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x86: disable zero mapping and add a boot pt for ap trampoline

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the application processor trampoline needs the trampoline physical
address to be mapped for the few instructions between loading the
page table and jumping to normal memory area; setup a new pt for them.

Also make it use its stack where it needs to be directly.

With that, x86 can finally remove the 0 page from its init mapping

Change-Id: Iab3f33a2ed22570eeb47b5ab6e068c9a17c25413
This commit is contained in:
Dominique Martinet
2019-02-06 16:55:14 +09:00
committed by Dominique Martinet
parent c59d8db1b3
commit 4f66d1be0f
4 changed files with 23 additions and 4 deletions
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8
arch/x86_64/kernel/cpu.c
View File

@ -824,11 +824,14 @@ void call_ap_func(void (*next_func)(void))
next_func();
}
struct page_table *get_init_page_table(void);
void setup_x86_ap(void (*next_func)(void))
{
unsigned long rsp;
cpu_disable_interrupt();
ihk_mc_load_page_table(get_init_page_table());
assign_processor_id();
init_smp_processor();
@ -1246,7 +1249,7 @@ void ihk_mc_set_page_fault_handler(void (*h)(void *, uint64_t, void *))
}
extern char trampoline_code_data[], trampoline_code_data_end[];
struct page_table *get_init_page_table(void);
struct page_table *get_boot_page_table(void);
unsigned long get_transit_page_table(void);
/* reusable, but not reentrant */
@ -1270,9 +1273,10 @@ void ihk_mc_boot_cpu(int cpuid, unsigned long pc)
memcpy(p, trampoline_code_data,
trampoline_code_data_end - trampoline_code_data);
p[1] = (unsigned long)virt_to_phys(get_init_page_table());
p[1] = (unsigned long)virt_to_phys(get_boot_page_table());
p[2] = (unsigned long)setup_x86_ap;
p[3] = pc;
p[4] = (unsigned long)get_x86_cpu_local_kstack(cpuid);
p[6] = (unsigned long)get_transit_page_table();
if (!p[6]) {
p[6] = p[1];

1
arch/x86_64/kernel/include/cpulocal.h
View File

@ -50,6 +50,7 @@ struct x86_cpu_local_variables {
struct x86_cpu_local_variables *get_x86_cpu_local_variable(int id);
struct x86_cpu_local_variables *get_x86_this_cpu_local(void);
void *get_x86_cpu_local_kstack(int id);
void *get_x86_this_cpu_kstack(void);

2
arch/x86_64/kernel/local.c
View File

@ -49,7 +49,7 @@ struct x86_cpu_local_variables *get_x86_cpu_local_variable(int id)
((char *)locals + (LOCALS_SPAN * id));
}
static void *get_x86_cpu_local_kstack(int id)
void *get_x86_cpu_local_kstack(int id)
{
return ((char *)locals + (LOCALS_SPAN * (id + 1)));
}

16
arch/x86_64/kernel/memory.c
View File

@ -108,6 +108,7 @@ struct page_table {
};
static struct page_table *init_pt;
static struct page_table *boot_pt;
static int init_pt_loaded = 0;
static ihk_spinlock_t init_pt_lock;
@ -2519,6 +2520,11 @@ struct page_table *get_init_page_table(void)
return init_pt;
}
struct page_table *get_boot_page_table(void)
{
return boot_pt;
}
static unsigned long fixed_virt;
static void init_fixed_area(struct page_table *pt)
{
@ -2695,10 +2701,18 @@ void init_page_table(void)
init_normal_area(init_pt);
init_linux_kernel_mapping(init_pt);
init_fixed_area(init_pt);
init_low_area(init_pt);
init_text_area(init_pt);
init_vsyscall_area(init_pt);
/* boot page table: needs zero mapping in order to execute the next
* instruction that jumps into regular regions
*/
boot_pt = ihk_mc_alloc_pages(1, IHK_MC_AP_CRITICAL);
memcpy(boot_pt, init_pt, sizeof(*boot_pt));
init_low_area(boot_pt);
if (memcmp(init_pt, boot_pt, sizeof(*init_pt)) == 0)
panic("init low area for boot pt did not affect toplevel entry");
load_page_table(init_pt);
init_pt_loaded = 1;
kprintf("Page table is now at 0x%lx\n", init_pt);