Custom BIOS input values can be updated by multiple sources, such as power
mode changes and sensor events, each triggering a custom BIOS input event.
When these events occur in rapid succession, new data may overwrite
previous values before they are processed, resulting in lost updates.
To address this, introduce a fixed-size, power-of-two ring buffer to
capture every custom BIOS input event, storing both the pending request
and its associated input values. Access to the ring buffer is synchronized
using a mutex.
The previous use of memset() to clear the pending request structure after
each event is removed, as each BIOS input value is now copied into the
buffer as a snapshot. Consumers now process entries directly from the ring
buffer, making explicit clearing of the pending request structure
unnecessary.
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Tested-by: Yijun Shen <Yijun.Shen@Dell.com>
Co-developed-by: Patil Rajesh Reddy <Patil.Reddy@amd.com>
Signed-off-by: Patil Rajesh Reddy <Patil.Reddy@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20251202042219.245173-1-Shyam-sundar.S-k@amd.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
*/
#include <linux/acpi.h>
+#include <linux/array_size.h>
+#include <linux/cleanup.h>
+#include <linux/dev_printk.h>
#include "pmf.h"
#define APMF_CQL_NOTIFICATION 2
req, sizeof(*req));
}
+/* Store custom BIOS inputs data in ring buffer */
+static void amd_pmf_custom_bios_inputs_rb(struct amd_pmf_dev *pmf_dev)
+{
+ struct pmf_cbi_ring_buffer *rb = &pmf_dev->cbi_buf;
+ int i;
+
+ guard(mutex)(&pmf_dev->cbi_mutex);
+
+ switch (pmf_dev->cpu_id) {
+ case AMD_CPU_ID_PS:
+ for (i = 0; i < ARRAY_SIZE(custom_bios_inputs_v1); i++)
+ rb->data[rb->head].val[i] = pmf_dev->req1.custom_policy[i];
+ rb->data[rb->head].preq = pmf_dev->req1.pending_req;
+ break;
+ case PCI_DEVICE_ID_AMD_1AH_M20H_ROOT:
+ case PCI_DEVICE_ID_AMD_1AH_M60H_ROOT:
+ for (i = 0; i < ARRAY_SIZE(custom_bios_inputs); i++)
+ rb->data[rb->head].val[i] = pmf_dev->req.custom_policy[i];
+ rb->data[rb->head].preq = pmf_dev->req.pending_req;
+ break;
+ default:
+ return;
+ }
+
+ if (CIRC_SPACE(rb->head, rb->tail, CUSTOM_BIOS_INPUT_RING_ENTRIES) == 0) {
+ /* Rare case: ensures the newest BIOS input value is kept */
+ dev_warn(pmf_dev->dev, "Overwriting BIOS input value, data may be lost\n");
+ rb->tail = (rb->tail + 1) & (CUSTOM_BIOS_INPUT_RING_ENTRIES - 1);
+ }
+
+ rb->head = (rb->head + 1) & (CUSTOM_BIOS_INPUT_RING_ENTRIES - 1);
+}
+
static void amd_pmf_handle_early_preq(struct amd_pmf_dev *pdev)
{
if (!pdev->cb_flag)
dev_dbg(pmf_dev->dev, "Pending request (preq): 0x%x\n", pmf_dev->req.pending_req);
amd_pmf_handle_early_preq(pmf_dev);
+
+ amd_pmf_custom_bios_inputs_rb(pmf_dev);
}
static void apmf_event_handler_v1(acpi_handle handle, u32 event, void *data)
dev_dbg(pmf_dev->dev, "Pending request (preq1): 0x%x\n", pmf_dev->req1.pending_req);
amd_pmf_handle_early_preq(pmf_dev);
+
+ amd_pmf_custom_bios_inputs_rb(pmf_dev);
}
static void apmf_event_handler(acpi_handle handle, u32 event, void *data)
#include <linux/debugfs.h>
#include <linux/iopoll.h>
#include <linux/module.h>
+#include <linux/mutex.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
if (err)
return err;
+ err = devm_mutex_init(dev->dev, &dev->cbi_mutex);
+ if (err)
+ return err;
+
apmf_acpi_init(dev);
platform_set_drvdata(pdev, dev);
amd_pmf_dbgfs_register(dev);
#define PMF_H
#include <linux/acpi.h>
+#include <linux/circ_buf.h>
#include <linux/input.h>
+#include <linux/mutex_types.h>
#include <linux/platform_device.h>
#include <linux/platform_profile.h>
#define APTS_MAX_STATES 16
#define CUSTOM_BIOS_INPUT_BITS GENMASK(16, 7)
#define BIOS_INPUTS_MAX 10
