Re: [PATCH kvmtool v2] Add emulation for CFI compatible flash memory

[Alexandru Elisei <alexandru.elisei@arm.com>]

Hi,

I guess the device hasn't been tested with Linux. This is what I'm getting when
trying to boot a Linux guest using the command:

$ ./lkvm run -c4 -m4096 -k /path/to/kernel -d /path/to/disk -p root="/dev/vda2" -F
flash.img

[    0.659167] physmap-flash 2000000.flash: physmap platform flash device: [mem
0x02000000-0x029fffff]
[    0.660444] Number of erase regions: 1
[    0.661036] Primary Vendor Command Set: 0001 (Intel/Sharp Extended)
[    0.661688] Primary Algorithm Table at 0031
[    0.662168] Alternative Vendor Command Set: 0000 (None)
[    0.662711] No Alternate Algorithm Table
[    0.663120] Vcc Minimum:  4.5 V
[    0.663450] Vcc Maximum:  5.5 V
[    0.663779] No Vpp line
[    0.664039] Typical byte/word write timeout: 2 µs
[    0.664590] Maximum byte/word write timeout: 2 µs
[    0.665240] Typical full buffer write timeout: 2 µs
[    0.665775] Maximum full buffer write timeout: 2 µs
[    0.666373] Typical block erase timeout: 2 ms
[    0.666828] Maximum block erase timeout: 2 ms
[    0.667282] Chip erase not supported
[    0.667659] Device size: 0x800000 bytes (8 MiB)
[    0.668137] Flash Device Interface description: 0x0006
[    0.668697]   - Unknown
[    0.668963] Max. bytes in buffer write: 0x40
[    0.669407] Number of Erase Block Regions: 1
[    0.669865]   Erase Region #0: BlockSize 0x8000 bytes, 160 blocks
[    0.672299] 2000000.flash: Found 2 x16 devices at 0x0 in 32-bit bank.
Manufacturer ID 0x000000 Chip ID 0x00ffff
[    0.681328] NOR chip too large to fit in mapping. Attempting to cope...
[    0.682046] Intel/Sharp Extended Query Table at 0x0031
[    0.682645] Using buffer write method
[    0.683031] Sum of regions (a00000) != total size of set of interleaved chips
(1000000)
[    0.683854] gen_probe: No supported Vendor Command Set found
[    0.684441] physmap-flash 2000000.flash: map_probe failed

I also defined DEBUG_CFI in drivers/mtd/chips/cfi_probe.c.

The Flash Device Interface description that we provide is wrong, it should 0x05.
More details below.

