RE: [PATCH v11 09/13] PCI: dwc: Add support for triggering legacy IRQs

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Hi Serge,

> From: Serge Semin, Sent: Thursday, March 23, 2023 1:18 AM
> 
> On Fri, Mar 10, 2023 at 09:35:06PM +0900, Yoshihiro Shimoda wrote:
> > Add support for triggering legacy IRQs by using outbound iATU.
> > Outbound iATU is utilized to send assert and de-assert INTx TLPs.
> > The message is generated based on the payloadless Msg TLP with type
> > 0x14, where 0x4 is the routing code implying the terminated at
> > Receiver message. The message code is specified as b1000xx for
> > the INTx assertion and b1001xx for the INTx de-assertion.
> >
> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
> > ---
> >  .../pci/controller/dwc/pcie-designware-ep.c   | 66 ++++++++++++--
> >  drivers/pci/controller/dwc/pcie-designware.c  | 88 +++++++++++++------
> >  drivers/pci/controller/dwc/pcie-designware.h  | 11 ++-
> >  3 files changed, 126 insertions(+), 39 deletions(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> > index 95efe14f1036..73b3844e8a09 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> > +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> > @@ -6,6 +6,7 @@
> >   * Author: Kishon Vijay Abraham I <kishon@xxxxxx>
> >   */
> >
> > +#include <linux/delay.h>
> >  #include <linux/of.h>
> >  #include <linux/platform_device.h>
> >
> > @@ -182,8 +183,8 @@ static int dw_pcie_ep_inbound_atu(struct dw_pcie_ep *ep, u8 func_no, int type,
> >  	return 0;
> >  }
> >
> > -static int dw_pcie_ep_outbound_atu(struct dw_pcie_ep *ep, u8 func_no,
> > -				   phys_addr_t phys_addr,
> > +static int dw_pcie_ep_outbound_atu(struct dw_pcie_ep *ep, u8 func_no, int type,
> > +				   u8 code, u8 routing, phys_addr_t phys_addr,
> >  				   u64 pci_addr, size_t size)
> >  {
> >  	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> > @@ -196,8 +197,9 @@ static int dw_pcie_ep_outbound_atu(struct dw_pcie_ep *ep, u8 func_no,
> >  		return -EINVAL;
> >  	}
> >
> > -	ret = dw_pcie_prog_ep_outbound_atu(pci, func_no, free_win, PCIE_ATU_TYPE_MEM,
> > -					   phys_addr, pci_addr, size);
> > +	ret = dw_pcie_prog_ep_outbound_atu(pci, func_no, free_win, type,
> > +					   code, routing, phys_addr, pci_addr,
> > +					   size);
> >  	if (ret)
> >  		return ret;
> >
> > @@ -306,7 +308,8 @@ static int dw_pcie_ep_map_addr(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
> >  	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
> >  	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> >
> > -	ret = dw_pcie_ep_outbound_atu(ep, func_no, addr, pci_addr, size);
> > +	ret = dw_pcie_ep_outbound_atu(ep, func_no, PCIE_ATU_TYPE_MEM, 0, 0,
> > +				      addr, pci_addr, size);
> >  	if (ret) {
> >  		dev_err(pci->dev, "Failed to enable address\n");
> >  		return ret;
> > @@ -479,14 +482,46 @@ static const struct pci_epc_ops epc_ops = {
> >  	.get_features		= dw_pcie_ep_get_features,
> >  };
> >
> > +static int dw_pcie_ep_send_msg(struct dw_pcie_ep *ep, u8 func_no, u8 code,
> > +			       u8 routing)
> > +{
> > +	struct pci_epc *epc = ep->epc;
> > +	int ret;
> > +
> > +	ret = dw_pcie_ep_outbound_atu(ep, func_no, PCIE_ATU_TYPE_MSG, code,
> > +				      routing, ep->intx_mem_phys, 0,
> > +				      epc->mem->window.page_size);
> > +	if (ret)
> > +		return ret;
> 
> < newline pls

I got it.

