From: Jacob Pan <jacob.jun.pan@xxxxxxxxx>
The Intel Moorestown platform has MPH and OTG EHCI controllers that have
internal SRAM that could be used as descriptors DMA pool caching. The SRAM is
exposed via PCI BAR1. The limitation here is the SRAM access should be 32bit
aligned. A separate patch "EHCI: Make ehci_qh structure items all 32bit aligned"
has been submitted to linux-usb mailling list.
Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxx>
Signed-off-by: Alek Du <alek.du@xxxxxxxxx>
Signed-off-by: Alan Cox <alan@xxxxxxxxxxxxxxx>
---
drivers/usb/core/buffer.c | 10 ++++++++++
drivers/usb/host/ehci-hcd.c | 3 ++-
drivers/usb/host/ehci-pci.c | 39 +++++++++++++++++++++++++++++++++++++++
drivers/usb/host/ehci.h | 8 +++++++-
include/linux/usb/hcd.h | 2 ++
5 files changed, 60 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/core/buffer.c b/drivers/usb/core/buffer.c
index 2c69654..150d4b8 100644
--- a/drivers/usb/core/buffer.c
+++ b/drivers/usb/core/buffer.c
@@ -115,6 +115,11 @@ void *hcd_buffer_alloc(
return kmalloc(size, mem_flags);
}
+ /* we won't use internal SRAM as data payload, we can't get
+ any benefits from it */
+ if (hcd->has_sram && hcd->sram_no_payload)
+ return dma_alloc_coherent(NULL, size, dma, mem_flags);
+
for (i = 0; i < HCD_BUFFER_POOLS; i++) {
if (size <= pool_max [i])
return dma_pool_alloc(hcd->pool [i], mem_flags, dma);
@@ -141,6 +146,11 @@ void hcd_buffer_free(
return;
}
+ if (hcd->has_sram && hcd->sram_no_payload) {
+ dma_free_coherent(NULL, size, addr, dma);
+ return;
+ }
+
for (i = 0; i < HCD_BUFFER_POOLS; i++) {
if (size <= pool_max [i]) {
dma_pool_free(hcd->pool [i], addr, dma);
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index b6fa99d..5d5d5f4 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -515,7 +515,8 @@ static void ehci_stop (struct usb_hcd *hcd)
ehci_work (ehci);
spin_unlock_irq (&ehci->lock);
ehci_mem_cleanup (ehci);
-
+ if (hcd->has_sram)
+ sram_deinit(hcd);
#ifdef EHCI_STATS
ehci_dbg (ehci, "irq normal %ld err %ld reclaim %ld (lost %ld)\n",
ehci->stats.normal, ehci->stats.error, ehci->stats.reclaim,
diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c
index 556e556..0ca7ccc 100644
--- a/drivers/usb/host/ehci-pci.c
+++ b/drivers/usb/host/ehci-pci.c
@@ -41,6 +41,39 @@ static int ehci_pci_reinit(struct ehci_hcd *ehci, struct pci_dev *pdev)
return 0;
}
+/* enable SRAM if sram detected */
+static void sram_init(struct usb_hcd *hcd)
+{
+ struct ehci_hcd *ehci = hcd_to_ehci(hcd);
+ struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
+
+ if (!hcd->has_sram)
+ return;
+ ehci->sram_addr = pci_resource_start(pdev, 1);
+ ehci->sram_size = pci_resource_len(pdev, 1);
+ ehci_info(ehci, "Found HCD SRAM at %x size:%x\n",
+ ehci->sram_addr, ehci->sram_size);
+ if (pci_request_region(pdev, 1, kobject_name(&pdev->dev.kobj))) {
+ ehci_warn(ehci, "SRAM request failed\n");
+ hcd->has_sram = 0;
+ } else if (!dma_declare_coherent_memory(&pdev->dev, ehci->sram_addr,
+ ehci->sram_addr, ehci->sram_size, DMA_MEMORY_MAP)) {
+ ehci_warn(ehci, "SRAM DMA declare failed\n");
+ pci_release_region(pdev, 1);
+ hcd->has_sram = 0;
+ }
+}
+
+static void sram_deinit(struct usb_hcd *hcd)
+{
+ struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
+
+ if (!hcd->has_sram)
+ return;
+ dma_release_declared_memory(&pdev->dev);
+ pci_release_region(pdev, 1);
+}
+
/* called during probe() after chip reset completes */
static int ehci_pci_setup(struct usb_hcd *hcd)
{
@@ -73,10 +106,16 @@ static int ehci_pci_setup(struct usb_hcd *hcd)
ehci->has_otg = 1;
#endif
force_otg_hc_mode = 1;
+ hcd->has_sram = 1;
+ hcd->sram_no_payload = 1;
+ sram_init(hcd);
} else if (pdev->device == 0x0806) {
ehci_info(ehci, "Detected Langwell MPH\n");
hcd->has_tt = 1;
ehci->has_hostpc = 1;
+ hcd->has_sram = 1;
+ hcd->sram_no_payload = 1;
+ sram_init(hcd);
}
}
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 74fb60b..debe66b 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -151,6 +151,8 @@ struct ehci_hcd { /* one per controller */
int (*otg_resume)(struct usb_hcd *hcd);
#endif
u8 sbrn; /* packed release number */
+ unsigned int sram_addr;
+ unsigned int sram_size;
/* irq statistics */
#ifdef EHCI_STATS
@@ -736,5 +738,9 @@ static inline u32 hc32_to_cpup (const struct ehci_hcd *ehci, const __hc32 *x)
#endif /* DEBUG */
/*-------------------------------------------------------------------------*/
-
+#ifdef CONFIG_PCI
+static void sram_deinit(struct usb_hcd *hcd);
+#else
+static void sram_deinit(struct usb_hcd *hcd) { return; };
+#endif
#endif /* __LINUX_EHCI_HCD_H */
diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index 9218694..5a33e8e 100644
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -119,6 +119,8 @@ struct usb_hcd {
unsigned wireless:1; /* Wireless USB HCD */
unsigned authorized_default:1;
unsigned has_tt:1; /* Integrated TT in root hub */
+ unsigned has_sram:1; /* Local SRAM for caching */
+ unsigned sram_no_payload:1; /* sram not for payload */
int irq; /* irq allocated */
void __iomem *regs; /* device memory/io */
--
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