parisc: Add Page Deallocation Table (PDT) support

The firmare in most parisc machines maintains a Page Deallocation Table (PDT)
which holds a list of physical memory addresses where hardware detected memory
errors (single bit and double bit errors).

This patch adds the missing PDC firmware calls and the logic to read the PDT
from firmware, report all current PDT entries and exclude the reported bad
memory from being used by Linux.

Signed-off-by: Helge Deller <deller@gmx.de>

1 files changed, 108 insertions, 0 deletions

diff --git a/arch/parisc/kernel/firmware.c b/arch/parisc/kernel/firmware.c
index 9d797ae4fa22..98190252c12f 100644
--- a/arch/parisc/kernel/firmware.c
+++ b/arch/parisc/kernel/firmware.c
@@ -957,6 +957,41 @@ int pdc_tod_read(struct pdc_tod *tod)
 }
 EXPORT_SYMBOL(pdc_tod_read);
 
+int pdc_mem_pdt_info(struct pdc_mem_retinfo *rinfo)
+{
+	int retval;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pdc_lock, flags);
+	retval = mem_pdc_call(PDC_MEM, PDC_MEM_MEMINFO, __pa(pdc_result), 0);
+	convert_to_wide(pdc_result);
+	memcpy(rinfo, pdc_result, sizeof(*rinfo));
+	spin_unlock_irqrestore(&pdc_lock, flags);
+
+	return retval;
+}
+
+int pdc_mem_pdt_read_entries(struct pdc_mem_read_pdt *pret,
+		unsigned long *pdt_entries_ptr)
+{
+	int retval;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pdc_lock, flags);
+	retval = mem_pdc_call(PDC_MEM, PDC_MEM_READ_PDT, __pa(pdc_result),
+			__pa(pdc_result2));
+	if (retval == PDC_OK) {
+		convert_to_wide(pdc_result);
+		memcpy(pret, pdc_result, sizeof(*pret));
+		convert_to_wide(pdc_result2);
+		memcpy(pdt_entries_ptr, pdc_result2,
+			pret->pdt_entries * sizeof(*pdt_entries_ptr));
+	}
+	spin_unlock_irqrestore(&pdc_lock, flags);
+
+	return retval;
+}
+
 /**
  * pdc_tod_set - Set the Time-Of-Day clock.
  * @sec: The number of seconds since epoch.
@@ -1383,6 +1418,79 @@ int pdc_pat_io_pci_cfg_write(unsigned long pci_addr, int pci_size, u32 val)
 
 	return retval;
 }
+
+/**
+ * pdc_pat_mem_pdc_info - Retrieve information about page deallocation table
+ * @rinfo: memory pdt information
+ *
+ */
+int pdc_pat_mem_pdt_info(struct pdc_pat_mem_retinfo *rinfo)
+{
+	int retval;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pdc_lock, flags);
+	retval = mem_pdc_call(PDC_PAT_MEM, PDC_PAT_MEM_PD_INFO,
+			__pa(&pdc_result));
+	if (retval == PDC_OK)
+		memcpy(rinfo, &pdc_result, sizeof(*rinfo));
+	spin_unlock_irqrestore(&pdc_lock, flags);
+
+	return retval;
+}
+
+/**
+ * pdc_pat_mem_read_cell_pdt - Read PDT entries from (old) PAT firmware
+ * @pret: array of PDT entries
+ * @pdt_entries_ptr: ptr to hold number of PDT entries
+ * @max_entries: maximum number of entries to be read
+ *
+ */
+int pdc_pat_mem_read_cell_pdt(struct pdc_pat_mem_read_pd_retinfo *pret,
+		unsigned long *pdt_entries_ptr, unsigned long max_entries)
+{
+	int retval;
+	unsigned long flags, entries;
+
+	spin_lock_irqsave(&pdc_lock, flags);
+	/* PDC_PAT_MEM_CELL_READ is available on early PAT machines only */
+	retval = mem_pdc_call(PDC_PAT_MEM, PDC_PAT_MEM_CELL_READ,
+			__pa(&pdc_result), parisc_cell_num, __pa(&pdc_result2));
+
+	if (retval == PDC_OK) {
+		/* build up return value as for PDC_PAT_MEM_PD_READ */
+		entries = min(pdc_result[0], max_entries);
+		pret->pdt_entries = entries;
+		pret->actual_count_bytes = entries * sizeof(unsigned long);
+		memcpy(pdt_entries_ptr, &pdc_result2, pret->actual_count_bytes);
+	}
+
+	spin_unlock_irqrestore(&pdc_lock, flags);
+	WARN_ON(retval == PDC_OK && pdc_result[0] > max_entries);
+
+	return retval;
+}
+/**
+ * pdc_pat_mem_read_pd_pdt - Read PDT entries from (newer) PAT firmware
+ * @pret: array of PDT entries
+ * @pdt_entries_ptr: ptr to hold number of PDT entries
+ *
+ */
+int pdc_pat_mem_read_pd_pdt(struct pdc_pat_mem_read_pd_retinfo *pret,
+		unsigned long *pdt_entries_ptr, unsigned long count,
+		unsigned long offset)
+{
+	int retval;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pdc_lock, flags);
+	retval = mem_pdc_call(PDC_PAT_MEM, PDC_PAT_MEM_PD_READ,
+		__pa(&pret), __pa(pdt_entries_ptr),
+		count, offset);
+	spin_unlock_irqrestore(&pdc_lock, flags);
+
+	return retval;
+}
 #endif /* CONFIG_64BIT */