64_REG_CR_DCR, ( IA64_DCR_DP | IA64_DCR_DK | IA64_DCR_DX | IA64_DCR_DR
| IA64_DCR_DA | IA64_DCR_DD | IA64_DCR_LC));
atomic_inc(&init_mm.mm_count);
current->active_mm = &init_mm;
BUG_ON(current->mm);
ia64_mmu_init(ia64_imva(cpu_data));
ia64_mca_cpu_init(ia64_imva(cpu_data));
/* Clear ITC to eliminate sched_clock() overflows in human time. */
ia64_set_itc(0);
/* disable all local interrupt sources: */
ia64_set_itv(1 << 16);
ia64_set_lrr0(1 << 16);
ia64_set_lrr1(1 << 16);
ia64_setreg(_IA64_REG_CR_PMV, 1 << 16);
ia64_setreg(_IA64_REG_CR_CMCV, 1 << 16);
/* clear TPR & XTP to enable all interrupt classes: */
ia64_setreg(_IA64_REG_CR_TPR, 0);
/* Clear any pending interrupts left by SAL/EFI */
while (ia64_get_ivr() != IA64_SPURIOUS_INT_VECTOR)
ia64_eoi();
#ifdef CONFIG_SMP
normal_xtp();
#endif
/* set ia64_ctx.max_rid to the maximum RID that is supported by all CPUs: */
if (ia64_pal_vm_summary(NULL, &vmi) == 0) {
max_ctx = (1U << (vmi.pal_vm_info_2_s.rid_size - 3)) - 1;
setup_ptcg_sem(vmi.pal_vm_info_2_s.max_purges, NPTCG_FROM_PAL);
} else {
printk(KERN_WARNING "cpu_init: PAL VM summary failed, assuming 18 RID bits\n");
max_ctx = (1U << 15) - 1; /* use architected minimum */
}
while (max_ctx < ia64_ctx.max_ctx) {
unsigned int old = ia64_ctx.max_ctx;
if (cmpxchg(&ia64_ctx.max_ctx, old, max_ctx) == old)
break;
}
if (ia64_pal_rse_info(&num_phys_stacked, NULL) != 0) {
printk(KERN_WARNING "cpu_init: PAL RSE info failed; assuming 96 physical "
"stacked regs\n");
num_phys_stacked = 96;
}
/* size of physical stacked register partition plus 8 bytes: */
[IA64] remove per-cpu ia64_phys_stacked_size_p8 It's not efficient to use a per-cpu variable just to store how many physical stack register a cpu has. Ever since the incarnation of ia64 up till upcoming Montecito processor, that variable has "glued" to 96. Having a variable in memory means that the kernel is burning an extra cacheline access on every syscall and kernel exit path. Such "static" value is better served with the instruction patching utility exists today. Convert ia64_phys_stacked_size_p8 into dynamic insn patching. This also has a pleasant side effect of eliminating access to per-cpu area while psr.ic=0 in the kernel exit path. (fixable for per-cpu DTC work, but why bother?) There are some concerns with the default value that the instruc- tion encoded in the kernel image. It shouldn't be concerned. The reasons are: (1) cpu_init() is called at CPU initialization. In there, we find out physical stack register size from PAL and patch two instructions in kernel exit code. The code in question can not be executed before the patching is done. (2) current implementation stores zero in ia64_phys_stacked_size_p8, and that's what the current kernel exit path loads the value with. With the new code, it is equivalent that we store reg size 96 in ia64_phys_stacked_size_p8, thus creating a better safety net. Given (1) above can never fail, having (2) is just a bonus. All in all, this patch allow one less memory reference in the kernel exit path, thus reducing syscall and interrupt return latency; and avoid polluting potential useful data in the CPU cache. Signed-off-by: Ken Chen <kenneth.w.chen@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2006-10-13 17:05:45 +00:00
if (num_phys_stacked > max_num_phys_stacked) {
ia64_patch_phys_stack_reg(num_phys_stacked*8 + 8);
max_num_phys_stacked = num_phys_stacked;
}
platform_cpu_init();
pm_idle = default_idle;
}
void __init
check_bugs (void)
{
ia64_patch_mckinley_e9((unsigned long) __start___mckinley_e9_bundles,
(unsigned long) __end___mckinley_e9_bundles);
}
static int __init run_dmi_scan(void)
{
dmi_scan_machine();
return 0;
}
core_initcall(run_dmi_scan);