On 2/7/20 12:19 PM, Andre Przywara wrote:
> From: Raphael Gault <raphael.gault@arm.com>
>
> The EDK II UEFI firmware implementation requires some storage for the EFI
> variables, which is typically some flash storage.
> Since this is already supported on the EDK II side, we add a CFI flash
> emulation to kvmtool.
> This is backed by a file, specified via the --flash or -F command line
> option. Any flash writes done by the guest will immediately be reflected
> into this file (kvmtool mmap's the file).
>
> This implements a CFI flash using the "Intel/Sharp extended command
> set", as specified in:
> - JEDEC JESD68.01
> - JEDEC JEP137B
> - Intel Application Note 646
> Some gaps in those specs have been filled by looking at real devices and
> other implementations (QEMU, Linux kernel driver).
>
> At the moment this relies on DT to advertise the base address of the
> flash memory (mapped into the MMIO address space) and is only enabled
> for ARM/ARM64. The emulation itself is architecture agnostic, though.
>
> This is one missing piece toward a working UEFI boot with kvmtool on
> ARM guests, the other is to provide writable PCI BARs, which is WIP.
>
> Signed-off-by: Raphael Gault <raphael.gault@arm.com>
> [Andre: rewriting and fixing]
> Signed-off-by: Andre Przywra <andre.przywara@arm.com>
> ---
> Hi,
>
> an update addressing Will's comments. I added coarse grained locking
> to the MMIO handler, to prevent concurrent vCPU accesses from messing up
> the internal CFI flash state machine.
> I also folded the actual flash array read access into the MMIO handler
> and fixed the other small issues.
>
> Cheers,
> Andre
>
>  Makefile                          |   6 +
>  arm/include/arm-common/kvm-arch.h |   3 +
>  builtin-run.c                     |   2 +
>  hw/cfi_flash.c                    | 546 ++++++++++++++++++++++++++++++
>  include/kvm/kvm-config.h          |   1 +
>  include/kvm/util.h                |   5 +
>  6 files changed, 563 insertions(+)
>  create mode 100644 hw/cfi_flash.c
>
> diff --git a/Makefile b/Makefile
> index 3862112c..7ed6fb5e 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -170,6 +170,7 @@ ifeq ($(ARCH), arm)
>  	CFLAGS		+= -march=armv7-a
>  
>  	ARCH_WANT_LIBFDT := y
> +	ARCH_HAS_FLASH_MEM := y
>  endif
>  
>  # ARM64
> @@ -182,6 +183,7 @@ ifeq ($(ARCH), arm64)
>  	ARCH_INCLUDE	+= -Iarm/aarch64/include
>  
>  	ARCH_WANT_LIBFDT := y
> +	ARCH_HAS_FLASH_MEM := y
>  endif
>  
>  ifeq ($(ARCH),mips)
> @@ -261,6 +263,10 @@ ifeq (y,$(ARCH_HAS_FRAMEBUFFER))
>  	endif
>  endif
>  
> +ifeq (y,$(ARCH_HAS_FLASH_MEM))
> +	OBJS	+= hw/cfi_flash.o
> +endif
> +
>  ifeq ($(call try-build,$(SOURCE_ZLIB),$(CFLAGS),$(LDFLAGS) -lz),y)
>  	CFLAGS_DYNOPT	+= -DCONFIG_HAS_ZLIB
>  	LIBS_DYNOPT	+= -lz
> diff --git a/arm/include/arm-common/kvm-arch.h b/arm/include/arm-common/kvm-arch.h
> index b9d486d5..2bb085f4 100644
> --- a/arm/include/arm-common/kvm-arch.h
> +++ b/arm/include/arm-common/kvm-arch.h
> @@ -21,6 +21,9 @@
>  #define ARM_GIC_DIST_SIZE	0x10000
>  #define ARM_GIC_CPUI_SIZE	0x20000
>  
> +#define ARM_FLASH_MMIO_BASE	0x2000000		/* 32 MB */
> +#define KVM_FLASH_MMIO_BASE	ARM_FLASH_MMIO_BASE
> +
>  #define ARM_IOPORT_SIZE		(ARM_MMIO_AREA - ARM_IOPORT_AREA)
>  #define ARM_VIRTIO_MMIO_SIZE	(ARM_AXI_AREA - (ARM_MMIO_AREA + ARM_GIC_SIZE))
>  #define ARM_PCI_CFG_SIZE	(1ULL << 24)
> diff --git a/builtin-run.c b/builtin-run.c
> index f8dc6c72..df8c6741 100644
> --- a/builtin-run.c
> +++ b/builtin-run.c
> @@ -138,6 +138,8 @@ void kvm_run_set_wrapper_sandbox(void)
>  			"Kernel command line arguments"),		\
>  	OPT_STRING('f', "firmware", &(cfg)->firmware_filename, "firmware",\
>  			"Firmware image to boot in virtual machine"),	\
> +	OPT_STRING('F', "flash", &(cfg)->flash_filename, "flash",\
> +			"Flash image to present to virtual machine"),	\
>  									\
>  	OPT_GROUP("Networking options:"),				\
>  	OPT_CALLBACK_DEFAULT('n', "network", NULL, "network params",	\
> diff --git a/hw/cfi_flash.c b/hw/cfi_flash.c
> new file mode 100644
> index 00000000..d7c0e7e8
> --- /dev/null
> +++ b/hw/cfi_flash.c
> @@ -0,0 +1,546 @@
> +#include <stdbool.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <linux/bitops.h>
> +#include <linux/err.h>
> +#include <linux/sizes.h>
> +#include <linux/types.h>
> +
> +#include "kvm/kvm.h"
> +#include "kvm/kvm-arch.h"
> +#include "kvm/devices.h"
> +#include "kvm/fdt.h"
> +#include "kvm/mutex.h"
> +#include "kvm/util.h"
> +
> +/* The EDK2 driver hardcodes two 16-bit chips on a 32-bit bus. */
> +#define CFI_NR_FLASH_CHIPS			2
> +
> +/* We always emulate a 32 bit bus width. */
> +#define CFI_BUS_WIDTH				4
> +
> +/* The *effective* size of an erase block (over all chips) */
> +#define FLASH_BLOCK_SIZE			SZ_64K
> +
> +#define PROGRAM_BUFF_SIZE_BITS			7
> +#define PROGRAM_BUFF_SIZE			(1U << PROGRAM_BUFF_SIZE_BITS)
> +
> +/* CFI commands */
> +#define CFI_CMD_LOCK_BLOCK			0x01
> +#define CFI_CMD_ALTERNATE_WORD_PROGRAM_SETUP	0x10
> +#define CFI_CMD_BLOCK_ERASE_SETUP		0x20
> +#define CFI_CMD_WORD_PROGRAM_SETUP		0x40
> +#define CFI_CMD_CLEAR_STATUS_REGISTER		0x50
> +#define CFI_CMD_LOCK_BLOCK_SETUP		0x60
> +#define CFI_CMD_READ_STATUS_REGISTER		0x70
> +#define CFI_CMD_READ_JEDEC			0x90
> +#define CFI_CMD_READ_CFI_QUERY			0x98
> +#define CFI_CMD_BUFFERED_PROGRAM_CONFIRM	0xd0
> +#define CFI_CMD_BLOCK_ERASE_CONFIRM		0xd0
> +#define CFI_CMD_UNLOCK_BLOCK			0xd0
> +#define CFI_CMD_BUFFERED_PROGRAM_SETUP		0xe8
> +#define CFI_CMD_READ_ARRAY			0xff
> +
> +/*
> + * CFI query table contents, as far as it is constant.
> + */
> +#define CFI_GEOM_OFFSET				0x27
> +static u8 cfi_query_table[] = {
> +		/* offset 0x10: CFI query identification string */
> +	'Q', 'R', 'Y',		/* ID string */
> +	0x01, 0x00,		/* primary command set: Intel/Sharp extended */
> +	0x31, 0x00,		/* address of primary extended query table */
> +	0x00, 0x00,		/* alternative command set: unused */
> +	0x00, 0x00,		/* address of alternative extended query table*/
> +		/* offset 0x1b: system interface information */
> +	0x45,			/* minimum Vcc voltage: 4.5V */
> +	0x55,			/* maximum Vcc voltage: 5.5V */
> +	0x00,			/* minimum Vpp voltage: 0.0V (unused) */
> +	0x00,			/* maximum Vpp voltage: 0.0V *(unused) */
> +	0x01,			/* timeout for single word program: 2 us */
> +	0x01,			/* timeout for multi-byte program: 2 us */
> +	0x01,			/* timeout for block erase: 2 ms */
> +	0x00,			/* timeout for full chip erase: not supported */
> +	0x00,			/* max timeout for single word program: 1x */
> +	0x00,			/* max timeout for mulit-byte program: 1x */
> +	0x00,			/* max timeout for block erase: 1x */
> +	0x00,			/* max timeout for chip erase: not supported */
> +		/* offset 0x27: flash geometry information */
> +	0x00,			/* size in power-of-2 bytes, filled later */
> +	0x06, 0x00,		/* interface description: 32 and 16 bits */