> > +	writel(0, ep->intx_mem);
> 
> < nelinew pls

I got it.

> > +	dw_pcie_ep_unmap_addr(epc, func_no, 0, ep->intx_mem_phys);
> > +
> > +	return 0;
> > +}
> > +
> > +static int __dw_pcie_ep_raise_legacy_irq(struct dw_pcie_ep *ep, u8 func_no,
> > +					 int intx)
> > +{
> > +	int ret;
> > +
> 
> > +	ret = dw_pcie_ep_send_msg(ep, func_no, PCIE_MSG_ASSERT_INTA + intx, 0x04);
> 
> 0x04 - magic number. Please create a macro for it.
> * PCIe specification clearly states what 0x04 means.

I understood it. The PCIE_MSG_ASSERT_INTA is also related to PCIe specification.
So, I'll create macros for it into include/linux/pci.h.

> > +	if (ret)
> > +		return ret;
> 
> < newline pls

I got it.

> > +	usleep_range(1000, 2000);
> 
> < newline pls

I got it.

> > +	return dw_pcie_ep_send_msg(ep, func_no, PCIE_MSG_DEASSERT_INTA + intx, 0x04);
> > +}
> > +
> >  int dw_pcie_ep_raise_legacy_irq(struct dw_pcie_ep *ep, u8 func_no)
> >  {
> >  	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> >  	struct device *dev = pci->dev;
> >
> > -	dev_err(dev, "EP cannot trigger legacy IRQs\n");
> > +	if (!ep->intx_mem) {
> > +		dev_err(dev, "EP cannot trigger legacy IRQs\n");
> > +		return -EINVAL;
> > +	}
> >
> > -	return -EINVAL;
> > +	return __dw_pcie_ep_raise_legacy_irq(ep, func_no, 0);
> >  }
> >  EXPORT_SYMBOL_GPL(dw_pcie_ep_raise_legacy_irq);
> >
> > @@ -617,6 +652,10 @@ void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
> >
> >  	dw_pcie_edma_remove(pci);
> >
> > +	if (ep->intx_mem)
> > +		pci_epc_mem_free_addr(epc, ep->intx_mem_phys, ep->intx_mem,
> > +				      epc->mem->window.page_size);
> > +
> >  	pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
> >  			      epc->mem->window.page_size);
> >
> > @@ -789,9 +828,14 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
> >  		goto err_exit_epc_mem;
> >  	}
> >
> > +	ep->intx_mem = pci_epc_mem_alloc_addr(epc, &ep->intx_mem_phys,
> > +					      epc->mem->window.page_size);
> > +	if (!ep->intx_mem)
> > +		dev_warn(dev, "Failed to reserve memory for INTx\n");
> > +
> >  	ret = dw_pcie_edma_detect(pci);
> >  	if (ret)
> > -		goto err_free_epc_mem;
> > +		goto err_free_epc_mem_intx;
> >
> >  	if (ep->ops->get_features) {
> >  		epc_features = ep->ops->get_features(ep);
> > @@ -808,7 +852,11 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
> >  err_remove_edma:
> >  	dw_pcie_edma_remove(pci);
> >
> > -err_free_epc_mem:
> > +err_free_epc_mem_intx:
> > +	if (ep->intx_mem)
> > +		pci_epc_mem_free_addr(epc, ep->intx_mem_phys, ep->intx_mem,
> > +				      epc->mem->window.page_size);
> > +
> >  	pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
> >  			      epc->mem->window.page_size);
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
> > index 47860da5738e..364926832126 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware.c
> > +++ b/drivers/pci/controller/dwc/pcie-designware.c
> > @@ -23,6 +23,17 @@
> >  #include "../../pci.h"
> >  #include "pcie-designware.h"
> >
> > +struct dw_pcie_outbound_atu {
> > +	u64 cpu_addr;
> > +	u64 pci_addr;
> > +	u64 size;
> > +	int index;
> > +	int type;
> > +	u8 func_no;
> > +	u8 code;
> > +	u8 routing;
> > +};
> 
> Please detach the __dw_pcie_prog_outbound_atu() method conversion to a
> pre-requisite patch to make this change smaller and easier to review.

