x86: Move find_smp_config() earlier and avoid bootmem usage

Move the find_smp_config() call to before bootmem is initialized.
Use reserve_early() instead of reserve_bootmem() in it.

This simplifies the code, we only need to call find_smp_config()
once and can remove the now unneeded reserve parameter from
x86_init_mpparse::find_smp_config.

We thus also reduce x86's dependency on bootmem allocations.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4B0BB9F2.70907@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

4 files changed, 18 insertions, 43 deletions

diff --git a/arch/x86/kernel/apic/numaq_32.c b/arch/x86/kernel/apic/numaq_32.c
index efa00e2b850..9c0629ceb52 100644
--- a/arch/x86/kernel/apic/numaq_32.c
+++ b/arch/x86/kernel/apic/numaq_32.c
@@ -264,11 +264,6 @@ static void __init smp_read_mpc_oem(struct mpc_table *mpc)
 static __init void early_check_numaq(void)
 {
         /*
-         * Find possible boot-time SMP configuration:
-         */
-        early_find_smp_config();
-
-        /*
          * get boot-time SMP configuration:
          */
         if (smp_found_config)
diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c
index 5be95ef4ffe..35a57c963df 100644
--- a/arch/x86/kernel/mpparse.c
+++ b/arch/x86/kernel/mpparse.c
@@ -667,36 +667,18 @@ void __init default_get_smp_config(unsigned int early)
          */
 }
 
-static void __init smp_reserve_bootmem(struct mpf_intel *mpf)
+static void __init smp_reserve_memory(struct mpf_intel *mpf)
 {
         unsigned long size = get_mpc_size(mpf->physptr);
-#ifdef CONFIG_X86_32
-        /*
-         * We cannot access to MPC table to compute table size yet,
-         * as only few megabytes from the bottom is mapped now.
-         * PC-9800's MPC table places on the very last of physical
-         * memory; so that simply reserving PAGE_SIZE from mpf->physptr
-         * yields BUG() in reserve_bootmem.
-         * also need to make sure physptr is below than max_low_pfn
-         * we don't need reserve the area above max_low_pfn
-         */
-        unsigned long end = max_low_pfn * PAGE_SIZE;
 
-        if (mpf->physptr < end) {
-                if (mpf->physptr + size > end)
-                        size = end - mpf->physptr;
-                reserve_bootmem_generic(mpf->physptr, size, BOOTMEM_DEFAULT);
-        }
-#else
-        reserve_bootmem_generic(mpf->physptr, size, BOOTMEM_DEFAULT);
-#endif
+        reserve_early(mpf->physptr, mpf->physptr+size, "MP-table mpc");
 }
 
-static int __init smp_scan_config(unsigned long base, unsigned long length,
-                                  unsigned reserve)
+static int __init smp_scan_config(unsigned long base, unsigned long length)
 {
         unsigned int *bp = phys_to_virt(base);
         struct mpf_intel *mpf;
+        unsigned long mem;
 
         apic_printk(APIC_VERBOSE, "Scan SMP from %p for %ld bytes.\n",
                         bp, length);
@@ -717,12 +699,10 @@ static int __init smp_scan_config(unsigned long base, unsigned long length,
                         printk(KERN_INFO "found SMP MP-table at [%p] %llx\n",
                                mpf, (u64)virt_to_phys(mpf));
 
-                        if (!reserve)
-                                return 1;
-                        reserve_bootmem_generic(virt_to_phys(mpf), sizeof(*mpf),
-                                                BOOTMEM_DEFAULT);
+                        mem = virt_to_phys(mpf);
+                        reserve_early(mem, mem + sizeof(*mpf), "MP-table mpf");
                         if (mpf->physptr)
-                                smp_reserve_bootmem(mpf);
+                                smp_reserve_memory(mpf);
 
                         return 1;
                 }
@@ -732,7 +712,7 @@ static int __init smp_scan_config(unsigned long base, unsigned long length,
         return 0;
 }
 
-void __init default_find_smp_config(unsigned int reserve)
+void __init default_find_smp_config(void)
 {
         unsigned int address;
 
@@ -744,9 +724,9 @@ void __init default_find_smp_config(unsigned int reserve)
          * 2) Scan the top 1K of base RAM
          * 3) Scan the 64K of bios
          */
-        if (smp_scan_config(0x0, 0x400, reserve) ||
-            smp_scan_config(639 * 0x400, 0x400, reserve) ||
-            smp_scan_config(0xF0000, 0x10000, reserve))
+        if (smp_scan_config(0x0, 0x400) ||
+            smp_scan_config(639 * 0x400, 0x400) ||
+            smp_scan_config(0xF0000, 0x10000))
                 return;
         /*
          * If it is an SMP machine we should know now, unless the
@@ -767,7 +747,7 @@ void __init default_find_smp_config(unsigned int reserve)
 
         address = get_bios_ebda();
         if (address)
-                smp_scan_config(address, 0x400, reserve);
+                smp_scan_config(address, 0x400);
 }
 
 #ifdef CONFIG_X86_IO_APIC
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index e3eae5965e4..cdb6a8a506d 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -913,6 +913,11 @@ void __init setup_arch(char **cmdline_p)
 
         early_acpi_boot_init();
 
+        /*
+         * Find and reserve possible boot-time SMP configuration:
+         */
+        find_smp_config();
+
 #ifdef CONFIG_ACPI_NUMA
         /*
          * Parse SRAT to discover nodes.
@@ -927,11 +932,6 @@ void __init setup_arch(char **cmdline_p)
 
         initmem_init(0, max_pfn, acpi, k8);
 
-        /*
-         * Find and reserve possible boot-time SMP configuration:
-         */
-        find_smp_config();
-
 #ifdef CONFIG_X86_64
         /*
          * dma32_reserve_bootmem() allocates bootmem which may conflict
diff --git a/arch/x86/kernel/visws_quirks.c b/arch/x86/kernel/visws_quirks.c
index f068553a1b1..1498efa964b 100644
--- a/arch/x86/kernel/visws_quirks.c
+++ b/arch/x86/kernel/visws_quirks.c
@@ -197,7 +197,7 @@ static void __init MP_processor_info(struct mpc_cpu *m)
         apic_version[m->apicid] = ver;
 }
 
-static void __init visws_find_smp_config(unsigned int reserve)
+static void __init visws_find_smp_config(void)
 {
         struct mpc_cpu *mp = phys_to_virt(CO_CPU_TAB_PHYS);
         unsigned short ncpus = readw(phys_to_virt(CO_CPU_NUM_PHYS));