EDAC/i10nm: Use readl() to access MMIO registers

commit 83ff51c upstream.

Instead of raw access, use readl() to access MMIO registers of
memory controller to avoid possible compiler re-ordering.

Fixes: d4dc89d ("EDAC, i10nm: Add a driver for Intel 10nm server processors")
Cc: <stable@vger.kernel.org>
Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/edac/i10nm_base.c

@@ -6,6 +6,7 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/io.h>
 #include <asm/cpu_device_id.h>
 #include <asm/intel-family.h>
 #include <asm/mce.h>
@@ -19,14 +20,16 @@
 #define i10nm_printk(level, fmt, arg...)	\
 	edac_printk(level, "i10nm", fmt, ##arg)
 
-#define I10NM_GET_SCK_BAR(d, reg)		\
+#define I10NM_GET_SCK_BAR(d, reg)	\
 	pci_read_config_dword((d)->uracu, 0xd0, &(reg))
 #define I10NM_GET_IMC_BAR(d, i, reg)	\
 	pci_read_config_dword((d)->uracu, 0xd8 + (i) * 4, &(reg))
 #define I10NM_GET_DIMMMTR(m, i, j)	\
-	(*(u32 *)((m)->mbase + 0x2080c + (i) * 0x4000 + (j) * 4))
+	readl((m)->mbase + 0x2080c + (i) * 0x4000 + (j) * 4)
 #define I10NM_GET_MCDDRTCFG(m, i, j)	\
-	(*(u32 *)((m)->mbase + 0x20970 + (i) * 0x4000 + (j) * 4))
+	readl((m)->mbase + 0x20970 + (i) * 0x4000 + (j) * 4)
+#define I10NM_GET_MCMTR(m, i)		\
+	readl((m)->mbase + 0x20ef8 + (i) * 0x4000)
 
 #define I10NM_GET_SCK_MMIO_BASE(reg)	(GET_BITFIELD(reg, 0, 28) << 23)
 #define I10NM_GET_IMC_MMIO_OFFSET(reg)	(GET_BITFIELD(reg, 0, 10) << 12)
@@ -134,7 +137,7 @@ static bool i10nm_check_ecc(struct skx_imc *imc, int chan)
 {
 	u32 mcmtr;
 
-	mcmtr = *(u32 *)(imc->mbase + 0x20ef8 + chan * 0x4000);
+	mcmtr = I10NM_GET_MCMTR(imc, chan);
 	edac_dbg(1, "ch%d mcmtr reg %x\n", chan, mcmtr);
 
 	return !!GET_BITFIELD(mcmtr, 2, 2);