To align with ACPI 6.3+, since bit_width can be any 8-bit value, we cannot depend on it being always on a clean 8b boundary. Instead, use access_width to determine the size and use the offset and width to shift and mask the bits we want to read/write out. Make sure to add a check for system memory since pcc redefines the access_width to subspace id. Signed-off-by: Jarred White <jarredwhite@xxxxxxxxxxxxxxxxxxx> --- Original thread https://lore.kernel.org/all/20230925180552.76071-1-jarredwhite@xxxxxxxxxxxxxxxxxxx/ --- changelog: v1-->v2: 1. Fixed coding style errors 2. Backwards compatibility with ioremapping of address still an open question. Suggestions are welcomed. drivers/acpi/cppc_acpi.c | 36 +++++++++++++++++++++++++++++++----- 1 file changed, 31 insertions(+), 5 deletions(-) diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index 7ff269a78c20..fb37e1727bf8 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -163,6 +163,13 @@ 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); +/* Use access_width to determine the total number of bits */ +#define ACCESS_WIDTH_TO_BITS(reg) 8 << ((reg)->access_width - 1) + +/* Shift and apply the mask for CPC reads/writes */ +#define MASK_VAL(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) { @@ -777,6 +784,7 @@ 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; if (!osc_cpc_flexible_adr_space_confirmed) { pr_debug("Flexible address space capability not supported\n"); @@ -784,7 +792,8 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr) goto out_free; } - addr = ioremap(gas_t->address, gas_t->bit_width/8); + access_width = ACCESS_WIDTH_TO_BITS(gas_t) / 8; + addr = ioremap(gas_t->address, access_width); if (!addr) goto out_free; cpc_ptr->cpc_regs[i-2].sys_mem_vaddr = addr; @@ -980,6 +989,7 @@ int __weak cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val) static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val) { void __iomem *vaddr = NULL; + int size; int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); struct cpc_reg *reg = ®_res->cpc_entry.reg; @@ -991,7 +1001,7 @@ static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val) *val = 0; if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { - u32 width = 8 << (reg->access_width - 1); + u32 width = ACCESS_WIDTH_TO_BITS(reg); u32 val_u32; acpi_status status; @@ -1015,7 +1025,12 @@ 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); - switch (reg->bit_width) { + if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) + size = ACCESS_WIDTH_TO_BITS(reg); + else + size = reg->bit_width; + + switch (size) { case 8: *val = readb_relaxed(vaddr); break; @@ -1034,18 +1049,22 @@ static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val) return -EFAULT; } + if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) + *val = MASK_VAL(*val); + return 0; } 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 = ®_res->cpc_entry.reg; if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { - u32 width = 8 << (reg->access_width - 1); + u32 width = ACCESS_WIDTH_TO_BITS(reg); acpi_status status; status = acpi_os_write_port((acpi_io_address)reg->address, @@ -1067,7 +1086,14 @@ 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); - switch (reg->bit_width) { + if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { + size = ACCESS_WIDTH_TO_BITS(reg); + val = MASK_VAL(val); + } else { + size = reg->bit_width; + } + + switch (size) { case 8: writeb_relaxed(val, vaddr); break; -- 2.34.1
