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powerpc/pseries/eeh: move pseries_eeh_err_inject() outside CONFIG_DEB…
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…UG_FS block

Makes pseries_eeh_err_inject() available even when debugfs
is disabled (CONFIG_DEBUG_FS=n). It moves eeh_debugfs_break_device()
and eeh_pe_inject_mmio_error() out of the CONFIG_DEBUG_FS block
and renames it as eeh_break_device().

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202409170509.VWC6jadC-lkp@intel.com/
Fixes: b0e2b82 ("powerpc/pseries/eeh: Fix pseries_eeh_err_inject")
Signed-off-by: Narayana Murty N <nnmlinux@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240917132445.3868016-1-nnmlinux@linux.ibm.com
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@NarayanamurtyN @mpe
NarayanamurtyN authored and mpe committed Sep 20, 2024
1 parent 699d53f commit 3af2e2f
Showing 1 changed file with 99 additions and 99 deletions.
198 changes: 99 additions & 99 deletions arch/powerpc/kernel/eeh.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1574,6 +1574,104 @@ static int proc_eeh_show(struct seq_file *m, void *v)
}
#endif /* CONFIG_PROC_FS */

static int eeh_break_device(struct pci_dev *pdev)
{
struct resource *bar = NULL;
void __iomem *mapped;
u16 old, bit;
int i, pos;

/* Do we have an MMIO BAR to disable? */
for (i = 0; i <= PCI_STD_RESOURCE_END; i++) {
struct resource *r = &pdev->resource[i];

if (!r->flags || !r->start)
continue;
if (r->flags & IORESOURCE_IO)
continue;
if (r->flags & IORESOURCE_UNSET)
continue;

bar = r;
break;
}

if (!bar) {
pci_err(pdev, "Unable to find Memory BAR to cause EEH with\n");
return -ENXIO;
}

pci_err(pdev, "Going to break: %pR\n", bar);

if (pdev->is_virtfn) {
#ifndef CONFIG_PCI_IOV
return -ENXIO;
#else
/*
* VFs don't have a per-function COMMAND register, so the best
* we can do is clear the Memory Space Enable bit in the PF's
* SRIOV control reg.
*
* Unfortunately, this requires that we have a PF (i.e doesn't
* work for a passed-through VF) and it has the potential side
* effect of also causing an EEH on every other VF under the
* PF. Oh well.
*/
pdev = pdev->physfn;
if (!pdev)
return -ENXIO; /* passed through VFs have no PF */

pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_SRIOV);
pos += PCI_SRIOV_CTRL;
bit = PCI_SRIOV_CTRL_MSE;
#endif /* !CONFIG_PCI_IOV */
} else {
bit = PCI_COMMAND_MEMORY;
pos = PCI_COMMAND;
}

/*
* Process here is:
*
* 1. Disable Memory space.
*
* 2. Perform an MMIO to the device. This should result in an error
* (CA / UR) being raised by the device which results in an EEH
* PE freeze. Using the in_8() accessor skips the eeh detection hook
* so the freeze hook so the EEH Detection machinery won't be
* triggered here. This is to match the usual behaviour of EEH
* where the HW will asynchronously freeze a PE and it's up to
* the kernel to notice and deal with it.
*
* 3. Turn Memory space back on. This is more important for VFs
* since recovery will probably fail if we don't. For normal
* the COMMAND register is reset as a part of re-initialising
* the device.
*
* Breaking stuff is the point so who cares if it's racy ;)
*/
pci_read_config_word(pdev, pos, &old);

mapped = ioremap(bar->start, PAGE_SIZE);
if (!mapped) {
pci_err(pdev, "Unable to map MMIO BAR %pR\n", bar);
return -ENXIO;
}

pci_write_config_word(pdev, pos, old & ~bit);
in_8(mapped);
pci_write_config_word(pdev, pos, old);

iounmap(mapped);

return 0;
}

int eeh_pe_inject_mmio_error(struct pci_dev *pdev)
{
return eeh_break_device(pdev);
}