I don't think this is correct. From Intel StrataFlash Embedded Memory (P30)
Family, table 34:

""n" such that n+1 specifies the bit field that represents the flash device width
capabilities as described in the table".

If you want to advertise 32 and 16 bit write capabilities, it should be 5 because
5+1=6. This is also the value that the Linux kernel checks for (see
include/linux/mtd/cfi.h, define CFI_INTERFACE_X16_BY_X32_ASYNC"). 6 actually means
32, 16 and 8 bit accesses.

This begs another question: why do we support both 16 and 32 bit accesses instead
of supporting only 32 bit?

> +	PROGRAM_BUFF_SIZE_BITS + 1 - CFI_NR_FLASH_CHIPS, 0x00,
> +				/* number of multi-byte writes */

Shouldn't the comment be maximum number of bytes in the write buffer?

> +	0x01,			/* one erase block region */
> +	0x00, 0x00, 0x00, 0x00, /* number and size of erase blocks, filled */
> +		/* offset 0x31: Intel primary algorithm extended query table */
> +	'P', 'R', 'I',
> +	'1', '0',		/* version 1.0 */
> +	0xa0, 0x00, 0x00, 0x00, /* optional features: instant lock & pm-read */
> +	0x00,			/* no functions after suspend */
> +	0x01, 0x00,		/* only lock bit supported */
> +	0x50,			/* best Vcc value: 5.0V */
> +	0x00,			/* best Vpp value: 0.0V (unused) */
> +	0x01,			/* number of protection register fields */
> +	0x00, 0x00, 0x00, 0x00,	/* protection field 1 description */
> +};

As an aside, I found it impossible to review the cfi_query_table array in its
current form. This is how I wrote the array so I could read it. I also took the
liberty to remove the offset when indexing the array, making read_cfi less error
prone, in my opinion:

