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path: root/drivers/misc/cxl/pci.c
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Diffstat (limited to 'drivers/misc/cxl/pci.c')
-rw-r--r--drivers/misc/cxl/pci.c618
1 files changed, 514 insertions, 104 deletions
diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index dc836071c..85761d7eb 100644
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c
@@ -24,6 +24,7 @@
#include <asm/io.h>
#include "cxl.h"
+#include <misc/cxl.h>
#define CXL_PCI_VSEC_ID 0x1280
@@ -133,7 +134,7 @@ u8 cxl_afu_cr_read8(struct cxl_afu *afu, int cr, u64 off)
return (val >> ((off & 0x3) * 8)) & 0xff;
}
-static DEFINE_PCI_DEVICE_TABLE(cxl_pci_tbl) = {
+static const struct pci_device_id cxl_pci_tbl[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_IBM, 0x0477), },
{ PCI_DEVICE(PCI_VENDOR_ID_IBM, 0x044b), },
{ PCI_DEVICE(PCI_VENDOR_ID_IBM, 0x04cf), },
@@ -369,6 +370,55 @@ static int init_implementation_adapter_regs(struct cxl *adapter, struct pci_dev
return 0;
}
+#define TBSYNC_CNT(n) (((u64)n & 0x7) << (63-6))
+#define _2048_250MHZ_CYCLES 1
+
+static int cxl_setup_psl_timebase(struct cxl *adapter, struct pci_dev *dev)
+{
+ u64 psl_tb;
+ int delta;
+ unsigned int retry = 0;
+ struct device_node *np;
+
+ if (!(np = pnv_pci_get_phb_node(dev)))
+ return -ENODEV;
+
+ /* Do not fail when CAPP timebase sync is not supported by OPAL */
+ of_node_get(np);
+ if (! of_get_property(np, "ibm,capp-timebase-sync", NULL)) {
+ of_node_put(np);
+ pr_err("PSL: Timebase sync: OPAL support missing\n");
+ return 0;
+ }
+ of_node_put(np);
+
+ /*
+ * Setup PSL Timebase Control and Status register
+ * with the recommended Timebase Sync Count value
+ */
+ cxl_p1_write(adapter, CXL_PSL_TB_CTLSTAT,
+ TBSYNC_CNT(2 * _2048_250MHZ_CYCLES));
+
+ /* Enable PSL Timebase */
+ cxl_p1_write(adapter, CXL_PSL_Control, 0x0000000000000000);
+ cxl_p1_write(adapter, CXL_PSL_Control, CXL_PSL_Control_tb);
+
+ /* Wait until CORE TB and PSL TB difference <= 16usecs */
+ do {
+ msleep(1);
+ if (retry++ > 5) {
+ pr_err("PSL: Timebase sync: giving up!\n");
+ return -EIO;
+ }
+ psl_tb = cxl_p1_read(adapter, CXL_PSL_Timebase);
+ delta = mftb() - psl_tb;
+ if (delta < 0)
+ delta = -delta;
+ } while (cputime_to_usecs(delta) > 16);
+
+ return 0;
+}
+
static int init_implementation_afu_regs(struct cxl_afu *afu)
{
/* read/write masks for this slice */
@@ -539,10 +589,18 @@ err:
static void cxl_unmap_slice_regs(struct cxl_afu *afu)
{
- if (afu->p2n_mmio)
+ if (afu->p2n_mmio) {
iounmap(afu->p2n_mmio);
- if (afu->p1n_mmio)
+ afu->p2n_mmio = NULL;
+ }
+ if (afu->p1n_mmio) {
iounmap(afu->p1n_mmio);
+ afu->p1n_mmio = NULL;
+ }
+ if (afu->afu_desc_mmio) {
+ iounmap(afu->afu_desc_mmio);
+ afu->afu_desc_mmio = NULL;
+ }
}
static void cxl_release_afu(struct device *dev)
