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path: root/drivers/misc/cxl/cxllib.c
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Diffstat (limited to 'drivers/misc/cxl/cxllib.c')
-rw-r--r--drivers/misc/cxl/cxllib.c246
1 files changed, 246 insertions, 0 deletions
diff --git a/drivers/misc/cxl/cxllib.c b/drivers/misc/cxl/cxllib.c
new file mode 100644
index 000000000000..5dba23ca2e5f
--- /dev/null
+++ b/drivers/misc/cxl/cxllib.c
@@ -0,0 +1,246 @@
+/*
+ * Copyright 2017 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/hugetlb.h>
+#include <linux/sched/mm.h>
+#include <asm/pnv-pci.h>
+#include <misc/cxllib.h>
+
+#include "cxl.h"
+
+#define CXL_INVALID_DRA ~0ull
+#define CXL_DUMMY_READ_SIZE 128
+#define CXL_DUMMY_READ_ALIGN 8
+#define CXL_CAPI_WINDOW_START 0x2000000000000ull
+#define CXL_CAPI_WINDOW_LOG_SIZE 48
+#define CXL_XSL_CONFIG_CURRENT_VERSION CXL_XSL_CONFIG_VERSION1
+
+
+bool cxllib_slot_is_supported(struct pci_dev *dev, unsigned long flags)
+{
+ int rc;
+ u32 phb_index;
+ u64 chip_id, capp_unit_id;
+
+ /* No flags currently supported */
+ if (flags)
+ return false;
+
+ if (!cpu_has_feature(CPU_FTR_HVMODE))
+ return false;
+
+ if (!cxl_is_power9())
+ return false;
+
+ if (cxl_slot_is_switched(dev))
+ return false;
+
+ /* on p9, some pci slots are not connected to a CAPP unit */
+ rc = cxl_calc_capp_routing(dev, &chip_id, &phb_index, &capp_unit_id);
+ if (rc)
+ return false;
+
+ return true;
+}
+EXPORT_SYMBOL_GPL(cxllib_slot_is_supported);
+
+static DEFINE_MUTEX(dra_mutex);
+static u64 dummy_read_addr = CXL_INVALID_DRA;
+
+static int allocate_dummy_read_buf(void)
+{
+ u64 buf, vaddr;
+ size_t buf_size;
+
+ /*
+ * Dummy read buffer is 128-byte long, aligned on a
+ * 256-byte boundary and we need the physical address.
+ */
+ buf_size = CXL_DUMMY_READ_SIZE + (1ull << CXL_DUMMY_READ_ALIGN);
+ buf = (u64) kzalloc(buf_size, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ vaddr = (buf + (1ull << CXL_DUMMY_READ_ALIGN) - 1) &
+ (~0ull << CXL_DUMMY_READ_ALIGN);
+
+ WARN((vaddr + CXL_DUMMY_READ_SIZE) > (buf + buf_size),
+ "Dummy read buffer alignment issue");
+ dummy_read_addr = virt_to_phys((void *) vaddr);
+ return 0;
+}
+
+int cxllib_get_xsl_config(struct pci_dev *dev, struct cxllib_xsl_config *cfg)
+{
+ int rc;
+ u32 phb_index;
+ u64 chip_id, capp_unit_id;
+
+ if (!cpu_has_feature(CPU_FTR_HVMODE))
+ return -EINVAL;
+
+ mutex_lock(&dra_mutex);
+ if (dummy_read_addr == CXL_INVALID_DRA) {
+ rc = allocate_dummy_read_buf();
+ if (rc) {
+ mutex_unlock(&dra_mutex);
+ return rc;
+ }
+ }
+ mutex_unlock(&dra_mutex);
+
+ rc = cxl_calc_capp_routing(dev, &chip_id, &phb_index, &capp_unit_id);
+ if (rc)
+ return rc;
+
+ rc = cxl_get_xsl9_dsnctl(capp_unit_id, &cfg->dsnctl);
+ if (rc)
+ return rc;
+ if (cpu_has_feature(CPU_FTR_POWER9_DD1)) {
+ /* workaround for DD1 - nbwind = capiind */
+ cfg->dsnctl |= ((u64)0x02 << (63-47));
+ }
+
+ cfg->version = CXL_XSL_CONFIG_CURRENT_VERSION;
+ cfg->log_bar_size = CXL_CAPI_WINDOW_LOG_SIZE;
+ cfg->bar_addr = CXL_CAPI_WINDOW_START;
+ cfg->dra = dummy_read_addr;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(cxllib_get_xsl_config);
+
+int cxllib_switch_phb_mode(struct pci_dev *dev, enum cxllib_mode mode,
+ unsigned long flags)
+{
+ int rc = 0;
+
+ if (!cpu_has_feature(CPU_FTR_HVMODE))
+ return -EINVAL;
+
+ switch (mode) {
+ case CXL_MODE_PCI:
+ /*
+ * We currently don't support going back to PCI mode
+ * However, we'll turn the invalidations off, so that
+ * the firmware doesn't have to ack them and can do
+ * things like reset, etc.. with no worries.
