Re: [V2 PATCH] powercap/intel_rapl: Fix a sparse warning

From: Rafael J. Wysocki
Date: Tue Aug 01 2023 - 07:47:26 EST

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On Tue, Jul 25, 2023 at 7:39 AM Zhang Rui <rui.zhang@xxxxxxxxx> wrote:
>
> Depends on the interface used, the RAPL registers can either be 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 causes 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@xxxxxxxxxx>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Closes: https://lore.kernel.org/oe-kbuild-all/202307031405.dy3druuy-lkp@xxxxxxxxx/
> Tested-by: Wang Wendy <wendy.wang@xxxxxxxxx>
> Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
> ---
> drivers/powercap/intel_rapl_common.c | 14 +++---
> drivers/powercap/intel_rapl_msr.c | 49 ++++++++++---------
> drivers/powercap/intel_rapl_tpmi.c | 17 +++----
> .../int340x_thermal/processor_thermal_rapl.c | 16 +++---
> include/linux/intel_rapl.h | 14 ++++--
> 5 files changed, 58 insertions(+), 52 deletions(-)
>
> diff --git a/drivers/powercap/intel_rapl_common.c b/drivers/powercap/intel_rapl_common.c
> index 4e646e5e48f6..8fac57b28f8a 100644
> --- a/drivers/powercap/intel_rapl_common.c
> +++ b/drivers/powercap/intel_rapl_common.c
> @@ -818,7 +818,7 @@ static int rapl_read_data_raw(struct rapl_domain *rd,
> return -EINVAL;
>
> ra.reg = rd->regs[rpi->id];
> - if (!ra.reg)
> + if (!ra.reg.val)
> return -EINVAL;
>
> /* non-hardware data are collected by the polling thread */
> @@ -830,7 +830,7 @@ static int rapl_read_data_raw(struct rapl_domain *rd,
> ra.mask = rpi->mask;
>
> if (rd->rp->priv->read_raw(get_rid(rd->rp), &ra)) {
> - pr_debug("failed to read reg 0x%llx for %s:%s\n", ra.reg, rd->rp->name, rd->name);
> + pr_debug("failed to read reg 0x%llx for %s:%s\n", ra.reg.val, rd->rp->name, rd->name);
> return -EIO;
> }
>
> @@ -920,7 +920,7 @@ static int rapl_check_unit_core(struct rapl_domain *rd)
> ra.mask = ~0;
> if (rd->rp->priv->read_raw(get_rid(rd->rp), &ra)) {
> pr_err("Failed to read power unit REG 0x%llx on %s:%s, exit.\n",
> - ra.reg, rd->rp->name, rd->name);
> + ra.reg.val, rd->rp->name, rd->name);
> return -ENODEV;
> }
>
> @@ -948,7 +948,7 @@ static int rapl_check_unit_atom(struct rapl_domain *rd)
> ra.mask = ~0;
> if (rd->rp->priv->read_raw(get_rid(rd->rp), &ra)) {
> pr_err("Failed to read power unit REG 0x%llx on %s:%s, exit.\n",
> - ra.reg, rd->rp->name, rd->name);
> + ra.reg.val, rd->rp->name, rd->name);
> return -ENODEV;
> }
>
> @@ -1135,7 +1135,7 @@ static int rapl_check_unit_tpmi(struct rapl_domain *rd)
> ra.mask = ~0;
