[coreboot-gerrit] Change in coreboot[master]: [RFC,WIP] cpu/x86/lapic: Drop xapic_write_atomic()

[Kyösti Mälkki (Code Review)]

Kyösti Mälkki has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/55199 )

Change subject: [RFC,WIP] cpu/x86/lapic: Drop xapic_write_atomic()
......................................................................

[RFC,WIP] cpu/x86/lapic: Drop xapic_write_atomic()

The memory clobber impacts code generator.

In linux kernel, the errata or quick X86_BUG_11AP is
documented to be specific quirk for Intel model 0x520.

Change-Id: Iec10335f603674bcef2e7494831cf11200795d38
Signed-off-by: Kyösti Mälkki 
---
M src/cpu/x86/lapic/lapic_cpu_init.c
M src/include/cpu/x86/lapic.h
2 files changed, 4 insertions(+), 15 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/99/55199/1

diff --git a/src/cpu/x86/lapic/lapic_cpu_init.c b/src/cpu/x86/lapic/lapic_cpu_init.c
index 22647bc..fe1c824 100644
--- a/src/cpu/x86/lapic/lapic_cpu_init.c
+++ b/src/cpu/x86/lapic/lapic_cpu_init.c
@@ -128,7 +128,7 @@
    	printk(BIOS_ERR, "ESR is 0x%x\n", lapic_read(LAPIC_ESR));
    	if (lapic_read(LAPIC_ESR)) {
    		printk(BIOS_ERR, "Try to reset ESR\n");
-			xapic_write_atomic(LAPIC_ESR, 0);
+			lapic_write(LAPIC_ESR, 0);
    		printk(BIOS_ERR, "ESR is 0x%x\n",
    			lapic_read(LAPIC_ESR));
    	}
diff --git a/src/include/cpu/x86/lapic.h b/src/include/cpu/x86/lapic.h
index 3c860ab..30c12e8 100644
--- a/src/include/cpu/x86/lapic.h
+++ b/src/include/cpu/x86/lapic.h
@@ -21,21 +21,10 @@
    write32((volatile void *)(uintptr_t)(LAPIC_DEFAULT_BASE + reg), v);
 }

-static inline void xapic_write_atomic(unsigned long reg, uint32_t v)
-{
-	volatile uint32_t *ptr;
-
-	ptr = (volatile uint32_t *)(LAPIC_DEFAULT_BASE + reg);
-
-	asm volatile ("xchgl %0, %1\n"
-		      : "+r" (v), "+m" (*(ptr))
-		      : : "memory", "cc");
-}
-
 static __always_inline void xapic_send_ipi(uint32_t icrlow, uint32_t apicid)
 {
-	xapic_write_atomic(LAPIC_ICR2, SET_LAPIC_DEST_FIELD(apicid));
-	xapic_write_atomic(LAPIC_ICR, icrlow);
+	xapic_write(LAPIC_ICR2, SET_LAPIC_DEST_FIELD(apicid));
+	xapic_write(LAPIC_ICR, icrlow);
 }

static __always_inline int xapic_busy(void)
@@ -115,7 +104,7 @@
    	value = xapic_read(reg);
    	value &= mask;
    	value |= or;
-		xapic_write_atomic(reg, value);
+		xapic_write(reg, value);
    }
 }