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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/parisc/kernel/pdt.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--arch/parisc/kernel/pdt.c362
1 files changed, 362 insertions, 0 deletions
diff --git a/arch/parisc/kernel/pdt.c b/arch/parisc/kernel/pdt.c
new file mode 100644
index 000000000..e391b175f
--- /dev/null
+++ b/arch/parisc/kernel/pdt.c
@@ -0,0 +1,362 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Page Deallocation Table (PDT) support
+ *
+ * The Page Deallocation Table (PDT) is maintained by firmware and holds a
+ * list of memory addresses in which memory errors were detected.
+ * The list contains both single-bit (correctable) and double-bit
+ * (uncorrectable) errors.
+ *
+ * Copyright 2017 by Helge Deller <deller@gmx.de>
+ *
+ * possible future enhancements:
+ * - add userspace interface via procfs or sysfs to clear PDT
+ */
+
+#include <linux/memblock.h>
+#include <linux/seq_file.h>
+#include <linux/kthread.h>
+#include <linux/initrd.h>
+#include <linux/pgtable.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+
+#include <asm/pdc.h>
+#include <asm/pdcpat.h>
+#include <asm/sections.h>
+
+enum pdt_access_type {
+ PDT_NONE,
+ PDT_PDC,
+ PDT_PAT_NEW,
+ PDT_PAT_CELL
+};
+
+static enum pdt_access_type pdt_type;
+
+/* PDT poll interval: 1 minute if errors, 5 minutes if everything OK. */
+#define PDT_POLL_INTERVAL_DEFAULT (5*60*HZ)
+#define PDT_POLL_INTERVAL_SHORT (1*60*HZ)
+static unsigned long pdt_poll_interval = PDT_POLL_INTERVAL_DEFAULT;
+
+/* global PDT status information */
+static struct pdc_mem_retinfo pdt_status;
+
+#define MAX_PDT_TABLE_SIZE PAGE_SIZE
+#define MAX_PDT_ENTRIES (MAX_PDT_TABLE_SIZE / sizeof(unsigned long))
+static unsigned long pdt_entry[MAX_PDT_ENTRIES] __page_aligned_bss;
+
+/*
+ * Constants for the pdt_entry format:
+ * A pdt_entry holds the physical address in bits 0-57, bits 58-61 are
+ * reserved, bit 62 is the perm bit and bit 63 is the error_type bit.
+ * The perm bit indicates whether the error have been verified as a permanent
+ * error (value of 1) or has not been verified, and may be transient (value
+ * of 0). The error_type bit indicates whether the error is a single bit error
+ * (value of 1) or a multiple bit error.
+ * On non-PAT machines phys_addr is encoded in bits 0-59 and error_type in bit
+ * 63. Those machines don't provide the perm bit.
+ */
+
+#define PDT_ADDR_PHYS_MASK (pdt_type != PDT_PDC ? ~0x3f : ~0x0f)
+#define PDT_ADDR_PERM_ERR (pdt_type != PDT_PDC ? 2UL : 0UL)
+#define PDT_ADDR_SINGLE_ERR 1UL
+
+/* report PDT entries via /proc/meminfo */
+void arch_report_meminfo(struct seq_file *m)
+{
+ if (pdt_type == PDT_NONE)
+ return;
+
+ seq_printf(m, "PDT_max_entries: %7lu\n",
+ pdt_status.pdt_size);
+ seq_printf(m, "PDT_cur_entries: %7lu\n",
+ pdt_status.pdt_entries);
+}
+
+static int get_info_pat_new(void)
+{
+ struct pdc_pat_mem_retinfo pat_rinfo;
+ int ret;
+
+ /* newer PAT machines like C8000 report info for all cells */
+ if (is_pdc_pat())
+ ret = pdc_pat_mem_pdt_info(&pat_rinfo);
+ else
+ return PDC_BAD_PROC;
+
+ pdt_status.pdt_size = pat_rinfo.max_pdt_entries;
+ pdt_status.pdt_entries = pat_rinfo.current_pdt_entries;
+ pdt_status.pdt_status = 0;
+ pdt_status.first_dbe_loc = pat_rinfo.first_dbe_loc;
+ pdt_status.good_mem = pat_rinfo.good_mem;
+
+ return ret;
+}
+
+static int get_info_pat_cell(void)
+{
+ struct pdc_pat_mem_cell_pdt_retinfo cell_rinfo;
+ int ret;
+
+ /* older PAT machines like rp5470 report cell info only */
+ if (is_pdc_pat())