> if (rd->rp->priv->read_raw(get_rid(rd->rp), &ra)) {
> pr_err("Failed to read power unit REG 0x%llx on %s:%s, exit.\n",
> - ra.reg, rd->rp->name, rd->name);
> + ra.reg.val, rd->rp->name, rd->name);
> return -ENODEV;
> }
>
> @@ -1411,8 +1411,8 @@ static int rapl_get_domain_unit(struct rapl_domain *rd)
> struct rapl_defaults *defaults = get_defaults(rd->rp);
> int ret;
>
> - if (!rd->regs[RAPL_DOMAIN_REG_UNIT]) {
> - if (!rd->rp->priv->reg_unit) {
> + if (!rd->regs[RAPL_DOMAIN_REG_UNIT].val) {
> + if (!rd->rp->priv->reg_unit.val) {
> pr_err("No valid Unit register found\n");
> return -ENODEV;
> }
> diff --git a/drivers/powercap/intel_rapl_msr.c b/drivers/powercap/intel_rapl_msr.c
> index 569e25eab1e1..dd471021f237 100644
> --- a/drivers/powercap/intel_rapl_msr.c
> +++ b/drivers/powercap/intel_rapl_msr.c
> @@ -34,28 +34,32 @@ static struct rapl_if_priv *rapl_msr_priv;
>
> static struct rapl_if_priv rapl_msr_priv_intel = {
> .type = RAPL_IF_MSR,
> - .reg_unit = MSR_RAPL_POWER_UNIT,
> - .regs[RAPL_DOMAIN_PACKAGE] = {
> - MSR_PKG_POWER_LIMIT, MSR_PKG_ENERGY_STATUS, MSR_PKG_PERF_STATUS, 0, MSR_PKG_POWER_INFO },
> - .regs[RAPL_DOMAIN_PP0] = {
> - MSR_PP0_POWER_LIMIT, MSR_PP0_ENERGY_STATUS, 0, MSR_PP0_POLICY, 0 },
> - .regs[RAPL_DOMAIN_PP1] = {
> - MSR_PP1_POWER_LIMIT, MSR_PP1_ENERGY_STATUS, 0, MSR_PP1_POLICY, 0 },
> - .regs[RAPL_DOMAIN_DRAM] = {
> - MSR_DRAM_POWER_LIMIT, MSR_DRAM_ENERGY_STATUS, MSR_DRAM_PERF_STATUS, 0, MSR_DRAM_POWER_INFO },
> - .regs[RAPL_DOMAIN_PLATFORM] = {
> - MSR_PLATFORM_POWER_LIMIT, MSR_PLATFORM_ENERGY_STATUS, 0, 0, 0},
> + .reg_unit.msr = MSR_RAPL_POWER_UNIT,
> + .regs[RAPL_DOMAIN_PACKAGE][RAPL_DOMAIN_REG_LIMIT].msr = MSR_PKG_POWER_LIMIT,
> + .regs[RAPL_DOMAIN_PACKAGE][RAPL_DOMAIN_REG_STATUS].msr = MSR_PKG_ENERGY_STATUS,
> + .regs[RAPL_DOMAIN_PACKAGE][RAPL_DOMAIN_REG_PERF].msr = MSR_PKG_PERF_STATUS,
> + .regs[RAPL_DOMAIN_PACKAGE][RAPL_DOMAIN_REG_INFO].msr = MSR_PKG_POWER_INFO,
> + .regs[RAPL_DOMAIN_PP0][RAPL_DOMAIN_REG_LIMIT].msr = MSR_PP0_POWER_LIMIT,
> + .regs[RAPL_DOMAIN_PP0][RAPL_DOMAIN_REG_STATUS].msr = MSR_PP0_ENERGY_STATUS,
> + .regs[RAPL_DOMAIN_PP0][RAPL_DOMAIN_REG_POLICY].msr = MSR_PP0_POLICY,
> + .regs[RAPL_DOMAIN_PP1][RAPL_DOMAIN_REG_LIMIT].msr = MSR_PP1_POWER_LIMIT,
> + .regs[RAPL_DOMAIN_PP1][RAPL_DOMAIN_REG_STATUS].msr = MSR_PP1_ENERGY_STATUS,
> + .regs[RAPL_DOMAIN_PP1][RAPL_DOMAIN_REG_POLICY].msr = MSR_PP1_POLICY,
> + .regs[RAPL_DOMAIN_DRAM][RAPL_DOMAIN_REG_LIMIT].msr = MSR_DRAM_POWER_LIMIT,
> + .regs[RAPL_DOMAIN_DRAM][RAPL_DOMAIN_REG_STATUS].msr = MSR_DRAM_ENERGY_STATUS,
> + .regs[RAPL_DOMAIN_DRAM][RAPL_DOMAIN_REG_PERF].msr = MSR_DRAM_PERF_STATUS,
