From: Andrew Cooper <andrew.cooper3@citrix.com>
Date: Fri, 13 Apr 2018 18:37:21 +0000 (+0100)
Subject: x86/io-apic: Fix 64bit MMIO accesses
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=10bd4aec5dfd0b572269a6ba359bbf798bc98c8c;p=people%2Fandrewcoop%2Fxen-test-framework.git

x86/io-apic: Fix 64bit MMIO accesses

While most of the IO-APIC registers are 64 bits wide, the spec states that
they must be accessed with 32bit accesses.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---

diff --git a/arch/x86/include/arch/io-apic.h b/arch/x86/include/arch/io-apic.h
index ec88865..400445c 100644
--- a/arch/x86/include/arch/io-apic.h
+++ b/arch/x86/include/arch/io-apic.h
@@ -37,9 +37,7 @@ static inline uint32_t ioapic_read32(unsigned int reg)
 
 static inline uint64_t ioapic_read64(unsigned int reg)
 {
-    *(volatile uint64_t *)_p(IOAPIC_DEFAULT_BASE + IOAPIC_REGSEL) = reg;
-
-    return *(volatile uint64_t *)_p(IOAPIC_DEFAULT_BASE + IOAPIC_IOWIN);
+    return ioapic_read32(reg) | (uint64_t)ioapic_read32(reg + 1) << 32;
 }
 
 static inline void ioapic_write32(unsigned int reg, uint32_t val)
@@ -50,8 +48,8 @@ static inline void ioapic_write32(unsigned int reg, uint32_t val)
 
 static inline void ioapic_write64(unsigned int reg, uint64_t val)
 {
-    *(volatile uint64_t *)_p(IOAPIC_DEFAULT_BASE + IOAPIC_REGSEL) = reg;
-    *(volatile uint64_t *)_p(IOAPIC_DEFAULT_BASE + IOAPIC_IOWIN) = val;
+    ioapic_write32(reg, val);
+    ioapic_write32(reg + 1, val >> 32);
 }
 
 #endif /* !XTF_X86_IO_APIC_H */