+ ret = pdc_pat_mem_pdt_cell_info(&cell_rinfo, parisc_cell_num);
+ else
+ return PDC_BAD_PROC;
+
+ pdt_status.pdt_size = cell_rinfo.max_pdt_entries;
+ pdt_status.pdt_entries = cell_rinfo.current_pdt_entries;
+ pdt_status.pdt_status = 0;
+ pdt_status.first_dbe_loc = cell_rinfo.first_dbe_loc;
+ pdt_status.good_mem = cell_rinfo.good_mem;
+
+ return ret;
+}
+
+static void report_mem_err(unsigned long pde)
+{
+ struct pdc_pat_mem_phys_mem_location loc;
+ unsigned long addr;
+ char dimm_txt[32];
+
+ addr = pde & PDT_ADDR_PHYS_MASK;
+
+ /* show DIMM slot description on PAT machines */
+ if (is_pdc_pat()) {
+ pdc_pat_mem_get_dimm_phys_location(&loc, addr);
+ sprintf(dimm_txt, "DIMM slot %02x, ", loc.dimm_slot);
+ } else
+ dimm_txt[0] = 0;
+
+ pr_warn("PDT: BAD MEMORY at 0x%08lx, %s%s%s-bit error.\n",
+ addr, dimm_txt,
+ pde & PDT_ADDR_PERM_ERR ? "permanent ":"",
+ pde & PDT_ADDR_SINGLE_ERR ? "single":"multi");
+}
+
+
+/*
+ * pdc_pdt_init()
+ *
+ * Initialize kernel PDT structures, read initial PDT table from firmware,
+ * report all current PDT entries and mark bad memory with memblock_reserve()
+ * to avoid that the kernel will use broken memory areas.
+ *
+ */
+void __init pdc_pdt_init(void)
+{
+ int ret, i;
+ unsigned long entries;
+ struct pdc_mem_read_pdt pdt_read_ret;
+
+ pdt_type = PDT_PAT_NEW;
+ ret = get_info_pat_new();
+
+ if (ret != PDC_OK) {
+ pdt_type = PDT_PAT_CELL;
+ ret = get_info_pat_cell();
+ }
+
+ if (ret != PDC_OK) {
+ pdt_type = PDT_PDC;
+ /* non-PAT machines provide the standard PDC call */
+ ret = pdc_mem_pdt_info(&pdt_status);
+ }
+
+ if (ret != PDC_OK) {
+ pdt_type = PDT_NONE;
+ pr_info("PDT: Firmware does not provide any page deallocation"
+ " information.\n");
+ return;
+ }
+
+ entries = pdt_status.pdt_entries;
+ if (WARN_ON(entries > MAX_PDT_ENTRIES))
+ entries = pdt_status.pdt_entries = MAX_PDT_ENTRIES;
+
+ pr_info("PDT: type %s, size %lu, entries %lu, status %lu, dbe_loc 0x%lx,"
+ " good_mem %lu MB\n",
+ pdt_type == PDT_PDC ? __stringify(PDT_PDC) :
+ pdt_type == PDT_PAT_CELL ? __stringify(PDT_PAT_CELL)
+ : __stringify(PDT_PAT_NEW),
+ pdt_status.pdt_size, pdt_status.pdt_entries,
+ pdt_status.pdt_status, pdt_status.first_dbe_loc,
+ pdt_status.good_mem / 1024 / 1024);
+
+ if (entries == 0) {
+ pr_info("PDT: Firmware reports all memory OK.\n");
+ return;
+ }
+
+ if (pdt_status.first_dbe_loc &&
+ pdt_status.first_dbe_loc <= __pa((unsigned long)&_end))
+ pr_crit("CRITICAL: Bad memory inside kernel image memory area!\n");
+
+ pr_warn("PDT: Firmware reports %lu entries of faulty memory:\n",
+ entries);
+
+ if (pdt_type == PDT_PDC)
+ ret = pdc_mem_pdt_read_entries(&pdt_read_ret, pdt_entry);
+ else {
+#ifdef CONFIG_64BIT
+ struct pdc_pat_mem_read_pd_retinfo pat_pret;
+
+ if (pdt_type == PDT_PAT_CELL)
+ ret = pdc_pat_mem_read_cell_pdt(&pat_pret, pdt_entry,
+ MAX_PDT_ENTRIES);
+ else
+ ret = pdc_pat_mem_read_pd_pdt(&pat_pret, pdt_entry,
+ MAX_PDT_TABLE_SIZE, 0);
+#else
+ ret = PDC_BAD_PROC;
+#endif
+ }
+
+ if (ret != PDC_OK) {
+ pdt_type = PDT_NONE;
+ pr_warn("PDT: Get PDT entries failed with %d\n", ret);
+ return;
+ }
+
+ for (i = 0; i < pdt_status.pdt_entries; i++) {
+ unsigned long addr;
+
+ report_mem_err(pdt_entry[i]);
+
+ addr = pdt_entry[i] & PDT_ADDR_PHYS_MASK;
+ if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) &&
+ addr >= initrd_start && addr < initrd_end)
+ pr_crit("CRITICAL: initrd possibly broken "
+ "due to bad memory!\n");
+
+ /* mark memory page bad */
+ memblock_reserve(pdt_entry[i] & PAGE_MASK, PAGE_SIZE);
+ num_poisoned_pages_inc();
+ }
+}
+
+
+/*
+ * This is the PDT kernel thread main loop.