+#define CUSTOM_BIOS_INPUT_RING_ENTRIES 64 /* Must be power of two for CIRC_* macros */
/* amd_pmf_send_cmd() set/get */
#define SET_CMD false
u32 custom_bios_inputs[BIOS_INPUTS_MAX];
};
+/**
+ * struct pmf_bios_input_entry - Snapshot of custom BIOS input event
+ * @val: Array of custom BIOS input values
+ * @preq: Pending request value associated with this event
+ */
+struct pmf_bios_input_entry {
+ u32 val[BIOS_INPUTS_MAX];
+ u32 preq;
+};
+
+struct pmf_cbi_ring_buffer {
+ struct pmf_bios_input_entry data[CUSTOM_BIOS_INPUT_RING_ENTRIES];
+ int head;
+ int tail;
+};
+
struct amd_pmf_dev {
void __iomem *regbase;
void __iomem *smu_virt_addr;
struct apmf_sbios_req_v1 req1;
struct pmf_bios_inputs_prev cb_prev; /* To preserve custom BIOS inputs */
bool cb_flag; /* To handle first custom BIOS input */
+ struct pmf_cbi_ring_buffer cbi_buf;
+ struct mutex cbi_mutex; /* Protects ring buffer access */
};
struct apmf_sps_prop_granular_v2 {
#include <acpi/button.h>
#include <linux/amd-pmf-io.h>
+#include <linux/cleanup.h>
#include <linux/power_supply.h>
#include <linux/units.h>
#include "pmf.h"
}
}
-static void amd_pmf_update_bios_inputs(struct amd_pmf_dev *pdev, u32 pending_req,
+static void amd_pmf_update_bios_inputs(struct amd_pmf_dev *pdev, struct pmf_bios_input_entry *data,
const struct amd_pmf_pb_bitmap *inputs,
- const u32 *custom_policy, struct ta_pmf_enact_table *in)
+ struct ta_pmf_enact_table *in)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE(custom_bios_inputs); i++) {
- if (!(pending_req & inputs[i].bit_mask))
+ if (!(data->preq & inputs[i].bit_mask))
continue;
- amd_pmf_set_ta_custom_bios_input(in, i, custom_policy[i]);
- pdev->cb_prev.custom_bios_inputs[i] = custom_policy[i];
- dev_dbg(pdev->dev, "Custom BIOS Input[%d]: %u\n", i, custom_policy[i]);
+ amd_pmf_set_ta_custom_bios_input(in, i, data->val[i]);
+ pdev->cb_prev.custom_bios_inputs[i] = data->val[i];
+ dev_dbg(pdev->dev, "Custom BIOS Input[%d]: %u\n", i, data->val[i]);
}
}
static void amd_pmf_get_custom_bios_inputs(struct amd_pmf_dev *pdev,
struct ta_pmf_enact_table *in)
{
+ struct pmf_cbi_ring_buffer *rb = &pdev->cbi_buf;
unsigned int i;
+ guard(mutex)(&pdev->cbi_mutex);
+
for (i = 0; i < ARRAY_SIZE(custom_bios_inputs); i++)
amd_pmf_set_ta_custom_bios_input(in, i, pdev->cb_prev.custom_bios_inputs[i]);
- if (!(pdev->req.pending_req || pdev->req1.pending_req))
+ if (CIRC_CNT(rb->head, rb->tail, CUSTOM_BIOS_INPUT_RING_ENTRIES) == 0)
return;
+ /* If no active custom BIOS input pending request, do not consume further work */
+ if (!rb->data[rb->tail].preq)
+ goto out_rbadvance;
+
if (!pdev->smart_pc_enabled)
return;
case PMF_IF_V1:
if (!is_apmf_bios_input_notifications_supported(pdev))
return;
- amd_pmf_update_bios_inputs(pdev, pdev->req1.pending_req, custom_bios_inputs_v1,
- pdev->req1.custom_policy, in);
+ amd_pmf_update_bios_inputs(pdev, &rb->data[rb->tail], custom_bios_inputs_v1, in);
break;
case PMF_IF_V2:
- amd_pmf_update_bios_inputs(pdev, pdev->req.pending_req, custom_bios_inputs,
- pdev->req.custom_policy, in);
+ amd_pmf_update_bios_inputs(pdev, &rb->data[rb->tail], custom_bios_inputs, in);
break;
default:
break;
}
- /* Clear pending requests after handling */
- memset(&pdev->req, 0, sizeof(pdev->req));
- memset(&pdev->req1, 0, sizeof(pdev->req1));
+out_rbadvance:
+ rb->tail = (rb->tail + 1) & (CUSTOM_BIOS_INPUT_RING_ENTRIES - 1);
}
static void amd_pmf_get_c0_residency(u16 *core_res, size_t size, struct ta_pmf_enact_table *in)
status = ret == TA_PMF_TYPE_SUCCESS;
if (status) {
dev->cb_flag = true;
+ dev->cbi_buf.head = 0;
+ dev->cbi_buf.tail = 0;
break;
}
amd_pmf_tee_deinit(dev);
projects / thirdparty / linux.git / commitdiff
