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Commit 1930bb5c authored by Scott Wood's avatar Scott Wood
Browse files

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: default avatarScott Wood <scottwood@freescale.com>
Cc: Mingkai Hu <Mingkai.hu@freescale.com>
parent 1112450a

arch/powerpc/sysdev/fsl_pci.c

+61 −23
Original line number Diff line number Diff line
@@ -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);



	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);



		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--;

		}



		win_idx--;

		hose->dma_window_base_cur = 0x00000000;

		hose->dma_window_size = (resource_size_t)sz;
@@ -343,6 +372,7 @@ static void setup_pci_atmu(struct pci_controller *hose) 


			piwar = (piwar & ~PIWAR_SZ_MASK) | (mem_log - 1);



			if (setup_inbound) {

				/* Setup inbound memory window */

				out_be32(&pci->piw[win_idx].pitar,  0x00000000);

				out_be32(&pci->piw[win_idx].piwbear,
@@ -350,6 +380,7 @@ static void setup_pci_atmu(struct pci_controller *hose) 
				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;



		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--;

			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);

			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--;

			}



			win_idx--;

			paddr += 1ull << mem_log;

		}