Revert "ACPI: CPPC: Use access_width over bit_width for system memory…

… accesses"

This reverts commit 4949aff which is
commit 2f4a4d6 upstream.

It breaks AmpereOne systems and should not have been added to the stable
tree just yet.

Link: https://lore.kernel.org/r/97d25ef7-dee9-4cc5-842a-273f565869b3@linux.microsoft.com
Reported-by: Easwar Hariharan <eahariha@linux.microsoft.com>
Cc: Jarred White <jarredwhite@linux.microsoft.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/acpi/cppc_acpi.c

@@ -161,13 +161,6 @@ show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, nominal_freq);
 show_cppc_data(cppc_get_perf_ctrs, cppc_perf_fb_ctrs, reference_perf);
 show_cppc_data(cppc_get_perf_ctrs, cppc_perf_fb_ctrs, wraparound_time);
 
-/* Check for valid access_width, otherwise, fallback to using bit_width */
-#define GET_BIT_WIDTH(reg) ((reg)->access_width ? (8 << ((reg)->access_width - 1)) : (reg)->bit_width)
-
-/* Shift and apply the mask for CPC reads/writes */
-#define MASK_VAL(reg, val) ((val) >> ((reg)->bit_offset & 			\
-					GENMASK(((reg)->bit_width), 0)))
-
 static ssize_t show_feedback_ctrs(struct kobject *kobj,
 		struct kobj_attribute *attr, char *buf)
 {
@@ -769,10 +762,8 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
 			} else if (gas_t->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
 				if (gas_t->address) {
 					void __iomem *addr;
-					size_t access_width;
 
-					access_width = GET_BIT_WIDTH(gas_t) / 8;
-					addr = ioremap(gas_t->address, access_width);
+					addr = ioremap(gas_t->address, gas_t->bit_width/8);
 					if (!addr)
 						goto out_free;
 					cpc_ptr->cpc_regs[i-2].sys_mem_vaddr = addr;
@@ -945,7 +936,6 @@ static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val)
 {
 	int ret_val = 0;
 	void __iomem *vaddr = NULL;
-	int size;
 	int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu);
 	struct cpc_reg *reg = &reg_res->cpc_entry.reg;
 
@@ -965,9 +955,7 @@ static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val)
 		return acpi_os_read_memory((acpi_physical_address)reg->address,
 				val, reg->bit_width);
 
-	size = GET_BIT_WIDTH(reg);
-
-	switch (size) {
+	switch (reg->bit_width) {
 	case 8:
 		*val = readb_relaxed(vaddr);
 		break;
@@ -986,16 +974,12 @@ static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val)
 		ret_val = -EFAULT;
 	}
 
-	if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
-		*val = MASK_VAL(reg, *val);
-
 	return ret_val;
 }
 
 static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
 {
 	int ret_val = 0;
-	int size;
 	void __iomem *vaddr = NULL;
 	int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu);
 	struct cpc_reg *reg = &reg_res->cpc_entry.reg;
@@ -1010,12 +994,7 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
 		return acpi_os_write_memory((acpi_physical_address)reg->address,
 				val, reg->bit_width);
 
-	size = GET_BIT_WIDTH(reg);
-
-	if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
-		val = MASK_VAL(reg, val);
-
-	switch (size) {
+	switch (reg->bit_width) {
 	case 8:
 		writeb_relaxed(val, vaddr);
 		break;