diff --git a/hw/cfi_flash.c b/hw/cfi_flash.c
index d7c0e7e80d69..65a90e288be8 100644
--- a/hw/cfi_flash.c
+++ b/hw/cfi_flash.c
@@ -46,45 +46,43 @@
  */
 #define CFI_GEOM_OFFSET                                0x27
 static u8 cfi_query_table[] = {
-               /* offset 0x10: CFI query identification string */
-       'Q', 'R', 'Y',          /* ID string */
-       0x01, 0x00,             /* primary command set: Intel/Sharp extended */
-       0x31, 0x00,             /* address of primary extended query table */
-       0x00, 0x00,             /* alternative command set: unused */
-       0x00, 0x00,             /* address of alternative extended query table*/
-               /* offset 0x1b: system interface information */
-       0x45,                   /* minimum Vcc voltage: 4.5V */
-       0x55,                   /* maximum Vcc voltage: 5.5V */
-       0x00,                   /* minimum Vpp voltage: 0.0V (unused) */
-       0x00,                   /* maximum Vpp voltage: 0.0V *(unused) */
-       0x01,                   /* timeout for single word program: 2 us */
-       0x01,                   /* timeout for multi-byte program: 2 us */
-       0x01,                   /* timeout for block erase: 2 ms */
-       0x00,                   /* timeout for full chip erase: not supported */
-       0x00,                   /* max timeout for single word program: 1x */
-       0x00,                   /* max timeout for mulit-byte program: 1x */
-       0x00,                   /* max timeout for block erase: 1x */
-       0x00,                   /* max timeout for chip erase: not supported */
-               /* offset 0x27: flash geometry information */
-       0x00,                   /* size in power-of-2 bytes, filled later */
-       0x06, 0x00,             /* interface description: 32 and 16 bits */
-       PROGRAM_BUFF_SIZE_BITS + 1 - CFI_NR_FLASH_CHIPS, 0x00,
+       [0x10] = 'Q', 'R', 'Y', /* ID string */
+       [0x13] = 0x01, 0x00,    /* primary command set: Intel/Sharp extended */
+       [0x15] = 0x31, 0x00,    /* address of primary extended query table */
+       [0x17] = 0x00, 0x00,    /* alternative command set: unused */
+       [0x19] = 0x00, 0x00,    /* address of alternative extended query table*/
+       /* System interface information */
+       [0x1b] = 0x45,          /* minimum Vcc voltage: 4.5V */
+       [0x1c] = 0x55,          /* maximum Vcc voltage: 5.5V */
+       [0x1d] = 0x00,          /* minimum Vpp voltage: 0.0V (unused) */
+       [0x1e] = 0x00,          /* maximum Vpp voltage: 0.0V *(unused) */
+       [0x1f] = 0x01,          /* timeout for single word program: 2 us */
+       [0x20] = 0x01,          /* timeout for multi-byte program: 2 us */
+       [0x21] = 0x01,          /* timeout for block erase: 2 ms */
+       [0x22] = 0x00,          /* timeout for full chip erase: not supported */
+       [0x23] = 0x00,          /* max timeout for single word program: 1x */
+       [0x24] = 0x00,          /* max timeout for mulit-byte program: 1x */
+       [0x25] = 0x00,          /* max timeout for block erase: 1x */
+       [0x26] = 0x00,          /* max timeout for chip erase: not supported */
+       /* Flash geometry information */
+       [0x27] = 0x00,          /* size in power-of-2 bytes, filled later */
+       [0x28] = 0x06, 0x00,    /* interface description: 32 and 16 bits */
+       [0x2a] = PROGRAM_BUFF_SIZE_BITS + 1 - CFI_NR_FLASH_CHIPS, 0x00,
                                /* number of multi-byte writes */
-       0x01,                   /* one erase block region */
-       0x00, 0x00, 0x00, 0x00, /* number and size of erase blocks, filled */
-               /* offset 0x31: Intel primary algorithm extended query table */
-       'P', 'R', 'I',
-       '1', '0',               /* version 1.0 */
-       0xa0, 0x00, 0x00, 0x00, /* optional features: instant lock & pm-read */
-       0x00,                   /* no functions after suspend */
-       0x01, 0x00,             /* only lock bit supported */
-       0x50,                   /* best Vcc value: 5.0V */
-       0x00,                   /* best Vpp value: 0.0V (unused) */
-       0x01,                   /* number of protection register fields */
-       0x00, 0x00, 0x00, 0x00, /* protection field 1 description */
+       [0x2c] = 0x01,          /* one erase block region */
+       [0x2d] = 0x00, 0x00, 0x00, 0x00, /* number and size of erase blocks, filled */
+       /* Intel primary algorithm extended query table */
+       [0x31] = 'P', 'R', 'I', /* ID string */
+       [0x34] = '1', '0',      /* version 1.0 */
+       [0x36] = 0xa0, 0x00, 0x00, 0x00, /* optional features: instant lock &
pm-read */
+       [0x40] = 0x00,          /* no functions after suspend */
+       [0x41] = 0x01, 0x00,    /* only lock bit supported */
...skipping...
+       [0x10] = 'Q', 'R', 'Y', /* ID string */
+       [0x13] = 0x01, 0x00,    /* primary command set: Intel/Sharp extended */
+       [0x15] = 0x31, 0x00,    /* address of primary extended query table */
+       [0x17] = 0x00, 0x00,    /* alternative command set: unused */
+       [0x19] = 0x00, 0x00,    /* address of alternative extended query table*/
+       /* System interface information */
+       [0x1b] = 0x45,          /* minimum Vcc voltage: 4.5V */
+       [0x1c] = 0x55,          /* maximum Vcc voltage: 5.5V */
+       [0x1d] = 0x00,          /* minimum Vpp voltage: 0.0V (unused) */
+       [0x1e] = 0x00,          /* maximum Vpp voltage: 0.0V *(unused) */
+       [0x1f] = 0x01,          /* timeout for single word program: 2 us */
+       [0x20] = 0x01,          /* timeout for multi-byte program: 2 us */
+       [0x21] = 0x01,          /* timeout for block erase: 2 ms */
+       [0x22] = 0x00,          /* timeout for full chip erase: not supported */
+       [0x23] = 0x00,          /* max timeout for single word program: 1x */
+       [0x24] = 0x00,          /* max timeout for mulit-byte program: 1x */
+       [0x25] = 0x00,          /* max timeout for block erase: 1x */
+       [0x26] = 0x00,          /* max timeout for chip erase: not supported */
+       /* Flash geometry information */
+       [0x27] = 0x00,          /* size in power-of-2 bytes, filled later */
+       [0x28] = 0x06, 0x00,    /* interface description: 32 and 16 bits */
+       [0x2a] = PROGRAM_BUFF_SIZE_BITS + 1 - CFI_NR_FLASH_CHIPS, 0x00,
                                /* number of multi-byte writes */
-       0x01,                   /* one erase block region */
-       0x00, 0x00, 0x00, 0x00, /* number and size of erase blocks, filled */
-               /* offset 0x31: Intel primary algorithm extended query table */
-       'P', 'R', 'I',
-       '1', '0',               /* version 1.0 */
-       0xa0, 0x00, 0x00, 0x00, /* optional features: instant lock & pm-read */
-       0x00,                   /* no functions after suspend */
-       0x01, 0x00,             /* only lock bit supported */
-       0x50,                   /* best Vcc value: 5.0V */
-       0x00,                   /* best Vpp value: 0.0V (unused) */
-       0x01,                   /* number of protection register fields */
-       0x00, 0x00, 0x00, 0x00, /* protection field 1 description */
+       [0x2c] = 0x01,          /* one erase block region */
+       [0x2d] = 0x00, 0x00, 0x00, 0x00, /* number and size of erase blocks, filled */
+       /* Intel primary algorithm extended query table */
+       [0x31] = 'P', 'R', 'I', /* ID string */
+       [0x34] = '1', '0',      /* version 1.0 */
+       [0x36] = 0xa0, 0x00, 0x00, 0x00, /* optional features: instant lock &
pm-read */
+       [0x40] = 0x00,          /* no functions after suspend */
+       [0x41] = 0x01, 0x00,    /* only lock bit supported */
+       [0x43] = 0x50,          /* best Vcc value: 5.0V */
+       [0x43] = 0x00,          /* best Vpp value: 0.0V (unused) */
+       [0x44] = 0x01,          /* number of protection register fields */
+       [0x45] = 0x00, 0x00, 0x00, 0x00,/* protection field 1 description */
 };
 
