powercap: intel_rapl: Fix a sparse warning in TPMI interface

Depends on the interface used, the RAPL registers can be either MSR
indexes or memory mapped IO addresses. Current RAPL common code uses u64
to save both MSR and memory mapped IO registers. With this, when
handling register address with an __iomem annotation, it triggers a
sparse warning like below:

sparse warnings: (new ones prefixed by >>)
>> drivers/powercap/intel_rapl_tpmi.c:141:41: sparse: sparse: incorrect type in initializer (different address spaces) @@     expected unsigned long long [usertype] *tpmi_rapl_regs @@     got void [noderef] __iomem * @@
   drivers/powercap/intel_rapl_tpmi.c:141:41: sparse:     expected unsigned long long [usertype] *tpmi_rapl_regs
   drivers/powercap/intel_rapl_tpmi.c:141:41: sparse:     got void [noderef] __iomem *

Fix the problem by using a union to save the registers instead.

Suggested-by: David Laight <David.Laight@ACULAB.COM>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202307031405.dy3druuy-lkp@intel.com/
Tested-by: Wang Wendy <wendy.wang@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 8 insertions, 9 deletions

diff --git a/drivers/powercap/intel_rapl_tpmi.c b/drivers/powercap/intel_rapl_tpmi.c
index 4f4f13ded225..891c90fefd8b 100644
--- a/drivers/powercap/intel_rapl_tpmi.c
+++ b/drivers/powercap/intel_rapl_tpmi.c
@@ -59,10 +59,10 @@ static struct powercap_control_type *tpmi_control_type;
 
 static int tpmi_rapl_read_raw(int id, struct reg_action *ra)
 {
-	if (!ra->reg)
+	if (!ra->reg.mmio)
 		return -EINVAL;
 
-	ra->value = readq((void __iomem *)ra->reg);
+	ra->value = readq(ra->reg.mmio);
 
 	ra->value &= ra->mask;
 	return 0;
@@ -72,15 +72,15 @@ static int tpmi_rapl_write_raw(int id, struct reg_action *ra)
 {
 	u64 val;
 
-	if (!ra->reg)
+	if (!ra->reg.mmio)
 		return -EINVAL;
 
-	val = readq((void __iomem *)ra->reg);
+	val = readq(ra->reg.mmio);
 
 	val &= ~ra->mask;
 	val |= ra->value;
 
-	writeq(val, (void __iomem *)ra->reg);
+	writeq(val, ra->reg.mmio);
 	return 0;
 }
 
@@ -138,8 +138,7 @@ static int parse_one_domain(struct tpmi_rapl_package *trp, u32 offset)
 	enum tpmi_rapl_register reg_index;
 	enum rapl_domain_reg_id reg_id;
 	int tpmi_domain_size, tpmi_domain_flags;
-	u64 *tpmi_rapl_regs = trp->base + offset;
-	u64 tpmi_domain_header = readq((void __iomem *)tpmi_rapl_regs);
+	u64 tpmi_domain_header = readq(trp->base + offset);
 
 	/* Domain Parent bits are ignored for now */
 	tpmi_domain_version = tpmi_domain_header & 0xff;
@@ -180,7 +179,7 @@ static int parse_one_domain(struct tpmi_rapl_package *trp, u32 offset)
 		return -EINVAL;
 	}
 
-	if (trp->priv.regs[domain_type][RAPL_DOMAIN_REG_UNIT]) {
+	if (trp->priv.regs[domain_type][RAPL_DOMAIN_REG_UNIT].mmio) {
 		pr_warn(FW_BUG "Duplicate Domain type %d\n", tpmi_domain_type);
 		return -EINVAL;
 	}
@@ -218,7 +217,7 @@ static int parse_one_domain(struct tpmi_rapl_package *trp, u32 offset)
 		default:
 			continue;
 		}
-		trp->priv.regs[domain_type][reg_id] = (u64)&tpmi_rapl_regs[reg_index];
+		trp->priv.regs[domain_type][reg_id].mmio = trp->base + offset + reg_index * 8;
 	}
 
 	return 0;