@@ -551,6 +609,9 @@ static void cxl_release_afu(struct device *dev)
pr_devel("cxl_release_afu\n");
+ idr_destroy(&afu->contexts_idr);
+ cxl_release_spa(afu);
+
kfree(afu);
}
@@ -656,7 +717,7 @@ static int sanitise_afu_regs(struct cxl_afu *afu)
*/
reg = cxl_p2n_read(afu, CXL_AFU_Cntl_An);
if ((reg & CXL_AFU_Cntl_An_ES_MASK) != CXL_AFU_Cntl_An_ES_Disabled) {
- dev_warn(&afu->dev, "WARNING: AFU was not disabled: %#.16llx\n", reg);
+ dev_warn(&afu->dev, "WARNING: AFU was not disabled: %#016llx\n", reg);
if (__cxl_afu_reset(afu))
return -EIO;
if (cxl_afu_disable(afu))
@@ -677,7 +738,7 @@ static int sanitise_afu_regs(struct cxl_afu *afu)
cxl_p2n_write(afu, CXL_SSTP0_An, 0x0000000000000000);
reg = cxl_p2n_read(afu, CXL_PSL_DSISR_An);
if (reg) {
- dev_warn(&afu->dev, "AFU had pending DSISR: %#.16llx\n", reg);
+ dev_warn(&afu->dev, "AFU had pending DSISR: %#016llx\n", reg);
if (reg & CXL_PSL_DSISR_TRANS)
cxl_p2n_write(afu, CXL_PSL_TFC_An, CXL_PSL_TFC_An_AE);
else
@@ -686,12 +747,12 @@ static int sanitise_afu_regs(struct cxl_afu *afu)
reg = cxl_p1n_read(afu, CXL_PSL_SERR_An);
if (reg) {
if (reg & ~0xffff)
- dev_warn(&afu->dev, "AFU had pending SERR: %#.16llx\n", reg);
+ dev_warn(&afu->dev, "AFU had pending SERR: %#016llx\n", reg);
cxl_p1n_write(afu, CXL_PSL_SERR_An, reg & ~0xffff);
}
reg = cxl_p2n_read(afu, CXL_PSL_ErrStat_An);
if (reg) {
- dev_warn(&afu->dev, "AFU had pending error status: %#.16llx\n", reg);
+ dev_warn(&afu->dev, "AFU had pending error status: %#016llx\n", reg);
cxl_p2n_write(afu, CXL_PSL_ErrStat_An, reg);
}
@@ -742,45 +803,70 @@ ssize_t cxl_afu_read_err_buffer(struct cxl_afu *afu, char *buf,
return count;
}
-static int cxl_init_afu(struct cxl *adapter, int slice, struct pci_dev *dev)
+static int cxl_configure_afu(struct cxl_afu *afu, struct cxl *adapter, struct pci_dev *dev)
{
- struct cxl_afu *afu;
- bool free = true;
int rc;
- if (!(afu = cxl_alloc_afu(adapter, slice)))
- return -ENOMEM;
-
- if ((rc = dev_set_name(&afu->dev, "afu%i.%i", adapter->adapter_num, slice)))
- goto err1;
-
if ((rc = cxl_map_slice_regs(afu, adapter, dev)))
- goto err1;
+ return rc;
if ((rc = sanitise_afu_regs(afu)))
- goto err2;
+ goto err1;
/* We need to reset the AFU before we can read the AFU descriptor */
if ((rc = __cxl_afu_reset(afu)))
- goto err2;
+ goto err1;
if (cxl_verbose)
dump_afu_descriptor(afu);
if ((rc = cxl_read_afu_descriptor(afu)))
- goto err2;
+ goto err1;
if ((rc = cxl_afu_descriptor_looks_ok(afu)))
- goto err2;
+ goto err1;
if ((rc = init_implementation_afu_regs(afu)))
- goto err2;
+ goto err1;
if ((rc = cxl_register_serr_irq(afu)))
- goto err2;
+ goto err1;
if ((rc = cxl_register_psl_irq(afu)))
- goto err3;
+ goto err2;
+
+ return 0;
+
+err2:
+ cxl_release_serr_irq(afu);
+err1:
+ cxl_unmap_slice_regs(afu);
+ return rc;
+}
+
+static void cxl_deconfigure_afu(struct cxl_afu *afu)
+{