-
 /*
  * Those states represent a subset of the CFI flash state machine.
  */
@@ -141,10 +139,7 @@ static int nr_erase_blocks(struct cfi_flash_device *sfdev)
  */
 static u8 read_cfi(struct cfi_flash_device *sfdev, u64 addr)
 {
-       if (addr < 0x10)                /* CFI information starts at 0x10 */
-               return 0;
-
-       if (addr - 0x10 > sizeof(cfi_query_table)) {
+       if (addr > sizeof(cfi_query_table)) {
                pr_debug("CFI query read access beyond the end of table");
                return 0;
        }
@@ -163,7 +158,7 @@ static u8 read_cfi(struct cfi_flash_device *sfdev, u64 addr)
                return ((FLASH_BLOCK_SIZE / 256 ) / CFI_NR_FLASH_CHIPS) >> 8;
        }
 
-       return cfi_query_table[addr - 0x10];
+       return cfi_query_table[addr];
 }
 
 static bool block_is_locked(struct cfi_flash_device *sfdev, u64 addr)

Thanks,
Alex
> +
> +
> +/*
> + * Those states represent a subset of the CFI flash state machine.
> + */
> +enum cfi_flash_state {
> +	READY,
> +	LOCK_SETUP,
> +	WP_SETUP,
> +	BP_SETUP,
> +	BP_LOAD,
> +	ERASE_SETUP,
> +};
> +
> +/*
> + * The device can be in several **Read** modes.
> + * We don't implement the asynchronous burst mode.
> + */
> +enum cfi_read_mode {
> +	READ_ARRAY,
> +	READ_STATUS,
> +	READ_DEVICE_ID,
> +	READ_QUERY,
> +};
> +
> +struct cfi_flash_device {
> +	struct device_header	dev_hdr;
> +	/* Protects the CFI state machine variables in this data structure. */
> +	struct mutex		mutex;
> +	u64			base_addr;
> +	u32			size;
> +
> +	void			*flash_memory;
> +	u8			program_buffer[PROGRAM_BUFF_SIZE * 4];
> +	unsigned long		*lock_bm;
> +	u64			last_address;
> +	unsigned int		buff_written;
> +	unsigned int		program_length;
> +
> +	enum cfi_flash_state	state;
> +	enum cfi_read_mode	read_mode;
> +	u16			rcr;
> +	u8			sr;
> +};
> +
> +static int nr_erase_blocks(struct cfi_flash_device *sfdev)
> +{
> +	return sfdev->size / FLASH_BLOCK_SIZE;
> +}
> +
> +/*
> + * CFI queries always deal with one byte of information, possibly mirrored
> + * to other bytes on the bus. This is dealt with in the callers.
> + * The address provided is the one for 8-bit addressing, and would need to
> + * be adjusted for wider accesses.
> + */
> +static u8 read_cfi(struct cfi_flash_device *sfdev, u64 addr)
> +{
> +	if (addr < 0x10)		/* CFI information starts at 0x10 */
> +		return 0;
> +
> +	if (addr - 0x10 > sizeof(cfi_query_table)) {
> +		pr_debug("CFI query read access beyond the end of table");
> +		return 0;
> +	}
> +
> +	/* Fixup dynamic information in the geometry part of the table. */
> +	switch (addr) {
> +	case CFI_GEOM_OFFSET:		/* device size in bytes, power of two */
> +		return pow2_size(sfdev->size / CFI_NR_FLASH_CHIPS);
> +	case CFI_GEOM_OFFSET + 6:	/* number of erase blocks, minus one */
> +		return (nr_erase_blocks(sfdev) - 1) & 0xff;
> +	case CFI_GEOM_OFFSET + 7:
> +		return (nr_erase_blocks(sfdev) - 1) >> 8;
> +	case CFI_GEOM_OFFSET + 8:	/* erase block size, in units of 256 */
> +		return ((FLASH_BLOCK_SIZE / 256 ) / CFI_NR_FLASH_CHIPS) & 0xff;
> +	case CFI_GEOM_OFFSET + 9:
> +		return ((FLASH_BLOCK_SIZE / 256 ) / CFI_NR_FLASH_CHIPS) >> 8;
> +	}
> +
> +	return cfi_query_table[addr - 0x10];
> +}
> +
> +static bool block_is_locked(struct cfi_flash_device *sfdev, u64 addr)
> +{
> +	int block_nr = addr / FLASH_BLOCK_SIZE;
> +
> +	return test_bit(block_nr, sfdev->lock_bm);
> +}
> +
> +#define DEV_ID_MASK 0x7ff
> +static u16 read_dev_id(struct cfi_flash_device *sfdev, u64 addr)
> +{
> +	switch ((addr & DEV_ID_MASK) / CFI_BUS_WIDTH) {
> +	case 0x0:				/* vendor ID */
