From 7170bdc777556dad87f92e6a73a6cc557bf3290e Mon Sep 17 00:00:00 2001 From: James Hogan Date: Mon, 28 Nov 2016 16:38:01 +0000 Subject: [PATCH] MIPS: Add return errors to protected cache ops MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The protected cache ops contain no out of line fixup code to return an error code in the event of a fault, with the cache op being skipped in that case. For KVM however we'd like to detect this case as page faulting will be disabled so it could happen during normal operation if the GVA page tables were flushed, and need to be handled by the caller. Add the out-of-line fixup code to load the error value -EFAULT into the return variable, and adapt the protected cache line functions to pass the error back to the caller. Signed-off-by: James Hogan Acked-by: Ralf Baechle Cc: Ralf Baechle Cc: Paolo Bonzini Cc: "Radim Krčmář" Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org --- arch/mips/include/asm/r4kcache.h | 55 +++++++++++++++++++++++++--------------- 1 file changed, 35 insertions(+), 20 deletions(-) diff --git a/arch/mips/include/asm/r4kcache.h b/arch/mips/include/asm/r4kcache.h index b42b513..7227c158 100644 --- a/arch/mips/include/asm/r4kcache.h +++ b/arch/mips/include/asm/r4kcache.h @@ -147,49 +147,64 @@ static inline void flush_scache_line(unsigned long addr) } #define protected_cache_op(op,addr) \ +({ \ + int __err = 0; \ __asm__ __volatile__( \ " .set push \n" \ " .set noreorder \n" \ " .set "MIPS_ISA_ARCH_LEVEL" \n" \ - "1: cache %0, (%1) \n" \ + "1: cache %1, (%2) \n" \ "2: .set pop \n" \ + " .section .fixup,\"ax\" \n" \ + "3: li %0, %3 \n" \ + " j 2b \n" \ + " .previous \n" \ " .section __ex_table,\"a\" \n" \ - " "STR(PTR)" 1b, 2b \n" \ + " "STR(PTR)" 1b, 3b \n" \ " .previous" \ - : \ - : "i" (op), "r" (addr)) + : "+r" (__err) \ + : "i" (op), "r" (addr), "i" (-EFAULT)); \ + __err; \ +}) + #define protected_cachee_op(op,addr) \ +({ \ + int __err = 0; \ __asm__ __volatile__( \ " .set push \n" \ " .set noreorder \n" \ " .set mips0 \n" \ " .set eva \n" \ - "1: cachee %0, (%1) \n" \ + "1: cachee %1, (%2) \n" \ "2: .set pop \n" \ + " .section .fixup,\"ax\" \n" \ + "3: li %0, %3 \n" \ + " j 2b \n" \ + " .previous \n" \ " .section __ex_table,\"a\" \n" \ - " "STR(PTR)" 1b, 2b \n" \ + " "STR(PTR)" 1b, 3b \n" \ " .previous" \ - : \ - : "i" (op), "r" (addr)) + : "+r" (__err) \ + : "i" (op), "r" (addr), "i" (-EFAULT)); \ + __err; \ +}) /* * The next two are for badland addresses like signal trampolines. */ -static inline void protected_flush_icache_line(unsigned long addr) +static inline int protected_flush_icache_line(unsigned long addr) { switch (boot_cpu_type()) { case CPU_LOONGSON2: - protected_cache_op(Hit_Invalidate_I_Loongson2, addr); - break; + return protected_cache_op(Hit_Invalidate_I_Loongson2, addr); default: #ifdef CONFIG_EVA - protected_cachee_op(Hit_Invalidate_I, addr); + return protected_cachee_op(Hit_Invalidate_I, addr); #else - protected_cache_op(Hit_Invalidate_I, addr); + return protected_cache_op(Hit_Invalidate_I, addr); #endif - break; } } @@ -199,21 +214,21 @@ static inline void protected_flush_icache_line(unsigned long addr) * caches. We're talking about one cacheline unnecessarily getting invalidated * here so the penalty isn't overly hard. */ -static inline void protected_writeback_dcache_line(unsigned long addr) +static inline int protected_writeback_dcache_line(unsigned long addr) { #ifdef CONFIG_EVA - protected_cachee_op(Hit_Writeback_Inv_D, addr); + return protected_cachee_op(Hit_Writeback_Inv_D, addr); #else - protected_cache_op(Hit_Writeback_Inv_D, addr); + return protected_cache_op(Hit_Writeback_Inv_D, addr); #endif } -static inline void protected_writeback_scache_line(unsigned long addr) +static inline int protected_writeback_scache_line(unsigned long addr) { #ifdef CONFIG_EVA - protected_cachee_op(Hit_Writeback_Inv_SD, addr); + return protected_cachee_op(Hit_Writeback_Inv_SD, addr); #else - protected_cache_op(Hit_Writeback_Inv_SD, addr); + return protected_cache_op(Hit_Writeback_Inv_SD, addr); #endif } -- 2.7.4