Re: [PATCH v1 4/4] power/amd_uncore: uncore power management support for AMD EPYC processors

["Hunt, David" <david.hunt@intel.com>]

On 20/07/2024 17:50, Sivaprasad Tummala wrote:
> This patch introduces driver support for power management of uncore
> components in AMD EPYC processors.
>
> Signed-off-by: Sivaprasad Tummala <sivaprasad.tummala@amd.com>
> ---
>   drivers/power/amd_uncore/amd_uncore.c | 321 ++++++++++++++++++++++++++
>   drivers/power/amd_uncore/amd_uncore.h | 226 ++++++++++++++++++
>   drivers/power/amd_uncore/meson.build  |  20 ++
>   drivers/power/meson.build             |   1 +
>   4 files changed, 568 insertions(+)
>   create mode 100644 drivers/power/amd_uncore/amd_uncore.c
>   create mode 100644 drivers/power/amd_uncore/amd_uncore.h
>   create mode 100644 drivers/power/amd_uncore/meson.build
>
> diff --git a/drivers/power/amd_uncore/amd_uncore.c b/drivers/power/amd_uncore/amd_uncore.c
> new file mode 100644
> index 0000000000..f15eaaa307
> --- /dev/null
> +++ b/drivers/power/amd_uncore/amd_uncore.c
> @@ -0,0 +1,321 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2024 Advanced Micro Devices, Inc.
> + */
> +
> +#include <errno.h>
> +#include <dirent.h>
> +#include <fnmatch.h>
> +
> +#include <rte_memcpy.h>
> +
> +#include "amd_uncore.h"
> +#include "power_common.h"
> +#include "e_smi/e_smi.h"
> +
> +#define MAX_UNCORE_FREQS 8
> +#define MAX_NUMA_DIE 8
> +
> +#define BUS_FREQ 1000
> +
> +struct  __rte_cache_aligned uncore_power_info {
> +	unsigned int die;                  /* Core die id */
> +	unsigned int pkg;                  /* Package id */
> +	uint32_t freqs[MAX_UNCORE_FREQS];  /* Frequency array */
> +	uint32_t nb_freqs;                 /* Number of available freqs */
> +	uint32_t curr_idx;                 /* Freq index in freqs array */
> +	uint32_t max_freq;            /* System max uncore freq */
> +	uint32_t min_freq;            /* System min uncore freq */
> +};
> +
> +static struct uncore_power_info uncore_info[RTE_MAX_NUMA_NODES][MAX_NUMA_DIE];
> +static int esmi_initialized;
> +
> +static int
> +set_uncore_freq_internal(struct uncore_power_info *ui, uint32_t idx)
> +{
> +	int ret;
> +
> +	if (idx >= MAX_UNCORE_FREQS || idx >= ui->nb_freqs) {
> +		POWER_LOG(DEBUG, "Invalid uncore frequency index %u, which "
> +				"should be less than %u", idx, ui->nb_freqs);
> +		return -1;
> +	}
> +
> +	ret = esmi_apb_disable(ui->pkg, idx);
> +	if (ret != ESMI_SUCCESS) {
> +		POWER_LOG(ERR, "DF P-state '%u' set failed for pkg %02u",
> +				idx, ui->pkg);
> +		return -1;
> +	}
> +
> +	POWER_DEBUG_LOG("DF P-state '%u' to be set for pkg %02u die %02u",
> +				idx, ui->pkg, ui->die);
> +
> +	/* write the minimum value first if the target freq is less than current max */
> +	ui->curr_idx = idx;
> +
> +	return 0;
> +}
> +
> +/*
> + * Fopen the sys file for the future setting of the uncore die frequency.
> + */


Comment may need updating, as function is not reading any sysfs files 
(for the moment, at least).


> +static int
> +power_init_for_setting_uncore_freq(struct uncore_power_info *ui)
> +{
> +	/* open and read all uncore sys files */


Comment may need updating, as function is not reading any sysfs files 
(for the moment, at least).



> +	/* Base max */
> +	ui->max_freq = 1800000;
> +	ui->min_freq = 1200000;
> +
> +	return 0;
> +}
> +
> +/*
> + * Get the available uncore frequencies of the specific die by reading the
> + * sys file.
> + */


Comment may need updating, as function is not reading any sysfs files. 3 
uncore frequencies hard-coded for the moment, may get via esmi or sysfs 
in the future.


> +static int
> +power_get_available_uncore_freqs(struct uncore_power_info *ui)
> +{
> +	int ret = -1;
> +	uint32_t i, num_uncore_freqs = 3;
> +	uint32_t fabric_freqs[] = {
> +	/* to be extended for probing support in future */
> +		1800,
> +		1444,
> +		1200
> +	};
> +
> +	if (num_uncore_freqs >= MAX_UNCORE_FREQS) {
> +		POWER_LOG(ERR, "Too many available uncore frequencies: %d",
> +				num_uncore_freqs);
> +		goto out;
> +	}
> +
> +	/* Generate the uncore freq bucket array. */
> +	for (i = 0; i < num_uncore_freqs; i++)
> +		ui->freqs[i] = fabric_freqs[i] * BUS_FREQ;
> +
> +	ui->nb_freqs = num_uncore_freqs;
> +
> +	ret = 0;
> +
> +	POWER_DEBUG_LOG("%d frequency(s) of pkg %02u die %02u are available",
> +			num_uncore_freqs, ui->pkg, ui->die);
> +
> +out:
> +	return ret;
> +}
> +


--snip--

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