+ */
+
+static int pdt_mainloop(void *unused)
+{
+ struct pdc_mem_read_pdt pdt_read_ret;
+ struct pdc_pat_mem_read_pd_retinfo pat_pret __maybe_unused;
+ unsigned long old_num_entries;
+ unsigned long *bad_mem_ptr;
+ int num, ret;
+
+ for (;;) {
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ old_num_entries = pdt_status.pdt_entries;
+
+ schedule_timeout(pdt_poll_interval);
+ if (kthread_should_stop())
+ break;
+
+ /* Do we have new PDT entries? */
+ switch (pdt_type) {
+ case PDT_PAT_NEW:
+ ret = get_info_pat_new();
+ break;
+ case PDT_PAT_CELL:
+ ret = get_info_pat_cell();
+ break;
+ default:
+ ret = pdc_mem_pdt_info(&pdt_status);
+ break;
+ }
+
+ if (ret != PDC_OK) {
+ pr_warn("PDT: unexpected failure %d\n", ret);
+ return -EINVAL;
+ }
+
+ /* if no new PDT entries, just wait again */
+ num = pdt_status.pdt_entries - old_num_entries;
+ if (num <= 0)
+ continue;
+
+ /* decrease poll interval in case we found memory errors */
+ if (pdt_status.pdt_entries &&
+ pdt_poll_interval == PDT_POLL_INTERVAL_DEFAULT)
+ pdt_poll_interval = PDT_POLL_INTERVAL_SHORT;
+
+ /* limit entries to get */
+ if (num > MAX_PDT_ENTRIES) {
+ num = MAX_PDT_ENTRIES;
+ pdt_status.pdt_entries = old_num_entries + num;
+ }
+
+ /* get new entries */
+ switch (pdt_type) {
+#ifdef CONFIG_64BIT
+ case PDT_PAT_CELL:
+ if (pdt_status.pdt_entries > MAX_PDT_ENTRIES) {
+ pr_crit("PDT: too many entries.\n");
+ return -ENOMEM;
+ }
+ ret = pdc_pat_mem_read_cell_pdt(&pat_pret, pdt_entry,
+ MAX_PDT_ENTRIES);
+ bad_mem_ptr = &pdt_entry[old_num_entries];
+ break;
+ case PDT_PAT_NEW:
+ ret = pdc_pat_mem_read_pd_pdt(&pat_pret,
+ pdt_entry,
+ num * sizeof(unsigned long),
+ old_num_entries * sizeof(unsigned long));
+ bad_mem_ptr = &pdt_entry[0];
+ break;
+#endif
+ default:
+ ret = pdc_mem_pdt_read_entries(&pdt_read_ret,
+ pdt_entry);
+ bad_mem_ptr = &pdt_entry[old_num_entries];
+ break;
+ }
+
+ /* report and mark memory broken */
+ while (num--) {
+ unsigned long pde = *bad_mem_ptr++;
+
+ report_mem_err(pde);
+
+#ifdef CONFIG_MEMORY_FAILURE
+ if ((pde & PDT_ADDR_PERM_ERR) ||
+ ((pde & PDT_ADDR_SINGLE_ERR) == 0))
+ memory_failure(pde >> PAGE_SHIFT, 0);
+ else
+ soft_offline_page(pde >> PAGE_SHIFT, 0);
+#else
+ pr_crit("PDT: memory error at 0x%lx ignored.\n"
+ "Rebuild kernel with CONFIG_MEMORY_FAILURE=y "
+ "for real handling.\n",
+ pde & PDT_ADDR_PHYS_MASK);
+#endif
+
+ }
+ }
+
+ return 0;
+}
+
+
+static int __init pdt_initcall(void)
+{
+ struct task_struct *kpdtd_task;
+
+ if (pdt_type == PDT_NONE)
+ return -ENODEV;
+
+ kpdtd_task = kthread_run(pdt_mainloop, NULL, "kpdtd");
+ if (IS_ERR(kpdtd_task))
+ return PTR_ERR(kpdtd_task);
+
+ return 0;
+}
+
+late_initcall(pdt_initcall);