+ cxl_release_psl_irq(afu);
+ cxl_release_serr_irq(afu);
+ cxl_unmap_slice_regs(afu);
+}
+
+static int cxl_init_afu(struct cxl *adapter, int slice, struct pci_dev *dev)
+{
+ struct cxl_afu *afu;
+ int rc;
+
+ afu = cxl_alloc_afu(adapter, slice);
+ if (!afu)
+ return -ENOMEM;
+
+ rc = dev_set_name(&afu->dev, "afu%i.%i", adapter->adapter_num, slice);
+ if (rc)
+ goto err_free;
+
+ rc = cxl_configure_afu(afu, adapter, dev);
+ if (rc)
+ goto err_free;
/* Don't care if this fails */
cxl_debugfs_afu_add(afu);
@@ -795,10 +881,6 @@ static int cxl_init_afu(struct cxl *adapter, int slice, struct pci_dev *dev)
if ((rc = cxl_sysfs_afu_add(afu)))
goto err_put1;
-
- if ((rc = cxl_afu_select_best_mode(afu)))
- goto err_put2;
-
adapter->afu[afu->slice] = afu;
if ((rc = cxl_pci_vphb_add(afu)))
@@ -806,21 +888,16 @@ static int cxl_init_afu(struct cxl *adapter, int slice, struct pci_dev *dev)
return 0;
-err_put2:
- cxl_sysfs_afu_remove(afu);
err_put1:
- device_unregister(&afu->dev);
- free = false;
+ cxl_deconfigure_afu(afu);
cxl_debugfs_afu_remove(afu);
- cxl_release_psl_irq(afu);
-err3:
- cxl_release_serr_irq(afu);
-err2:
- cxl_unmap_slice_regs(afu);
-err1:
- if (free)
- kfree(afu);
+ device_unregister(&afu->dev);
return rc;
+
+err_free:
+ kfree(afu);
+ return rc;
+
}
static void cxl_remove_afu(struct cxl_afu *afu)
@@ -840,10 +917,7 @@ static void cxl_remove_afu(struct cxl_afu *afu)
cxl_context_detach_all(afu);
cxl_afu_deactivate_mode(afu);
- cxl_release_psl_irq(afu);
- cxl_release_serr_irq(afu);
- cxl_unmap_slice_regs(afu);
-
+ cxl_deconfigure_afu(afu);
device_unregister(&afu->dev);
}
@@ -852,6 +926,12 @@ int cxl_reset(struct cxl *adapter)
struct pci_dev *dev = to_pci_dev(adapter->dev.parent);
int rc;
+ if (adapter->perst_same_image) {
+ dev_warn(&dev->dev,
+ "cxl: refusing to reset/reflash when perst_reloads_same_image is set.\n");
+ return -EINVAL;
+ }
+
dev_info(&dev->dev, "CXL reset\n");
/* pcie_warm_reset requests a fundamental pci reset which includes a
@@ -872,7 +952,7 @@ static int cxl_map_adapter_regs(struct cxl *adapter, struct pci_dev *dev)
if (pci_request_region(dev, 0, "priv 1 regs"))
goto err2;
- pr_devel("cxl_map_adapter_regs: p1: %#.16llx %#llx, p2: %#.16llx %#llx",
+ pr_devel("cxl_map_adapter_regs: p1: %#016llx %#llx, p2: %#016llx %#llx",
p1_base(dev), p1_size(dev), p2_base(dev), p2_size(dev));
if (!(adapter->p1_mmio = ioremap(p1_base(dev), p1_size(dev))))
@@ -896,10 +976,16 @@ err1:
static void cxl_unmap_adapter_regs(struct cxl *adapter)
{
- if (adapter->p1_mmio)
+ if (adapter->p1_mmio) {
iounmap(adapter->p1_mmio);
- if (adapter->p2_mmio)
+ adapter->p1_mmio = NULL;
+ pci_release_region(to_pci_dev(adapter->dev.parent), 2);
+ }
+ if (adapter->p2_mmio) {
iounmap(adapter->p2_mmio);
+ adapter->p2_mmio = NULL;
+ pci_release_region(to_pci_dev(adapter->dev.parent), 0);
+ }
}