> +		return 0x0000;
> +	case 0x1:				/* device ID */
> +		return 0xffff;
> +	case 0x2:
> +		return block_is_locked(sfdev, addr & ~DEV_ID_MASK);
> +	case 0x5:
> +		return sfdev->rcr;
> +	default:			/* Ignore the other entries. */
> +		return 0;
> +	}
> +}
> +
> +static void lock_block(struct cfi_flash_device *sfdev, u64 addr, bool lock)
> +{
> +	int block_nr = addr / FLASH_BLOCK_SIZE;
> +
> +	if (lock)
> +		set_bit(block_nr, sfdev->lock_bm);
> +	else
> +		clear_bit(block_nr, sfdev->lock_bm);
> +}
> +
> +static void word_program(struct cfi_flash_device *sfdev,
> +			 u64 addr, void *data, int len)
> +{
> +	if (block_is_locked(sfdev, addr)) {
> +		sfdev->sr |= 0x12;
> +		return;
> +	}
> +
> +	memcpy(sfdev->flash_memory + addr, data, len);
> +}
> +
> +/* Reset the program buffer state to prepare for follow-up writes. */
> +static void buffer_setup(struct cfi_flash_device *sfdev)
> +{
> +	memset(sfdev->program_buffer, 0, sizeof(sfdev->program_buffer));
> +	sfdev->last_address = ~0ULL;
> +	sfdev->buff_written = 0;
> +}
> +
> +static bool buffer_program(struct cfi_flash_device *sfdev,
> +			   u64 addr, void *buffer, int len)
> +{
> +	unsigned int buf_addr;
> +
> +	if (sfdev->buff_written >= sfdev->program_length)
> +		return false;
> +
> +	/*
> +	 * The first word written into the buffer after the setup command
> +	 * happens to be the base address for the buffer.
> +	 * All subsequent writes need to be within this address and this
> +	 * address plus the buffer size, so keep this value around.
> +	 */
> +	if (sfdev->last_address == ~0ULL)
> +		sfdev->last_address = addr;
> +
> +	if (addr < sfdev->last_address)
> +		return false;
> +	buf_addr = addr - sfdev->last_address;
> +	if (buf_addr >= PROGRAM_BUFF_SIZE)
> +		return false;
> +
> +	memcpy(sfdev->program_buffer + buf_addr, buffer, len);
> +	sfdev->buff_written++;
> +
> +	return true;
> +}
> +
> +static void buffer_confirm(struct cfi_flash_device *sfdev)
> +{
> +	if (block_is_locked(sfdev, sfdev->last_address)) {
> +		sfdev->sr |= 0x12;
> +		return;
> +	}
> +	memcpy(sfdev->flash_memory + sfdev->last_address,
> +	       sfdev->program_buffer,
> +	       sfdev->buff_written * sizeof(u32));
> +}
> +
> +static void block_erase_confirm(struct cfi_flash_device *sfdev, u64 addr)
> +{
> +	if (block_is_locked(sfdev, addr)) {
> +		sfdev->sr |= 0x12;
> +		return;
> +	}
> +
> +	memset(sfdev->flash_memory + addr, 0xFF, FLASH_BLOCK_SIZE);
> +}
> +
> +static void cfi_flash_mmio(struct kvm_cpu *vcpu,
> +			   u64 addr, u8 *data, u32 len, u8 is_write,
> +			   void *context)
> +{
> +	struct cfi_flash_device *sfdev = context;
> +	u64 faddr = addr - sfdev->base_addr;
> +	u32 value;
> +
> +	if (!is_write) {
> +		u16 cfi_value = 0;
> +
> +		mutex_lock(&sfdev->mutex);
> +
> +		switch (sfdev->read_mode) {
> +		case READ_ARRAY:
> +			/* just copy the requested bytes from the array */
> +			memcpy(data, sfdev->flash_memory + faddr, len);
> +			goto out_unlock;
> +		case READ_STATUS:
> +			cfi_value = sfdev->sr;
> +			break;
> +		case READ_DEVICE_ID:
> +			cfi_value = read_dev_id(sfdev, faddr);
> +			break;
> +		case READ_QUERY:
> +			cfi_value = read_cfi(sfdev, faddr / CFI_BUS_WIDTH);
> +			break;
> +		}
> +		switch (len) {
> +		case 1:
> +			*data = cfi_value;
> +			break;
> +		case 8: memset(data + 4, 0, 4);
> +			/* fall-through */
> +		case 4:
> +			if (CFI_NR_FLASH_CHIPS == 2)
> +				memcpy(data + 2, &cfi_value, 2);
> +			else
> +				memset(data + 2, 0, 2);
> +			/* fall-through */
> +		case 2:
> +			memcpy(data, &cfi_value, 2);
> +			break;
> +		default:
