3 files changed, 37 insertions, 44 deletions

diff --git a/cpu/ppc4xx/440spe_pcie.c b/cpu/ppc4xx/440spe_pcie.c
index bf68cc1..2d0b406 100644
--- a/cpu/ppc4xx/440spe_pcie.c
+++ b/cpu/ppc4xx/440spe_pcie.c
@@ -40,31 +40,24 @@ enum {
 	LNKW_X8			= 0x8
 };
 
-static inline int pcie_in_8(const volatile unsigned char __iomem *addr)
+static void pcie_dmer_disable(void)
 {
-	int ret;
-
-	PCIE_IN(lbzx, ret, addr);
-
-	return ret;
-}
-
-static inline int pcie_in_le16(const volatile unsigned short __iomem *addr)
-{
-	int ret;
-
-	PCIE_IN(lhbrx, ret, addr)
-
-	return ret;
+	mtdcr (DCRN_PEGPL_CFG(DCRN_PCIE0_BASE),
+		mfdcr (DCRN_PEGPL_CFG(DCRN_PCIE0_BASE)) | GPL_DMER_MASK_DISA);
+	mtdcr (DCRN_PEGPL_CFG(DCRN_PCIE1_BASE),
+		mfdcr (DCRN_PEGPL_CFG(DCRN_PCIE1_BASE)) | GPL_DMER_MASK_DISA);
+	mtdcr (DCRN_PEGPL_CFG(DCRN_PCIE2_BASE),
+		mfdcr (DCRN_PEGPL_CFG(DCRN_PCIE2_BASE)) | GPL_DMER_MASK_DISA);
 }
 
-static inline unsigned pcie_in_le32(const volatile unsigned __iomem *addr)
+static void pcie_dmer_enable(void)
 {
-	unsigned ret;
-
-	PCIE_IN(lwbrx, ret, addr);
-
-	return ret;
+	mtdcr (DCRN_PEGPL_CFG (DCRN_PCIE0_BASE),
+		mfdcr (DCRN_PEGPL_CFG(DCRN_PCIE0_BASE)) & ~GPL_DMER_MASK_DISA);
+	mtdcr (DCRN_PEGPL_CFG (DCRN_PCIE1_BASE),
+		mfdcr (DCRN_PEGPL_CFG(DCRN_PCIE1_BASE)) & ~GPL_DMER_MASK_DISA);
+	mtdcr (DCRN_PEGPL_CFG (DCRN_PCIE2_BASE),
+		mfdcr (DCRN_PEGPL_CFG(DCRN_PCIE2_BASE)) & ~GPL_DMER_MASK_DISA);
 }
 
 
@@ -81,17 +74,27 @@ static int pcie_read_config(struct pci_controller *hose, unsigned int devfn,
 	devfn = PCI_BDF(0,0,0);
 	offset += devfn << 4;
 
+	/*
+	 * Reading from configuration space of non-existing device can
+	 * generate transaction errors. For the read duration we suppress
+	 * assertion of machine check exceptions to avoid those.
+	 */
+	pcie_dmer_disable ();
+
 	switch (len) {
 	case 1:
-		*val = pcie_in_8(hose->cfg_data + offset);
+		*val = in_8(hose->cfg_data + offset);
 		break;
 	case 2:
-		*val = pcie_in_le16((u16 *)(hose->cfg_data + offset));
+		*val = in_le16((u16 *)(hose->cfg_data + offset));
 		break;
 	default:
-		*val = pcie_in_le32((u32*)(hose->cfg_data + offset));
+		*val = in_le32((u32*)(hose->cfg_data + offset));
 		break;
 	}
+
+	pcie_dmer_enable ();
+
 	return 0;
 }
 
@@ -107,6 +110,11 @@ static int pcie_write_config(struct pci_controller *hose, unsigned int devfn,
 	devfn = PCI_BDF(0,0,0);
 	offset += devfn << 4;
 
+	/*
+	 * Suppress MCK exceptions, similar to pcie_read_config()
+	 */
+	pcie_dmer_disable ();
+
 	switch (len) {
 	case 1:
 		out_8(hose->cfg_data + offset, val);
@@ -118,6 +126,9 @@ static int pcie_write_config(struct pci_controller *hose, unsigned int devfn,
 		out_le32((u32 *)(hose->cfg_data + offset), val);
 		break;
 	}
+
+	pcie_dmer_enable ();
+
 	return 0;
 }
 
diff --git a/cpu/ppc4xx/440spe_pcie.h b/cpu/ppc4xx/440spe_pcie.h
index eb7cecf..38745eb 100644
--- a/cpu/ppc4xx/440spe_pcie.h
+++ b/cpu/ppc4xx/440spe_pcie.h
@@ -38,6 +38,7 @@
 #define DCRN_PEGPL_REGBAL(base)		(base + 0x13)
 #define DCRN_PEGPL_REGMSK(base)		(base + 0x14)
 #define DCRN_PEGPL_SPECIAL(base)	(base + 0x15)
+#define DCRN_PEGPL_CFG(base)		(base + 0x16)
 
 /*
  * System DCRs (SDRs)
@@ -161,20 +162,7 @@
 	mtdcr(DCRN_SDR0_CFGADDR, offset); \
 	mtdcr(DCRN_SDR0_CFGDATA,data);})
 
-#define PCIE_IN(opcode, ret, addr) \
-	__asm__ __volatile__(			\
-		"sync\n"			\
-		#opcode " %0,0,%1\n"		\
-		"1: twi 0,%0,0\n"		\
-		"isync\n"			\
-		"b 3f\n"			\
-		"2: li %0,-1\n"			\
-		"3:\n"				\
-		".section __ex_table,\"a\"\n"	\
-		".balign 4\n"			\
-		".long 1b,2b\n"			\
-		".previous\n"			\
-		: "=r" (ret) : "r" (addr), "m" (*addr));
+#define GPL_DMER_MASK_DISA	0x02000000
 
 int ppc440spe_init_pcie(void);
 int ppc440spe_init_pcie_rootport(int port);
diff --git a/cpu/ppc4xx/traps.c b/cpu/ppc4xx/traps.c
index f5365cb..38b6f89 100644
--- a/cpu/ppc4xx/traps.c
+++ b/cpu/ppc4xx/traps.c
@@ -151,12 +151,6 @@ MachineCheckException(struct pt_regs *regs)
 	int uncorr_ecc = 0;
 #endif
 
-	/* Probing PCI(E) using config cycles may cause this exception
-	 * when a device is not present. To gracefully recover in such
-	 * scenarios config read/write routines need to be instrumented in
-	 * order to return via fixup handler. For examples refer to
-	 * pcie_in_8(), pcie_in_le16() and pcie_in_le32()
-	 */
 	if ((fixup = search_exception_table(regs->nip)) != 0) {
 		regs->nip = fixup;
 		val = mfspr(MCSR);