static int cxl_read_vsec(struct cxl *adapter, struct pci_dev *dev)
@@ -928,7 +1014,6 @@ static int cxl_read_vsec(struct cxl *adapter, struct pci_dev *dev)
CXL_READ_VSEC_BASE_IMAGE(dev, vsec, &adapter->base_image);
CXL_READ_VSEC_IMAGE_STATE(dev, vsec, &image_state);
adapter->user_image_loaded = !!(image_state & CXL_VSEC_USER_IMAGE_LOADED);
- adapter->perst_loads_image = true;
adapter->perst_select_user = !!(image_state & CXL_VSEC_USER_IMAGE_LOADED);
CXL_READ_VSEC_NAFUS(dev, vsec, &adapter->slices);
@@ -950,6 +1035,32 @@ static int cxl_read_vsec(struct cxl *adapter, struct pci_dev *dev)
return 0;
}
+/*
+ * Workaround a PCIe Host Bridge defect on some cards, that can cause
+ * malformed Transaction Layer Packet (TLP) errors to be erroneously
+ * reported. Mask this error in the Uncorrectable Error Mask Register.
+ *
+ * The upper nibble of the PSL revision is used to distinguish between
+ * different cards. The affected ones have it set to 0.
+ */
+static void cxl_fixup_malformed_tlp(struct cxl *adapter, struct pci_dev *dev)
+{
+ int aer;
+ u32 data;
+
+ if (adapter->psl_rev & 0xf000)
+ return;
+ if (!(aer = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR)))
+ return;
+ pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, &data);
+ if (data & PCI_ERR_UNC_MALF_TLP)
+ if (data & PCI_ERR_UNC_INTN)
+ return;
+ data |= PCI_ERR_UNC_MALF_TLP;
+ data |= PCI_ERR_UNC_INTN;
+ pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, data);
+}
+
static int cxl_vsec_looks_ok(struct cxl *adapter, struct pci_dev *dev)
{
if (adapter->vsec_status & CXL_STATUS_SECOND_PORT)
@@ -988,81 +1099,140 @@ static void cxl_release_adapter(struct device *dev)
pr_devel("cxl_release_adapter\n");
+ cxl_remove_adapter_nr(adapter);
+
kfree(adapter);
}
-static struct cxl *cxl_alloc_adapter(struct pci_dev *dev)
+static struct cxl *cxl_alloc_adapter(void)
{
struct cxl *adapter;
if (!(adapter = kzalloc(sizeof(struct cxl), GFP_KERNEL)))
return NULL;
- adapter->dev.parent = &dev->dev;
- adapter->dev.release = cxl_release_adapter;
- pci_set_drvdata(dev, adapter);
spin_lock_init(&adapter->afu_list_lock);
+ if (cxl_alloc_adapter_nr(adapter))
+ goto err1;
+
+ if (dev_set_name(&adapter->dev, "card%i", adapter->adapter_num))
+ goto err2;
+
return adapter;
+
+err2:
+ cxl_remove_adapter_nr(adapter);
+err1:
+ kfree(adapter);
+ return NULL;
}
+#define CXL_PSL_ErrIVTE_tberror (0x1ull << (63-31))
+
static int sanitise_adapter_regs(struct cxl *adapter)
{
- cxl_p1_write(adapter, CXL_PSL_ErrIVTE, 0x0000000000000000);
+ /* Clear PSL tberror bit by writing 1 to it */
+ cxl_p1_write(adapter, CXL_PSL_ErrIVTE, CXL_PSL_ErrIVTE_tberror);
return cxl_tlb_slb_invalidate(adapter);
}
-static struct cxl *cxl_init_adapter(struct pci_dev *dev)
+/* This should contain *only* operations that can safely be done in
+ * both creation and recovery.
