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authorScott Wood <scottwood@freescale.com>2015-10-07 06:48:08 +0300
committerScott Wood <scottwood@freescale.com>2015-10-17 08:36:37 +0300
commit1930bb5ccf77da3bf1483e2cd85a12ec9c0ed0f6 (patch)
tree478a9ac249f4406466fd20a84ad5de4f4c6f0026 /arch/powerpc/sysdev/fsl_pci.c
parent1112450a18dfcc26dd18000e20bf06bda27f2bad (diff)
downloadlinux-1930bb5ccf77da3bf1483e2cd85a12ec9c0ed0f6.tar.xz
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>
Diffstat (limited to 'arch/powerpc/sysdev/fsl_pci.c')
-rw-r--r--arch/powerpc/sysdev/fsl_pci.c84
1 files changed, 61 insertions, 23 deletions
diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c
index c42609dde8d2..1c65ef92768d 100644
--- a/arch/powerpc/sysdev/fsl_pci.c
+++ b/arch/powerpc/sysdev/fsl_pci.c
@@ -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;
}