On 10/3/2017 5:01 AM, George Cherian wrote: > Hi Prakash, > > On 09/29/2017 04:49 AM, Prakash, Prashanth wrote: >> Hi George, >> >> On 9/19/2017 11:24 PM, George Cherian wrote: >>> Based on ACPI 6.2 Section 8.4.7.1.9 If the PCC register space is used, >>> all PCC registers, for all processors in the same performance >>> domain (as defined by _PSD), must be defined to be in the same subspace. >>> Based on Section 14.1 of ACPI specification, it is possible to have a >>> maximum of 256 PCC subspace ids. Add support of multiple PCC subspace id >>> instead of using a single global pcc_data structure. >>> >>> While at that fix the time_delta check in send_pcc_cmd() so that last_mpar_reset >>> and mpar_count is initialized properly. >>> >>> Signed-off-by: George Cherian <george.cherian@xxxxxxxxxx> >>> --- >>> drivers/acpi/cppc_acpi.c | 243 +++++++++++++++++++++++++++++------------------ >>> 1 file changed, 153 insertions(+), 90 deletions(-) >>> >>> diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c >>> index e5b47f0..3ae79ef 100644 >>> --- a/drivers/acpi/cppc_acpi.c >>> +++ b/drivers/acpi/cppc_acpi.c >>> @@ -75,13 +75,16 @@ struct cppc_pcc_data { >>> /* Wait queue for CPUs whose requests were batched */ >>> wait_queue_head_t pcc_write_wait_q; >>> + ktime_t last_cmd_cmpl_time; >>> + ktime_t last_mpar_reset; >>> + int mpar_count; >>> + int refcount; >>> }; >>> -/* Structure to represent the single PCC channel */ >>> -static struct cppc_pcc_data pcc_data = { >>> - .pcc_subspace_idx = -1, >>> - .platform_owns_pcc = true, >>> -}; >>> +/* Array to represent the PCC channel per subspace id */ >>> +static struct cppc_pcc_data *pcc_data[MAX_PCC_SUBSPACES]; >>> +/* The cpu_pcc_subspace_idx containsper CPU subspace id */ >>> +static DEFINE_PER_CPU(int, cpu_pcc_subspace_idx); >>> /* >>> * The cpc_desc structure contains the ACPI register details >>> @@ -93,7 +96,8 @@ static struct cppc_pcc_data pcc_data = { >>> static DEFINE_PER_CPU(struct cpc_desc *, cpc_desc_ptr); >>> /* pcc mapped address + header size + offset within PCC subspace */ >>> -#define GET_PCC_VADDR(offs) (pcc_data.pcc_comm_addr + 0x8 + (offs)) >>> +#define GET_PCC_VADDR(offs, pcc_ss_id) (pcc_data[pcc_ss_id]->pcc_comm_addr + \ >>> + 0x8 + (offs)) >>> /* Check if a CPC register is in PCC */ >>> #define CPC_IN_PCC(cpc) ((cpc)->type == ACPI_TYPE_BUFFER && \ >>> @@ -188,13 +192,16 @@ static struct kobj_type cppc_ktype = { >>> .default_attrs = cppc_attrs, >>> }; >>> -static int check_pcc_chan(bool chk_err_bit) >>> +static int check_pcc_chan(int pcc_ss_id, bool chk_err_bit) >>> { >>> int ret = -EIO, status = 0; >>> - struct acpi_pcct_shared_memory __iomem *generic_comm_base = pcc_data.pcc_comm_addr; >>> - ktime_t next_deadline = ktime_add(ktime_get(), pcc_data.deadline); >>> + struct cppc_pcc_data *pcc_ss_data = pcc_data[pcc_ss_id]; >>> + struct acpi_pcct_shared_memory __iomem *generic_comm_base = >>> + pcc_ss_data->pcc_comm_addr; >>> + ktime_t next_deadline = ktime_add(ktime_get(), >>> + pcc_ss_data->deadline); >>> - if (!pcc_data.platform_owns_pcc) >>> + if (!pcc_ss_data->platform_owns_pcc) >>> return 0; >>> /* Retry in case the remote processor was too slow to catch up. */ >>> @@ -219,7 +226,7 @@ static int check_pcc_chan(bool chk_err_bit) >>> } >>> if (likely(!ret)) >>> - pcc_data.platform_owns_pcc = false; >>> + pcc_ss_data->platform_owns_pcc = false; >>> else >>> pr_err("PCC check channel failed. Status=%x\n", status); >>> @@ -230,13 +237,12 @@ static int check_pcc_chan(bool chk_err_bit) >>> * This function transfers