I got it. I'll make such a patch.

> > +
> >  static const char * const dw_pcie_app_clks[DW_PCIE_NUM_APP_CLKS] = {
> >  	[DW_PCIE_DBI_CLK] = "dbi",
> >  	[DW_PCIE_MSTR_CLK] = "mstr",
> > @@ -464,56 +475,58 @@ static inline u32 dw_pcie_enable_ecrc(u32 val)
> >  	return val | PCIE_ATU_TD;
> >  }
> >
> > -static int __dw_pcie_prog_outbound_atu(struct dw_pcie *pci, u8 func_no,
> > -				       int index, int type, u64 cpu_addr,
> > -				       u64 pci_addr, u64 size)
> > +static int __dw_pcie_prog_outbound_atu(struct dw_pcie *pci,
> > +				       struct dw_pcie_outbound_atu *atu)
> >  {
> >  	u32 retries, val;
> >  	u64 limit_addr;
> >
> >  	if (pci->ops && pci->ops->cpu_addr_fixup)
> > -		cpu_addr = pci->ops->cpu_addr_fixup(pci, cpu_addr);
> > +		atu->cpu_addr = pci->ops->cpu_addr_fixup(pci, atu->cpu_addr);
> >
> > -	limit_addr = cpu_addr + size - 1;
> > +	limit_addr = atu->cpu_addr + atu->size - 1;
> >
> > -	if ((limit_addr & ~pci->region_limit) != (cpu_addr & ~pci->region_limit) ||
> > -	    !IS_ALIGNED(cpu_addr, pci->region_align) ||
> > -	    !IS_ALIGNED(pci_addr, pci->region_align) || !size) {
> > +	if ((limit_addr & ~pci->region_limit) != (atu->cpu_addr & ~pci->region_limit) ||
> > +	    !IS_ALIGNED(atu->cpu_addr, pci->region_align) ||
> > +	    !IS_ALIGNED(atu->pci_addr, pci->region_align) || !atu->size) {
> >  		return -EINVAL;
> >  	}
> >
> > -	dw_pcie_writel_atu_ob(pci, index, PCIE_ATU_LOWER_BASE,
> > -			      lower_32_bits(cpu_addr));
> > -	dw_pcie_writel_atu_ob(pci, index, PCIE_ATU_UPPER_BASE,
> > -			      upper_32_bits(cpu_addr));
> > +	dw_pcie_writel_atu_ob(pci, atu->index, PCIE_ATU_LOWER_BASE,
> > +			      lower_32_bits(atu->cpu_addr));
> > +	dw_pcie_writel_atu_ob(pci, atu->index, PCIE_ATU_UPPER_BASE,
> > +			      upper_32_bits(atu->cpu_addr));
> >
> > -	dw_pcie_writel_atu_ob(pci, index, PCIE_ATU_LIMIT,
> > +	dw_pcie_writel_atu_ob(pci, atu->index, PCIE_ATU_LIMIT,
> >  			      lower_32_bits(limit_addr));
> >  	if (dw_pcie_ver_is_ge(pci, 460A))
> > -		dw_pcie_writel_atu_ob(pci, index, PCIE_ATU_UPPER_LIMIT,
> > +		dw_pcie_writel_atu_ob(pci, atu->index, PCIE_ATU_UPPER_LIMIT,
> >  				      upper_32_bits(limit_addr));
> >
