[PATCH] nios2: Fix ioremap

* [PATCH] nios2: Fix ioremap
@ 2019-12-05  2:41 Guenter Roeck
  2019-12-05 14:25 ` Christoph Hellwig
  2019-12-12  8:53 ` Tan, Ley Foon
  0 siblings, 2 replies; 3+ messages in thread
From: Guenter Roeck @ 2019-12-05  2:41 UTC (permalink / raw)
  To: Ley Foon Tan; +Cc: nios2-dev, linux-kernel, Guenter Roeck, Christoph Hellwig

Commit 5ace77e0b41a ("nios2: remove __ioremap") removed the following code,
with the argument that cacheflag is always 0 and the expression would
therefore always be false.

	if (IS_MAPPABLE_UNCACHEABLE(phys_addr) &&
	    IS_MAPPABLE_UNCACHEABLE(last_addr) &&
	    !(cacheflag & _PAGE_CACHED))
		return (void __iomem *)(CONFIG_NIOS2_IO_REGION_BASE + phys_addr);

This did not take the "!" in the expression into account. Result is that
nios2 images no longer boot. Restoring the removed code fixes the problem.

Fixes: 5ace77e0b41a ("nios2: remove __ioremap")
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 arch/nios2/mm/ioremap.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/nios2/mm/ioremap.c b/arch/nios2/mm/ioremap.c
index b56af759dcdf..819bdfcc2e71 100644
--- a/arch/nios2/mm/ioremap.c
+++ b/arch/nios2/mm/ioremap.c
@@ -138,6 +138,14 @@ void __iomem *ioremap(unsigned long phys_addr, unsigned long size)
 				return NULL;
 	}
 
+	/*
+	 * Map uncached objects in the low part of address space to
+	 * CONFIG_NIOS2_IO_REGION_BASE
+	 */
+	if (IS_MAPPABLE_UNCACHEABLE(phys_addr) &&
+	    IS_MAPPABLE_UNCACHEABLE(last_addr))
+		return (void __iomem *)(CONFIG_NIOS2_IO_REGION_BASE + phys_addr);
+
 	/* Mappings have to be page-aligned */
 	offset = phys_addr & ~PAGE_MASK;
 	phys_addr &= PAGE_MASK;
-- 
2.17.1


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