Commit db674ed4 authored by Sylvain Munaut's avatar Sylvain Munaut Committed by Linus Torvalds
Browse files

[PATCH] ppc32: Fix MPC52xx configuration space access 



This patch takes care of an errata of the MPC5200 by avoiding 32 bits access
in type 1 configuration accesses.  All others accesses are still 32 bits wide.
 It also adds some mb() since the simple out_be(...) are not sufficient in
this case.

Signed-off-by: default avatarSylvain Munaut <tnt@246tNt.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent dbeb198d

arch/ppc/syslib/mpc52xx_pci.c

+69 −14
Original line number Diff line number Diff line
@@ -24,6 +24,12 @@ 
#include <asm/machdep.h>





/* This macro is defined to activate the workaround for the bug

   435 of the MPC5200 (L25R). With it activated, we don't do any

   32 bits configuration access during type-1 cycles */

#define MPC5200_BUG_435_WORKAROUND





static int

mpc52xx_pci_read_config(struct pci_bus *bus, unsigned int devfn,

				int offset, int len, u32 *val)
@@ -40,17 +46,39 @@ mpc52xx_pci_read_config(struct pci_bus *bus, unsigned int devfn, 
		((bus->number - hose->bus_offset) << 16) |

		(devfn << 8) |

		(offset & 0xfc));



	mb();



#ifdef MPC5200_BUG_435_WORKAROUND

	if (bus->number != hose->bus_offset) {

		switch (len) {

			case 1:

				value = in_8(((u8 __iomem *)hose->cfg_data) + (offset & 3));

				break;

			case 2:

				value = in_le16(((u16 __iomem *)hose->cfg_data) + ((offset>>1) & 1));

				break;



			default:

				value = in_le16((u16 __iomem *)hose->cfg_data) |

					(in_le16(((u16 __iomem *)hose->cfg_data) + 1) << 16);

				break;

		}

	}

	else

#endif

	{

		value = in_le32(hose->cfg_data);



		if (len != 4) {

			value >>= ((offset & 0x3) << 3);

			value &= 0xffffffff >> (32 - (len << 3));

		}

	}



	*val = value;



	out_be32(hose->cfg_addr, 0);

	mb();



	return PCIBIOS_SUCCESSFUL;

}
@@ -71,7 +99,31 @@ mpc52xx_pci_write_config(struct pci_bus *bus, unsigned int devfn, 
		((bus->number - hose->bus_offset) << 16) |

		(devfn << 8) |

		(offset & 0xfc));



	mb();



#ifdef MPC5200_BUG_435_WORKAROUND

	if (bus->number != hose->bus_offset) {

		switch (len) {

			case 1:

				out_8(((u8 __iomem *)hose->cfg_data) +

					(offset & 3), val);

				break;

			case 2:

				out_le16(((u16 __iomem *)hose->cfg_data) +

					((offset>>1) & 1), val);

				break;



			default:

				out_le16((u16 __iomem *)hose->cfg_data,

					(u16)val);

				out_le16(((u16 __iomem *)hose->cfg_data) + 1,

					(u16)(val>>16));

				break;

		}

	}

	else

#endif

	{

		if (len != 4) {

			value = in_le32(hose->cfg_data);
@@ -84,8 +136,11 @@ mpc52xx_pci_write_config(struct pci_bus *bus, unsigned int devfn, 
		}



		out_le32(hose->cfg_data, val);

	}

	mb();



	out_be32(hose->cfg_addr, 0);

	mb();



	return PCIBIOS_SUCCESSFUL;

}

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