+ */
+static int cxl_configure_adapter(struct cxl *adapter, struct pci_dev *dev)
{
- struct cxl *adapter;
- bool free = true;
int rc;
+ adapter->dev.parent = &dev->dev;
+ adapter->dev.release = cxl_release_adapter;
+ pci_set_drvdata(dev, adapter);
- if (!(adapter = cxl_alloc_adapter(dev)))
- return ERR_PTR(-ENOMEM);
+ rc = pci_enable_device(dev);
+ if (rc) {
+ dev_err(&dev->dev, "pci_enable_device failed: %i\n", rc);
+ return rc;
+ }
if ((rc = cxl_read_vsec(adapter, dev)))
- goto err1;
+ return rc;
if ((rc = cxl_vsec_looks_ok(adapter, dev)))
- goto err1;
+ return rc;
+
+ cxl_fixup_malformed_tlp(adapter, dev);
if ((rc = setup_cxl_bars(dev)))
- goto err1;
+ return rc;
if ((rc = switch_card_to_cxl(dev)))
- goto err1;
-
- if ((rc = cxl_alloc_adapter_nr(adapter)))
- goto err1;
-
- if ((rc = dev_set_name(&adapter->dev, "card%i", adapter->adapter_num)))
- goto err2;
+ return rc;
if ((rc = cxl_update_image_control(adapter)))
- goto err2;
+ return rc;
if ((rc = cxl_map_adapter_regs(adapter, dev)))
- goto err2;
+ return rc;
if ((rc = sanitise_adapter_regs(adapter)))
- goto err2;
+ goto err;
if ((rc = init_implementation_adapter_regs(adapter, dev)))
- goto err3;
+ goto err;
if ((rc = pnv_phb_to_cxl_mode(dev, OPAL_PHB_CAPI_MODE_CAPI)))
- goto err3;
+ goto err;
/* If recovery happened, the last step is to turn on snooping.
* In the non-recovery case this has no effect */
- if ((rc = pnv_phb_to_cxl_mode(dev, OPAL_PHB_CAPI_MODE_SNOOP_ON))) {
- goto err3;
- }
+ if ((rc = pnv_phb_to_cxl_mode(dev, OPAL_PHB_CAPI_MODE_SNOOP_ON)))
+ goto err;
+
+ if ((rc = cxl_setup_psl_timebase(adapter, dev)))
+ goto err;
if ((rc = cxl_register_psl_err_irq(adapter)))
- goto err3;
+ goto err;
+
+ return 0;
+
+err:
+ cxl_unmap_adapter_regs(adapter);
+ return rc;
+
+}
+
+static void cxl_deconfigure_adapter(struct cxl *adapter)
+{
+ struct pci_dev *pdev = to_pci_dev(adapter->dev.parent);
+
+ cxl_release_psl_err_irq(adapter);
+ cxl_unmap_adapter_regs(adapter);
+
+ pci_disable_device(pdev);
+}
+
+static struct cxl *cxl_init_adapter(struct pci_dev *dev)
+{
+ struct cxl *adapter;
+ int rc;
+
+ adapter = cxl_alloc_adapter();
+ if (!adapter)
+ return ERR_PTR(-ENOMEM);
+
+ /* Set defaults for parameters which need to persist over
+ * configure/reconfigure
+ */
+ adapter->perst_loads_image = true;
+ adapter->perst_same_image = false;
+
+ rc = cxl_configure_adapter(adapter, dev);
+ if (rc) {
+ pci_disable_device(dev);
+ cxl_release_adapter(&adapter->dev);
+ return ERR_PTR(rc);
+ }
/* Don't care if this one fails: */
cxl_debugfs_adapter_add(adapter);
@@ -1080,37 +1250,25 @@ static struct cxl *cxl_init_adapter(struct pci_dev *dev)
return adapter;
err_put1:
- device_unregister(&adapter->dev);
- free = false;
+ /* This should mirror cxl_remove_adapter, except without the
+ * sysfs parts
+ */
cxl_debugfs_adapter_remove(adapter);
- cxl_release_psl_err_irq(adapter);
-err3:
- cxl_unmap_adapter_regs(adapter);
