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Commit 09752a12 authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Jason Cooper
Browse files

bus: mvebu-mbus: Avoid setting an undefined window size 



The mbus hardware requires a power of two size, and size aligned base.
Currently, if a non-power of two is passed in to the low level routines
they configure the register in a way that results in undefined behaviour.

Call WARN and return EINVAL instead.

Also, update the debugfs routines to show a message if there is an
invalid register setting.

All together this makes the recent problems with silent failure
of PCI very obvious, noisy and debuggable.

Signed-off-by: default avatarJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1397823593-1932-6-git-send-email-thomas.petazzoni@free-electrons.com


Signed-off-by: default avatarJason Cooper <jason@lakedaemon.net>
parent b6d07e02

drivers/bus/mvebu-mbus.c

+16 −0
Original line number Diff line number Diff line
@@ -56,6 +56,7 @@ 
#include <linux/of.h>

#include <linux/of_address.h>

#include <linux/debugfs.h>

#include <linux/log2.h>



/*

 * DDR target is the same on all platforms.
@@ -266,6 +267,17 @@ static int mvebu_mbus_setup_window(struct mvebu_mbus_state *mbus, 
		mbus->soc->win_cfg_offset(win);

	u32 ctrl, remap_addr;



	if (!is_power_of_2(size)) {

		WARN(true, "Invalid MBus window size: 0x%zx\n", size);

		return -EINVAL;

	}



	if ((base & (phys_addr_t)(size - 1)) != 0) {

		WARN(true, "Invalid MBus base/size: %pa len 0x%zx\n", &base,

		     size);

		return -EINVAL;

	}



	ctrl = ((size - 1) & WIN_CTRL_SIZE_MASK) |

		(attr << WIN_CTRL_ATTR_SHIFT)    |

		(target << WIN_CTRL_TGT_SHIFT)   |
@@ -413,6 +425,10 @@ static int mvebu_devs_debug_show(struct seq_file *seq, void *v) 
			   win, (unsigned long long)wbase,

			   (unsigned long long)(wbase + wsize), wtarget, wattr);



		if (!is_power_of_2(wsize) ||

		    ((wbase & (u64)(wsize - 1)) != 0))

			seq_puts(seq, " (Invalid base/size!!)");



		if (win < mbus->soc->num_remappable_wins) {

			seq_printf(seq, " (remap %016llx)\n",

				   (unsigned long long)wremap);