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ACPI: CPPC: Fix access width used for PCC registers 

commit 2f4a4d63a1 ("ACPI: CPPC: Use access_width over bit_width for system
memory accesses") modified cpc_read()/cpc_write() to use access_width to
read CPC registers.

However, for PCC registers the access width field in the ACPI register
macro specifies the PCC subspace ID.  For non-zero PCC subspace ID it is
incorrectly treated as access width. This causes errors when reading
from PCC registers in the CPPC driver.

For PCC registers, base the size of read/write on the bit width field.
The debug message in cpc_read()/cpc_write() is updated to print relevant
information for the address space type used to read the register.

Fixes: 2f4a4d63a1 ("ACPI: CPPC: Use access_width over bit_width for system memory accesses")
Signed-off-by: Vanshidhar Konda <vanshikonda@os.amperecomputing.com>
Tested-by: Jarred White <jarredwhite@linux.microsoft.com>
Reviewed-by: Jarred White <jarredwhite@linux.microsoft.com>
Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com>
Cc: 5.15+ <stable@vger.kernel.org> # 5.15+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Vanshidhar Konda 2024-04-11 16:18:44 -07:00 committed by Rafael J. Wysocki
parent 05d92ee782
commit f489c94802
1 changed files with 37 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

53
drivers/acpi/cppc_acpi.c
View File

@ -1002,14 +1002,14 @@ static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val)
}
*val = 0;
size = GET_BIT_WIDTH(reg);
if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
u32 width = GET_BIT_WIDTH(reg);
u32 val_u32;
acpi_status status;
status = acpi_os_read_port((acpi_io_address)reg->address,
&val_u32, width);
&val_u32, size);
if (ACPI_FAILURE(status)) {
pr_debug("Error: Failed to read SystemIO port %llx\n",
reg->address);
@ -1018,17 +1018,22 @@ static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val)
*val = val_u32;
return 0;
} else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM && pcc_ss_id >= 0)
} else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM && pcc_ss_id >= 0) {
/*
* For registers in PCC space, the register size is determined
* by the bit width field; the access size is used to indicate
* the PCC subspace id.
*/
size = reg->bit_width;
vaddr = GET_PCC_VADDR(reg->address, pcc_ss_id);
}
else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
vaddr = reg_res->sys_mem_vaddr;
else if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE)
return cpc_read_ffh(cpu, reg, val);
else
return acpi_os_read_memory((acpi_physical_address)reg->address,
val, reg->bit_width);
size = GET_BIT_WIDTH(reg);
val, size);
switch (size) {
case 8:
@ -1044,8 +1049,13 @@ static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val)
*val = readq_relaxed(vaddr);
break;
default:
pr_debug("Error: Cannot read %u bit width from PCC for ss: %d\n",
reg->bit_width, pcc_ss_id);
if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
pr_debug("Error: Cannot read %u bit width from system memory: 0x%llx\n",
size, reg->address);
} else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) {
pr_debug("Error: Cannot read %u bit width from PCC for ss: %d\n",
size, pcc_ss_id);
}
return -EFAULT;
}
@ -1063,12 +1073,13 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu);
struct cpc_reg *reg = &reg_res->cpc_entry.reg;
size = GET_BIT_WIDTH(reg);
if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
u32 width = GET_BIT_WIDTH(reg);
acpi_status status;
status = acpi_os_write_port((acpi_io_address)reg->address,
(u32)val, width);
(u32)val, size);
if (ACPI_FAILURE(status)) {
pr_debug("Error: Failed to write SystemIO port %llx\n",
reg->address);
@ -1076,17 +1087,22 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
}
return 0;
} else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM && pcc_ss_id >= 0)
} else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM && pcc_ss_id >= 0) {
/*
* For registers in PCC space, the register size is determined
* by the bit width field; the access size is used to indicate
* the PCC subspace id.
*/
size = reg->bit_width;
vaddr = GET_PCC_VADDR(reg->address, pcc_ss_id);
}
else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
vaddr = reg_res->sys_mem_vaddr;
else if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE)
return cpc_write_ffh(cpu, reg, val);
else
return acpi_os_write_memory((acpi_physical_address)reg->address,
val, reg->bit_width);
size = GET_BIT_WIDTH(reg);
val, size);
if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
val = MASK_VAL(reg, val);
@ -1105,8 +1121,13 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
writeq_relaxed(val, vaddr);
break;
default:
pr_debug("Error: Cannot write %u bit width to PCC for ss: %d\n",
reg->bit_width, pcc_ss_id);
if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
pr_debug("Error: Cannot write %u bit width to system memory: 0x%llx\n",
size, reg->address);
} else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) {
pr_debug("Error: Cannot write %u bit width to PCC for ss: %d\n",
size, pcc_ss_id);
}
ret_val = -EFAULT;
break;
}