-err2:
- cxl_remove_adapter_nr(adapter);
-err1:
- if (free)
- kfree(adapter);
+ cxl_deconfigure_adapter(adapter);
+ device_unregister(&adapter->dev);
return ERR_PTR(rc);
}
static void cxl_remove_adapter(struct cxl *adapter)
{
- struct pci_dev *pdev = to_pci_dev(adapter->dev.parent);
-
- pr_devel("cxl_release_adapter\n");
+ pr_devel("cxl_remove_adapter\n");
cxl_sysfs_adapter_remove(adapter);
cxl_debugfs_adapter_remove(adapter);
- cxl_release_psl_err_irq(adapter);
- cxl_unmap_adapter_regs(adapter);
- cxl_remove_adapter_nr(adapter);
- device_unregister(&adapter->dev);
+ cxl_deconfigure_adapter(adapter);
- pci_release_region(pdev, 0);
- pci_release_region(pdev, 2);
- pci_disable_device(pdev);
+ device_unregister(&adapter->dev);
}
static int cxl_probe(struct pci_dev *dev, const struct pci_device_id *id)
@@ -1122,21 +1280,21 @@ static int cxl_probe(struct pci_dev *dev, const struct pci_device_id *id)
if (cxl_verbose)
dump_cxl_config_space(dev);
- if ((rc = pci_enable_device(dev))) {
- dev_err(&dev->dev, "pci_enable_device failed: %i\n", rc);
- return rc;
- }
-
adapter = cxl_init_adapter(dev);
if (IS_ERR(adapter)) {
dev_err(&dev->dev, "cxl_init_adapter failed: %li\n", PTR_ERR(adapter));
- pci_disable_device(dev);
return PTR_ERR(adapter);
}
for (slice = 0; slice < adapter->slices; slice++) {
- if ((rc = cxl_init_afu(adapter, slice, dev)))
+ if ((rc = cxl_init_afu(adapter, slice, dev))) {
dev_err(&dev->dev, "AFU %i failed to initialise: %i\n", slice, rc);
+ continue;
+ }
+
+ rc = cxl_afu_select_best_mode(adapter->afu[slice]);
+ if (rc)
+ dev_err(&dev->dev, "AFU %i failed to start: %i\n", slice, rc);
}
return 0;
@@ -1160,10 +1318,262 @@ static void cxl_remove(struct pci_dev *dev)
cxl_remove_adapter(adapter);
}
+static pci_ers_result_t cxl_vphb_error_detected(struct cxl_afu *afu,
+ pci_channel_state_t state)
+{
+ struct pci_dev *afu_dev;
+ pci_ers_result_t result = PCI_ERS_RESULT_NEED_RESET;
+ pci_ers_result_t afu_result = PCI_ERS_RESULT_NEED_RESET;
+
+ /* There should only be one entry, but go through the list
+ * anyway
+ */
+ list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) {
+ if (!afu_dev->driver)
+ continue;
+
+ afu_dev->error_state = state;
+
+ if (afu_dev->driver->err_handler)
+ afu_result = afu_dev->driver->err_handler->error_detected(afu_dev,
+ state);
+ /* Disconnect trumps all, NONE trumps NEED_RESET */
+ if (afu_result == PCI_ERS_RESULT_DISCONNECT)
+ result = PCI_ERS_RESULT_DISCONNECT;
+ else if ((afu_result == PCI_ERS_RESULT_NONE) &&
+ (result == PCI_ERS_RESULT_NEED_RESET))
+ result = PCI_ERS_RESULT_NONE;
+ }
+ return result;
+}
+
+static pci_ers_result_t cxl_pci_error_detected(struct pci_dev *pdev,
+ pci_channel_state_t state)
+{
+ struct cxl *adapter = pci_get_drvdata(pdev);
+ struct cxl_afu *afu;
+ pci_ers_result_t result = PCI_ERS_RESULT_NEED_RESET;
+ int i;
+
+ /* At this point, we could still have an interrupt pending.
