powerpc/fsl_pci: Don't set up inbound windows in kdump crash kernel

Otherwise, because the top end of the crash kernel is treated as the
absolute top of memory rather than the beginning of a reserved region,
in-flight DMA from the previous kernel that targets areas above the
crash kernel can trigger a storm of PCI errors.  We only do this for
kdump, not normal kexec, in case kexec is being used to upgrade to a
kernel that wants a different inbound memory map.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Cc: Mingkai Hu <Mingkai.hu@freescale.com>
This commit is contained in:
Scott Wood 2015-10-06 22:48:08 -05:00
parent 1112450a18
commit 1930bb5ccf
1 changed files with 61 additions and 23 deletions

View File

@ -179,6 +179,19 @@ static int setup_one_atmu(struct ccsr_pci __iomem *pci,
return i;
}
static bool is_kdump(void)
{
struct device_node *node;
node = of_find_node_by_type(NULL, "memory");
if (!node) {
WARN_ON_ONCE(1);
return false;
}
return of_property_read_bool(node, "linux,usable-memory");
}
/* atmu setup for fsl pci/pcie controller */
static void setup_pci_atmu(struct pci_controller *hose)
{
@ -192,6 +205,16 @@ static void setup_pci_atmu(struct pci_controller *hose)
const char *name = hose->dn->full_name;
const u64 *reg;
int len;
bool setup_inbound;
/*
* If this is kdump, we don't want to trigger a bunch of PCI
* errors by closing the window on in-flight DMA.
*
* We still run most of the function's logic so that things like
* hose->dma_window_size still get set.
*/
setup_inbound = !is_kdump();
if (early_find_capability(hose, 0, 0, PCI_CAP_ID_EXP)) {
if (in_be32(&pci->block_rev1) >= PCIE_IP_REV_2_2) {
@ -204,8 +227,11 @@ static void setup_pci_atmu(struct pci_controller *hose)
/* Disable all windows (except powar0 since it's ignored) */
for(i = 1; i < 5; i++)
out_be32(&pci->pow[i].powar, 0);
for (i = start_idx; i < end_idx; i++)
out_be32(&pci->piw[i].piwar, 0);
if (setup_inbound) {
for (i = start_idx; i < end_idx; i++)
out_be32(&pci->piw[i].piwar, 0);
}
/* Setup outbound MEM window */
for(i = 0, j = 1; i < 3; i++) {
@ -278,6 +304,7 @@ static void setup_pci_atmu(struct pci_controller *hose)
/* Setup inbound mem window */
mem = memblock_end_of_DRAM();
pr_info("%s: end of DRAM %llx\n", __func__, mem);
/*
* The msi-address-64 property, if it exists, indicates the physical
@ -320,12 +347,14 @@ static void setup_pci_atmu(struct pci_controller *hose)
piwar |= ((mem_log - 1) & PIWAR_SZ_MASK);
/* Setup inbound memory window */
out_be32(&pci->piw[win_idx].pitar, 0x00000000);
out_be32(&pci->piw[win_idx].piwbar, 0x00000000);
out_be32(&pci->piw[win_idx].piwar, piwar);
win_idx--;
if (setup_inbound) {
/* Setup inbound memory window */
out_be32(&pci->piw[win_idx].pitar, 0x00000000);
out_be32(&pci->piw[win_idx].piwbar, 0x00000000);
out_be32(&pci->piw[win_idx].piwar, piwar);
}
win_idx--;
hose->dma_window_base_cur = 0x00000000;
hose->dma_window_size = (resource_size_t)sz;
@ -343,13 +372,15 @@ static void setup_pci_atmu(struct pci_controller *hose)
piwar = (piwar & ~PIWAR_SZ_MASK) | (mem_log - 1);
/* Setup inbound memory window */
out_be32(&pci->piw[win_idx].pitar, 0x00000000);
out_be32(&pci->piw[win_idx].piwbear,
pci64_dma_offset >> 44);
out_be32(&pci->piw[win_idx].piwbar,
pci64_dma_offset >> 12);
out_be32(&pci->piw[win_idx].piwar, piwar);
if (setup_inbound) {
/* Setup inbound memory window */
out_be32(&pci->piw[win_idx].pitar, 0x00000000);
out_be32(&pci->piw[win_idx].piwbear,
pci64_dma_offset >> 44);
out_be32(&pci->piw[win_idx].piwbar,
pci64_dma_offset >> 12);
out_be32(&pci->piw[win_idx].piwar, piwar);
}
/*
* install our own dma_set_mask handler to fixup dma_ops
@ -362,12 +393,15 @@ static void setup_pci_atmu(struct pci_controller *hose)
} else {
u64 paddr = 0;
/* Setup inbound memory window */
out_be32(&pci->piw[win_idx].pitar, paddr >> 12);
out_be32(&pci->piw[win_idx].piwbar, paddr >> 12);
out_be32(&pci->piw[win_idx].piwar, (piwar | (mem_log - 1)));
win_idx--;
if (setup_inbound) {
/* Setup inbound memory window */
out_be32(&pci->piw[win_idx].pitar, paddr >> 12);
out_be32(&pci->piw[win_idx].piwbar, paddr >> 12);
out_be32(&pci->piw[win_idx].piwar,
(piwar | (mem_log - 1)));
}
win_idx--;
paddr += 1ull << mem_log;
sz -= 1ull << mem_log;
@ -375,11 +409,15 @@ static void setup_pci_atmu(struct pci_controller *hose)
mem_log = ilog2(sz);
piwar |= (mem_log - 1);
out_be32(&pci->piw[win_idx].pitar, paddr >> 12);
out_be32(&pci->piw[win_idx].piwbar, paddr >> 12);
out_be32(&pci->piw[win_idx].piwar, piwar);
win_idx--;
if (setup_inbound) {
out_be32(&pci->piw[win_idx].pitar,
paddr >> 12);
out_be32(&pci->piw[win_idx].piwbar,
paddr >> 12);
out_be32(&pci->piw[win_idx].piwar, piwar);
}
win_idx--;
paddr += 1ull << mem_log;
}