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pci: pci_mvebu: Fix read_config() with PCI_SIZE_8 or PCI_SIZE_16

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When reading 8 or 16 bits from config space, use appropriate readb() or
readw() calls. This ensures that PCIe controller does not read more bits
from endpoint card as asked by read_config() function.

Technically there should not be an issue with reading data from config
space which are not later used as there are no clear-by-read registers.
But it is better to use correct read operation based on requested size.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Stefan Roese <sr@denx.de>
This commit is contained in:
Pali Rohár 2021-10-22 16:22:09 +02:00 committed by Stefan Roese
parent daa9bfdb9c
commit 657177ad8e
1 changed files with 15 additions and 2 deletions
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17
drivers/pci/pci_mvebu.c
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@ -184,9 +184,22 @@ static int mvebu_pcie_read_config(const struct udevice *bus, pci_dev_t bdf,
writel(PCIE_CONF_ADDR(bdf, offset), pcie->base + PCIE_CONF_ADDR_OFF);
/* read data */
data = readl(pcie->base + PCIE_CONF_DATA_OFF);
switch (size) {
case PCI_SIZE_8:
data = readb(pcie->base + PCIE_CONF_DATA_OFF + (offset & 3));
break;
case PCI_SIZE_16:
data = readw(pcie->base + PCIE_CONF_DATA_OFF + (offset & 2));
break;
case PCI_SIZE_32:
data = readl(pcie->base + PCIE_CONF_DATA_OFF);
break;
default:
return -EINVAL;
}
debug("(addr,size,val)=(0x%04x, %d, 0x%08x)\n", offset, size, data);
*valuep = pci_conv_32_to_size(data, offset, size);
*valuep = data;
return 0;
}