> + .regs[RAPL_DOMAIN_DRAM][RAPL_DOMAIN_REG_INFO].msr = MSR_DRAM_POWER_INFO,
> + .regs[RAPL_DOMAIN_PLATFORM][RAPL_DOMAIN_REG_LIMIT].msr = MSR_PLATFORM_POWER_LIMIT,
> + .regs[RAPL_DOMAIN_PLATFORM][RAPL_DOMAIN_REG_STATUS].msr = MSR_PLATFORM_ENERGY_STATUS,
> .limits[RAPL_DOMAIN_PACKAGE] = BIT(POWER_LIMIT2),
> .limits[RAPL_DOMAIN_PLATFORM] = BIT(POWER_LIMIT2),
> };
>
> static struct rapl_if_priv rapl_msr_priv_amd = {
> .type = RAPL_IF_MSR,
> - .reg_unit = MSR_AMD_RAPL_POWER_UNIT,
> - .regs[RAPL_DOMAIN_PACKAGE] = {
> - 0, MSR_AMD_PKG_ENERGY_STATUS, 0, 0, 0 },
> - .regs[RAPL_DOMAIN_PP0] = {
> - 0, MSR_AMD_CORE_ENERGY_STATUS, 0, 0, 0 },
> + .reg_unit.msr = MSR_AMD_RAPL_POWER_UNIT,
> + .regs[RAPL_DOMAIN_PACKAGE][RAPL_DOMAIN_REG_STATUS].msr = MSR_AMD_PKG_ENERGY_STATUS,
> + .regs[RAPL_DOMAIN_PP0][RAPL_DOMAIN_REG_STATUS].msr = MSR_AMD_CORE_ENERGY_STATUS,
> };
>
> /* Handles CPU hotplug on multi-socket systems.
> @@ -99,10 +103,8 @@ static int rapl_cpu_down_prep(unsigned int cpu)
>
> static int rapl_msr_read_raw(int cpu, struct reg_action *ra)
> {
> - u32 msr = (u32)ra->reg;
> -
> - if (rdmsrl_safe_on_cpu(cpu, msr, &ra->value)) {
> - pr_debug("failed to read msr 0x%x on cpu %d\n", msr, cpu);
> + if (rdmsrl_safe_on_cpu(cpu, ra->reg.msr, &ra->value)) {
> + pr_debug("failed to read msr 0x%x on cpu %d\n", ra->reg.msr, cpu);
> return -EIO;
> }
> ra->value &= ra->mask;
> @@ -112,17 +114,16 @@ static int rapl_msr_read_raw(int cpu, struct reg_action *ra)
> static void rapl_msr_update_func(void *info)
> {
> struct reg_action *ra = info;
> - u32 msr = (u32)ra->reg;
> u64 val;
>
> - ra->err = rdmsrl_safe(msr, &val);
> + ra->err = rdmsrl_safe(ra->reg.msr, &val);
> if (ra->err)
> return;
>
> val &= ~ra->mask;
> val |= ra->value;
>
> - ra->err = wrmsrl_safe(msr, val);
> + ra->err = wrmsrl_safe(ra->reg.msr, val);
> }
>
> static int rapl_msr_write_raw(int cpu, struct reg_action *ra)
> @@ -171,7 +172,7 @@ static int rapl_msr_probe(struct platform_device *pdev)
>
> if (id) {
> rapl_msr_priv->limits[RAPL_DOMAIN_PACKAGE] |= BIT(POWER_LIMIT4);
> - rapl_msr_priv->regs[RAPL_DOMAIN_PACKAGE][RAPL_DOMAIN_REG_PL4] =
> + rapl_msr_priv->regs[RAPL_DOMAIN_PACKAGE][RAPL_DOMAIN_REG_PL4].msr =
> MSR_VR_CURRENT_CONFIG;
> pr_info("PL4 support detected.\n");
> }
> 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;
> diff --git a/drivers/thermal/intel/int340x_thermal/processor_thermal_rapl.c b/drivers/thermal/intel/int340x_thermal/processor_thermal_rapl.c
> index 013f1633f082..2f00fc3bf274 100644
> --- a/drivers/thermal/intel/int340x_thermal/processor_thermal_rapl.c
> +++ b/drivers/thermal/intel/int340x_thermal/processor_thermal_rapl.c
> @@ -57,10 +57,10 @@ static int rapl_mmio_cpu_down_prep(unsigned int cpu)
>
> static int rapl_mmio_read_raw(int cpu, 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;
> }
> @@ -69,13 +69,13 @@ static int rapl_mmio_write_raw(int cpu, 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;
> }
>
> @@ -92,13 +92,13 @@ int proc_thermal_rapl_add(struct pci_dev *pdev, struct proc_thermal_device *proc
> for (domain = RAPL_DOMAIN_PACKAGE; domain < RAPL_DOMAIN_MAX; domain++) {
> for (reg = RAPL_DOMAIN_REG_LIMIT; reg < RAPL_DOMAIN_REG_MAX; reg++)
> if (rapl_regs->regs[domain][reg])
> - rapl_mmio_priv.regs[domain][reg] =
> - (u64)proc_priv->mmio_base +
> + rapl_mmio_priv.regs[domain][reg].mmio =
> + proc_priv->mmio_base +
> rapl_regs->regs[domain][reg];
> rapl_mmio_priv.limits[domain] = rapl_regs->limits[domain];
> }
> rapl_mmio_priv.type = RAPL_IF_MMIO;
> - rapl_mmio_priv.reg_unit = (u64)proc_priv->mmio_base + rapl_regs->reg_unit;
> + rapl_mmio_priv.reg_unit.mmio = proc_priv->mmio_base + rapl_regs->reg_unit;
>
> rapl_mmio_priv.read_raw = rapl_mmio_read_raw;
> rapl_mmio_priv.write_raw = rapl_mmio_write_raw;
> diff --git a/include/linux/intel_rapl.h b/include/linux/intel_rapl.h
> index e6936cb25047..33f21bd85dbf 100644
> --- a/include/linux/intel_rapl.h
> +++ b/include/linux/intel_rapl.h
> @@ -100,10 +100,16 @@ struct rapl_package;
>
> #define RAPL_DOMAIN_NAME_LENGTH 16
>
> +union rapl_reg {
> + void __iomem *mmio;
> + u32 msr;
> + u64 val;
> +};
> +
> struct rapl_domain {
> char name[RAPL_DOMAIN_NAME_LENGTH];
> enum rapl_domain_type id;
> - u64 regs[RAPL_DOMAIN_REG_MAX];
> + union rapl_reg regs[RAPL_DOMAIN_REG_MAX];
> struct powercap_zone power_zone;
> struct rapl_domain_data rdd;
> struct rapl_power_limit rpl[NR_POWER_LIMITS];
> @@ -116,7 +122,7 @@ struct rapl_domain {
> };
>
> struct reg_action {
> - u64 reg;
> + union rapl_reg reg;
> u64 mask;
> u64 value;
> int err;
> @@ -143,8 +149,8 @@ struct rapl_if_priv {
> enum rapl_if_type type;
> struct powercap_control_type *control_type;
> enum cpuhp_state pcap_rapl_online;
> - u64 reg_unit;
> - u64 regs[RAPL_DOMAIN_MAX][RAPL_DOMAIN_REG_MAX];
> + union rapl_reg reg_unit;
> + union rapl_reg regs[RAPL_DOMAIN_MAX][RAPL_DOMAIN_REG_MAX];
> int limits[RAPL_DOMAIN_MAX];
> int (*read_raw)(int id, struct reg_action *ra);
> int (*write_raw)(int id, struct reg_action *ra);
> --

Applied (with some edits in the subject and changelog) as 6.5-rc
material, thanks!

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