+ * Let's try to get them out of the way before they do
+ * anything we don't like.
+ */
+ schedule();
+
+ /* If we're permanently dead, give up. */
+ if (state == pci_channel_io_perm_failure) {
+ /* Tell the AFU drivers; but we don't care what they
+ * say, we're going away.
+ */
+ for (i = 0; i < adapter->slices; i++) {
+ afu = adapter->afu[i];
+ cxl_vphb_error_detected(afu, state);
+ }
+ return PCI_ERS_RESULT_DISCONNECT;
+ }
+
+ /* Are we reflashing?
+ *
+ * If we reflash, we could come back as something entirely
+ * different, including a non-CAPI card. As such, by default
+ * we don't participate in the process. We'll be unbound and
+ * the slot re-probed. (TODO: check EEH doesn't blindly rebind
+ * us!)
+ *
+ * However, this isn't the entire story: for reliablity
+ * reasons, we usually want to reflash the FPGA on PERST in
+ * order to get back to a more reliable known-good state.
+ *
+ * This causes us a bit of a problem: if we reflash we can't
+ * trust that we'll come back the same - we could have a new
+ * image and been PERSTed in order to load that
+ * image. However, most of the time we actually *will* come
+ * back the same - for example a regular EEH event.
+ *
+ * Therefore, we allow the user to assert that the image is
+ * indeed the same and that we should continue on into EEH
+ * anyway.
+ */
+ if (adapter->perst_loads_image && !adapter->perst_same_image) {
+ /* TODO take the PHB out of CXL mode */
+ dev_info(&pdev->dev, "reflashing, so opting out of EEH!\n");
+ return PCI_ERS_RESULT_NONE;
+ }
+
+ /*
+ * At this point, we want to try to recover. We'll always
+ * need a complete slot reset: we don't trust any other reset.
+ *
+ * Now, we go through each AFU:
+ * - We send the driver, if bound, an error_detected callback.
+ * We expect it to clean up, but it can also tell us to give
+ * up and permanently detach the card. To simplify things, if
+ * any bound AFU driver doesn't support EEH, we give up on EEH.
+ *
+ * - We detach all contexts associated with the AFU. This
+ * does not free them, but puts them into a CLOSED state
+ * which causes any the associated files to return useful
+ * errors to userland. It also unmaps, but does not free,
+ * any IRQs.
+ *
+ * - We clean up our side: releasing and unmapping resources we hold
+ * so we can wire them up again when the hardware comes back up.
+ *
+ * Driver authors should note:
+ *
+ * - Any contexts you create in your kernel driver (except
+ * those associated with anonymous file descriptors) are
+ * your responsibility to free and recreate. Likewise with
+ * any attached resources.
+ *
+ * - We will take responsibility for re-initialising the
+ * device context (the one set up for you in
+ * cxl_pci_enable_device_hook and accessed through
+ * cxl_get_context). If you've attached IRQs or other
+ * resources to it, they remains yours to free.
+ *
+ * You can call the same functions to release resources as you
+ * normally would: we make sure that these functions continue
+ * to work when the hardware is down.
+ *
+ * Two examples:
+ *
+ * 1) If you normally free all your resources at the end of
+ * each request, or if you use anonymous FDs, your
+ * error_detected callback can simply set a flag to tell
+ * your driver not to start any new calls. You can then
+ * clear the flag in the resume callback.
+ *
+ * 2) If you normally allocate your resources on startup:
+ * * Set a flag in error_detected as above.
+ * * Let CXL detach your contexts.
+ * * In slot_reset, free the old resources and allocate new ones.
+ * * In resume, clear the flag to allow things to start.