the ownership of the PCC to the platform >>> * So it must be called while holding write_lock(pcc_lock) >>> */ >>> -static int send_pcc_cmd(u16 cmd) >>> +static int send_pcc_cmd(int pcc_ss_id, u16 cmd) >>> { >>> int ret = -EIO, i; >>> + struct cppc_pcc_data *pcc_ss_data = pcc_data[pcc_ss_id]; >>> struct acpi_pcct_shared_memory *generic_comm_base = >>> - (struct acpi_pcct_shared_memory *) pcc_data.pcc_comm_addr; >>> - static ktime_t last_cmd_cmpl_time, last_mpar_reset; >>> - static int mpar_count; >>> + (struct acpi_pcct_shared_memory *)pcc_ss_data->pcc_comm_addr; >>> unsigned int time_delta; >>> /* >>> @@ -249,24 +255,25 @@ static int send_pcc_cmd(u16 cmd) >>> * before write completion, so first send a WRITE command to >>> * platform >>> */ >>> - if (pcc_data.pending_pcc_write_cmd) >>> - send_pcc_cmd(CMD_WRITE); >>> + if (pcc_ss_data->pending_pcc_write_cmd) >>> + send_pcc_cmd(pcc_ss_id, CMD_WRITE); >>> - ret = check_pcc_chan(false); >>> + ret = check_pcc_chan(pcc_ss_id, false); >>> if (ret) >>> goto end; >>> } else /* CMD_WRITE */ >>> - pcc_data.pending_pcc_write_cmd = FALSE; >>> + pcc_ss_data->pending_pcc_write_cmd = FALSE; >>> /* >>> * Handle the Minimum Request Turnaround Time(MRTT) >>> * "The minimum amount of time that OSPM must wait after the completion >>> * of a command before issuing the next command, in microseconds" >>> */ >>> - if (pcc_data.pcc_mrtt) { >>> - time_delta = ktime_us_delta(ktime_get(), last_cmd_cmpl_time); >>> - if (pcc_data.pcc_mrtt > time_delta) >>> - udelay(pcc_data.pcc_mrtt - time_delta); >>> + if (pcc_ss_data->pcc_mrtt) { >>> + time_delta = ktime_us_delta(ktime_get(), >>> + pcc_ss_data->last_cmd_cmpl_time); >>> + if (pcc_ss_data->pcc_mrtt > time_delta) >>> + udelay(pcc_ss_data->pcc_mrtt - time_delta); >>> } >>> /* >>> @@ -280,18 +287,19 @@ static int send_pcc_cmd(u16 cmd) >>> * not send the request to the platform after hitting the MPAR limit in >>> * any 60s window >>> */ >>> - if (pcc_data.pcc_mpar) { >>> - if (mpar_count == 0) { >>> - time_delta = ktime_ms_delta(ktime_get(), last_mpar_reset); >>> - if (time_delta < 60 * MSEC_PER_SEC) { >>> + if (pcc_ss_data->pcc_mpar) { >>> + if (pcc_ss_data->mpar_count == 0) { >>> + time_delta = ktime_ms_delta(ktime_get(), >>> + pcc_ss_data->last_mpar_reset); >>> + if ((time_delta < 60 * MSEC_PER_SEC) && pcc_ss_data->last_mpar_reset) { >>> pr_debug("PCC cmd not sent due to MPAR limit"); >>> ret = -EIO; >>> goto end; >>> } >>> - last_mpar_reset = ktime_get(); >>> - mpar_count = pcc_data.pcc_mpar; >>> + pcc_ss_data->last_mpar_reset = ktime_get(); >>> + pcc_ss_data->mpar_count = pcc_ss_data->pcc_mpar; >>> } >>> - mpar_count--; >>> + pcc_ss_data->mpar_count--; >>> } >>> /* Write to the shared comm region. */ >>> @@ -300,10 +308,10 @@ static int send_pcc_cmd(u16 cmd) >>> /* Flip CMD COMPLETE bit */ >>> writew_relaxed(0, &generic_comm_base->status); >>> - pcc_data.platform_owns_pcc = true; >>> + pcc_ss_data->platform_owns_pcc = true; >>> /* Ring doorbell */ >>> - ret = mbox_send_message(pcc_data.pcc_channel, &cmd); >>> + ret = mbox_send_message(pcc_ss_data->pcc_channel, &cmd); >>> if (ret < 0) { >>> pr_err("Err sending PCC mbox message. cmd:%d, ret:%d\n", >>> cmd, ret); >>> @@ -311,15 +319,15 @@ static int send_pcc_cmd(u16 cmd) >>> } >>> /* wait for completion and check for PCC errro bit */ >>> - ret = check_pcc_chan(true); >>> + ret = check_pcc_chan(pcc_ss_id, true); >>> - if (pcc_data.pcc_mrtt) >>> - last_cmd_cmpl_time = ktime_get(); >>> + if (pcc_ss_data->pcc_mrtt) >>> + pcc_ss_data->last_cmd_cmpl_time = ktime_get(); >>> - if (pcc_data.pcc_channel->mbox->txdone_irq) >>> - mbox_chan_txdone(pcc_data.pcc_channel, ret); >>> + if (pcc_ss_data->pcc_channel->mbox->txdone_irq) >>> + mbox_chan_txdone(pcc_ss_data->pcc_channel, ret); >>> else >>> - mbox_client_txdone(pcc_data.pcc_channel, ret); >>> + mbox_client_txdone(pcc_ss_data->pcc_channel, ret); >>> end: >>> if (cmd == CMD_WRITE) { >>> @@ -329,12 +337,12 @@ static int send_pcc_cmd(u16 cmd) >>> if (!desc) >>> continue; >>> - if (desc->write_cmd_id == pcc_data.pcc_write_cnt) >>> + if (desc->write_cmd_id == pcc_ss_data->pcc_write_cnt) >>> desc->write_cmd_status = ret; >>> } >>> } >>> - pcc_data.pcc_write_cnt++; >>> - wake_up_all(&pcc_data.pcc_write_wait_q); >>> + pcc_ss_data->pcc_write_cnt++; >>> + wake_up_all(&pcc_ss_data->pcc_write_wait_q); >>> } >>> return ret; >>> @@ -536,16 +544,16 @@ int acpi_get_psd_map(struct cppc_cpudata **all_cpu_data) >>> } >>> EXPORT_SYMBOL_GPL(acpi_get_psd_map); >>> -static int register_pcc_channel(int pcc_subspace_idx) >>> +static int register_pcc_channel(int pcc_ss_idx) >>> { >>> struct acpi_pcct_hw_reduced *cppc_ss; >>> u64 usecs_lat; >>> - if (pcc_subspace_idx >= 0) { >>> - pcc_data.pcc_channel = pcc_mbox_request_channel(&cppc_mbox_cl, >>> - pcc_subspace_idx); >>> + if (pcc_ss_idx >= 0) { >>> + pcc_data[pcc_ss_idx]->pcc_channel = >>> + pcc_mbox_request_channel(&cppc_mbox_cl, pcc_ss_idx); >>> - if (IS_ERR(pcc_data.pcc_channel)) { >>> + if (IS_ERR(pcc_data[pcc_ss_idx]->pcc_channel)) { >>> pr_err("Failed to find PCC communication channel\n"); >>> return -ENODEV; >>> } >>> @@ -556,7 +564,7 @@ static int register_pcc_channel(int pcc_subspace_idx) >>> * PCC channels) and stored pointers to the >>> * subspace communication region in con_priv. >>> */ >>> - cppc_ss = (pcc_data.pcc_channel)->con_priv; >>> + cppc_ss = (pcc_data[pcc_ss_idx]->pcc_channel)->con_priv; >>> if (!cppc_ss) { >>> pr_err("No PCC subspace found for CPPC\n"); >>> @@ -569,19 +577,20 @@ static int register_pcc_channel(int pcc_subspace_idx) >>> * So add an arbitrary amount of wait on top of Nominal. >>> */ >>> usecs_lat = NUM_RETRIES * cppc_ss->latency; >>> - pcc_data.deadline = ns_to_ktime(usecs_lat * NSEC_PER_USEC); >>> - pcc_data.pcc_mrtt = cppc_ss->min_turnaround_time; >>> - pcc_data.pcc_mpar = cppc_ss->max_access_rate; >>> - pcc_data.pcc_nominal = cppc_ss->latency; >>> - >>> - pcc_data.pcc_comm_addr = acpi_os_ioremap(cppc_ss->base_address, cppc_ss->length); >>> - if (!pcc_data.pcc_comm_addr) { >>> + pcc_data[pcc_ss_idx]->deadline = ns_to_ktime(usecs_lat * NSEC_PER_USEC); >>> + pcc_data[pcc_ss_idx]->pcc_mrtt = cppc_ss->min_turnaround_time; >>> + pcc_data[pcc_ss_idx]->pcc_mpar = cppc_ss->max_access_rate; >>> + pcc_data[pcc_ss_idx]->pcc_nominal = cppc_ss->latency; >>> + >>> + pcc_data[pcc_ss_idx]->pcc_comm_addr = >>> + acpi_os_ioremap(cppc_ss->base_address, cppc_ss->length); >>> + if (!pcc_data[pcc_ss_idx]->pcc_comm_addr) { >>> pr_err("Failed to ioremap PCC comm region mem\n"); >>> return -ENOMEM; >>> } >>> /* Set flag so that we dont come here for each CPU. */ >>> - pcc_data.pcc_channel_acquired = true; >>> + pcc_data[pcc_ss_idx]->pcc_channel_acquired = true; >>> } >>> return 0; >>> @@ -600,6 +609,39 @@ bool __weak cpc_ffh_supported(void) >>> return false; >>> } >>> + >>> +/** >>> + * pcc_data_alloc() - Allocate the pcc_data memory for pcc subspace >>> + * >>> + * Check and allocate the cppc_pcc_data memory. >>> + * In some processor configurations it is possible that same subspace >>> + * is shared between multiple CPU's. This