[PATCH V2] PCI: dwc: Add support to handle prefetchable memory mapping
From: Vidya Sagar
Date: Tue Oct 20 2020 - 15:59:45 EST
DWC sub-system currently doesn't differentiate between prefetchable and
non-prefetchable memory aperture entries in the 'ranges' property and
provides ATU mapping only for the first memory aperture entry out of all
the entries present. This was introduced by the
commit 0f71c60ffd26 ("PCI: dwc: Remove storing of PCI resources").
Mapping for a memory apreture is required if its CPU address and the bus
address are different and the current mechanism works only if the memory
aperture which needs mapping happens to be the first entry. It doesn't
work either if the memory aperture that needs mapping is not the first
entry or if both prefetchable and non-prefetchable apertures need mapping.
This patch fixes this issue by differentiating between prefetchable and
non-prefetchable apertures in the 'ranges' property there by removing the
dependency on the order in which they are specified and adds support for
mapping prefetchable aperture using ATU region-3 if required.
Fixes: 0f71c60ffd26 ("PCI: dwc: Remove storing of PCI resources")
Link: http://patchwork.ozlabs.org/project/linux-pci/patch/20200513190855.23318-1-vidyas@xxxxxxxxxx/
Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
---
V2:
* Rewrote commit subject and description
* Addressed review comments from Lorenzo
.../pci/controller/dwc/pcie-designware-host.c | 42 ++++++++++++++++---
drivers/pci/controller/dwc/pcie-designware.c | 12 +++---
drivers/pci/controller/dwc/pcie-designware.h | 4 +-
3 files changed, 46 insertions(+), 12 deletions(-)
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index db547ee6ff3a..dae6da39bb90 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -521,9 +521,42 @@ static struct pci_ops dw_pcie_ops = {
.write = pci_generic_config_write,
};
+static void dw_pcie_setup_mem_atu(struct pcie_port *pp,
+ struct resource_entry *win)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+
+ /* Check for prefetchable memory aperture */
+ if (win->res->flags & IORESOURCE_PREFETCH && win->offset) {
+ /* Number of view ports must at least be 4 to enable mapping */
+ if (pci->num_viewport < 4) {
+ dev_warn(pci->dev,
+ "Insufficient ATU regions to map Prefetchable memory\n");
+ } else {
+ dw_pcie_prog_outbound_atu(pci,
+ PCIE_ATU_REGION_INDEX3,
+ PCIE_ATU_TYPE_MEM,
+ win->res->start,
+ win->res->start - win->offset,
+ resource_size(win->res));
+ }
+ } else if (win->offset) { /* Non-prefetchable memory aperture */
+ if (upper_32_bits(resource_size(win->res)))
+ dev_warn(pci->dev,
+ "Memory resource size exceeds max for 32 bits\n");
+ dw_pcie_prog_outbound_atu(pci,
+ PCIE_ATU_REGION_INDEX0,
+ PCIE_ATU_TYPE_MEM,
+ win->res->start,
+ win->res->start - win->offset,
+ resource_size(win->res));
+ }
+}
+
void dw_pcie_setup_rc(struct pcie_port *pp)
{
u32 val, ctrl, num_ctrls;
+ struct resource_entry *win;
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
/*
@@ -578,13 +611,10 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
* ATU, so we should not program the ATU here.
*/
if (pp->bridge->child_ops == &dw_child_pcie_ops) {
- struct resource_entry *entry =
- resource_list_first_type(&pp->bridge->windows, IORESOURCE_MEM);
+ resource_list_for_each_entry(win, &pp->bridge->windows)
+ if (resource_type(win->res) == IORESOURCE_MEM)
+ dw_pcie_setup_mem_atu(pp, win);
- dw_pcie_prog_outbound_atu(pci, PCIE_ATU_REGION_INDEX0,
- PCIE_ATU_TYPE_MEM, entry->res->start,
- entry->res->start - entry->offset,
- resource_size(entry->res));
if (pci->num_viewport > 2)
dw_pcie_prog_outbound_atu(pci, PCIE_ATU_REGION_INDEX2,
PCIE_ATU_TYPE_IO, pp->io_base,
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index c2dea8fc97c8..b5e438b70cd5 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -228,7 +228,7 @@ static void dw_pcie_writel_ob_unroll(struct dw_pcie *pci, u32 index, u32 reg,
static void dw_pcie_prog_outbound_atu_unroll(struct dw_pcie *pci, u8 func_no,
int index, int type,
u64 cpu_addr, u64 pci_addr,
- u32 size)
+ u64 size)
{
u32 retries, val;
u64 limit_addr = cpu_addr + size - 1;
@@ -245,8 +245,10 @@ static void dw_pcie_prog_outbound_atu_unroll(struct dw_pcie *pci, u8 func_no,
lower_32_bits(pci_addr));
dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_UPPER_TARGET,
upper_32_bits(pci_addr));
- dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_REGION_CTRL1,
- type | PCIE_ATU_FUNC_NUM(func_no));
+ val = type | PCIE_ATU_FUNC_NUM(func_no);
+ val = upper_32_bits(size - 1) ?
+ val | PCIE_ATU_INCREASE_REGION_SIZE : val;
+ dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_REGION_CTRL1, val);
dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_REGION_CTRL2,
PCIE_ATU_ENABLE);
@@ -267,7 +269,7 @@ static void dw_pcie_prog_outbound_atu_unroll(struct dw_pcie *pci, u8 func_no,
static void __dw_pcie_prog_outbound_atu(struct dw_pcie *pci, u8 func_no,
int index, int type, u64 cpu_addr,
- u64 pci_addr, u32 size)
+ u64 pci_addr, u64 size)
{
u32 retries, val;
@@ -311,7 +313,7 @@ static void __dw_pcie_prog_outbound_atu(struct dw_pcie *pci, u8 func_no,
}
void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index, int type,
- u64 cpu_addr, u64 pci_addr, u32 size)
+ u64 cpu_addr, u64 pci_addr, u64 size)
{
__dw_pcie_prog_outbound_atu(pci, 0, index, type,
cpu_addr, pci_addr, size);
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 9d2f511f13fa..21dd06831b50 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -80,10 +80,12 @@
#define PCIE_ATU_VIEWPORT 0x900
#define PCIE_ATU_REGION_INBOUND BIT(31)
#define PCIE_ATU_REGION_OUTBOUND 0
+#define PCIE_ATU_REGION_INDEX3 0x3
#define PCIE_ATU_REGION_INDEX2 0x2
#define PCIE_ATU_REGION_INDEX1 0x1
#define PCIE_ATU_REGION_INDEX0 0x0
#define PCIE_ATU_CR1 0x904
+#define PCIE_ATU_INCREASE_REGION_SIZE BIT(13)
#define PCIE_ATU_TYPE_MEM 0x0
#define PCIE_ATU_TYPE_IO 0x2
#define PCIE_ATU_TYPE_CFG0 0x4
@@ -295,7 +297,7 @@ void dw_pcie_upconfig_setup(struct dw_pcie *pci);
int dw_pcie_wait_for_link(struct dw_pcie *pci);
void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index,
int type, u64 cpu_addr, u64 pci_addr,
- u32 size);
+ u64 size);
void dw_pcie_prog_ep_outbound_atu(struct dw_pcie *pci, u8 func_no, int index,
int type, u64 cpu_addr, u64 pci_addr,
u32 size);
--
2.17.1