+ */
+ for (i = 0; i < adapter->slices; i++) {
+ afu = adapter->afu[i];
+
+ result = cxl_vphb_error_detected(afu, state);
+
+ /* Only continue if everyone agrees on NEED_RESET */
+ if (result != PCI_ERS_RESULT_NEED_RESET)
+ return result;
+
+ cxl_context_detach_all(afu);
+ cxl_afu_deactivate_mode(afu);
+ cxl_deconfigure_afu(afu);
+ }
+ cxl_deconfigure_adapter(adapter);
+
+ return result;
+}
+
+static pci_ers_result_t cxl_pci_slot_reset(struct pci_dev *pdev)
+{
+ struct cxl *adapter = pci_get_drvdata(pdev);
+ struct cxl_afu *afu;
+ struct cxl_context *ctx;
+ struct pci_dev *afu_dev;
+ pci_ers_result_t afu_result = PCI_ERS_RESULT_RECOVERED;
+ pci_ers_result_t result = PCI_ERS_RESULT_RECOVERED;
+ int i;
+
+ if (cxl_configure_adapter(adapter, pdev))
+ goto err;
+
+ for (i = 0; i < adapter->slices; i++) {
+ afu = adapter->afu[i];
+
+ if (cxl_configure_afu(afu, adapter, pdev))
+ goto err;
+
+ if (cxl_afu_select_best_mode(afu))
+ goto err;
+
+ cxl_pci_vphb_reconfigure(afu);
+
+ list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) {
+ /* Reset the device context.
+ * TODO: make this less disruptive
+ */
+ ctx = cxl_get_context(afu_dev);
+
+ if (ctx && cxl_release_context(ctx))
+ goto err;
+
+ ctx = cxl_dev_context_init(afu_dev);
+ if (!ctx)
+ goto err;
+
+ afu_dev->dev.archdata.cxl_ctx = ctx;
+
+ if (cxl_afu_check_and_enable(afu))
+ goto err;
+
+ afu_dev->error_state = pci_channel_io_normal;
+
+ /* If there's a driver attached, allow it to
+ * chime in on recovery. Drivers should check
+ * if everything has come back OK, but
+ * shouldn't start new work until we call
+ * their resume function.
+ */
+ if (!afu_dev->driver)
+ continue;
+
+ if (afu_dev->driver->err_handler &&
+ afu_dev->driver->err_handler->slot_reset)
+ afu_result = afu_dev->driver->err_handler->slot_reset(afu_dev);
+
+ if (afu_result == PCI_ERS_RESULT_DISCONNECT)
+ result = PCI_ERS_RESULT_DISCONNECT;
+ }
+ }
+ return result;
+
+err:
+ /* All the bits that happen in both error_detected and cxl_remove
+ * should be idempotent, so we don't need to worry about leaving a mix
+ * of unconfigured and reconfigured resources.
+ */
+ dev_err(&pdev->dev, "EEH recovery failed. Asking to be disconnected.\n");
+ return PCI_ERS_RESULT_DISCONNECT;
+}
+
+static void cxl_pci_resume(struct pci_dev *pdev)
+{
+ struct cxl *adapter = pci_get_drvdata(pdev);
+ struct cxl_afu *afu;
+ struct pci_dev *afu_dev;
+ int i;
+
+ /* Everything is back now. Drivers should restart work now.
+ * This is not the place to be checking if everything came back up
+ * properly, because there's no return value: do that in slot_reset.
+ */
+ for (i = 0; i < adapter->slices; i++) {
+ afu = adapter->afu[i];
+
+ list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) {
+ if (afu_dev->driver && afu_dev->driver->err_handler &&
+ afu_dev->driver->err_handler->resume)
+ afu_dev->driver->err_handler->resume(afu_dev);
+ }
+ }
+}
+
+static const struct pci_error_handlers cxl_err_handler = {
+ .error_detected = cxl_pci_error_detected,
+ .slot_reset = cxl_pci_slot_reset,
+ .resume = cxl_pci_resume,
+};
+
struct pci_driver cxl_pci_driver = {
.name = "cxl-pci",
.id_table = cxl_pci_tbl,
.probe = cxl_probe,
.remove = cxl_remove,
.shutdown = cxl_remove,
+ .err_handler = &cxl_err_handler,
};