#ifdef CONFIG_DEBUG_FS


Expand Down Expand Up @@ -1725,99 +1823,6 @@ static const struct file_operations eeh_dev_check_fops = {
.read = eeh_debugfs_dev_usage,
};

static int eeh_debugfs_break_device(struct pci_dev *pdev)
{
struct resource *bar = NULL;
void __iomem *mapped;
u16 old, bit;
int i, pos;

/* Do we have an MMIO BAR to disable? */
for (i = 0; i <= PCI_STD_RESOURCE_END; i++) {
struct resource *r = &pdev->resource[i];

if (!r->flags || !r->start)
continue;
if (r->flags & IORESOURCE_IO)
continue;
if (r->flags & IORESOURCE_UNSET)
continue;

bar = r;
break;
}

if (!bar) {
pci_err(pdev, "Unable to find Memory BAR to cause EEH with\n");
return -ENXIO;
}

pci_err(pdev, "Going to break: %pR\n", bar);

if (pdev->is_virtfn) {
#ifndef CONFIG_PCI_IOV
return -ENXIO;
#else
/*
* VFs don't have a per-function COMMAND register, so the best
* we can do is clear the Memory Space Enable bit in the PF's
* SRIOV control reg.
*
* Unfortunately, this requires that we have a PF (i.e doesn't
* work for a passed-through VF) and it has the potential side
* effect of also causing an EEH on every other VF under the
* PF. Oh well.
*/
pdev = pdev->physfn;
if (!pdev)
return -ENXIO; /* passed through VFs have no PF */

pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_SRIOV);
pos += PCI_SRIOV_CTRL;
bit = PCI_SRIOV_CTRL_MSE;
#endif /* !CONFIG_PCI_IOV */
} else {
bit = PCI_COMMAND_MEMORY;
pos = PCI_COMMAND;
}

/*
* Process here is:
*
* 1. Disable Memory space.
*
* 2. Perform an MMIO to the device. This should result in an error
* (CA / UR) being raised by the device which results in an EEH
* PE freeze. Using the in_8() accessor skips the eeh detection hook
* so the freeze hook so the EEH Detection machinery won't be
* triggered here. This is to match the usual behaviour of EEH
* where the HW will asynchronously freeze a PE and it's up to
* the kernel to notice and deal with it.
*
* 3. Turn Memory space back on. This is more important for VFs
* since recovery will probably fail if we don't. For normal
* the COMMAND register is reset as a part of re-initialising
* the device.
*
* Breaking stuff is the point so who cares if it's racy ;)
*/
pci_read_config_word(pdev, pos, &old);

mapped = ioremap(bar->start, PAGE_SIZE);
if (!mapped) {
pci_err(pdev, "Unable to map MMIO BAR %pR\n", bar);
return -ENXIO;
}

pci_write_config_word(pdev, pos, old & ~bit);
in_8(mapped);
pci_write_config_word(pdev, pos, old);

iounmap(mapped);

return 0;
}

static ssize_t eeh_dev_break_write(struct file *filp,
const char __user *user_buf,
size_t count, loff_t *ppos)
Expand All @@ -1829,7 +1834,7 @@ static ssize_t eeh_dev_break_write(struct file *filp,
if (IS_ERR(pdev))
return PTR_ERR(pdev);

ret = eeh_debugfs_break_device(pdev);
ret = eeh_break_device(pdev);
pci_dev_put(pdev);

if (ret < 0)
Expand All @@ -1844,11 +1849,6 @@ static const struct file_operations eeh_dev_break_fops = {
.read = eeh_debugfs_dev_usage,
};

int eeh_pe_inject_mmio_error(struct pci_dev *pdev)
{
return eeh_debugfs_break_device(pdev);
}

static ssize_t eeh_dev_can_recover(struct file *filp,
const char __user *user_buf,
size_t count, loff_t *ppos)
Expand Down

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