ap_start64() currently serves as the 64-bit entrypoint for non-EFI
tests.
Having ap_start64() and save_id() written in asm prevents sharing these
routines between EFI and non-EFI tests.
Rewrite them in C and use ap_start64 as the 64-bit entrypoint in the EFI
boot flow.
With this, EFI tests support -smp > 1. smptest.efi now passes.
Signed-off-by: Varad Gautam <varad.gautam@xxxxxxxx>
---
lib/x86/asm/setup.h | 3 +++
lib/x86/setup.c | 57 +++++++++++++++++++++++++++++++++-----------
lib/x86/smp.c | 1 +
x86/cstart64.S | 30 -----------------------
x86/efi/efistart64.S | 5 ----
5 files changed, 47 insertions(+), 49 deletions(-)
diff --git a/lib/x86/asm/setup.h b/lib/x86/asm/setup.h
index 24d4fa9..8502e7d 100644
--- a/lib/x86/asm/setup.h
+++ b/lib/x86/asm/setup.h
@@ -16,4 +16,7 @@ efi_status_t setup_efi(efi_bootinfo_t *efi_bootinfo);
void setup_5level_page_table(void);
#endif /* CONFIG_EFI */
+void save_id(void);
+void ap_start64(void);
+
#endif /* _X86_ASM_SETUP_H_ */
diff --git a/lib/x86/setup.c b/lib/x86/setup.c
index e5a690a..261fd9b 100644
--- a/lib/x86/setup.c
+++ b/lib/x86/setup.c
@@ -14,8 +14,12 @@
#include "apic.h"
#include "apic-defs.h"
#include "asm/setup.h"
+#include "processor.h"
+#include "atomic.h"
extern char edata;
+extern unsigned char online_cpus[(MAX_TEST_CPUS + 7) / 8];
+extern unsigned cpu_online_count;
struct mbi_bootinfo {
u32 flags;
@@ -170,10 +174,27 @@ void setup_multiboot(struct mbi_bootinfo *bi)
#ifdef CONFIG_EFI
/* From x86/efi/efistart64.S */
+
extern void update_cs(void);
extern void setup_segments64(u64 gs_base);
extern u8 stacktop;
+#endif
+
+static void setup_gdt_tss(void)
+{
+ size_t tss_offset;
+
+ /* 64-bit setup_tss does not use the stacktop argument. */
+ tss_offset = setup_tss(NULL);
+ load_gdt_tss(tss_offset);
+#ifdef CONFIG_EFI
+ update_cs();
+ u64 gs_base = (u64)(&stacktop) - (PAGE_SIZE * (apic_id() + 1));
+ setup_segments64(gs_base);
+#endif
+}
+#ifdef CONFIG_EFI
static efi_status_t setup_memory_allocator(efi_bootinfo_t *efi_bootinfo)
{
int i;
@@ -270,20 +291,6 @@ static void setup_page_table(void)
write_cr3((ulong)&ptl4);
}
-static void setup_gdt_tss(void)
-{
- size_t tss_offset;
- u64 gs_base;
-
- /* 64-bit setup_tss does not use the stacktop argument. */
- tss_offset = setup_tss(NULL);
- load_gdt_tss(tss_offset);
-
- update_cs();
- gs_base = (u64)(&stacktop) - (PAGE_SIZE * (apic_id() + 1));
- setup_segments64(gs_base);
-}
-
efi_status_t setup_efi(efi_bootinfo_t *efi_bootinfo)
{
efi_status_t status;
@@ -330,6 +337,7 @@ efi_status_t setup_efi(efi_bootinfo_t *efi_bootinfo)
mask_pic_interrupts();
setup_page_table();
enable_apic();
+ save_id();
ap_init();
enable_x2apic();
smp_init();
@@ -352,3 +360,24 @@ void setup_libcflat(void)
add_setup_arg("bootloader");
}
}
+
+void save_id(void)
+{
+ u32 id = apic_id();
+
+ /* atomic_fetch_or() emits `lock or %dl, (%eax)` */
+ atomic_fetch_or(&online_cpus[id / 8], (1 << (id % 8)));
+}
+
+void ap_start64(void)
+{
+ reset_apic();
+ load_idt();
+ setup_gdt_tss();
+ save_id();
+ enable_apic();
+ enable_x2apic();
+ sti();
+ atomic_fetch_inc(&cpu_online_count);
+ asm volatile("1: hlt; jmp 1b");
+}
diff --git a/lib/x86/smp.c b/lib/x86/smp.c
index 4ddb459..eec8d2b 100644
--- a/lib/x86/smp.c
+++ b/lib/x86/smp.c
@@ -22,6 +22,7 @@ static atomic_t active_cpus;
extern u8 sipi_entry;
extern u8 sipi_end;
volatile unsigned cpu_online_count = 1;
+unsigned char online_cpus[(MAX_TEST_CPUS + 7) / 8];
static __attribute__((used)) void ipi(void)
{
diff --git a/x86/cstart64.S b/x86/cstart64.S
index 45009d4..e0d4ab5 100644
--- a/x86/cstart64.S
+++ b/x86/cstart64.S
@@ -126,33 +126,6 @@ gdt32_descr:
sipi_end:
.code64
-save_id:
- movl $(APIC_DEFAULT_PHYS_BASE + APIC_ID), %eax
- movl (%rax), %eax
- shrl $24, %eax
- lock btsl %eax, online_cpus
- retq
-
-ap_start64:
-.retry:
- xor %eax, %eax
- lock btsl %eax, ap_lock
- jc .retry
- call reset_apic
- call load_idt
- load_tss
- call enable_apic
- call save_id
- call enable_x2apic
- sti
- xor %eax, %eax
- lock btr %eax, ap_lock
- nop
- lock incw cpu_online_count
-
-1: hlt
- jmp 1b
-
start64:
call reset_apic
call load_idt
@@ -191,6 +164,3 @@ setup_5level_page_table:
lretq
lvl5:
retq
-
-online_cpus:
- .fill (max_cpus + 7) / 8, 1, 0
diff --git a/x86/efi/efistart64.S b/x86/efi/efistart64.S
index c8fd3a2..99a3802 100644
--- a/x86/efi/efistart64.S
+++ b/x86/efi/efistart64.S
@@ -102,8 +102,3 @@ sipi_end:
.code32
#include "../start32.S"
-
-.code64:
-
-ap_start64:
- jmp ap_start64
--
2.32.0