> > -	dw_pcie_writel_atu_ob(pci, index, PCIE_ATU_LOWER_TARGET,
> > -			      lower_32_bits(pci_addr));
> > -	dw_pcie_writel_atu_ob(pci, index, PCIE_ATU_UPPER_TARGET,
> > -			      upper_32_bits(pci_addr));
> > +	dw_pcie_writel_atu_ob(pci, atu->index, PCIE_ATU_LOWER_TARGET,
> > +			      lower_32_bits(atu->pci_addr));
> > +	dw_pcie_writel_atu_ob(pci, atu->index, PCIE_ATU_UPPER_TARGET,
> > +			      upper_32_bits(atu->pci_addr));
> >
> > -	val = type | PCIE_ATU_FUNC_NUM(func_no);
> > -	if (upper_32_bits(limit_addr) > upper_32_bits(cpu_addr) &&
> > +	val = atu->type | atu->routing | PCIE_ATU_FUNC_NUM(atu->func_no);
> > +	if (upper_32_bits(limit_addr) > upper_32_bits(atu->cpu_addr) &&
> >  	    dw_pcie_ver_is_ge(pci, 460A))
> >  		val |= PCIE_ATU_INCREASE_REGION_SIZE;
> >  	if (dw_pcie_ver_is(pci, 490A))
> >  		val = dw_pcie_enable_ecrc(val);
> > -	dw_pcie_writel_atu_ob(pci, index, PCIE_ATU_REGION_CTRL1, val);
> > +	dw_pcie_writel_atu_ob(pci, atu->index, PCIE_ATU_REGION_CTRL1, val);
> >
> > -	dw_pcie_writel_atu_ob(pci, index, PCIE_ATU_REGION_CTRL2, PCIE_ATU_ENABLE);
> > +	val = PCIE_ATU_ENABLE;
> > +	if (atu->type == PCIE_ATU_TYPE_MSG)
> > +		val |= PCIE_ATU_INHIBIT_PAYLOAD | PCIE_ATU_HEADER_SUB_ENABLE | atu->code;
> > +	dw_pcie_writel_atu_ob(pci, atu->index, PCIE_ATU_REGION_CTRL2, val);
> >
> >  	/*
> >  	 * Make sure ATU enable takes effect before any subsequent config
> >  	 * and I/O accesses.
> >  	 */
> >  	for (retries = 0; retries < LINK_WAIT_MAX_IATU_RETRIES; retries++) {
> > -		val = dw_pcie_readl_atu_ob(pci, index, PCIE_ATU_REGION_CTRL2);
> > +		val = dw_pcie_readl_atu_ob(pci, atu->index, PCIE_ATU_REGION_CTRL2);
> >  		if (val & PCIE_ATU_ENABLE)
> >  			return 0;
> >
> > @@ -528,16 +541,33 @@ static int __dw_pcie_prog_outbound_atu(struct dw_pcie *pci, u8 func_no,
> >  int dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index, int type,
> >  			      u64 cpu_addr, u64 pci_addr, u64 size)
> >  {
> > -	return __dw_pcie_prog_outbound_atu(pci, 0, index, type,
> > -					   cpu_addr, pci_addr, size);
> > +	struct dw_pcie_outbound_atu atu;
> > +
> 
> > +	memset(&atu, 0, sizeof(atu));
> 
> can be replaced with struct dw_pcie_outbound_atu atu = {0};

