[cns3xxx]: fix pcie abort handling

Signed-off-by: Tim Harvey <tharvey@gateworks.com>


git-svn-id: svn://svn.openwrt.org/openwrt/trunk@33564 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 128 insertions, 0 deletions

diff --git a/target/linux/cns3xxx/patches-3.3/108-cns3xxx_pcie-abort.patch b/target/linux/cns3xxx/patches-3.3/108-cns3xxx_pcie-abort.patch
new file mode 100644
index 000000000..788b620a8
--- /dev/null
+++ b/target/linux/cns3xxx/patches-3.3/108-cns3xxx_pcie-abort.patch
@@ -0,0 +1,128 @@
+--- a/arch/arm/mach-cns3xxx/pcie.c
++++ b/arch/arm/mach-cns3xxx/pcie.c
+@@ -92,6 +92,78 @@ static void __iomem *cns3xxx_pci_cfg_bas
+ 	return base + offset;
+ }
+ 
++static inline int check_master_abort(struct pci_bus *bus, unsigned int devfn, int where)
++{
++	struct cns3xxx_pcie *cnspci = pbus_to_cnspci(bus);
++
++  /* check PCI-compatible status register after access */
++	if (cnspci->linked) {
++		u32 host_base, sreg, ereg;
++
++		host_base = cnspci->cfg_bases[CNS3XXX_HOST_TYPE].virtual;
++		sreg = __raw_readw(host_base + 0x6) & 0xF900;
++		ereg = __raw_readl(host_base + 0x104); // Uncorrectable Error Status Reg
++
++		if (sreg | ereg) {
++			/* SREG:
++			 *  BIT15 - Detected Parity Error
++			 *  BIT14 - Signaled System Error
++			 *  BIT13 - Received Master Abort
++			 *  BIT12 - Received Target Abort
++			 *  BIT11 - Signaled Target Abort
++			 *  BIT08 - Master Data Parity Error
++			 *
++			 * EREG:
++			 *  BIT20 - Unsupported Request
++			 *  BIT19 - ECRC
++			 *  BIT18 - Malformed TLP
++			 *  BIT17 - Receiver Overflow
++			 *  BIT16 - Unexpected Completion
++			 *  BIT15 - Completer Abort
++			 *  BIT14 - Completion Timeout
++			 *  BIT13 - Flow Control Protocol Error
++			 *  BIT12 - Poisoned TLP
++			 *  BIT04 - Data Link Protocol Error
++			 *
++			 * TODO: see Documentation/pci-error-recovery.txt
++			 *    implement error_detected handler
++			 */
++/*
++			printk("pci error: %04d:%02x:%02x.%02x sreg=0x%04x ereg=0x%08x", pci_domain_nr(bus), bus->number, PCI_SLOT(devfn), PCI_FUNC(devfn), sreg, ereg);
++			if (sreg & BIT(15)) printk(" <PERR");
++			if (sreg & BIT(14)) printk(" >SERR");
++			if (sreg & BIT(13)) printk(" <MABRT");
++			if (sreg & BIT(12)) printk(" <TABRT");
++			if (sreg & BIT(11)) printk(" >TABRT");
++			if (sreg & BIT( 8)) printk(" MPERR");
++
++			if (ereg & BIT(20)) printk(" Unsup");
++			if (ereg & BIT(19)) printk(" ECRC");
++			if (ereg & BIT(18)) printk(" MTLP");
++			if (ereg & BIT(17)) printk(" OFLOW");
++			if (ereg & BIT(16)) printk(" Unex");
++			if (ereg & BIT(15)) printk(" ABRT");
++			if (ereg & BIT(14)) printk(" COMPTO");
++			if (ereg & BIT(13)) printk(" FLOW");
++			if (ereg & BIT(12)) printk(" PTLP");
++			if (ereg & BIT( 4)) printk(" DLINK");
++			printk("\n");
++*/
++			pr_debug("%s failed port%d sreg=0x%04x\n", __func__,
++				cnspci->hw_pci.domain, sreg);
++
++			/* make sure the status bits are reset */
++			__raw_writew(sreg, host_base + 6);
++			__raw_writel(ereg, host_base + 0x104);
++			return 1;
++		}
++	}
++	else
++		return 1;
++
++  return 0;
++}
++
+ static int cns3xxx_pci_read_config(struct pci_bus *bus, unsigned int devfn,
+ 				   int where, int size, u32 *val)
+ {
+@@ -108,6 +180,11 @@ static int cns3xxx_pci_read_config(struc
+ 
+ 	v = __raw_readl(base);
+ 
++	if (check_master_abort(bus, devfn, where)) {
++		printk(KERN_ERR "pci error: %04d:%02x:%02x.%02x %02x(%d)= master_abort on read\n", pci_domain_nr(bus), bus->number, PCI_SLOT(devfn), PCI_FUNC(devfn), where, size);
++		return PCIBIOS_DEVICE_NOT_FOUND;
++	}
++
+ 	if (bus->number == 0 && devfn == 0 &&
+ 			(where & 0xffc) == PCI_CLASS_REVISION) {
+ 		/*
+@@ -137,11 +214,19 @@ static int cns3xxx_pci_write_config(stru
+ 		return PCIBIOS_SUCCESSFUL;
+ 
+ 	v = __raw_readl(base);
++	if (check_master_abort(bus, devfn, where)) {
++		printk(KERN_ERR "pci error: %04d:%02x:%02x.%02x %02x(%d)=0x%08x master_abort on read\n", pci_domain_nr(bus), bus->number, PCI_SLOT(devfn), PCI_FUNC(devfn), where, size, val);
++		return PCIBIOS_DEVICE_NOT_FOUND;
++	}
+ 
+ 	v &= ~(mask << shift);
+ 	v |= (val & mask) << shift;
+ 
+ 	__raw_writel(v, base);
++	if (check_master_abort(bus, devfn, where)) {
++		printk(KERN_ERR "pci error: %04d:%02x:%02x.%02x %02x(%d)=0x%08x master_abort on write\n", pci_domain_nr(bus), bus->number, PCI_SLOT(devfn), PCI_FUNC(devfn), where, size, val);
++		return PCIBIOS_DEVICE_NOT_FOUND;
++	}
+ 
+ 	return PCIBIOS_SUCCESSFUL;
+ }
+@@ -360,8 +445,14 @@ static void __init cns3xxx_pcie_hw_init(
+ static int cns3xxx_pcie_abort_handler(unsigned long addr, unsigned int fsr,
+ 				      struct pt_regs *regs)
+ {
++#if 0
++/* R14_ABORT = PC+4 for XSCALE but not ARM11MPCORE
++ * ignore imprecise aborts and use PCI-compatible Status register to
++ * determine errors instead
++ */
+ 	if (fsr & (1 << 10))
+ 		regs->ARM_pc += 4;
++#endif
+ 	return 0;
+ }
+