// SPDX-License-Identifier: GPL-2.0
#define pr_fmt(fmt) "papr-scm: " fmt
#include <linux/of.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/ndctl.h>
#include <linux/sched.h>
#include <linux/libnvdimm.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/seq_buf.h>
#include <linux/nd.h>
#include <asm/plpar_wrappers.h>
#include <asm/papr_pdsm.h>
#include <asm/mce.h>
#define BIND_ANY_ADDR (~0ul)
#define PAPR_SCM_DIMM_CMD_MASK \
((1ul << ND_CMD_GET_CONFIG_SIZE) | \
(1ul << ND_CMD_GET_CONFIG_DATA) | \
(1ul << ND_CMD_SET_CONFIG_DATA) | \
(1ul << ND_CMD_CALL))
/* DIMM health bitmap bitmap indicators */
/* SCM device is unable to persist memory contents */
#define PAPR_PMEM_UNARMED (1ULL << (63 - 0))
/* SCM device failed to persist memory contents */
#define PAPR_PMEM_SHUTDOWN_DIRTY (1ULL << (63 - 1))
/* SCM device contents are persisted from previous IPL */
#define PAPR_PMEM_SHUTDOWN_CLEAN (1ULL << (63 - 2))
/* SCM device contents are not persisted from previous IPL */
#define PAPR_PMEM_EMPTY (1ULL << (63 - 3))
/* SCM device memory life remaining is critically low */
#define PAPR_PMEM_HEALTH_CRITICAL (1ULL << (63 - 4))
/* SCM device will be garded off next IPL due to failure */
#define PAPR_PMEM_HEALTH_FATAL (1ULL << (63 - 5))
/* SCM contents cannot persist due to current platform health status */
#define PAPR_PMEM_HEALTH_UNHEALTHY (1ULL << (63 - 6))
/* SCM device is unable to persist memory contents in certain conditions */
#define PAPR_PMEM_HEALTH_NON_CRITICAL (1ULL << (63 - 7))
/* SCM device is encrypted */
#define PAPR_PMEM_ENCRYPTED (1ULL << (63 - 8))
/* SCM device has been scrubbed and locked */
#define PAPR_PMEM_SCRUBBED_AND_LOCKED (1ULL << (63 - 9))
/* Bits status indicators for health bitmap indicating unarmed dimm */
#define PAPR_PMEM_UNARMED_MASK (PAPR_PMEM_UNARMED | \
PAPR_PMEM_HEALTH_UNHEALTHY)
/* Bits status indicators for health bitmap indicating unflushed dimm */
#define PAPR_PMEM_BAD_SHUTDOWN_MASK (PAPR_PMEM_SHUTDOWN_DIRTY)
/* Bits status indicators for health bitmap indicating unrestored dimm */
#define PAPR_PMEM_BAD_RESTORE_MASK (PAPR_PMEM_EMPTY)
/* Bit status indicators for smart event notification */
#define PAPR_PMEM_SMART_EVENT_MASK (PAPR_PMEM_HEALTH_CRITICAL | \
PAPR_PMEM_HEALTH_FATAL | \
PAPR_PMEM_HEALTH_UNHEALTHY)
#define PAPR_SCM_PERF_STATS_EYECATCHER __stringify(SCMSTATS)
#define PAPR_SCM_PERF_STATS_VERSION 0x1
/* Struct holding a single performance metric */
struct papr_scm_perf_stat {
u8 stat_id[8];
__be64 stat_val;
} __packed;
/* Struct exchanged between kernel and PHYP for fetching drc perf stats */
struct papr_scm_perf_stats {
u8 eye_catcher[8];
/* Should be PAPR_SCM_PERF_STATS_VERSION */
__be32 stats_version;
/* Number of stats following */
__be32 num_statistics;
/* zero or more performance matrics */
struct papr_scm_perf_stat scm_statistic[];
} __packed;
/* private struct associated with each region */
struct papr_scm_priv {
struct platform_device *pdev;
struct device_node *dn;
uint32_t drc_index;
uint64_t blocks;
uint64_t block_size;
int metadata_size;
bool is_volatile;
uint64_t bound_addr;
struct nvdimm_bus_descriptor bus_desc;
struct nvdimm_bus *bus;
struct nvdimm *nvdimm;
struct resource res;
struct nd_region *region;
struct nd_interleave_set nd_set;
struct list_head region_list;
/* Protect dimm health data from concurrent read/writes */
struct mutex health_mutex;
/* Last time the health information of the dimm was updated */
unsigned long lasthealth_jiffies;
/* Health information for the dimm */
u64 health_bitmap;
/* length of the stat buffer as expected by phyp */
size_t stat_buffer_len;
};
static LIST_HEAD(papr_nd_regions);
static DEFINE_MUTEX(papr_ndr_lock);
static int drc_pmem_bind(struct papr_scm_priv *p)
{
unsigned long ret[PLPAR_HCALL_BUFSIZE];
uint64_t saved = 0;
uint64_t token;
int64_t rc;
/*
* When the hypervisor cannot map all the requested memory in a single
* hcall it returns H_BUSY and we call again with the token until
* we get H_SUCCESS. Aborting the retry loop before getting H_SUCCESS
* leave the system in an undefined state, so we wait.
*/
token = 0;
do {
rc = plpar_hcall(H_SCM_BIND_MEM, ret, p->drc_index, 0,
p->blocks, BIND_ANY_ADDR, token);
token = ret[0];
if (!saved)
saved = ret[1];
cond_resched();
} while (rc == H_BUSY);
if (rc)
return rc;
p->bound_addr = saved;
dev_dbg(&p->pdev->dev, "bound drc 0x%x to 0x%lx\n",
p->drc_index, (unsigned long)saved);
return rc;
}
static void drc_pmem_unbind(struct papr_scm_priv *p)
{
unsigned long ret[PLPAR_HCALL_BUFSIZE];
uint64_t token = 0;
int64_t rc;
dev_dbg(&p->pdev->dev, "u