Commit 321ab6a5 authored by Lennert Buytenhek's avatar Lennert Buytenhek Committed by Russell King

[PATCH] ARM: 2752/1: disable ixp2000 PCI I/O software workaround on chips that don't need it

Patch from Lennert Buytenhek

The later ixp2000 models don't need the PCI I/O workaround that we
currently perform.  Add a config option to disable the workaround,
and panic on boot if a kernel without the workaround is booted on a
buggy chip.  As only pre-production ixp2000s need the workaround,
the default is for it not to be configured in.
Signed-off-by: default avatarLennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 3cd9e19e
......@@ -99,6 +99,7 @@ CONFIG_ARCH_ENP2611=y
# CONFIG_ARCH_IXDP2800 is not set
# CONFIG_ARCH_IXDP2401 is not set
# CONFIG_ARCH_IXDP2801 is not set
# CONFIG_IXP2000_SUPPORT_BROKEN_PCI_IO is not set
#
# Processor Type
......
......@@ -100,6 +100,7 @@ CONFIG_ARCH_IXDP2400=y
CONFIG_ARCH_IXDP2X00=y
# CONFIG_ARCH_IXDP2401 is not set
# CONFIG_ARCH_IXDP2801 is not set
# CONFIG_IXP2000_SUPPORT_BROKEN_PCI_IO is not set
#
# Processor Type
......
......@@ -100,6 +100,7 @@ CONFIG_ARCH_SUPPORTS_BIG_ENDIAN=y
CONFIG_ARCH_IXDP2401=y
# CONFIG_ARCH_IXDP2801 is not set
CONFIG_ARCH_IXDP2X01=y
# CONFIG_IXP2000_SUPPORT_BROKEN_PCI_IO is not set
#
# Processor Type
......
......@@ -100,6 +100,7 @@ CONFIG_ARCH_IXDP2800=y
CONFIG_ARCH_IXDP2X00=y
# CONFIG_ARCH_IXDP2401 is not set
# CONFIG_ARCH_IXDP2801 is not set
# CONFIG_IXP2000_SUPPORT_BROKEN_PCI_IO is not set
#
# Processor Type
......
......@@ -100,6 +100,7 @@ CONFIG_ARCH_SUPPORTS_BIG_ENDIAN=y
# CONFIG_ARCH_IXDP2401 is not set
CONFIG_ARCH_IXDP2801=y
CONFIG_ARCH_IXDP2X01=y
# CONFIG_IXP2000_SUPPORT_BROKEN_PCI_IO is not set
#
# Processor Type
......
......@@ -54,6 +54,14 @@ config ARCH_IXDP2X01
depends on ARCH_IXDP2401 || ARCH_IXDP2801
default y
config IXP2000_SUPPORT_BROKEN_PCI_IO
bool "Support broken PCI I/O on older IXP2000s"
default y
help
Say 'N' here if you only intend to run your kernel on an
IXP2000 B0 or later model and do not need the PCI I/O
byteswap workaround. Say 'Y' otherwise.
endmenu
endif
......@@ -198,6 +198,19 @@ clear_master_aborts(void)
void __init
ixp2000_pci_preinit(void)
{
#ifndef CONFIG_IXP2000_SUPPORT_BROKEN_PCI_IO
/*
* Configure the PCI unit to properly byteswap I/O transactions,
* and verify that it worked.
*/
ixp2000_reg_write(IXP2000_PCI_CONTROL,
(*IXP2000_PCI_CONTROL | PCI_CONTROL_IEE));
if ((*IXP2000_PCI_CONTROL & PCI_CONTROL_IEE) == 0)
panic("IXP2000: PCI I/O is broken on this ixp model, and "
"the needed workaround has not been configured in");
#endif
hook_fault_code(16+6, ixp2000_pci_abort_handler, SIGBUS,
"PCI config cycle to non-existent device");
}
......
......@@ -17,16 +17,21 @@
#define IO_SPACE_LIMIT 0xffffffff
#define __mem_pci(a) (a)
#define ___io(p) ((void __iomem *)((p)+IXP2000_PCI_IO_VIRT_BASE))
/*
* The IXP2400 before revision B0 asserts byte lanes for PCI I/O
* The A? revisions of the IXP2000s assert byte lanes for PCI I/O
* transactions the other way round (MEM transactions don't have this
* issue), so we need to override the standard functions. B0 and later
* have a bit that can be set to 1 to get the 'proper' behavior, but
* since that isn't available on the A? revisions we just keep doing
* things manually.
* issue), so if we want to support those models, we need to override
* the standard I/O functions.
*
* B0 and later have a bit that can be set to 1 to get the proper
* behavior for I/O transactions, which then allows us to use the
* standard I/O functions. This is what we do if the user does not
* explicitly ask for support for pre-B0.
*/
#ifdef CONFIG_IXP2000_SUPPORT_BROKEN_PCI_IO
#define ___io(p) ((void __iomem *)((p)+IXP2000_PCI_IO_VIRT_BASE))
#define alignb(addr) (void __iomem *)((unsigned long)(addr) ^ 3)
#define alignw(addr) (void __iomem *)((unsigned long)(addr) ^ 2)
......@@ -119,6 +124,9 @@
#define ioport_map(port, nr) ___io(port)
#define ioport_unmap(addr)
#else
#define __io(p) ((void __iomem *)((p)+IXP2000_PCI_IO_VIRT_BASE))
#endif
#ifdef CONFIG_ARCH_IXDP2X01
......
......@@ -241,7 +241,7 @@
#define PCI_CONTROL_BE_DEI (1 << 21) /* Big Endian Data Enable In */
#define PCI_CONTROL_BE_BEO (1 << 20) /* Big Endian Byte Enable Out */
#define PCI_CONTROL_BE_BEI (1 << 19) /* Big Endian Byte Enable In */
#define PCI_CONTROL_PNR (1 << 17) /* PCI Not Reset bit */
#define PCI_CONTROL_IEE (1 << 17) /* I/O cycle Endian swap Enable */
#define IXP2000_PCI_RST_REL (1 << 2)
#define CFG_RST_DIR (*IXP2000_PCI_CONTROL & IXP2000_PCICNTL_PCF)
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment