Re: [PATCH 2/2] PCI: designware: use iATU0 for cfg and IO, iATU1 for MEM

From: Fabrice Gasnier
Date: Thu Apr 23 2015 - 03:36:28 EST


Hi Jisheng,

On 04/22/2015 02:58 PM, Jisheng Zhang wrote:
Most transactions' type are cfg0 and MEM, so the Current iATU usage is not
balanced, iATU0 is hot while iATU1 is rarely used. This patch refactors
the iATU usage: iATU0 for cfg and IO, iATU1 for MEM. This allocation
ideas comes from Minghuan Lian<Minghuan.Lian@xxxxxxxxxxxxx>:

http://www.spinics.net/lists/linux-pci/msg40440.html

Signed-off-by: Jisheng Zhang<jszhang@xxxxxxxxxxx>
---
drivers/pci/host/pcie-designware.c | 83 +++++++++++++++++++++-----------------
1 file changed, 47 insertions(+), 36 deletions(-)

diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
index 1da1446..bb81c8ad 100644
--- a/drivers/pci/host/pcie-designware.c
+++ b/drivers/pci/host/pcie-designware.c
@@ -508,6 +508,13 @@ int dw_pcie_host_init(struct pcie_port *pp)
if (pp->ops->host_init)
pp->ops->host_init(pp);
+ dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX0,
+ PCIE_ATU_TYPE_IO, pp->io_mod_base,
+ pp->io_bus_addr, pp->io_size);
+ dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX1,
+ PCIE_ATU_TYPE_MEM, pp->mem_mod_base,
+ pp->mem_bus_addr, pp->mem_size);
+
Some platforms doesn't have support for ATU. I think this is the reason to have
rd_other_conf / wr_other_conf ops in the driver.
IMO, this is not suitable to have this in the initialization routine for all platforms.

Regards,
Fabrice
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