imx6 and keystone PCIe abort handling

From: Bjorn Helgaas <helgaas@kernel.org>
To: Murali Karicheri <m-karicheri2@ti.com>,
	Richard Zhu <hongxing.zhu@nxp.com>,
	Lucas Stach <l.stach@pengutronix.de>
Cc: Russell King <linux@armlinux.org.uk>,
	Andrew Murray <andrew.murray@arm.com>,
	linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: imx6 and keystone PCIe abort handling
Date: Thu, 12 Dec 2019 18:32:36 -0600	[thread overview]
Message-ID: <20191213003236.GA43783@google.com> (raw)

Hi folks,

Why are ks_pcie_fault() and imx6q_pcie_abort_handler() different?  I
think they're doing the same thing, and the "instr & 0x0e100090" part
is the same, but only imx6 has the "instr & 0x0c100000" part.  And the
return values are different in some cases.

Could/should these be shared somehow?  They're both under #ifdef
CONFIG_ARM, so maybe it could be provided by arch/arm?

  static int ks_pcie_fault(unsigned long addr, unsigned int fsr,
			   struct pt_regs *regs)
  {
	  unsigned long instr = *(unsigned long *) instruction_pointer(regs);

	  if ((instr & 0x0e100090) == 0x00100090) {
		  int reg = (instr >> 12) & 15;

		  regs->uregs[reg] = -1;
		  regs->ARM_pc += 4;
	  }

	  return 0;
  }

  static int imx6q_pcie_abort_handler(unsigned long addr,
		  unsigned int fsr, struct pt_regs *regs)
  {
	  unsigned long pc = instruction_pointer(regs);
	  unsigned long instr = *(unsigned long *)pc;
	  int reg = (instr >> 12) & 15;

	  /*
	   * If the instruction being executed was a read,
	   * make it look like it read all-ones.
	   */
	  if ((instr & 0x0c100000) == 0x04100000) {
		  unsigned long val;

		  if (instr & 0x00400000)
			  val = 255;
		  else
			  val = -1;

		  regs->uregs[reg] = val;
		  regs->ARM_pc += 4;
		  return 0;
	  }

	  if ((instr & 0x0e100090) == 0x00100090) {
		  regs->uregs[reg] = -1;
		  regs->ARM_pc += 4;
		  return 0;
	  }

	  return 1;
  }