+ * So always return EPERM (can't go back to PCI) or
+ * EBUSY if we couldn't even turn off snooping
+ */
+ rc = pnv_phb_to_cxl_mode(dev, OPAL_PHB_CAPI_MODE_SNOOP_OFF);
+ if (rc)
+ rc = -EBUSY;
+ else
+ rc = -EPERM;
+ break;
+ case CXL_MODE_CXL:
+ /* DMA only supported on TVT1 for the time being */
+ if (flags != CXL_MODE_DMA_TVT1)
+ return -EINVAL;
+ rc = pnv_phb_to_cxl_mode(dev, OPAL_PHB_CAPI_MODE_DMA_TVT1);
+ if (rc)
+ return rc;
+ rc = pnv_phb_to_cxl_mode(dev, OPAL_PHB_CAPI_MODE_SNOOP_ON);
+ break;
+ default:
+ rc = -EINVAL;
+ }
+ return rc;
+}
+EXPORT_SYMBOL_GPL(cxllib_switch_phb_mode);
+
+/*
+ * When switching the PHB to capi mode, the TVT#1 entry for
+ * the Partitionable Endpoint is set in bypass mode, like
+ * in PCI mode.
+ * Configure the device dma to use TVT#1, which is done
+ * by calling dma_set_mask() with a mask large enough.
+ */
+int cxllib_set_device_dma(struct pci_dev *dev, unsigned long flags)
+{
+ int rc;
+
+ if (flags)
+ return -EINVAL;
+
+ rc = dma_set_mask(&dev->dev, DMA_BIT_MASK(64));
+ return rc;
+}
+EXPORT_SYMBOL_GPL(cxllib_set_device_dma);
+
+int cxllib_get_PE_attributes(struct task_struct *task,
+ unsigned long translation_mode,
+ struct cxllib_pe_attributes *attr)
+{
+ struct mm_struct *mm = NULL;
+
+ if (translation_mode != CXL_TRANSLATED_MODE &&
+ translation_mode != CXL_REAL_MODE)
+ return -EINVAL;
+
+ attr->sr = cxl_calculate_sr(false,
+ task == NULL,
+ translation_mode == CXL_REAL_MODE,
+ true);
+ attr->lpid = mfspr(SPRN_LPID);
+ if (task) {
+ mm = get_task_mm(task);
+ if (mm == NULL)
+ return -EINVAL;
+ /*
+ * Caller is keeping a reference on mm_users for as long
+ * as XSL uses the memory context
+ */
+ attr->pid = mm->context.id;
+ mmput(mm);
+ } else {
+ attr->pid = 0;
+ }
+ attr->tid = 0;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(cxllib_get_PE_attributes);
+
+int cxllib_handle_fault(struct mm_struct *mm, u64 addr, u64 size, u64 flags)
+{
+ int rc;
+ u64 dar;
+ struct vm_area_struct *vma = NULL;
+ unsigned long page_size;
+
+ if (mm == NULL)
+ return -EFAULT;
+
+ down_read(&mm->mmap_sem);
+
+ for (dar = addr; dar < addr + size; dar += page_size) {
+ if (!vma || dar < vma->vm_start || dar > vma->vm_end) {
+ vma = find_vma(mm, addr);
+ if (!vma) {
+ pr_err("Can't find vma for addr %016llx\n", addr);
+ rc = -EFAULT;
+ goto out;
+ }
+ /* get the size of the pages allocated */
+ page_size = vma_kernel_pagesize(vma);
+ }
+
+ rc = cxl_handle_mm_fault(mm, flags, dar);
+ if (rc) {
+ pr_err("cxl_handle_mm_fault failed %d", rc);
+ rc = -EFAULT;
+ goto out;
+ }
+ }
+ rc = 0;
+out:
+ up_read(&mm->mmap_sem);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(cxllib_handle_fault);

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