> +			pr_debug("CFI flash: illegal access length %d for read mode %d",
> +				 len, sfdev->read_mode);
> +			break;
> +		}
> +
> +		goto out_unlock;
> +	}
> +
> +	if (len > 4) {
> +		pr_info("CFI flash: MMIO %d-bit write access not supported",
> +			 len * 8);
> +		return;
> +	}
> +
> +	memcpy(&value, data, len);
> +
> +	mutex_lock(&sfdev->mutex);
> +
> +	switch (sfdev->state) {
> +	case READY:			/* handled below */
> +		break;
> +
> +	case LOCK_SETUP:
> +		switch (value & 0xff) {
> +		case CFI_CMD_LOCK_BLOCK:
> +			lock_block(sfdev, faddr, true);
> +			sfdev->read_mode = READ_STATUS;
> +			break;
> +		case CFI_CMD_UNLOCK_BLOCK:
> +			lock_block(sfdev, faddr, false);
> +			sfdev->read_mode = READ_STATUS;
> +			break;
> +		default:
> +			sfdev->sr |= 0x30;
> +			break;
> +		}
> +		sfdev->state = READY;
> +		goto out_unlock;
> +
> +	case WP_SETUP:
> +		word_program(sfdev, faddr, data, len);
> +		sfdev->read_mode = READ_STATUS;
> +		sfdev->state = READY;
> +		goto out_unlock;
> +
> +	case BP_LOAD:
> +		if (buffer_program(sfdev, faddr, data, len))
> +			goto out_unlock;
> +
> +		if ((value & 0xFF) == CFI_CMD_BUFFERED_PROGRAM_CONFIRM) {
> +			buffer_confirm(sfdev);
> +			sfdev->read_mode = READ_STATUS;
> +		} else {
> +			pr_debug("CFI flash: BP_LOAD: expected CONFIRM(0xd0), got 0x%x @ 0x%llx",
> +				 value, faddr);
> +			sfdev->sr |= 0x10;
> +		}
> +		sfdev->state = READY;
> +		goto out_unlock;
> +
> +	case BP_SETUP:
> +		sfdev->program_length = (value & 0xffff) + 1;
> +		if (sfdev->program_length > PROGRAM_BUFF_SIZE / 4)
> +			sfdev->program_length = PROGRAM_BUFF_SIZE / 4;
> +		sfdev->state = BP_LOAD;
> +		sfdev->read_mode = READ_STATUS;
> +		goto out_unlock;
> +
> +	case ERASE_SETUP:
> +		if ((value & 0xff) == CFI_CMD_BLOCK_ERASE_CONFIRM)
> +			block_erase_confirm(sfdev, faddr);
> +		else
> +			sfdev->sr |= 0x30;
> +
> +		sfdev->state = READY;
> +		sfdev->read_mode = READ_STATUS;
> +		goto out_unlock;
> +	}
> +
> +	/* write commands in READY state */
> +	switch (value & 0xFF) {
> +	case CFI_CMD_READ_JEDEC:
> +		sfdev->read_mode = READ_DEVICE_ID;
> +		break;
> +	case CFI_CMD_READ_STATUS_REGISTER:
> +		sfdev->read_mode = READ_STATUS;
> +		break;
> +	case CFI_CMD_READ_CFI_QUERY:
> +		sfdev->read_mode = READ_QUERY;
> +		break;
> +	case CFI_CMD_CLEAR_STATUS_REGISTER:
> +		sfdev->sr = 0x80;
> +		break;
> +	case CFI_CMD_WORD_PROGRAM_SETUP:
> +	case CFI_CMD_ALTERNATE_WORD_PROGRAM_SETUP:
> +		sfdev->state = WP_SETUP;
> +		sfdev->read_mode = READ_STATUS;
> +		break;
> +	case CFI_CMD_LOCK_BLOCK_SETUP:
> +		sfdev->state = LOCK_SETUP;
> +		break;
> +	case CFI_CMD_BLOCK_ERASE_SETUP:
> +		sfdev->state = ERASE_SETUP;
> +		sfdev->read_mode = READ_STATUS;
> +		break;
> +	case CFI_CMD_BUFFERED_PROGRAM_SETUP:
> +		buffer_setup(sfdev);
> +		sfdev->state = BP_SETUP;
> +		sfdev->read_mode = READ_STATUS;
> +		break;
> +	case CFI_CMD_BUFFERED_PROGRAM_CONFIRM:
> +		pr_debug("CFI flash: unexpected confirm command 0xD0");
> +		break;
> +	default:
> +		pr_debug("CFI flash: unknown command 0x%x", value);
> +		/* fall through */
> +	case CFI_CMD_READ_ARRAY:
> +		sfdev->read_mode = READ_ARRAY;
> +		break;
> +	}
> +
> +out_unlock:
> +	mutex_unlock(&sfdev->mutex);
> +}
> +
> +#ifdef CONFIG_HAS_LIBFDT
> +static void generate_cfi_flash_fdt_node(void *fdt,
> +					struct device_header *dev_hdr,
> +					void (*generate_irq_prop)(void *fdt,
> +								  u8 irq,
> +								enum irq_type))
> +{
> +	struct cfi_flash_device *sfdev;
> +	u64 reg_prop[2];
> +
> +	sfdev = container_of(dev_hdr, struct cfi_flash_device, dev_hdr);
> +	reg_prop[0] = cpu_to_fdt64(sfdev->base_addr);