I'll fix it.

> > +	atu.index = index;
> > +	atu.type = type;
> > +	atu.cpu_addr = cpu_addr;
> > +	atu.pci_addr = pci_addr;
> > +	atu.size = size;
> > +	return __dw_pcie_prog_outbound_atu(pci, &atu);
> >  }
> >
> >  int dw_pcie_prog_ep_outbound_atu(struct dw_pcie *pci, u8 func_no, int index,
> > -				 int type, u64 cpu_addr, u64 pci_addr,
> > -				 u64 size)
> > +				 int type, u8 code, u8 routing, u64 cpu_addr,
> > +				 u64 pci_addr, u64 size)
> 
> The __dw_pcie_prog_outbound_atu() conversion has a near zero value
> if dw_pcie_prog_ep_outbound_atu() will be left with the bunch of arguments.
> The same concerns the dw_pcie_ep_outbound_atu() method which now accepts
> eight arguments.

I agree. So, I'll fix these functions somehow.

> >  {
> > -	return __dw_pcie_prog_outbound_atu(pci, func_no, index, type,
> > -					   cpu_addr, pci_addr, size);
> > +	struct dw_pcie_outbound_atu atu;
> > +
> 
> > +	memset(&atu, 0, sizeof(atu));
> 
> can be replaced with struct dw_pcie_outbound_atu atu = {0};

I got it.

Best regards,
Yoshihiro Shimoda

> -Serge(y)
> 
> > +	atu.func_no = func_no;
> > +	atu.index = index;
> > +	atu.type = type;
> > +	atu.code = code;
> > +	atu.routing = routing;
> > +	atu.cpu_addr = cpu_addr;
> > +	atu.pci_addr = pci_addr;
> > +	atu.size = size;
> > +	return __dw_pcie_prog_outbound_atu(pci, &atu);
> >  }
> >
> >  static inline u32 dw_pcie_readl_atu_ib(struct dw_pcie *pci, u32 index, u32 reg)
> > diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> > index 36f3e2c818fe..3dbadb8043ab 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware.h
> > +++ b/drivers/pci/controller/dwc/pcie-designware.h
> > @@ -147,11 +147,14 @@
> >  #define PCIE_ATU_TYPE_IO		0x2
> >  #define PCIE_ATU_TYPE_CFG0		0x4
> >  #define PCIE_ATU_TYPE_CFG1		0x5
> > +#define PCIE_ATU_TYPE_MSG		0x10
> >  #define PCIE_ATU_TD			BIT(8)
> >  #define PCIE_ATU_FUNC_NUM(pf)           ((pf) << 20)
> >  #define PCIE_ATU_REGION_CTRL2		0x004
> >  #define PCIE_ATU_ENABLE			BIT(31)
> >  #define PCIE_ATU_BAR_MODE_ENABLE	BIT(30)
> > +#define PCIE_ATU_INHIBIT_PAYLOAD	BIT(22)
> > +#define PCIE_ATU_HEADER_SUB_ENABLE	BIT(21)
> >  #define PCIE_ATU_FUNC_NUM_MATCH_EN      BIT(19)
> >  #define PCIE_ATU_LOWER_BASE		0x008
> >  #define PCIE_ATU_UPPER_BASE		0x00C
> > @@ -244,6 +247,9 @@
> >  /* Default eDMA LLP memory size */
> >  #define DMA_LLP_MEM_SIZE		PAGE_SIZE
> >
> > +#define PCIE_MSG_ASSERT_INTA		0x20
> > +#define PCIE_MSG_DEASSERT_INTA		0x24
> > +
> >  struct dw_pcie;
> >  struct dw_pcie_rp;
> >  struct dw_pcie_ep;
> > @@ -352,6 +358,8 @@ struct dw_pcie_ep {
> >  	unsigned long		*ob_window_map;
> >  	void __iomem		*msi_mem;
> >  	phys_addr_t		msi_mem_phys;
> > +	void __iomem		*intx_mem;
> > +	phys_addr_t		intx_mem_phys;
> >  	struct pci_epf_bar	*epf_bar[PCI_STD_NUM_BARS];
> >  };
> >
> > @@ -420,7 +428,8 @@ int dw_pcie_wait_for_link(struct dw_pcie *pci);
> >  int dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index, int type,
> >  			      u64 cpu_addr, u64 pci_addr, u64 size);
> >  int dw_pcie_prog_ep_outbound_atu(struct dw_pcie *pci, u8 func_no, int index,
> > -				 int type, u64 cpu_addr, u64 pci_addr, u64 size);
> > +				 int type, u8 code, u8 routing, u64 cpu_addr,
> > +				 u64 pci_addr, u64 size);
> >  int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int index, int type,
> >  			     u64 cpu_addr, u64 pci_addr, u64 size);
> >  int dw_pcie_prog_ep_inbound_atu(struct dw_pcie *pci, u8 func_no, int index,
> > --
> > 2.25.1
> >
> >




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