is seen especially in CPU's >>> + * with hardware multi-threading support. >>> + * >>> + * Return: 0 for success, errno for failure >>> + */ >>> +int pcc_data_alloc(int pcc_ss_id) >>> +{ >>> + int loop; >>> + >>> + if (pcc_ss_id < 0) >> Above should be (pcc_ss_id < 0 || pcc_ss_id >= MAX_PCC_SUBSPACES) > Yes we can have this additional check. >>> + return -EINVAL; >>> + >>> + for (loop = 0; pcc_data[loop] != NULL; loop++) { >>> + if (pcc_data[loop]->pcc_subspace_idx == pcc_ss_id) { >>> + pcc_data[loop]->refcount++; >>> + return 0; >>> + } >>> + } >> Why do we need the above for loop? can't it be direct array lookup? >> if (pcc_data[pcc_ss_id]) { >> //increment ref_count and return >> } > Yes, we could get rid of the loop and increment the reference directly if already allocated. > >> >> Also, we should remove the pcc_subspace_idx from cppc_pcc_data structure, >> it is no longer useful and probably adds to confusion. > Please see below >>> + >>> + pcc_data[pcc_ss_id] = kzalloc(sizeof(struct cppc_pcc_data), GFP_KERNEL); >>> + if (!pcc_data[pcc_ss_id]) >>> + return -ENOMEM; >>> + pcc_data[pcc_ss_id]->pcc_subspace_idx = pcc_ss_id; >>> + pcc_data[pcc_ss_id]->refcount++; >>> + >>> + return 0; >>> +} >>> /* >>> * An example CPC table looks like the following. >>> * >>> @@ -661,6 +703,7 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr) >>> struct device *cpu_dev; >>> acpi_handle handle = pr->handle; >>> unsigned int num_ent, i, cpc_rev; >>> + int pcc_subspace_id = -1; >>> acpi_status status; >>> int ret = -EFAULT; >>> @@ -733,12 +776,9 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr) >>> * so extract it only once. >>> */ >>> if (gas_t->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) { >>> - if (pcc_data.pcc_subspace_idx < 0) >>> - pcc_data.pcc_subspace_idx = gas_t->access_width; >>> - else if (pcc_data.pcc_subspace_idx != gas_t->access_width) { >>> - pr_debug("Mismatched PCC ids.\n"); >> We need to retain the above checks to make sure all PCC registers >> within a _CPC package is under same subspace. The Spec still requires: >> "If the PCC register space is used, all PCC registers, for all processors in >> the same performance domain (as defined by _PSD), must be defined >> to be in the same subspace." > > So that means we need to maintain the pcc_subspace_idx in cppc_pcc_data. > If so, then I can move the check inside pcc_data_alloc(). We need the pcc_subspace_idx for checking only withing the context of this function, so tracking that data in a local variable will be sufficient. >> >>> + pcc_subspace_id = gas_t->access_width; >>> + if (pcc_data_alloc(pcc_subspace_id)) >>> goto out_free; >> We need to call pcc_data_alloc(to increment the reference) only once per CPU, >> otherwise acpi_cppc_processor_exit( ) will never free the memory allocated in >> pcc_data. > > It is infact called only once per CPU, The refcounting was added in case if multiple CPU's share the same domain for eg: > In instances, where CPU have hardware multi-threading support. > or in cases where all CPU's are controlled using single subspace (as earlier). No, it is getting called for every PCC registers within a _CPC package, instead it needs to be called only once per _CPC package irrespective of number of PCC registers within the_CPC package. > > Do you see any issue with acpi_cppc_processor_exit() in the earlier cases, where refcount remains > 0 and the memory not getting freed-up? >> >> >> -- >> Thanks, >> Prashanth >> -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html