> +	reg_prop[1] = cpu_to_fdt64(sfdev->size);
> +
> +	_FDT(fdt_begin_node(fdt, "flash"));
> +	_FDT(fdt_property_cell(fdt, "bank-width", CFI_BUS_WIDTH));
> +	_FDT(fdt_property_cell(fdt, "#address-cells", 0x1));
> +	_FDT(fdt_property_cell(fdt, "#size-cells", 0x1));
> +	_FDT(fdt_property_string(fdt, "compatible", "cfi-flash"));
> +	_FDT(fdt_property_string(fdt, "label", "System-firmware"));
> +	_FDT(fdt_property(fdt, "reg", &reg_prop, sizeof(reg_prop)));
> +	_FDT(fdt_end_node(fdt));
> +}
> +#else
> +#define generate_cfi_flash_fdt_node NULL
> +#endif
> +
> +static struct cfi_flash_device *create_flash_device_file(struct kvm *kvm,
> +							 const char *filename)
> +{
> +	struct cfi_flash_device *sfdev;
> +	struct stat statbuf;
> +	unsigned int value;
> +	int ret;
> +	int fd;
> +
> +	fd = open(filename, O_RDWR);
> +	if (fd < 0)
> +		return ERR_PTR(-errno);
> +	if (fstat(fd, &statbuf) < 0) {
> +		close(fd);
> +		return ERR_PTR(-errno);
> +	}
> +
> +	sfdev = malloc(sizeof(struct cfi_flash_device));
> +	if (!sfdev) {
> +		close(fd);
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	sfdev->size = (statbuf.st_size + 4095) & ~0xfffUL;
> +	sfdev->flash_memory = mmap(NULL, statbuf.st_size,
> +				   PROT_READ | PROT_WRITE, MAP_SHARED,
> +				   fd, 0);
> +	if (sfdev->flash_memory == MAP_FAILED) {
> +		close(fd);
> +		free(sfdev);
> +		return ERR_PTR(-errno);
> +	}
> +	sfdev->base_addr = KVM_FLASH_MMIO_BASE;
> +	sfdev->state = READY;
> +	sfdev->read_mode = READ_ARRAY;
> +	sfdev->sr = 0x80;
> +	sfdev->rcr = 0xbfcf;
> +
> +	value = roundup(nr_erase_blocks(sfdev), BITS_PER_LONG) / 8;
> +	sfdev->lock_bm = malloc(value);
> +	memset(sfdev->lock_bm, 0, value);
> +
> +	sfdev->dev_hdr.bus_type = DEVICE_BUS_MMIO;
> +	sfdev->dev_hdr.data = generate_cfi_flash_fdt_node;
> +	mutex_init(&sfdev->mutex);
> +	ret = device__register(&sfdev->dev_hdr);
> +	if (ret) {
> +		free(sfdev->flash_memory);
> +		free(sfdev);
> +		return ERR_PTR(ret);
> +	}
> +
> +	ret = kvm__register_mmio(kvm,
> +				 sfdev->base_addr, sfdev->size,
> +				 false, cfi_flash_mmio, sfdev);
> +	if (ret) {
> +		device__unregister(&sfdev->dev_hdr);
> +		free(sfdev->flash_memory);
> +		free(sfdev);
> +		return ERR_PTR(ret);
> +	}
> +
> +	return sfdev;
> +}
> +
> +static int flash__init(struct kvm *kvm)
> +{
> +	struct cfi_flash_device *sfdev;
> +
> +	if (!kvm->cfg.flash_filename)
> +		return 0;
> +
> +	sfdev = create_flash_device_file(kvm, kvm->cfg.flash_filename);
> +	if (IS_ERR(sfdev))
> +		return PTR_ERR(sfdev);
> +
> +	return 0;
> +}
> +dev_init(flash__init);
> diff --git a/include/kvm/kvm-config.h b/include/kvm/kvm-config.h
> index a052b0bc..f4a8b831 100644
> --- a/include/kvm/kvm-config.h
> +++ b/include/kvm/kvm-config.h
> @@ -35,6 +35,7 @@ struct kvm_config {
>  	const char *vmlinux_filename;
>  	const char *initrd_filename;
>  	const char *firmware_filename;
> +	const char *flash_filename;
>  	const char *console;
>  	const char *dev;
>  	const char *network;
> diff --git a/include/kvm/util.h b/include/kvm/util.h
> index 4ca7aa93..5c37f0b7 100644
> --- a/include/kvm/util.h
> +++ b/include/kvm/util.h
> @@ -104,6 +104,11 @@ static inline unsigned long roundup_pow_of_two(unsigned long x)
>  	return x ? 1UL << fls_long(x - 1) : 0;
>  }
>  
> +static inline int pow2_size(unsigned long x)
> +{
> +	return (sizeof(x) * 8) - __builtin_clzl(x - 1);
> +}
> +
>  struct kvm;
>  void *mmap_hugetlbfs(struct kvm *kvm, const char *htlbfs_path, u64 size);
>  void *mmap_anon_or_hugetlbfs(struct kvm *kvm, const char *hugetlbfs_path, u64 size);
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm