6.6-stable review patch. If anyone has any objections, please let me know.
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From: Damien Le Moal dlemoal@kernel.org
commit 64f093c4d99d797b68b407a9d8767aadc3e3ea7a upstream.
The Rockchip PCIe endpoint controller handles PCIe transfers addresses by masking the lower bits of the programmed PCI address and using the same number of lower bits masked from the CPU address space used for the mapping. For a PCI mapping of <size> bytes starting from <pci_addr>, the number of bits masked is the number of address bits changing in the address range [pci_addr..pci_addr + size - 1].
However, rockchip_pcie_prog_ep_ob_atu() calculates num_pass_bits only using the size of the mapping, resulting in an incorrect number of mask bits depending on the value of the PCI address to map.
Fix this by introducing the helper function rockchip_pcie_ep_ob_atu_num_bits() to correctly calculate the number of mask bits to use to program the address translation unit. The number of mask bits is calculated depending on both the PCI address and size of the mapping, and clamped between 8 and 20 using the macros ROCKCHIP_PCIE_AT_MIN_NUM_BITS and ROCKCHIP_PCIE_AT_MAX_NUM_BITS. As defined in the Rockchip RK3399 TRM V1.3 Part2, Sections 17.5.5.1.1 and 17.6.8.2.1, this clamping is necessary because:
1) The lower 8 bits of the PCI address to be mapped by the outbound region are ignored. So a minimum of 8 address bits are needed and imply that the PCI address must be aligned to 256.
2) The outbound memory regions are 1MB in size. So while we can specify up to 63-bits for the PCI address (num_bits filed uses bits 0 to 5 of the outbound address region 0 register), we must limit the number of valid address bits to 20 to match the memory window maximum size (1 << 20 = 1MB).
Fixes: cf590b078391 ("PCI: rockchip: Add EP driver for Rockchip PCIe controller") Link: https://lore.kernel.org/r/20241017015849.190271-2-dlemoal@kernel.org Signed-off-by: Damien Le Moal dlemoal@kernel.org Signed-off-by: Krzysztof Wilczyński kwilczynski@kernel.org Signed-off-by: Bjorn Helgaas bhelgaas@google.com Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/pci/controller/pcie-rockchip-ep.c | 16 +++++++++++++--- drivers/pci/controller/pcie-rockchip.h | 4 ++++ 2 files changed, 17 insertions(+), 3 deletions(-)
--- a/drivers/pci/controller/pcie-rockchip-ep.c +++ b/drivers/pci/controller/pcie-rockchip-ep.c @@ -63,15 +63,25 @@ static void rockchip_pcie_clear_ep_ob_at ROCKCHIP_PCIE_AT_OB_REGION_DESC1(region)); }
+static int rockchip_pcie_ep_ob_atu_num_bits(struct rockchip_pcie *rockchip, + u64 pci_addr, size_t size) +{ + int num_pass_bits = fls64(pci_addr ^ (pci_addr + size - 1)); + + return clamp(num_pass_bits, + ROCKCHIP_PCIE_AT_MIN_NUM_BITS, + ROCKCHIP_PCIE_AT_MAX_NUM_BITS); +} + static void rockchip_pcie_prog_ep_ob_atu(struct rockchip_pcie *rockchip, u8 fn, u32 r, u64 cpu_addr, u64 pci_addr, size_t size) { - int num_pass_bits = fls64(size - 1); + int num_pass_bits; u32 addr0, addr1, desc0;
- if (num_pass_bits < 8) - num_pass_bits = 8; + num_pass_bits = rockchip_pcie_ep_ob_atu_num_bits(rockchip, + pci_addr, size);
addr0 = ((num_pass_bits - 1) & PCIE_CORE_OB_REGION_ADDR0_NUM_BITS) | (lower_32_bits(pci_addr) & PCIE_CORE_OB_REGION_ADDR0_LO_ADDR); --- a/drivers/pci/controller/pcie-rockchip.h +++ b/drivers/pci/controller/pcie-rockchip.h @@ -245,6 +245,10 @@ (PCIE_EP_PF_CONFIG_REGS_BASE + (((fn) << 12) & GENMASK(19, 12))) #define ROCKCHIP_PCIE_EP_VIRT_FUNC_BASE(fn) \ (PCIE_EP_PF_CONFIG_REGS_BASE + 0x10000 + (((fn) << 12) & GENMASK(19, 12))) + +#define ROCKCHIP_PCIE_AT_MIN_NUM_BITS 8 +#define ROCKCHIP_PCIE_AT_MAX_NUM_BITS 20 + #define ROCKCHIP_PCIE_AT_IB_EP_FUNC_BAR_ADDR0(fn, bar) \ (PCIE_CORE_AXI_CONF_BASE + 0x0828 + (fn) * 0x0040 + (bar) * 0x0008) #define ROCKCHIP_PCIE_AT_IB_EP_FUNC_BAR_ADDR1(fn, bar) \